Association Between Diagnosis-to-Limb Revascularization Time and Clinical Outcomes in Outpatients With Chronic Limb-Threatening Ischemia: Insights From the CLIPPER Cohort.

BACKGROUND: The extent and consequences of ischemia in patients with chronic limb-threatening ischemia (CLTI) may change rapidly, and delays from diagnosis to revascularization may worsen outcomes. We sought to describe the association between time from diagnosis to endovascular lower extremity revascularization (diagnosis-to-limb revascularization [D2L] time) and clinical outcomes in outpatients with CLTI. METHODS AND RESULTS: In the CLIPPER cohort, comprising patients between 66 and 86 years old diagnosed with CLTI betweeen 2010 and 2019, we used Medicare claims data to identify patients who underwent outpatient endovascular revascularization within 180 days of diagnosis. We described the risk-adjusted association between D2L time and clinical outcomes. Among 1 130 065 patients aged between 66 and 86 years with CLTI, 99 221 (8.8%) underwent outpatient endovascular lower extremity revascularization within 180 days of their CLTI diagnosis. Among patients with D2L time <30 days, there was no association between D2L time and all-cause death or major lower extremity amputation. However, among patients with D2L time >30 days, each additional 10-day increase in D2L time was associated with a 2.5% greater risk of major amputation (hazard ratio, 1.025 [95% CI, 1.014-1.036]). There was no association between D2L time and all-cause death. CONCLUSIONS: A delay of >30 days from CLTI diagnosis to lower extremity endovascular revascularization was associated with an increased risk of major lower extremity amputation among patients undergoing outpatient endovascular revascularization. Improving systems of care to reduce D2L time could reduce amputations.

Evaluation of short-term mortality in patients with Medicare undergoing endovascular interventions for chronic limb-threatening ischemia.

INTRODUCTION: Patients with chronic limb-threatening ischemia (CLTI) have high mortality rates after revascularization. Risk stratification for short-term outcomes is challenging. We aimed to develop machine-learning models to rank predictive variables for 30-day and 90-day all-cause mortality after peripheral vascular intervention (PVI). METHODS: Patients undergoing PVI for CLTI in the Medicare-linked Vascular Quality Initiative were included. Sixty-six preprocedural variables were included. Random survival forest (RSF) models were constructed for 30-day and 90-day all-cause mortality in the training sample and evaluated in the testing sample. Predictive variables were ranked based on the frequency that they caused branch splitting nearest the root node by importance-weighted relative importance plots. Model performance was assessed by the Brier score, continuous ranked probability score, out-of-bag error rate, and Harrell's C-index. RESULTS: A total of 10,114 patients were included. The crude mortality rate was 4.4% at 30 days and 10.6% at 90 days. RSF models commonly identified stage 5 chronic kidney disease (CKD), dementia, congestive heart failure (CHF), age, urgent procedures, and need for assisted care as the most predictive variables. For both models, eight of the top 10 variables were either medical comorbidities or functional status variables. Models showed good discrimination (C-statistic 0.72 and 0.73) and calibration (Brier score 0.03 and 0.10). CONCLUSION: RSF models for 30-day and 90-day all-cause mortality commonly identified CKD, dementia, CHF, need for assisted care at home, urgent procedures, and age as the most predictive variables as critical factors in CLTI. Results may help guide individualized risk-benefit treatment conversations regarding PVI.

Patients living farther from a tertiary care center are more likely to undergo peripheral arterial bypass for acute and chronic limb-threatening ischemia.

OBJECTIVE: The aim of this study was to assess the association between the proximity to the tertiary care hospital and the severity of peripheral arterial disease (PAD) at the time of lower extremity bypass (LEB) in a rural-urban mix region. METHODS: Patients undergoing LEB from 2010 to 2020 at Penn State Milton S. Hershey Medical Center were reviewed and stratified into two study groups based on a median distance from hospital (ie, Group I: ≥34 miles and Group II: <34 miles). Patients' demographic features, preoperative data including comorbidities, and medications were analyzed. A univariate analysis for the patient characteristics between the two study groups, along with evaluation of postoperative outcomes, and a multivariate predictive modeling to study the PAD stage as the indication of LEB was performed. A P-value of < .05 was set as a significant difference between the groups for all the analyses. RESULTS: There were 175 patients (49.9%) in Group I and 176 patients (50.1%) in Group II with a mean age of 65 ± 11.92 years (median, 64.61 years). No significant difference was observed in gender (P = .530), age (P = .906), and functional status (P = .830) between study groups. It was observed that patients in Group I were more likely to be overweight or obese (71.3% vs 57%; P = .007) and had a prior history of myocardial infarction (24.3% vs 15.3%; P = .036) in comparison to Group II. No postoperative outcomes were found to be statistically different between the study groups. The multivariate analyses based on various confounders displayed that patients in Group I had 56% higher likelihood of LEB for chronic limb-threatening ischemia (adjusted odds ratio, 1.56; 95% confidence interval, 0.92-2.62; P = .042). Group I patients also had five times higher odds of LEB for acute limb ischemia (adjusted odds ratio, 5.07; 95% confidence interval, 1.42-18.13; P = .012) as compared with those in the Group II. CONCLUSIONS: Patients' proximity to a major tertiary hospital may have implications on the disease progression for patients with PAD and could also be related to inadequate vascular services in primary and secondary hospitals. Lack of preventive care and disease management in regions afar from a tertiary hospital could be other implicating factors and highlights the need for outreach programs, along with distribution of vascular specialists, to reduce geographical disparities and ensure equity in access to care.

