Updated estimates for the burden of chronic limb-threatening ischemia in the Medicare population.

OBJECTIVE: Estimates of chronic limb-threatening ischemia (CLTI) based on diagnosis codes of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) suggest a prevalence of 0.23%-0.32% and incidence of 0.20%-0.26% among Medicare patients. ICD-10-CM includes 144 CLTI diagnosis codes, allowing improved specificity in identifying affected patients. We sought to use ICD-10-CM diagnosis codes to determine the prevalence of CLTI among Medicare patients and describe the patient cohort affected by this condition. METHODS: Using two years of data from Centers for Medicare and Medicaid Services, we identified all patients that had at least one CLTI diagnosis code to determine prevalence and incidence rates. Sensitivity analyses were performed to compare our methodology to prior publications and quantify the extent of missed diagnoses. The number and type of vascular procedures that occurred after diagnosis were tabulated. A cohort of patients with two or more CLTI diagnosis codes were then identified for further descriptive analysis. Associations between patient demographics and survival were analyzed using Cox proportional hazards models. RESULTS: Over 65 million patients were enrolled in Medicare in 2017 to 2018. Of these, 480,227 had diagnosis of CLTI, with a corresponding to a 1-year incidence of 0.33% and a 2-year prevalence of 0.74%. Patients underwent an average of 43.6 vascular procedures per 100 person-years. Sensitivity analyses identified 89,805 additional patients that had a diagnosis code of peripheral arterial disease who underwent revascularization or amputation. Patients with CLTI were predominantly male (56.2%), white (76.4%), and qualified for Medicare due to age (64.0%). Thirty-seven percent were dual-eligible. One-year survival was 77.7%, significantly lower than estimated actuarial survival adjusted for age, sex, and race (95.1%; P < .001). Cox proportional hazards models demonstrate significantly increased mortality for men vs women (hazard ratio, 1.07; 95% confidence interval, 1.04-1.10; P < .001), but no association between race and overall survival (hazard ratio, 0.99; 95% confidence interval, 0.98-1.01; P = .83). CONCLUSIONS: Using ICD-10-CM diagnosis codes, we demonstrated slightly higher incidence and prevalence of CLTI than in published literature, reflecting our more complete methodology. Sensitivity analyses suggest that increased complexity of the highly specific ICD-10-CM coding may diminish capture of CLTI. Inclusion of patients with non-CLTI peripheral arterial disease diagnoses produces moderate increases in incidence and prevalence at the cost of decreased specificity in identifying patients with CLTI. Medicare patients with CLTI are older, and more commonly male, black, and dual eligible compared with the general Medicare population. Observed mid-term survival for patients with CLTI is significantly lower than actuarial estimates, confirming the importance of focused efforts on identifying and aligning goals of care in this complex patient population.

Poor utilization of palliative care among Medicare patients with chronic limb-threatening ischemia.

OBJECTIVE: Patients with chronic limb-threatening ischemia (CLTI) experience high annual mortality and would benefit from timely palliative care intervention. We sought to better characterize use of palliative care among patients with CLTI in the Medicare population. METHODS: Using Medicare data from 2017 to 2018, we identified patients with CLTI, defined as two or more encounters with a CLTI diagnosis code. Palliative care evaluations were identified using ICD-10-CM Z51.5 "Encounter for palliative care." Time intervals between CLTI diagnosis, palliative consultation, and death or end of follow-up were calculated. Associations between patient demographics, comorbidities, and palliative care consultation were assessed. RESULTS: A total of 12,133 Medicare enrollees with complete data were categorized as having CLTI. Of these, 7.4% (894) underwent a palliative care evaluation at a median of 170 days (interquartile range, 45-352 days) from their CLTI diagnosis. Compared with those who did not undergo evaluation, palliative patients were more likely to be dual eligible for Medicaid (45.2% vs 38.1%; P < .001) and had more comorbid conditions (P < .001). After controlling for gender and race, age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.02-1.04), dual eligibility (OR, 1.40; 95% CI, 1.22-1.62), solid organ malignancy (OR, 2.82; 95% CI, 1.92-4.14), hematologic malignancy (OR, 2.24; 95% CI, 1.27-3.98), congestive heart failure (OR, 1.44; 95% CI, 1.15-1.88), complicated diabetes (OR, 1.35; 95% CI, 1.11-1.65), dementia (OR, 1.32; 95% CI, 1.04-1.66), and severe renal failure (OR, 1.56; 85% CI. 1.24-1.98) were independently associated with palliative care evaluation. During mean follow up of 410 ± 220 days, 16.9% (2044) of patients died at a mean of 268 (±189) days after their CLTI diagnosis. Among living patients, only 3.2% (325) underwent palliative evaluation. Comparatively, 27.8% (569) of patients who died received palliative care at a median of 196 days (interquartile range, 55-362 days) after their diagnosis and 15 days (interquartile range, 5-63 days) prior to death. CONCLUSIONS: Despite high mortality, palliative care services were rarely provided to Medicare patients with CLTI. Age, medical complexity, and income status may play a role in the decision to consult palliative care. When obtained, evaluations occurred closer to time of death than to time of CLTI diagnosis, suggesting misuse of palliative care as end-of-life care.

Association of Premature Menopause With Risk of Abdominal Aortic Aneurysm in the Women's Health Initiative.

