Association Between Mental Health Burden, Clinical Presentation, and Outcomes in Individuals With Symptomatic Peripheral Artery Disease: A Scientific Statement From the American Heart Association.

Along with the rising burden of peripheral artery disease (PAD), mental health concerns are increasingly being recognized as a comorbidity to address in the chronic disease management of symptomatic PAD. Apart from a high prevalence of comorbid mental health conditions, the role of pain and changing health behaviors and the broader impacts of illness and adaptation to living with PAD require specialized behavioral health expertise. This scientific statement builds a case that this expertise should be integrated within the multidisciplinary PAD team. Furthermore, areas such as cognitive dysfunction and palliative care are highlighted as needing psychological interventions. Although much of the evidence of the efficacy of psychological and psychotropic interventions has been extrapolated from other cardiovascular populations, evidence for the role of psychological interventions for behavior change, for example, uptake of exercise regimens, is increasingly being accrued within PAD. Areas for behavioral health needs and interactions with PAD treatment are discussed, including the use of opioids, depression management, anxiety and stress reduction interventions, the use of benzodiazepines and antidepressants, smoking cessation, rehabilitation trajectories after amputation, and the role of cognitive decline for PAD treatment and outcomes. A case summary highlights the stigma around mental health and vascular disease and the fragmentation of care. This scientific statement provides remarks for building a road map for integrated behavioral PAD care and potential solutions to overcome these barriers. Instrumental to reaching these changes are interprofessional advocacy efforts and initiatives that help break down the stigma around mental health and promote evidence-based collaborative, nonhierarchical, and multidisciplinary PAD care.

Cost-effectiveness analysis of ankle-brachial index screening in patients with coronary artery disease to optimize medical management.

INTRODUCTION: Screening for peripheral artery disease (PAD) with the ankle-brachial index (ABI) test is currently not recommended in the general population; however, previous studies advocate screening in high-risk populations. Although providers may be hesitant to prescribe low-dose rivaroxaban to patients with coronary artery disease (CAD) alone, given the reduction in cardiovascular events and death associated with rivaroxaban, screening for PAD with the ABI test and accordingly prescribing rivaroxaban may provide additional benefits. We sought to describe the cost-effectiveness of screening for PAD in patients with CAD to optimize this high-risk populations' medical management. METHODS: We used a Markov model to evaluate the ABI test in patients with CAD. We assumed that all patients screened would be candidates for low-dose rivaroxaban. We assessed the cost of ABI screening at $100 per patient and added additional charges for physician visits ($100) and rivaroxaban cost ($470 per month). We used a 30-day cycle and performed analysis over 35 years. We evaluated quality-adjusted life years (QALYs) from previous studies and determined the incremental cost-effectiveness ratio (ICER) according to our model. We performed a deterministic and probabilistic sensitivity analyses of variables with uncertainty and reported them in a Tornado diagram showing the variables with the greatest effect on the ICER. RESULTS: Our model estimates decision costs to screen or not screen at $94,953 and $82,553, respectively. The QALYs gained from screening was 0.060, generating an ICER of $207,491 per QALY. Factors most influential on the ICER were the reduction in all-cause mortality associated with rivaroxaban and the prohibitively high cost of rivaroxaban. If rivaroxaban cost less than $95 per month, this would make screening cost-effective based on a willingness to pay threshold of $50,000 per QALY. CONCLUSIONS: According to our model, screening patients with CAD for PAD to start low-dose rivaroxaban is not currently cost-effective due to insufficient reduction in all-cause mortality and high medication costs. Nevertheless, vascular surgeons have a unique opportunity to prescribe or advocate for low-dose rivaroxaban in patients with PAD to improve cardiovascular outcomes.

Analysis of Medicare Payments and Patient Outcomes With Pre-Operative Imaging for Carotid Endarterectomy.