Impact of Intensity of Vascular Care Preceding Major Amputation Among Patients With Chronic Limb-Threatening Ischemia.

BACKGROUND: Lower-limb amputation rates in patients with chronic limb-threatening ischemia vary across the United States, with marked disparities in amputation rates by gender, race, and income status. We evaluated the association of patient, hospital, and geographic characteristics with the intensity of vascular care received the year before a major lower-limb amputation and how intensity of care associates with outcomes after amputation. METHODS: Using Medicare claims data (2016-2019), beneficiaries diagnosed with chronic limb-threatening ischemia who underwent a major lower-limb amputation were identified. We examined patient, hospital, and geographic characteristics associated with the intensity of vascular care received the year before amputation. Secondary objectives evaluated all-cause mortality and adverse events following amputation. RESULTS: Of 33 036 total Medicare beneficiaries undergoing major amputation, 7885 (23.9%) were due to chronic limb-threatening ischemia; of these, 4988 (63.3%) received low-intensity and 2897 (36.7%) received high-intensity vascular care. Mean age, 76.6 years; women, 38.9%; Black adults, 24.5%; and of low income, 35.2%. After multivariable adjustment, those of low income (odds ratio, 0.65 [95% CI, 0.58-0.72]; P<0.001), and to a lesser extent, men (odds ratio, 0.89 [95% CI, 0.81-0.98]; P=0.019), and those who received care at a safety-net hospital (odds ratio, 0.87 [95% CI, 0.78-0.97]; P=0.012) were most likely to receive low intensity of care before amputation. High-intensity care was associated with a lower risk of all-cause mortality 2 years following amputation (hazard ratio, 0.79 [95% CI, 0.74-0.85]; P<0.001). CONCLUSIONS: Patients who were of low-income status, and to a lesser extent, men, or those cared for at safety-net hospitals were most likely to receive low-intensity vascular care. Low-intensity care was associated with worse long-term event-free survival. These data emphasize the continued disparities that exist in contemporary vascular practice.

Association between readmission care fragmentation and outcomes after interventions for peripheral arterial disease.

OBJECTIVE: Lower extremity revascularization (LER) for peripheral artery disease is complicated by the frequent need for readmission. However, it is unclear if readmission to a nonindex LER facility (ie, a facility different from the one where the LER was performed) compared with the index LER facility is associated with worse outcomes. METHODS: This was a national cohort study of older adults who underwent open, endovascular, or hybrid LER for peripheral artery disease (January 1, 2010, to December 31, 2018) in the Vascular Quality Initiative who were readmitted within 90 days of their vascular procedure. This dataset was linked to Medicare claims and the American Hospital Association Annual Survey. The primary outcome was 90-day mortality and the secondary outcome was major amputation at 90 days after LER. The primary exposure was the location of the first readmission after LER (categorized as occurring at the index LER facility vs a nonindex LER facility). Generalized estimating equations logistic regression models were used to assess the association between readmission location and 90-day mortality and amputation. RESULTS: Among 42,429 patients who underwent LER, 33.0% were readmitted within 90 days. Of those who were readmitted, 27.3% were readmitted to a nonindex LER facility, and 42.2% of all readmissions were associated with procedure-related complications. Compared with patients readmitted to the index LER facility, those readmitted to a nonindex facility had a lower proportion of procedure-related reasons for readmission (21.5% vs 50.1%; P < .001). Most of the patients readmitted to a nonindex LER facility lived further than 31 miles from the index LER facility (39.2% vs 19.6%; P < .001) and were readmitted to a facility with a total bed size of <250 (60.1% vs 11.9%; P < .001). Readmission to a nonindex LER facility was not associated with 90-day mortality or 90-day amputation. However, readmission for a procedure-related complication was associated with major amputation (90-day amputation: adjusted odds ratio, 3.33; 95% confidence interval, 2.89-3.82). CONCLUSIONS: Readmission after LER for a procedure-related complication is associated with subsequent amputation. This finding suggests that quality improvement efforts should focus on understanding various types of procedure-related failure after LER and its role in limb salvage.

Proximal Femur Replacements for an Oncologic Indication Offer a Durable Endoprosthetic Reconstruction Option: A 40-year Experience.