OBJECTIVE: To determine if premature menopause and early menarche are associated with increased risk of AAA, and to explore potential effect modification by smoking history. SUMMARY OF BACKGROUND DATA: Despite worse outcomes for women with AAA, no studies have prospectively examined sex-specific risk factors, such as premature menopause and early menarche, with risk of AAA in a large, ethnically diverse cohort of women. METHODS: This was a post-hoc analysis of Women's Health Initiative participants who were beneficiaries of Medicare Parts A&B fee-for-service. AAA cases and interventions were identified from claims data. Follow-up period included Medicare coverage until death, end of follow-up or end of coverage inclusive of 2017. RESULTS: Of 101,119 participants included in the analysis, the mean age was 63 years and median follow-up was 11.3 years. Just under 10,000 (9.4%) women experienced premature menopause and 22,240 (22%) experienced early men-arche. Women with premature menopause were more likely to be overweight, Black, have >20 pack years of smoking, history of cardiovascular disease, hypertension, and early menarche. During 1,091,840 person-years of follow-up, 1125 women were diagnosed with AAA, 134 had premature menopause (11.9%), 93 underwent surgical intervention and 45 (48%) required intervention for ruptured AAA. Premature menopause was associated with increased risk of AAA [hazard ratio 1.37 (1.14, 1.66)], but the association was no longer significant after multivariable adjustment for demographics and cardiovascular disease risk factors. Amongst women with ≥20 pack year smoking history (n = 19,286), 2148 (11.1%) had premature menopause, which was associated with greater risk of AAA in all models [hazard ratio 1.63 (1.24, 2.23)]. Early menarche was not associated with increased risk of AAA. CONCLUSIONS: This study finds that premature menopause may be an important risk factor for AAA in women with significant smoking history. There was no significant association between premature menopause and risk of AAA amongst women who have never smoked. These results suggest an opportunity to develop strategies for better screening, risk reduction and stratification, and outcome improvement in the comprehensive vascular care of women.

A Vascular Quality Initiative frailty assessment predicts postdischarge mortality in patients undergoing arterial reconstruction.

BACKGROUND: Frailty assessment adds important prognostic information during preoperative decision-making but can be cumbersome to implement into routine clinical care. We developed and tested an abbreviated method of frailty assessment using variables routinely collected by the Vascular Quality Initiative (VQI) registry. METHODS: An abbreviated frailty score (the simple Vascular Quality Initiative-Frailty Score [VQI-FS]) was developed using 11 or fewer VQI variables (hypertension, congestive heart failure, coronary artery disease, peripheral vascular disease, diabetes, chronic obstructive pulmonary disease, renal impairment, anemia, underweight, nonhome residence, and nonambulatory status) that map to recognized frailty domains in the Comprehensive Geriatric Assessment and the literature. Nonemergent cases registered in the VQI from 2010 to 2017 (n = 265,632) in seven registries (carotid endarterectomy, n = 77,111; carotid artery stenting, n = 13,215; endovascular abdominal aortic aneurysm repair, n = 29,607; open abdominal aortic aneurysm repair, n = 7442; infrainguinal bypass, n = 33,128; suprainguinal bypass, n = 10,661; and peripheral vascular intervention, n = 94,468) were analyzed using logistic regression models to determine the predictive power of the VQI-FS for perioperative and longer term (9-month) mortality. Nomograms were created using weighted regression coefficients to assist in individualized frailty assessment and estimation of 9-month mortality. RESULTS: The VQI-FS, using equal weighting of these 11 VQI variables, effectively predicted 9-month mortality with an area under the curve of 0.724 by receiver operating characteristic curve analysis. However, differential weighting of the variables allowed simplification of the model to only seven variables (congestive heart failure, renal impairment, chronic obstructive pulmonary disease, not living at home, not ambulatory, anemia, and underweight status); hypertension, coronary artery disease, peripheral vascular disease, and diabetes had relatively low predictive power. Adding procedure-specific risk further improved performance of the model with a final area under the curve on receiver operating characteristic curve analysis of 0.758. Model calibration was excellent with predicted/observed regression line slope of 0.991 and intercept of 5.449e-04. CONCLUSIONS: A differentially weighted abbreviated VQI-FS using seven variables in addition to procedure-specific risk has strong correlation with 9-month mortality. Nomograms incorporating patient- and procedure-adjusted risk can effectively predict 9-month mortality. Reliable estimates of longer term mortality should assist in preoperative decision-making for vascular procedures that often carry substantial risk of mortality.

Anatomic feasibility of off-the-shelf thoracic single side-branched endograft in patients with blunt traumatic thoracic aortic injury.

OBJECTIVE: The advent of thoracic single side-branched endograft (TSSBE) has provided a treatment option to obviate the need for open cervical debranching of the left subclavian artery (LSA), thereby enabling total endovascular incorporation of the LSA during thoracic endovascular aortic repair (TEVAR). In a previous study of patients with type B aortic dissection who had required zone 2 TEVAR, the anatomic feasibility of this device was demonstrated to range from 28% to 35%, suggesting limited applicability of the currently available designs. The objectives of the present study were twofold: (1) to evaluate the anatomic feasibility of TSSBE in blunt traumatic thoracic aortic injury (BTAI) patients who would require LSA revascularization; and (2) to describe the anatomic characteristics of the supra-aortic arch branches that could be used to improve future device design. METHODS: A retrospective review was performed of BTAI patients who had undergone TEVAR at a single institution from November 2013 to October 2018. Preoperative computed tomography angiograms were analyzed using three-dimensional reconstruction to quantify the aortic diameter, distance and arc length between branch vessels, and the LSA diameter and length. We calculated the proportion of patients who had met all aortic and LSA anatomic requirements for TSSBE proposed by investigational protocols. We also assessed the effect of anatomic requirement modifications on device suitability. Finally, we assessed the local anatomic relationship between the supra-aortic branches. RESULTS: A total of 41 patients (63% men; median age, 39 years; range, 23-88 years; 68% normal aortic arch pattern, 32% bovine aortic arch pattern) with BTAI who had required TEVAR involving the LSA and were, thus, considered potential candidates for TSSBE were included. Of the 41 patients, 13 (32%; 7 with a bovine aortic arch and 6 with a normal aortic arch) had met all proposed aortic and LSA anatomic requirements for TSSBE. An appropriate aortic diameter, LSA diameter, and LSA length to its first branch were observed in 100%, 95%, and 66% of the patients, respectively. An insufficient distance between the arch branch vessels, observed in 41%, was the most common exclusionary criterion. The median clock-face position of the LSA was 12:00 (interquartile range, 30 minutes) in the normal arch group and 11:45 (interquartile range, 15 minutes) in the bovine arch group. CONCLUSIONS: Despite the numerous potential advantages of TSSBE, only 32% of patients with BTAI requiring LSA revascularization had met all the aortic and LSA anatomic requirements, justifying the need for additional designs. Better characterization and mapping of the aortic arch branches will improve future device design and application.