OBJECTIVE: The use of radiographic evaluation of carotid disease may vary, and current guidelines do not strongly recommend the use of cross-sectional imaging (CSI) prior to surgical intervention. We sought to describe the trends in preoperative carotid imaging and evaluate the associated clinical outcomes and Medicare payments for patients undergoing carotid endarterectomy (CEA) for asymptomatic carotid disease. METHODS: We used a 20% Medicare sample from 2006 to 2014 identifying patients undergoing CEA for asymptomatic disease. We evaluated preoperative carotid ultrasound and CSI use: CT or MRI of the neck prior to CEA. We calculated average payments of each study from the carrier file and revenue center file. Imaging payments included both the professional component (PC) and the technical component (TC). Claims with a reimbursement of $0 and studies where payment for both the TC and PC could not be identified were excluded from the overall calculation to determine average payment per study. Inpatient reimbursements according to DRG 37-39 were calculated. We compared hospital length of stay (LOS), in hospital stroke, carotid re-exploration, and mortality according to CSI use. RESULTS: A total of 58,993 CEAs were identified with pre-operative carotid imaging. The average age was 74.8 ± 7.5 years, and 56.0% were men. A total of 19,678 (33%) patients had ultrasound alone with an average of (2.4 ± 1.9) exams prior to CEA. A total of 39,315 patients underwent CSI prior to CEA with 2.5 ± 2.1 ultrasounds, 0.95 ± 0.86 neck CTs and 0.47 ± 0.7 MRIs per patient. The average payment for ultrasound was $140 ± 40, $282 ± 94 for CT and $410 ± 146 for MRI. The average inpatient reimbursements were $7,413 ± 4,215 for patients without CSI compared with $7,792 ± 3,921 for patients with CSI, P < 0.001. The average LOS during CEA admission was 2.5 ± 3.7days. Patients with CSI had a slightly lower percentage of patients being discharged by postoperative day 2 compared with ultrasound alone (88.9% vs. 91.5%, respectively, P < 0.001). The overall in-hospital stroke rate was 0.38% and carotid re-exploration rate was 1.0% and there was no statistical significant difference between groups. Median follow-up was 3.9 years, and mortality at 8 years was 50% and did not statistically differ between groups. CONCLUSIONS: Our analysis found preoperative imaging to include CSI in nearly two-thirds of patients prior to CEA for asymptomatic disease. As imaging and inpatient payments were higher with patients with CSI further work is needed to understand when CSI is appropriate prior to surgical intervention to appropriately allocate healthcare resources.

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.

Incidence and Risk Factors for Deep Vein Thrombosis after Radiofrequency and Laser Ablation of the Lower Extremity Veins.

BACKGROUND: The rates of thromboembolic complications such as deep vein thrombosis (DVT) after venous ablation procedures for symptomatic superficial venous insufficiency are controversial. We sought to describe the risk factors for and incidence of DVT after radiofrequency ablation (RFA) and laser ablation (LA). METHODS: We queried the Truven Health Marketscan Database from 2007-16 for patients who underwent RFA or LA and had a follow-up duplex ultrasound within 30 days of the ablation procedure. The primary outcome was DVT at 7 and 30 days identified by International Classification of Diseases-9 and International Classification of Diseases-10 codes. Multivariable regression was used to evaluate the patient and procedural variables associated with a DVT at 30 days, expressed as odds ratios (ORs) with a 95% confidence interval (95% CI). Patients and procedures with a previous DVT diagnosis were excluded. RESULTS: A total of 256,999 patients underwent 433,286 ablation procedures: 192,195 (44.4%) RFA and 241,091 LA. Of these, 8,203 (1.9%) had a newly diagnosed DVT within 7 days and 13,347 (3.1%) within 30 days of the procedure. The incidence of DVT decreased over the study period. LA (2.8%) demonstrated a lower incidence of DVT at 30 days compared with RFA (3.4%), P < 0.001. On multivariable regression, LA (OR, 0.82; 95% CI 0.80-0.85) was again associated with a decreased risk for 30-day DVT, as was female gender (OR, 0.74; 95% CI, 0.71-0.77), and sclerotherapy performed on the same day (OR, 0.91; 95% CI, 0.85-0.98). A diagnosis of peripheral artery disease (OR, 1.23; 95% CI, 1.16-1.31) and concomitant stab phlebectomy (OR, 1.43; 95% CI, 1.37-1.49) was associated with an increased risk of DVT within 30 days. CONCLUSIONS: The incidence of newly diagnosed DVT within 30 days of an ablation procedure was 3.2%. The risk for DVT decreased in recent years, and LA was associated with an 18% decreased risk compared with RFA.

Comparison of mid-term graft patency in common femoral versus superficial femoral artery inflow for infra-geniculate bypass in the vascular quality initiative.