BACKGROUND: Proximal femur replacements (PFRs) are an effective surgical option to treat primary and metastatic tumors causing large bony defects in the proximal femur. Given the relative rarity of these indications, current studies on PFR for oncologic indications are generally limited by patient volume or relatively short-term follow-up. Because recent advances in systemic therapy have improved the prognosis of patients who undergo limb salvage surgery for musculoskeletal tumors, data on the long-term durability of endoprosthetic reconstructions have become increasingly important. QUESTIONS/PURPOSES: (1) How does the long-term survival of cemented bipolar PFRs compare with patient survival in patients who underwent PFR for benign, aggressive, and metastatic tumors? (2) What are common reasons for revisions of primary PFRs? (3) Which factors are associated with survival of primary PFRs? (4) What is the survivorship free from conversion of bipolar PFRs to THA? METHODS: Between January 1, 1980, and December 31, 2020, we treated 812 patients with an endoprosthetic reconstruction for an oncologic indication. All patients who underwent a primary PFR for an oncologic indication were included in this study. The study cohort consisted of 122 patients receiving a primary PFR. Eighteen patients did not reach a censored endpoint such as death, revision, or amputation within 2 years. Thirty-three patients died within 2 years of their surgery. Of the 122 patients with primary PFRs, 39 did not reach a censored endpoint and have not been seen within the past 5 years. However, the mean follow-up time for these patients was longer than 10 years. The Social Security Death Index was queried to identify any patients who may have died but might not have been captured by our database To allow for adequate follow-up, endoprosthetic reconstructions performed after December 31, 2020 were excluded. The mean age at the time of the index surgery was 48 ± 22 years. The mean follow-up time of surviving patients was 7 ± 8 years. All PFRs were performed using a bipolar hemiarthroplasty with a cemented stem, and all implants were considered comparable. Demographic, oncologic, procedural, and outcome data including prosthesis survival, patient survival, complication rates, and rates of conversion to THA were analyzed. Patient, prosthesis, and limb salvage survival rates were generated, with implant revision as the endpoint and death as a competing risk. Statistical significance was defined as p < 0.05. RESULTS: Generally, patients with benign or low-grade (Stage I) disease outlived their implants (100% patient survival through 30 years; p = 0.02), whereas the opposite was true in patients with high-grade, localized Stage II disease (64% patient survival at 5 years [95% CI 49% to 76%]; p = 0.001) or widespread Stage III metastatic disease (6.2% patient survival at 5 years [95% CI 0.5% to 24%]; p < 0.001). Primary PFR implant survival at 5, 10, 20, and 30 years was 97% (95% CI 90% to 99%), 81% (95% CI 67% to 90%), 69% (95% CI 46% to 84%), and 51% (95% CI 24% to 73%), respectively. Eight percent (10 of 122) of primary PFRs were revised for any reason. The most common causes of revision were aseptic loosening (3% [four of 122]), infection (3% [three of 122]), breakage of the implant (2% [two of 122]), and tumor progression (1% [one of 122]). Follow-up time was the only factor that was associated with revision of primary PFRs. Neither segment length nor stem length were associated with revision of primary. Six percent (seven of 122) of PFRs were converted to THA at a mean 15 ± 8 years from the index procedure. Survivorship free from conversion to THA (accounting for death as a competing risk) was 94% (95% CI 85% to 99%), 86% (95% CI 68% to 94%). and 77% (95% CI 51% to 91%) at 10, 20, and 30 years, respectively. CONCLUSION: Cemented bipolar PFRs for an oncologic indication are a relatively durable reconstruction technique. Given the relative longevity and efficacy of PFRs demonstrated in our study, especially in patients with high-grade or metastatic disease where implant survival until all-cause revision was longer than patient survival, surgeons should continue to seriously consider PFRs in appropriate patients. The relative rarity of these reconstructions limits the number of patients in this study as well as in current research; thus, further multi-institutional collaborations are needed to provide the most accurate prognostic data for our patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

Early peripheral vascular interventions for claudication are associated with higher rates of late interventions and progression to chronic limb threatening ischemia.