Lipoprotein(a) levels and risk of abdominal aortic aneurysm in the Women's Health Initiative.

OBJECTIVE: Few studies have prospectively examined the associations of lipoprotein(a) [Lp(a)] levels with the risk of abdominal aortic aneurysm (AAA), especially in women. Accounting for commonly recognized risk factors, we investigated the baseline Lp(a) levels and the risk of AAA among postmenopausal women participating in the ongoing national Women's Health Initiative. METHODS: Women's Health Initiative participants with baseline Lp(a) levels available who were beneficiaries of Medicare parts A and B fee-for-service at study enrollment or who had aged into Medicare at any point were included. Participants with missing covariate data or known AAA at baseline were excluded. Thoracic aneurysms were excluded owing to the different pathophysiology. The AAA cases and interventions were identified using the International Classification of Diseases, 9th and 10th revision, codes and Current Procedural Terminology codes from claims data. Hazard ratios were computed using Cox proportional hazard models according to the quintiles of Lp(a). RESULTS: The mean age of the 6615 participants included in the analysis was 65.3 years. Of the 6615 participants, 66.6% were non-Hispanic white, 18.9% were black, 7% were Hispanic and 4.7% were Asian/Pacific Islander. Compared with the participants in the lowest Lp(a) quintile, those in higher quintiles were more likely to be overweight, black, and former or current smokers, to have hypertension, hyperlipidemia, and a history of cardiovascular disease, and to use menopausal hormone therapy and statins. During 65,476 person-years of follow-up, with a median of 10.4 years, 415 women had been diagnosed with an AAA and 36 had required intervention. More than one half had required intervention for a ruptured AAA. We failed to find a statistically significant association between Lp(a) levels and incident AAA. Additional sensitivity analyses stratified by race, with exclusion of statin users and alternative categorizations of Lp(a) using log-transformed levels, tertiles, and a cutoff of >50 mg/dL, were conducted, which did not reveal any significant associations. CONCLUSIONS: We found no statistically significant association between Lp(a) levels and the risk of AAA in a large and well-phenotyped sample of postmenopausal women. Women with high Lp(a) levels were more likely to be overweight, black, and former or current smokers, and to have hypertension, hyperlipidemia, and a history of cardiovascular disease, or to use hormone therapy and statins compared with those with lower Lp(a) levels. These findings differ from previous prospective, case-control, and meta-analysis studies that had supported a significant relationship between higher Lp(a) levels and an increased risk of AAA. Differences in the association could have resulted from study limitations or sex differences.

Underutilization of Palliative Care for Patients with Advanced Peripheral Arterial Disease.

BACKGROUND: Advanced peripheral arterial disease is associated with an overall annual mortality between 20-40%. Amputees are at particularly high risk for perioperative and long-term mortality and may benefit from palliative care programs to improve quality of life and to align medical treatments with their goals of care. As studies of palliative care in vascular patients are scarce, we sought to examine palliative care utilization using below knee amputation (BKA) as a surrogate for advanced peripheral arterial disease. METHODS: All patients who underwent below knee amputation over a 5-year period at a single large academic medical center were identified through chart review. Demographics, preoperative conditions, intraoperative factors, and perioperative outcomes were recorded. The primary outcome was palliative care consultation at the time of the amputation. The secondary outcomes included one-year mortality and palliative care consultation prior to death. RESULTS: The cohort comprised 111 patients (76 men, 35 women) who received BKA for chronic limb threatening ischemia. Three patients (2.7%) received palliative care consultations at the time of their amputation. Of these, one had been obtained remotely for an oncologic condition and the others for surgical decision-making. Follow-up was available for 73 patients. One-year mortality was 21.9% (n = 16) at a mean of 102 ± 86 days after BKA. Among patients who died within 1 year of their amputation, 37.5% (n = 6) received palliative care consultations prior to their death. The median interval between amputation and palliative consultation was 26 (IQR 14-81) days. The median interval between palliative consultation and death was 9 (IQR 4-39) days. CONCLUSION: Palliative care services were rarely provided to patients with advanced peripheral arterial disease. When obtained, consultations occurred closer to death than to amputation suggesting a missed opportunity to receive the benefits of early evaluation. Future studies can be aimed at identifying a cohort of vascular patients who would most benefit from early palliative evaluation and determining if palliative consultations alter health care utilization patterns and outcomes for vascular patients.

Correlation of Patient Activation Measure Level with Patient Characteristics and Type of Vascular Disease.

BACKGROUND: Patient activation or level of engagement in one's medical care is linked to hospital readmissions and worse outcomes in a number of diseases. Patients with higher levels of activation are typically guiding their care rather than acting as passive observers of care. This study aims to determine if either patient demographics or type of vascular disease can predict patient activation. METHODS: All patients presenting over a 4-month period to an outpatient vascular clinic were asked to complete the Patient Activation Measure (PAM) survey. In total, 257 completed surveys were collected. Survey responses were scored on a Likert scale with anchors. Responses are tallied with a score of 1-100 and converted to summary levels 1-4 in accordance with the previously validated scoring system. Level 1 patients are considered disengaged and overwhelmed. Patients in level 2 are becoming aware of their health care, but still struggle. Level 3 patients are taking action, while level 4 represents patients who are maintaining healthy behaviors and pushing further. Chi-squared test and multivariable regression were then performed to determine if patient characteristics or type of disease correlated with activation levels. RESULTS: In total, 257 patients completed the survey. The mean participant age was 67 years (±15). Sixteen percent of patients lived alone, 58% were married, and in 39% mean household income was <$50,000. Overall, 21 patients (8.2%) were classified as level 1, 65 (25%) level 2, 94 (37%) level 3, and 77 (30%) level 4. The group comprised 32% peripheral artery disease (PAD), 20% carotid, 18% aortic/aneurysm, 14% venous, and 16% were various other vascular diseases. Over each disease group there was a wide range of activation, but no significant difference between the type of vascular disease and activation level. Chronic limb-threatening ischemia (CLTI) patients comprised 35% (n = 29) of the PAD group, and 66% of these patients reported an activation level of 3 (n = 10) or 4 (n = 9). There was no difference in the levels of activation reported by the CLTI patients compared to the general PAD cohort (P = 0.99). Multivariable analysis demonstrated that age, level of education, household income, and type of vascular disease correlated with PAM score, but there was no correlation between length of symptoms, race, or gender. CONCLUSIONS: Patient activation is unpredictable using patient characteristics or type of vascular disease, and CLTI patients report high activation levels. Quality databases that collect only patient demographics may not fully capture patient predictors of poor outcomes. Use of the PAM survey should be further explored in vascular patients to correlate activation level with vascular-specific outcomes.

Outcome comparison of thoracic endovascular aortic repair performed outside versus inside proximal landing zone length recommendation.

OBJECTIVE: Success of thoracic endovascular aortic repair (TEVAR) relies heavily on the proximal landing zone (PLZ) sealing. Most instructions for use of thoracic endografts recommend a PLZ length of at least 2 cm. Because of the complex aortic anatomic features, TEVAR landing in zone 1 to zone 3 may not meet this requirement. The aim of this study was to examine whether 2-cm PLZ nonadherence was related to adverse outcomes after TEVAR. METHODS: A retrospective review was performed of patients who underwent zone 1, zone 2, and zone 3 landing TEVAR at a single institution between November 2013 and October 2018. Preoperative and postoperative computed tomography angiography images were analyzed using three-dimensional reconstruction. The patients were categorized into two groups: PLZ ≥2 cm (adherence group) and PLZ <2 cm (nonadherence group). Collected data included patient and anatomic characteristics. Primary outcomes were type IA endoleak, retrograde dissection, and graft migration. RESULTS: The cohort comprised 63 patients (18 in the adherence group and 45 in the nonadherence group) with a mean age of 53.3 ± 20.6 years. Indications for TEVAR were blunt thoracic aortic injury (65.1%), thoracic aneurysm (23.8%), penetrating ulcer (9.5%), and type B dissection (1.6%). Mean PLZ length was significantly shorter for the nonadherence group (8 ± 7 mm for the nonadherence group vs 34 ± 15 mm for the adherence group; P < .0001). PLZ location (2 zone 1, 15 zone 2, 46 zone 3) and oversizing (19.4% ± 8.3% for the adherence group; 20.3% ± 10.2% for the nonadherence group; P = .7) were similar between the groups. The mean PLZ aortic diameter of the adherence group was significantly larger than that of the nonadherence group (29 ± 5 mm for the adherence group; 25 ± 5 mm for the nonadherence group; P = .004). Mean follow-up time was 126.7 days (range, 0-644 days) for the adherence group and 233.8 days (range, 0-1750 days) for the nonadherence group (P = .2). During the study period, no primary outcome was observed in the adherence group, whereas 12 adverse events occurred in 10 patients in the nonadherence group (type IA endoleak, n = 10; graft migration, n = 1; retrograde dissection, n = 1). Of 10 type IA endoleaks, five were immediate (4 resolved spontaneously, 1 remained persistent) and five were delayed (1 resolved spontaneously, 1 remained persistent, 1 ruptured causing death, 2 required total arch replacement). CONCLUSIONS: Achieving recommended sealing zone of 2-cm centerline length is paramount to avoid device-related adverse outcomes. We recommend careful surveillance in patients undergoing urgent TEVAR with <2-cm PLZ.

Evaluation of regional variations in length of stay after elective, uncomplicated carotid endarterectomy in North America.

OBJECTIVE: The objective of this study was to evaluate factors affecting regional variation in length of stay (LOS) after elective, uncomplicated carotid endarterectomy (CEA). METHODS: Data were obtained from the Vascular Quality Initiative database and included patients with complete data who received elective CEA without complications between 2012 and 2017 across 18 regions in North America and 294 centers. The main outcome measure was LOS >1 day after surgery (LOS >1 postoperative day [POD]). Using least absolute shrinkage and selection operator regression, multivariable modeling, and mixed-effects general linear modeling, we evaluated whether regional variations in LOS were independent of demographic, clinical, or center-related factors and to what extent these factors accounted for postoperative variation in LOS. RESULTS: A total of 36,004 patients were included. Mean postprocedure LOS was 1.6 ± 6.6 days. Overall, 24% of patients had an LOS >1 POD. After adjustment for important demographic, clinical, and center-related factors, the region in which a patient was treated independently and significantly affected LOS after elective, uncomplicated CEA. Region and center of treatment accounted for 18% of LOS variation. Demographic, clinical, and surgical factors accounted for another 32% of variation in LOS. Of these factors, postoperative discharge to a facility other than home (odds ratio [OR], 6.3; confidence interval [CI], 5.2-7.6), use of intravenous (IV) vasoactive agents (OR, 3.2; CI, 3-3.4), intraoperative drain placement (OR, 1.4; CI, 1.3-1.55), and female sex (OR, 1.4; CI, 1.3-1.5) were associated with longer LOS. Factors associated with LOS ≤1 POD included preoperative aspirin (OR, 0.88; CI, 0.8-0.96) and statin use (OR, 0.9; CI, 0.83-0.98), high surgeon volume (highest quartile: OR, 0.68; CI, 0.5-0.87), and completion evaluation after CEA (eg, Doppler, ultrasound; OR, 0.87; CI, 0.8-0.95). We also found that use of IV vasoactive medications varied significantly across regions, independent of demographic and clinical factors. CONCLUSIONS: Significant regional variation in LOS exists after elective, uncomplicated CEA even after controlling for a wide range of important factors, indicating that there remain unmeasured causes of longer LOS in some regions. Even so, modification of certain clinical practices may reduce overall LOS. Regional differences in use of IV vasoactive medications not driven by clinical factors warrant further analysis, given the strong association with longer LOS.

Initial financial impact of office-based laboratories on Medicare payments for percutaneous interventions for peripheral artery disease.