OBJECTIVE: Despite societal guidelines that peripheral vascular intervention (PVI) should not be the first-line therapy for intermittent claudication, a significant number of patients will undergo PVI for claudication within 6 months of diagnosis. The aim of the present study was to investigate the association of early PVI for claudication with subsequent interventions. METHODS: We evaluated 100% of Medicare fee-for-service claims to identify all beneficiaries with a new diagnosis of claudication from January 1, 2015 to December 31, 2017. The primary outcome was late intervention, defined as any femoropopliteal PVI performed >6 months after the claudication diagnosis (through June 30, 2021). Kaplan-Meier curves were used to compare the cumulative incidence of late PVI for claudication patients with early (≤6 months) PVI vs those without early PVI. A hierarchical Cox proportional hazards model was used to evaluate the patient- and physician-level characteristics associated with late PVIs. RESULTS: A total of 187,442 patients had a new diagnosis of claudication during the study period, of whom 6069 (3.2%) had undergone early PVI. After a median follow-up of 4.39 years (interquartile range, 3.62-5.17 years), 22.5% of the early PVI patients had undergone late PVI vs 3.6% of those without early PVI (P < .001). Patients treated by high use physicians of early PVI (≥2 standard deviations; physician outliers) were more likely to have received late PVI than were patients treated by standard use physician of early PVI (9.8% vs 3.9%; P < .001). Patients who had undergone early PVI (16.4% vs 7.8%) and patients treated by outlier physicians (9.7% vs 8.0%) were more likely to have developed CLTI (P < .001 for both). After adjustment, the patient factors associated with late PVI included receipt of early PVI (adjusted hazard ratio [aHR], 6.89; 95% confidence interval [CI], 6.42-7.40) and Black race (vs White; aHR, 1.19; 95% CI, 1.10-1.30). The only physician factor associated with late PVI was a majority of practice in an ambulatory surgery center or office-based laboratory, with an increasing proportion of ambulatory surgery center or office-based laboratory services associated with significantly increased rates of late PVI (quartile 4 vs quartile 1; aHR, 1.57; 95% CI, 1.41-1.75). CONCLUSIONS: Early PVI after the diagnosis of claudication was associated with higher late PVI rates compared with early nonoperative management. High use physicians of early PVI for claudication performed more late PVIs than did their peers, especially those primarily delivering care in high reimbursement settings. The appropriateness of early PVI for claudication needs critical evaluation, as do the incentives surrounding the delivery of these interventions in ambulatory intervention suites.

Area Deprivation Index is not predictive of worse outcomes after open lower extremity revascularization.

OBJECTIVE: Prior research has shown that socioeconomic status (SES) is associated with higher rates of diabetes, peripheral vascular disease, and amputation. We sought to determine whether SES or insurance type increases the risk of mortality, major adverse limb events (MALE), or hospital length of stay (LOS) after open lower extremity revascularization. METHODS: We conducted a retrospective analysis of patients who underwent open lower extremity revascularization at a single tertiary care center from January 2011 to March 2017 (n = 542). SES was determined using state Area Deprivation Index (ADI), a validated metric determined by income, education, employment, and housing quality by census block group. Patients undergoing amputation in this same time period (n = 243) were included to compare rates of revascularization to amputation by ADI and insurance status. For patients undergoing revascularization or amputation procedures on both limbs, each limb was treated individually for this analysis. We performed a multivariate analysis of the association between ADI and insurance type with mortality, MALE, and LOS using Cox proportional hazard models, including confounding variables such as age, gender, smoking status, body mass index, hyperlipidemia, hypertension, and diabetes. The cohort with an ADI quintile of 1, meaning least deprived, and the Medicare cohort were used for reference. P values of <.05 were considered statistically significant. RESULTS: We included 246 patients undergoing open lower extremity revascularization and 168 patients undergoing amputation. Controlling for age, gender, smoking status, body mass index, hyperlipidemia, hypertension, and diabetes, ADI was not an independent predictor of mortality (P = .838), MALE (P = .094), or hospital LOS (P = .912). Controlling for the same confounders, uninsured status was independently predictive of mortality (P = .033), but not MALE (P = .088) or hospital LOS (P = .125). There was no difference in the distribution of revascularizations or amputations by ADI (P = .628), but there was higher proportion of uninsured patients undergoing amputation compared with revascularization (P < .001). CONCLUSIONS: This study suggests that ADI is not associated with an increased risk of mortality or MALE in patients undergoing open lower extremity revascularization, but that uninsured patients are at higher risk of mortality after revascularization. These findings indicate that individuals undergoing open lower extremity revascularization at this single tertiary care teaching hospital received similar care, regardless of their ADI. Further study is warranted to understand the specific barriers that uninsured patients face.

Comparison of lower extremity bypass and peripheral vascular intervention for chronic limb-threatening ischemia in the Medicare-linked Vascular Quality Initiative.