OBJECTIVE: Percutaneous interventions for peripheral artery disease (PAD) are transitioning away from hospital-based settings to office-based laboratories (OBLs). Those in favor of OBL use reference lower hospitalization rates and high efficiency; however, critics claim financial incentives may lead to multiple procedures and higher atherectomy use. We sought to determine how Medicare payments are affected by OBL use. METHODS: We identified physicians performing percutaneous interventions for PAD from 2006 to 2013 in a 20% Medicare sample. Physicians performing a majority of interventions at OBLs were classified as high OBL users; control physicians performed interventions at hospital-based settings. The primary outcomes were total Medicare payments at 30 days and 1 year. Generalized log-gamma regression models were used to evaluate factors influencing payments reported as a percentage change and 95% confidence interval (95% CI). A secondary analysis was performed of physicians who transitioned from hospital-based settings to OBLs, "switch physicians." A multivariate model with difference-in-differences regression was used to evaluate the effects of transitioning to OBLs. RESULTS: A total of 89 high OBL users performed percutaneous interventions on 887 patients, and 3715 control physicians treated 54,213 patients during the time period. Payments for patients treated by high OBL users were significantly higher compared with control physicians at 30 days ($4465), 90 days ($8925), and 1 year ($27,436). Major factors increasing payments at 1 year were treatment by a high OBL user (49%; 95% CI, 42%-56%), hospital admissions (127%; 95% CI, 123%-131%), repeated lower extremity procedures (41%; 95% CI, 39%-43%), and lower extremity wound (20%; 95% CI,18%-22%). Factors decreasing payments at 1 year were living in a rural setting (8%; 95% CI, 7%-9%) and dementia (5%; 95% CI, 3%-7%). Analysis of 292 switch physicians identified 3888 patients treated before OBLs (pre-switch) and 3246 after OBLs (post-switch). Transitioning to OBLs was associated with higher payments at 30 days and 90 days, and this increase was higher compared with control physicians. CONCLUSIONS: These findings highlight that OBL use for PAD interventions significantly influences Medicare payments, and its widespread adaptation should be made with caution. The main factors driving payments were hospitalization admissions, repeated lower extremity procedures, and wound status. Further work is needed to evaluate the appropriate use of OBLs to optimize patient outcomes and resource allocations.

Variation in center-level frailty burden and the impact of frailty on long-term survival in patients undergoing elective repair for abdominal aortic aneurysms.

OBJECTIVE: Frailty is increasingly recognized as a key determinant in predicting postoperative outcomes. Centers that see more frail patients may not be captured in risk adjustment, potentially accounting for poorer outcomes in hospital comparisons. We aimed to (1) determine the effect of frailty on long-term mortality in patients undergoing elective abdominal aortic aneurysm (AAA) repair and (2) evaluate the variability in frailty burden among centers in the Vascular Quality Initiative (VQI) database. METHODS: Patients undergoing elective open and endovascular AAA repair (2003-2017) were identified, and those with complete data on component variables of the VQI-derived Risk Analysis Index (VQI-RAI) and centers with ≥10 AAA repairs were included. VQI-RAI characteristics are sex, age, body mass index, renal failure, congestive heart failure, dyspnea, preoperative ambulation, and functional status. Frailty was defined as VQI-RAI ≥35 based on prior work in surgical patients using other quality improvement databases. This corresponds to the top 12% of patients at risk in the VQI. Center-level VQI-RAI differences were assessed by analysis of variance test. Relationships between frailty and survival were compared by Kaplan-Meier analysis and the log-rank test for open and endovascular procedures. Multivariable hierarchical Cox proportional hazards regression models were calculated with random intercepts for center, controlling for frailty, race, insurance, AAA diameter, procedure type, AAA case mix, and year. RESULTS: A total of 15,803 patients from 185 centers were included. Mean VQI-RAI scores were 27.6 (standard deviation, 5.9; range, 4-56) and varied significantly across centers (F = 2.41, P < .001). The percentage of frail patients per center ranged from 0% to 40.0%. In multivariable analysis, frailty was independently associated with long-term mortality (hazard ratio, 2.88; 95% confidence interval, 2.6-3.2) after accounting for covariates and center-level variance. Open AAA repair was not associated with long-term mortality after adjusting for frailty (hazard ratio, 0.98; 95% confidence interval, 0.86-1.13). There was a statistically significant difference in the percentage of frail patients compared with nonfrail patients who were discharged to a rehabilitation facility or nursing home after both open (40.5% vs 17.8%; P < .0001) and endovascular repair (17.7% vs 4.6%; P < .0001). CONCLUSIONS: There is considerable variability of preoperative frailty among VQI centers performing elective AAA repair. Adjusting for center-level variation, frailty but not procedure type had a significant association with long-term mortality; however, frailty and procedure type were both associated with nonhome discharge. Routine measurement of frailty preoperatively by centers to identify high-risk patients may help mitigate procedural and long-term outcomes and improve shared decision-making regarding AAA repair.

Association of opioid use and peripheral artery disease.

BACKGROUND: Prescription opioids account for 40% of all U.S. opioid overdose deaths, and national efforts have intensified to reduce opioid prescriptions. Little is known about the relationship between peripheral artery disease (PAD) and high-risk opioid use. The objectives of this study were to evaluate this relationship and to assess the impact of PAD treatment on opiate use. METHODS: In this retrospective cohort study, the Truven Health MarketScan database (Truven Health Analytics, Ann Arbor, Mich), a deidentified national private insurance claims database, was queried to identify patients with PAD (two or more International Classification of Diseases, Ninth Revision diagnosis codes of PAD ≥2 months apart, with at least 2 years of continuous enrollment) from 2007 to 2015. Critical limb ischemia (CLI) was defined as the presence of rest pain, ulcers, or gangrene. The primary outcome was high opioid use, defined as two or more opioid prescriptions within a 1-year period. Multivariable analysis was used to determine risk factors for high opioid use. RESULTS: A total of 178,880 patients met the inclusion criteria, 35% of whom had CLI. Mean ± standard deviation follow-up time was 5.3 ± 2.1 years. An average of 24.7% of patients met the high opioid use criteria in any given calendar year, with a small but significant decline in high opioid use after 2010 (P < .01). During years of high opioid use, 5.9 ± 5.5 yearly prescriptions were filled. A new diagnosis of PAD increased high opioid use (21.7% before diagnosis vs 27.3% after diagnosis; P < .001). A diagnosis of CLI was also associated with increased high opioid use (25.4% before diagnosis vs 34.5% after diagnosis; P < .001). Multivariable analysis identified back pain (odds ratio [OR], 1.89; 95% confidence interval [CI], 1.84-1.93; P < .001) and illicit drug use (OR, 1.87; 95% CI, 1.72-2.03; P < .001) as the highest predictors of high opioid use. A diagnosis of CLI was also associated with higher risk (OR, 1.61; 95% CI, 1.57-1.64; P < .001). A total of 43,443 PAD patients (24.3%) underwent 80,816 PAD-related procedures. After exclusion of periprocedural opioid prescriptions (4.9% of all opioid prescriptions), the yearly percentage of high opioid users increased from 25.8% before treatment to 29.6% after treatment (P < .001). CONCLUSIONS: Patients with PAD are at increased risk for high opioid use, with nearly one-quarter meeting described criteria. CLI and treatment for PAD additionally increase high opioid use. In addition to heightened awareness and active opioid management, our findings warrant further investigation into underlying causes and deterrents of high-risk opioid use.

Variability in hospital costs for carotid artery revascularization.

OBJECTIVE: The objective of this study was to understand drivers of cost for carotid endarterectomy (CEA) and carotid artery stenting (CAS) and to compare variation in cost among cases performed by vascular surgery (VS) with other services (OSs). METHODS: We collected internal hospital claims data for CEA and CAS between September 2013 and August 2015 and performed a financial analysis of all hospital costs including room accommodations, medications, medical and surgical supplies, imaging, and laboratory tests. Cases were stratified by presence of symptoms and procedure type, and costs of procedures performed by VS were compared with those performed by OSs. RESULTS: The cohort comprised 144 patients (78 asymptomatic, 66 symptomatic; 44 CAS, 100 CEA) receiving unilateral revascularization. VS (24 CAS, 70 CEA) and neurosurgery and neurointerventional radiology services (20 CAS, 30 CEA) performed all procedures. Age (71 ± 9 years vs 70 ± 11 years; P = .8) and length of stay (1.7 ± 2.1 days vs 2.2 ± 2.4 days; P = .73) were similar for VS and OSs. Symptoms were present before revascularization for 46% and were more commonly treated by OSs (78% vs 29%; P < .001). Case mix index was similar after stratifying by symptoms (asymptomatic, 1.28 ± 0.35 vs 1.39 ± 0.42 [P = .5]; symptomatic, 1.66 ± 0.73 vs 1.82 ± 0.81 [P = .9]). The largest cost components were operating room (OR)-related costs, beds, and supplies, together accounting for 76% of costs. Asymptomatic patients had 37% lower average hospital costs. For asymptomatic CAS, average index hospitalization cost was 17% less for VS compared with OSs because of 78% lower intensive care unit costs, 44% lower OR-related costs, 40% lower medication costs, and 24% lower cardiac testing costs. VS had 22% higher supply costs. For asymptomatic CEA, average index hospitalization costs were 22% lower for VS, driven by lower OR-related costs (28%), medications (28%), imaging (62%), and neurointerventional monitoring (64%). Costs were 38% higher for CAS vs CEA. For symptomatic CAS, costs were similar for both groups. For symptomatic CEA, total costs were 14% lower for VS compared with OSs, driven by 25% lower OR-related costs, 62% lower neurointerventional monitoring, 20% step-down beds, and 28% lower supply costs (and counterbalanced by 117% higher intensive care unit costs). CONCLUSIONS: VS average hospital costs were lower for asymptomatic CAS and all CEAs compared with OSs. Drivers of higher cost appear to be attributed to variation in physicians' practice as well as patients' complexity, affording an opportunity to reduce cost by establishing standard practices when appropriate.

Utilization of regional versus general anesthesia and its impact on lower extremity bypass outcomes.

OBJECTIVE: Previous studies evaluating general anesthesia (GA) vs regional (epidural/spinal) anesthesia (RA) for infrainguinal bypass have produced conflicting results. The purpose of this study was to analyze the factors associated with contemporary use of RA and to determine whether it is associated with improved outcomes after infrainguinal bypass in patients with critical limb ischemia. METHODS: Using the Vascular Quality Initiative infrainguinal database, a retrospective review identified all critical limb ischemia patients who received an infrainguinal bypass from 2011 through 2016. Patients were then separated by GA or RA. Primary outcomes were perioperative mortality, complications, and length of stay. Predictive factors for RA and perioperative outcomes were analyzed using a mixed-effects model to adjust for center differences. RESULTS: There were 16,052 patients identified to have a lower extremity bypass during this time frame with 572 (3.5%) receiving RA. There was a wide variation in the use of RA, with 31% of participating centers not using it at all. Age (67.2 vs 70.3 years; P < .001), chronic obstructive pulmonary disease (25.7% vs 30.9%; P < .001), and urgency of the operation (75.7% vs 80.4%; P = .01) were found to be independently associated with receiving a regional anesthetic. Univariate and multivariate analysis demonstrated that length of stay (6.8 days vs 5.7 days; P < .01), postoperative congestive heart failure (2.3% vs 1.1%; P = .040), and change in renal function (5.7% vs 2.9%; P = .005) were all significant outcomes in favor of RA. There was a trend toward lower mortality rates; however, this did not reach statistical significance. Rates of myocardial infarction, pulmonary complications, and stroke were not found to be statistically different. Coarsened exact matching continued to demonstrate a difference in length of stay and rates of new-onset congestive heart failure in favor of RA. CONCLUSIONS: RA is an infrequent but effective form of anesthesia for infrainguinal bypass surgery. Elderly patients and those with underlying respiratory problems may benefit from this form of anesthesia. Further evaluation within institutions should be performed to identify which patients would most benefit from RA or GA.

Impact of office-based laboratories on physician practice patterns and outcomes after percutaneous vascular interventions for peripheral artery disease.