OBJECTIVE: There is a relative lack of comparative effectiveness research on revascularization for patients with chronic limb-threatening ischemia (CLTI). We examined the association between lower extremity bypass (LEB) vs peripheral vascular intervention (PVI) for CLTI and 30-day and 5-year all-cause mortality and 30-day and 5-year amputation. METHODS: Patients undergoing LEB and PVI of the below-the-knee popliteal and infrapopliteal arteries between 2014 and 2019 were queried from the Vascular Quality Initiative, and outcomes data were obtained from the Medicare claims-linked Vascular Implant Surveillance and Interventional Outcomes Network database. Propensity scores were calculated on 15 variables using a logistic regression model to control for imbalances between treatment groups. A 1:1 matching method was used. Kaplan-Meier survival curves and hierarchical Cox proportional hazards regression with a random intercept for site and operator nested in site to account for clustered data compared 30-day and 5-year all-cause mortality between groups. Thirty-day and 5-year amputation were subsequently compared using competing risk analysis to account for the competing risk of death. RESULTS: There was a total of 2075 patients in each group. The overall mean age was 71 ± 11 years, 69% were male, and 76% were white, 18% were black, and 6% were of Hispanic ethnicity. Baseline clinical and demographic characteristics in the matched cohort were balanced between groups. There was no association between all-cause mortality over 30 days and LEB vs PVI (cumulative incidence, 2.3% vs 2.3% by Kaplan Meier; log-rank P-value = .906; hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.62-1.44; P-value = .80). All-cause mortality over 5 years was lower for LEB vs PVI (cumulative incidence, 55.9% vs 60.1% by Kaplan Meier; log-rank P-value < .001; HR, 0.77; 95% CI, 0.70-0.86; P-value < .001). Accounting for competing risk of death, amputation over 30 days was also lower in LEB vs PVI (cumulative incidence function, 1.9% vs 3.0%; Fine and Gray P-value = .025; subHR, 0.63; 95% CI, 0.42-0.95; P-value = .025). There was no association between amputation over 5 years and LEB vs PVI (cumulative incidence function, 22.6% vs 23.4%; Fine and Gray P-value = .184; subHR, 0.91; 95% CI, 0.79-1.05; P-value = .184). CONCLUSIONS: In the Vascular Quality Initiative-linked Medicare registry, LEB vs PVI for CLTI was associated with a lower risk of 30-day amputation and 5-year all-cause mortality. These results will serve as a foundation to validate recently published randomized controlled trial data, and to broaden the comparative effectiveness evidence base for CLTI.

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 between sex and long-term outcomes of endovascular treatment for peripheral artery disease.

BACKGROUND: Endovascular peripheral vascular intervention (PVI) has become the primary revascularization technique used for peripheral artery disease (PAD). Yet, there is limited understanding of long-term outcomes of PVI among women versus men. In this study, our objective was to investigate sex differences in the long-term outcomes of patients undergoing PVI. METHODS: We performed a cohort study of patients undergoing PVI for PAD from January 1, 2010 to September 30, 2015 using data in the Vascular Quality Initiative (VQI) registry. Patients were linked to fee-for-service Medicare claims to identify late outcomes including major amputation, reintervention, major adverse limb event (major amputation or reintervention [MALE]), and mortality. Sex differences in outcomes were evaluated using cumulative incidence curves, Gray's test, and mixed effects Cox proportional hazards regression accounting for patient and lesion characteristics using inverse probability weighted estimates. RESULTS: In this cohort of 15,437 patients, 44% (n = 6731) were women. Women were less likely to present with claudication than men (45% vs. 49%, p < 0.001, absolute standardized difference, d = 0.08) or be able to ambulate independently (ambulatory: 70% vs. 76%, p < 0.001, d = 0.14). There were no major sex differences in lesion characteristics, except for an increased frequency of tibial artery treatment in men (23% vs. 18% in women, p < 0.001, d = 0.12). Among patients with claudication, women had a higher risk-adjusted rate of major amputation (hazard ratio [HR] = 1.72, 95% confidence interval [CI]: 1.18-2.49), but a lower risk of mortality (HR = 0.86, 95% CI: 0.75-0.99). There were no sex differences in reintervention or MALE for patients with claudication. However, among patients with chronic limb-threatening ischemia, women had a lower risk-adjusted hazard of major amputation (HR = 0.79, 95% CI: 0.67-0.93), MALE (HR = 0.86, 95% CI: 0.78-0.96), and mortality (HR = 0.86, 95% CI: 0.79-0.94). CONCLUSION: There is significant heterogeneity in PVI outcomes among men and women, especially after stratifying by symptom severity. A lower overall mortality in women with claudication was accompanied by a higher risk of major amputation. Men with chronic limb-threatening ischemia had a higher risk of major amputation, MALE, and mortality. Developing sex-specific approaches to PVI that prioritizes limb outcomes in women can improve the quality of vascular care for men and women.

Assessment of 3-Year Patency after Endoluminal versus Surgical Bypass Therapy for Complex Femoropopliteal Artery Disease.

PURPOSE: To compare the 3-year clinical outcomes of endoluminal bypass with those of surgical bypass for complex femoropopliteal (FP) arterial lesions. MATERIALS AND METHODS: In this retrospective multicenter study, 530 patients with symptomatic peripheral artery disease (Rutherford classification 1-3, 66.0%; 4-6, 34.0%) who underwent either endoluminal bypass with Viabahn stent grafts (n = 276) or surgical bypass (n = 254) (with saphenous vein grafts, 74.4%; prosthetic grafts, 25.6%) for FP arterial lesions between 2010 and 2018 were analyzed. The propensity score-matched analysis was performed to compare the 3-year clinical outcomes of endoluminal bypass with those of surgical bypass. The primary end point was primary patency (freedom from restenosis). The secondary end points were secondary patency, freedom from target lesion revascularization (TLR), limb salvage, and overall survival. The interaction effect of baseline characteristics on the association of the revascularization strategy with the risk of restenosis was analyzed using the Poisson mixed-effect model. RESULTS: The propensity score-matched analysis extracted 107 pairs. After propensity score matching, the primary patency rate at 1, 2, and 3 years was 84.5%, 75.1%, and 70.9%, respectively, for the endoluminal bypass group versus 78.6%, 73.3%, and 72.0%, respectively, for the surgical bypass group (P = .65). There was no significant difference in secondary patency, freedom from TLR, limb salvage, and overall survival (all P > .05). The subsequent interaction analysis revealed that the involvement of popliteal lesions, small distal reference vessel diameters, and long lesions favored surgical bypass over endoluminal bypass because of improved primary patency (all P for interaction < .05). CONCLUSIONS: The 3-year clinical outcomes after endoluminal bypass or surgical bypass for FP arterial lesions were similar.