BACKGROUND: Percutaneous vascular interventions (PVIs) for peripheral artery disease have shifted from hospital-based facilities to office-based laboratories (OBLs). The transition to OBLs is due to a variety of factors such as technology advancement, increased efficiency, and financial incentives. We evaluated the impact of physicians switching to OBLs use from hospital-based facilities on procedure volume, procedure type, and patient outcomes. METHODS: We identified patients with PVI for lower extremity peripheral artery disease from 2006 to 2013 in a 20% Medicare sample and identified physicians who transitioned from predominantly hospital-based facilities to OBLs (switch physicians) and compared them with those who did not use OBLs (control physicians). The main outcomes investigated were average number of PVIs at 30 days and 1 year and atherectomy usage. Patient outcomes included above-ankle amputation, major adverse limb events, and death. We used a difference-in-difference model to control for time effects in a multivariate regression model, reported as an odds ratio (OR) and 95% confidence interval (CI). RESULTS: The cohort comprised 292 switch physicians, who treated 7134 patients (3888 before OBL use and 3246 after transitioning to OBLs), and 3715 control physicians treating 54,213 patients (36,327 in the preperiod and 17,886 in the postperiod). Switch and control physicians both treated more patients with lower extremity wounds during the study period; however, this increase was greater for control physician (0.7% vs 5.5%, P < .001). On average, patients treated by switch physicians had 0.05 (95% CI, 0.03-0.07; P < .001) underwent more PVIs within 30 days and 0.12 more PVIs (95% CI, 0.08-0.16; P < .001) within 1 year of the initial revascularization procedure after the physician transitioned to an OBL. Similarly, patients treated by switch physicians underwent 0.02 (95% CI, 0.01-0.03; P = .002) more atherectomy procedures at 30 days and 0.03 (95% CI, 0.01-0.05; P = .008) more atherectomy procedures at 1 year. Transitioning to OBLs was also associated with a decreased risk in above-ankle amputation at 30 days (OR, 0.58; 95% CI, 0.38-0.97; P = .009) and 1 year (OR, 0.75; 95% CI, 0.60-0.95; P = .01). However, no statistical difference was observed for major adverse limb events and mortality rates at 30 days and 1 year because patients treated by switch and control physicians experienced similar decreases. CONCLUSIONS: Transitioning to OBLs was associated higher 30-day and 1-year PVI rates and atherectomy rates. Although transitioning to OBLs was associated with lower rates of above-ankle amputations, switch physicians treated a lower number of patients with lower extremity wounds.

Benefit of multidisciplinary wound care center on the volume and outcomes of a vascular surgery practice.

OBJECTIVE: Multidisciplinary care is recommended for the treatment of patients with ischemic and diabetic wounds. In addition to integrating care from multiple specialties, outpatient wound care centers provide an opportunity for continuity and organization of care after revascularization or hospitalization. The purpose of this study was to assess changes in the practice patterns and outcomes of patients treated by a tertiary care vascular surgery practice after the introduction of an affiliated outpatient wound care center. METHODS: A prospective institutional database was used to identify patients who underwent lower-extremity revascularization, amputation, or surgical debridement during consecutive 3-year periods before (BWC; n = 735) and after (AWC; n = 1503) the opening of an affiliated wound care center. Patients were included if they underwent intervention for atherosclerotic peripheral arterial disease or diabetic foot ulcers (DFUs). Changes in case volume, surgical indication, and procedural characteristics were assessed. Clinical outcomes included freedom from lower-extremity amputations and mortality. RESULTS: We identified a total of 1751 procedures performed in 1249 limbs that met inclusion criteria. After the opening of the wound clinic, procedures related to limb salvage represented a greater proportion of overall cases performed by the vascular service (19% vs 26%; P < .0001). The volume of lower-extremity interventions increased by 64%, from 662 procedures in the BWC period to 1085 procedures in the AWC period. There was no difference in type of revascularization performed between the two study periods, although surgical debridements (from 8.9% to 13%; P = .01) and infrapopliteal endovascular interventions (from 21% to 28%; P = .04) significantly increased. Compared with BWC patients, AWC patients more frequently presented with DFUs (7.3% vs 13%; P = .002) and chronic wounds (39% vs 45%; P = .05). At 1 year of follow-up, major amputation rates were significantly lower in the AWC group than in the BWC cohort (5.5% vs 8.8%; P = .04). Treatment during the AWC period was associated with a reduced risk of major amputation (adjusted hazard ratio, 0.41; 95% confidence interval, 0.27-0.62; P < .001), but no difference in all-cause mortality. CONCLUSIONS: The opening of an outpatient wound center affiliated with a tertiary vascular surgical practice was associated with a higher volume of limb salvage patients and procedures. The risk of major amputation decreased following the opening of the wound care center. Integrating vascular surgeons into wound centers may result in a synergistic system that promotes more aggressive and effective limb salvage.

Episode-based cost reduction for endovascular aneurysm repair.

OBJECTIVE: Effective strategies to reduce costs associated with endovascular aneurysm repair (EVAR) remain elusive for many medical centers. In this study, targeted interventions to reduce inpatient EVAR costs were identified and implemented. METHODS: From June 2015 to February 2016, we analyzed the EVAR practice at a high-volume academic medical center to identify, to rank, and ultimately to reduce procedure-related costs. In this analysis, per-patient direct costs to the hospital were compared before (September 2013-May 2015) and after (March 2016-January 2017) interventions were implemented. Improvement efforts concentrated on three categories that accounted for a majority of costs: implants, rooming costs, and computed tomography scans performed during the index hospitalization. RESULTS: Costs were compared between 141 EVAR procedures before implementation (PRE period) and 47 EVAR procedures after implementation (POST period). Based on data obtained through the Society for Vascular Surgery EVAR Cost Demonstration Project, it was determined that implantable device costs were higher than those at peer institutions. New purchasing strategies were implemented, resulting in a 30.8% decrease in per-case device costs between the PRE and POST periods. Care pathways were modified to reduce use of and costs for computed tomography scans obtained during the index hospitalization. Compared with baseline, per-case imaging costs decreased by 92.9% (P < .001), including a 99.0% (P = .001) reduction in postprocessing costs. Care pathways were also implemented to reduce preprocedural rooming for patients traveling long distances the day before surgery, resulting in a 50% decrease in utilization rate (35.4% PRE to 17.0% POST; P = .021), without having a significant impact on median postprocedural length of stay (PRE, 2 days [interquartile range, 1-11 days]; POST, 2 days [1-7 days]; P = .185). Medication costs also decreased by 38.2% (P < .001) as a hospital-wide effort. CONCLUSIONS: Excessive costs associated with EVAR threaten the sustainability of these procedures in health care organizations. Targeted cost reduction efforts can effectively reduce expenses without compromising quality or limiting patients' access.

Metformin prescription status and abdominal aortic aneurysm disease progression in the U.S. veteran population.

BACKGROUND: Identification of a safe and effective medical therapy for abdominal aortic aneurysm (AAA) disease remains a significant unmet medical need. Recent small cohort studies indicate that metformin, the world's most commonly prescribed oral hypoglycemic agent, may limit AAA enlargement. We sought to validate these preliminary observations in a larger cohort. METHODS: All patients with asymptomatic AAA disease managed in the Veterans Affairs Health Care System between 2003 and 2013 were identified by International Classification of Diseases, Ninth Revision codes. Those with a concomitant diagnosis of diabetes mellitus who also received two or more abdominal imaging studies (computed tomography, magnetic resonance imaging, or ultrasound) documenting the presence and size of an AAA, separated by at least 1 year, were included for review. Maximal AAA diameters were determined from radiologic reports. Further data acquisition was censored after surgical AAA repair, when performed. Comorbidities, active smoking status, and outpatient medication records (within 6 months of AAA diagnosis) were also queried. Yearly AAA enlargement rates, as a function of metformin treatment status, were compared using two statistical models expressed in millimeters per year: a multivariate linear regression (model 1) and a multivariate mixed-effects model with random intercept and random slope (model 2). RESULTS: A total of 13,834 patients with 58,833 radiographic records were included in the analysis, with radiology imaging follow-up of 4.2 ± 2.6 years (mean ± standard deviation). The average age of the patients at AAA diagnosis was 69.8 ± 7.8 years, and 39.7% had a metformin prescription within ±6 months of AAA. The mean growth rate for AAAs in the entire cohort was 1.4 ± 2.0 mm/y by model 1 analysis and 1.3 ± 1.6 mm/y by model 2 analysis. The unadjusted mean rate of AAA growth was 1.2 ± 1.9 mm/y for patients prescribed metformin compared with 1.5 ± 2.2 mm/y for those without (P < .001), a 20% decrease. This effect remained significant when adjusted for variables relevant on AAA progression: metformin prescription was associated with a reduction in yearly AAA growth rate of -0.23 mm (95% confidence interval, -0.35 to -0.16; P < .001) by model 1 analysis and 0.20 mm/y (95% confidence interval, -0.26 to -0.14; P < .001) by model 2 analysis. A subset analysis of 7462 patients with baseline AAA size of 35 to 49 mm showed a similar inhibitory effect (1.4 ± 2.0 mm/y to 1.7 ± 2.2 mm/y; P < .001). Patients' factors associated with an increased yearly AAA growth rate were baseline AAA size, metastatic solid tumors, active smoking, chronic obstructive pulmonary disease, and chronic renal disease. Factors associated with decreased yearly AAA growth rates included prescriptions for angiotensin II type 1 receptor blockers or sulfonylureas and the presence of diabetes-related complications. CONCLUSIONS: In a nationwide analysis of diabetic Veterans Affairs patients, prescription for metformin was associated with decreased AAA enlargement. These findings provide further support for the conduct of prospective clinical trials to test the ability of metformin to limit progression of early AAA disease.

Infrarenal endovascular aneurysm repair with large device (34- to 36-mm) diameters is associated with higher risk of proximal fixation failure.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has become the standard of care for infrarenal aneurysms. Endografts are commercially available in proximal diameters up to 36 mm, allowing proximal seal in necks up to 32 mm. We sought to further investigate clinical outcomes after standard EVAR in patients requiring large main body devices. METHODS: We performed a retrospective review of a prospectively maintained database for all patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms at a single institution from 2000 to 2016. Only endografts with the option of a 34- to 36-mm proximal diameter were included. Requisite patient demographics, anatomic and device-related variables, and relevant clinical outcomes and imaging were reviewed. The primary outcome in this study was proximal fixation failure, which was a composite of type IA endoleak and stent graft migration >10 mm after EVAR. Outcomes were stratified by device diameter for the large-diameter device cohort (34-36 mm) and the normal-diameter device cohort (<34 mm). RESULTS: There were 500 patients treated with EVAR who met the inclusion criteria. A total of 108 (21.6%) patients received large-diameter devices. There was no difference between the large-diameter cohort and the normal-diameter cohort in terms of 30-day (0.9% vs 0.95%; P = .960) or 1-year mortality (9.0% vs 6.2%; P = .920). Proximal fixation failure occurred in 24 of 392 (6.1%) patients in the normal-diameter cohort and 26 of 108 (24%) patients in the large-diameter cohort (P < .001). There were 13 (3.3%) type IA endoleaks in the normal-diameter cohort and 16 (14.8%) in the large-diameter cohort (P < .001). Stent graft migration (>10 mm) occurred in 15 (3.8%) in the normal-diameter cohort and 16 (14.8%) in the large-diameter cohort (P < .001). After multivariate analysis, only the use of Talent (Medtronic, Minneapolis, Minn) endografts (odds ratio [OR], 4.50; 95% confidence interval [CI], 1.18-17.21) and neck diameter ≥29 mm (OR, 2.50; 95% CI, 1.12-5.08) remained significant independent risk factors for development of proximal fixation failure (OR, 3.99; 95% CI, 1.75-9.11). CONCLUSIONS: Standard EVAR in patients with large infrarenal necks ≥29 mm requiring a 34- to 36-mm-diameter endograft is independently associated with an increased rate of proximal fixation failure. This group of patients should be considered for more proximal seal strategies with fenestrated or branched devices vs open repair. Also, this group likely needs more stringent radiographic follow-up.