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.

Mangled Extremity Severity Score in the Assessment of Extremity Injuries - Is it Reliable?

The mangled extremity severity score (MESS) was established 28 years ago to decide performing an amputation in cases of limb trauma. It assigns points for 4 aspects of the injury: the extent of soft tissue and skeletal injury, limb ischemia and ischemic duration, shock, and age. A score of 7 or higher indicates that primary amputation is required. Thirty-one patients with MESS scores of 7 to 8 underwent limb salvage surgeries, with 13 limbs being saved and 18 limbs being amputated. Upper extremities trauma had a salvage rate of 62.5%, whereas lower extremity trauma had a salvage rate of 20%. MESS is not a sensitive predictor of amputation in upper limb trauma, but it is useful in lower limb injuries.

Open Repair Versus Endovascular Repair in the Treatment of Symptomatic Popliteal Artery Aneurysms.

BACKGROUND: Endovascular and open surgical modalities are currently used to treat popliteal artery aneurysms (PAA). However, there is limited data on the comparative durability of both repairs to guide physicians especially in the treatment of patients presenting symptomatic. We aimed to study the comparative effectiveness of endovascular PAA repair (EPAR) versus open PAA repair (OPAR). METHODS: The vascular quality initiative (VQI)-Medicare linked database was queried for patients with symptomatic PAA who underwent OPAR or EPAR from January 2010 to December 2018. Kaplan-Meier estimates, log-rank tests and multivariable Cox proportional hazard regression were employed to study the outcomes of amputation free survival (AFS), freedom from first reintervention, freedom from major amputation, and overall survival in 2 years following the index procedure. RESULTS: A total of 1,375 patients were studied, of which 23.7% (n = 326) were treated with EPAR. Patients treated with OPAR were younger, less likely to have coronary artery disease (CAD) and chronic kidney disease (CKD), but more likely to be smokers and to present with acute lower extremity ischemia. OPAR treated patients had better 2-year AFS (84.5% vs. 72.5%, P < 0.001) and overall survival (86.2% vs. 74.7%, P < 0.001). Freedom from major amputation at 2 years were comparable between EPAR and OPAR (95.5% vs. 97.7%, P = 0.164) in the overall cohort. Within the sub cohort of patients with acute limb ischemia, freedom from major amputation was significantly higher for OPAR compared to EPAR (97.4% vs. 90.6%, P = 0.021). After adjustment for confounders, OPAR was associated with decreased risk of amputation or death (aHR, 0.62; 95% CI, 0.48-0.80; P < 0.001) and mortality (aHR, 0.63; 95% CI, 0.48-0.81; P < 0.001) at 2 years. OPAR and EPAR had comparable adjusted risk of 2-year major amputation in the overall cohort. However, for patients presenting with acute limb ischemia OPAR was associated with 72% lower risk of 2-year major amputation compared to EPAR (aHR, 0.28; 95% CI, 0.10-0.83; P = 0.021). CONCLUSIONS: In this multi-institutional observational study of symptomatic popliteal aneurysms, OPAR was associated with significantly better amputation free and overall survival compared to EPAR. For patients with acute limb ischemia, OPAR was associated with reduced risk of amputation. These findings suggest that OPAR may be superior to EPAR in the treatment of symptomatic PAA. A consideration of OPAR as first line definitive treatment for symptomatic PAA patients who are good surgical candidates is suggested.

Racial and ethnic disparities in 3-year outcomes following infrainguinal bypass for chronic limb-threatening ischemia.

OBJECTIVE: Black and Hispanic patients have had higher rates of chronic limb-threatening ischemia (CLTI) and experienced worse perioperative outcomes after lower extremity bypass compared with White patients. The underlying reasons for these disparities have remained unclear, and data on 3-year outcomes are limited. Therefore, we examined the differences in 3-year outcomes after open infrainguinal bypass for CLTI stratified by race/ethnicity and explored the potential factors contributing to these differences. METHODS: We identified all CLTI patients who had undergone primary open infrainguinal bypass in the Vascular Quality Initiative registry from 2003 to 2017 with linkage to Medicare claims through 2018 for the 3-year outcomes. Our primary outcomes were the 3-year rates of major amputation, reintervention, and mortality. We also recorded the 30-day major adverse limb events (MALE) defined as major amputation or reintervention. We used Kaplan-Meier estimation methods and multivariable Cox regression analyses to evaluate the outcomes stratified by race/ethnicity and identify contributing factors. RESULTS: Of the 7108 patients with CLTI, 5599 (79%) were non-Hispanic White, 1053 (15%) were Black, 48 (1%) were Asian, and 408 (6%) were Hispanic patients. Compared with White patients, Black patients had higher rates of 3-year major amputation (Black vs White, 32% vs 19%; hazard ratio [HR], 1.9; 95% confidence interval [CI], 1.7-2.2), reintervention (Black vs White, 61% vs 57%; HR, 1.2; 95% CI, 1.1-1.3), and 30-day MALE (Black vs White, 8.1% vs 4.9%; HR, 1.3; 95% CI, 1.2-1.4) but lower mortality (Black vs White, 38% vs 42%; HR, 0.9; 95% CI, 0.8-0.99). Hispanic patients also experienced higher rates of amputation (Hispanic vs White, 27% vs 19%; HR, 1.6; 95% CI, 1.3-2.0), reintervention (Hispanic vs White, 70% vs 57%; HR, 1.4; 95% CI, 1.2-1.6), and MALE (Hispanic vs White, 8.7% vs 4.9%; HR, 1.5; 95% CI, 1.3-1.7. However, mortality was similar between the two groups (Hispanic vs White, 38% vs 42%; HR, 0.88; 95% CI, 0.76-1.0). The low number of Asian patients prevented a meaningful assessment of amputation (Asian vs White, 20% vs 19%; HR, 0.93; 95% CI, 0.44-2.0), reintervention (Asian vs White, 55% vs 57%; HR, 0.79; 95% CI, 0.51-1.2), MALE (Asian vs White, 8.5% vs 4.9%; HR, 0.71; 95% CI, 0.46-1.1), or mortality (Asian vs White, 36% vs 42%; HR, 0.83; 95% CI, 0.52-1.3). In the adjusted analyses, the association of Black race and Hispanic ethnicity with amputation and reintervention was explained by differences in the demographic characteristics (ie, age, sex) and baseline comorbidities (ie, tobacco use, diabetes, renal disease). CONCLUSIONS: Compared with White patients, Black and Hispanic patients had higher 3-year major amputation and reintervention rates. However, mortality was lower for Black patients than for the White patients and similar between Hispanic and White patients. Disparities in amputation and reintervention were partly attributable to differences in demographic characteristics and the higher prevalence of comorbidities in Black and Hispanic patients with CLTI. Future work is necessary to determine whether interventions to improve access to care and reduce the burden of comorbidities in these populations will confer limb salvage benefits.

Differences in Comorbidities Explain Black-White Disparities in Outcomes After Femoropopliteal Endovascular Intervention.

BACKGROUND: Black adults have a higher incidence of peripheral artery disease and limb amputations than White adults in the United States. Given that peripheral endovascular intervention (PVI) is now the primary revascularization strategy for peripheral artery disease, it is important to understand whether racial differences exist in PVI incidence and outcomes. METHODS: Data from fee-for-service Medicare beneficiaries ≥66 years of age from 2016 to 2018 were evaluated to determine age- and sex-standardized population-level incidences of femoropopliteal PVI among Black and White adults over the 3-year study period. Patients' first inpatient or outpatient PVIs were identified through claims codes. Age- and sex-standardized risks of the composite outcome of death and major amputation within 1 year of PVI were examined by race. RESULTS: Black adults underwent 928 PVIs per 100 000 Black beneficiaries compared with 530 PVIs per 100 000 White beneficiaries (risk ratio, 1.75 [95% CI, 1.73-1.77]; P<0.01). Black adults who underwent PVI were younger (mean age, 74.5 years versus 76.4 years; P<0.01), were more likely to be female (52.8% versus 42.7%; P<0.01), and had a higher burden of diabetes (70.6% versus 56.0%; P<0.01), chronic kidney disease (67.5% versus 56.6%; P<0.01), and heart failure (47.4% versus 41.7%; P<0.01) than White adults. When analyzed by indication for revascularization, Black adults were more likely to undergo PVI for chronic limb-threatening ischemia than White adults (13 023 per 21 352 [61.0%] versus 59 956 per 120 049 [49.9%]; P<0.01). There was a strong association between Black race and the composite outcome at 1 year (odds ratio, 1.21 [95% CI, 1.16-1.25]). This association persisted after adjustment for socioeconomic status (odds ratio, 1.08 [95% CI, 1.03-1.13]) but was eliminated after adjustment for comorbidities (odds ratio, 0.96 [95% CI, 0.92-1.01]). CONCLUSIONS: Among fee-for-service Medicare beneficiaries, Black adults had substantially higher population-level PVI incidence and were significantly more likely to experience adverse events after PVI than White adults. The association between Black race and adverse outcomes appears to be driven by a higher burden of comorbidities. This analysis emphasizes the critical need for early identification and aggressive management of peripheral artery disease risk factors and comorbidities to reduce Black-White disparities in the development and progression of peripheral artery disease and the risk of adverse events after PVI.

A Systematic Review of Cost-Utility Analyses in Chronic Limb-Threatening Ischemia.

BACKGROUND: To review and describe the available literature on cost-utility analysis of revascularization and non-revascularization treatment approaches in chronic limb-threatening ischemia. METHODS: A systematic review was performed on cost-utility analysis studies evaluating revascularization (open surgery or endovascular), major lower extremity amputation, or conservative management in adult chronic limb-threatening ischemia patients. Six bibliographic databases and online registries were searched for English language articles up to August 2021. The outcome for cost-utility analysis was quality-adjusted in life years. Procedures were compared using incremental cost-effectiveness ratios which were converted to 2021 United States dollars. Study reporting quality was assessed using the 2022 Consolidated Health Economic Evaluation Reporting Standards statement. The study was registered in International Prospective Register of Systematic Reviews (CRD42021273602). RESULTS: Three trial-based and five model-based studies were included for review. Studies met between 14/28 and 20/28 criteria of the Consolidated Health Economic Evaluation Reporting Standards CHEERS statement. Only one study was written according to standardized reporting guidelines. Most studies evaluated infrainguinal disease, and adopted a health care provider perspective. There was a large variation in the incremental cost-effectiveness ratios presented across studies. Open surgical revascularization (incremental cost-effectiveness ratios: $3,678, $58,828, and $72,937), endovascular revascularization (incremental cost-effectiveness ratios: $52,036, $125,329, and $149,123), and mixed open or endovascular revascularization (incremental cost-effectiveness ratio: $8,094) maybe more cost-effective than conservative management. CONCLUSIONS: The application of cost-utility analyses in chronic limb-threatening ischemia is in its infancy. Revascularization in infrainguinal disease may be favored over major lower extremity amputation or conservative management. However, data is inadequate to support recommendations for a specific treatment. This review identifies short and long-term considerations to address the current state of evidence. Cost-utility analysis is an important tool in healthcare policy and should be encouraged amongst the vascular surgical community.

COVID-19-related Peripheral Arterial Thrombosis Treated in a Large Health Maintenance Organization.

BACKGROUND: COVID-19 was initially identified as an acute respiratory disease, but it was quickly recognized that multiple organ systems could be affected. Venous thrombosis and pulmonary embolism have been well reported. However, there is a paucity of data on COVID-19-related arterial thrombosis. We examined the incidence, characteristics, treatment, and outcome in patients with acute COVID-19-related arterial thrombosis in a large health maintenance organization (HMO). METHODS: A retrospective multicenter case review was performed from March 2020 to March 2021. Cases were identified through a questionnaire sent to vascular surgeons. Patient characteristics, imaging, treatment, and outcome were reviewed. Successful revascularization was defined as restoration of blood flow with viability of the end organ and absence of death within 30 days. Limb salvage was defined as prevention of major amputation (transtibial or transfemoral) and absence of death in 30 days. RESULTS: There were 37,845 patients admitted with COVID-19 complications during this time. Among this group, 26 patients (0.07%) had COVID-19-related arterial thrombosis. The mean age was 61.7 years (range, 33-82 years) with 20 men (77%) and 6 women (23%). Ethnic minorities comprised 25 of 26 cases (96%). Peripheral arterial disease (PAD) was present in 4 of 26 (15%), active smoking in 1 of 26 (3.8%), and diabetes in 19 of 26 (73%) cases. Most patients developed acute arterial ischemia in the outpatient setting, 20 of 26 (77%). Of the outpatients, 6 of 20 (30%) had asymptomatic COVID-19 and 14 of 20 (70%) had only mild upper respiratory symptoms. Distribution of ischemia was as follows: 23 patients had at least one lower extremity ischemia, one patient had cerebral and lower extremity, one had mesenteric and lower extremity, and one had upper extremity ischemia. Revascularization was attempted in 21 patients, of which 12 of 21 (57%) were successful. Limb salvage was successful in 13 of 26 (50%) patients. The overall mortality was 31% (8/26). CONCLUSIONS: Our experience in a large HMO revealed that the incidence of COVID-19-related arterial thrombosis was low. The actual incidence is likely to be higher since our method of case collection was incomplete. The majority of arterial thrombosis occurred in the outpatient setting in patients with asymptomatic or mild/moderate COVID-19 respiratory disease. Acute ischemia was the inciting factor for hospitalization in these cases. Acute lower extremity ischemia was the most common presentation, and limb salvage rate was lower than that expected when compared to ischemia related to PAD. Arterial thrombosis associated with COVID-19 portends a significantly higher mortality. Education of primary care providers is paramount to prevent delayed diagnosis as most patients initially developed ischemia in the outpatient setting and did not have a high cardiovascular risk profile.