OBJECTIVES: The superficial femoral artery can be used as inflow for infra-geniculate bypass, but progressive proximal occlusive disease may affect graft durability. We sought to evaluate the effect of superficial femoral artery versus common femoral artery inflow on infra-geniculate bypass patency within a large contemporary multicenter registry. METHODS: The vascular quality initiative was queried from 2013 to 2019 to identify patients with >30-day patency follow-up, Rutherford chronic limb ischemia stage 1-6, and an infra-geniculate bypass, excluding those with prior ipsilateral bypass. The cohort was stratified by inflow vessel, with primary, primary-assisted, and secondary patency serving as the primary outcome variables. Multivariate Cox-proportional hazard models and radius-based propensity-score matching were performed to reduce treatment-selection bias due to clinical covariates. RESULTS: A total of 11,190 bypass procedures were performed (8378 common femoral artery inflow, 2812 superficial femoral artery) on 10,110 patients, with a mean follow-up of 12.8 months (range 1-98). Patients receiving superficial femoral artery inflow bypasses were more commonly male (p = 0.002), obese (p < 0.0001) and had chronic, limb threatening ischemia (p < 0.0001), whereas those with common femoral artery inflow were older (p < 0.0004), and had higher baseline comorbidities including smoking (p < 0.0001), coronary disease (p < 0.0001), and pulmonary disease (p < 0.0001). On life-table analysis, there was no significant difference in three year estimated primary (32.1 vs 30.1%, p = 0.928), primary assisted (60.5 vs 65.8%, p = 0.191), or secondary patency (62.5 vs 66.7%, p = 0.139) between superficial femoral artery and common femoral artery inflow groups, respectively. A multivariate Cox model found no significant association between inflow vessel and primary patency (0.96 [0.88-1.04], HR [95%CI]), primary-assisted (1.07 [0.95-1.20], HR [95%CI]), or secondary patency (1.08 [0.96-1.22]). In a propensity-matched cohort (n = 11,151), there were small but statistically significant differences in primary, primary-assisted, and secondary patency at latest follow-up (non-time-to-event data) between groups. The largest difference was observed when evaluating secondary patency, with common femoral artery inflow having a marginally higher secondary patency of 88.1% compared to 85.6% for those with superficial femoral artery inflow at latest follow-up (p = 0.009). CONCLUSIONS: Within the vascular quality initiative, there is no significant difference in life-table determined three-year primary, primary-assisted, and secondary patency between infra-geniculate bypasses using common femoral artery inflow compared to superficial femoral artery inflow. Small, statistically significant differences exist in primary, primary-assisted, and secondary patency favoring common femoral artery inflow after propensity score matching. Long-term follow-up data are required in the vascular quality initiative to better evaluate bypass graft durability as this study was limited by a mean follow-up of one year.

Association of Blood Pressure Measurements With Peripheral Artery Disease Events.

BACKGROUND: Current guidelines recommend treating hypertension in patients with peripheral artery disease (PAD) to reduce the risk of cardiac events and stroke, but the effect of reducing blood pressure on lower extremity PAD events is largely unknown. We investigated the association of blood pressure with lower extremity PAD events using data from the ALLHAT trial (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial). METHODS: ALLHAT investigated the effect of different antihypertensive medication classes (chlorthalidone, amlodipine, lisinopril, or doxazosin) on cardiovascular events. With the use of these data, the primary outcome in our analysis was time to first lower extremity PAD event, defined as PAD-related hospitalization, procedures, medical treatment, or PAD-related death. Given the availability of longitudinal standardized blood pressure measurements, we analyzed systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure as time-varying categorical variables (reference categories 120-129 mm Hg for SBP, 70-79 mm Hg for DBP, and 45-54 mm Hg for pulse pressure) in separate models. We used extended Cox regression with death as a competing risk to calculate the association of each blood pressure component with PAD events, and report the results as subdistribution hazard ratios and 95% CIs. RESULTS: The present analysis included 33 357 patients with an average age of 67.4 years, 53.1% men, 59.7% white race, and 36.2% with diabetes mellitus. The median baseline blood pressure was 146/84 mm Hg. Participants were followed for a median of 4.3 (interquartile range, 3.6-5.3) years, during which time 1489 (4.5%) had a lower extremity PAD event, and 4148 (12.4%) died. In models adjusted for demographic and clinical characteristics, SBP <120 mm Hg was associated with a 26% (CI, 5%-52%; P=0.015) higher hazard and SBP≥160 mm Hg was associated with a 21% (CI, 0%-48%; P=0.050) higher hazard for a PAD event, in comparison with SBP 120 to 129 mm Hg. In contrast, lower, but not higher, DBP was associated with a higher hazard of PAD events: for DBP <60 mm Hg (hazard ratio, 1.72; CI, 1.38-2.16). Pulse pressure had a U-shaped association with PAD events. CONCLUSIONS: In this reanalysis of data from ALLHAT, we found a higher rate of lower extremity PAD events with higher and lower SBP and pulse pressure and with lower DBP. Given the recent revised blood pressure guidelines advocating lower SBP targets for overall cardiovascular risk reduction, further refinement of optimal blood pressure targets specific to PAD is needed. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00000542.

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.

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.

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.

Arteriovenous Fistula and Graft Construction in Patients with Implantable Cardiac Devices: Does Side Matter?

BACKGROUND: Limited reports have documented the effect cardiac implantable electronic devices (CIEDs) have on arteriovenous (AV) access patency. Current recommendations suggest placing the access on the contralateral side of the CIEDs, as there is concern for increased central venous stenosis and access failure. The goal of this study is to review our single-center AV access patency rates for dialysis patients with an ipsilateral or contralateral side CIED. METHODS: A retrospective review was performed from 2008 to 2016 at a single institution identifying all patients who have received a CIED and the diagnosis of end-stage renal disease (ESRD). Medical records were queried to identify each patient's dialysis access and whether it was ipsilateral or contralateral to the CIED. Primary outcomes of study were primary and secondary patency rates. RESULTS: A total of 44 patients were identified to have ESRD and CIED. Of these patients, 28 patients with fistulas or grafts (13 ipsilateral and 15 contralateral) had follow-up with regards to their AV access. There were 3 primary failures in both groups. For patients who had the CIED placed after already starting the dialysis, patency was based on when the cardiac device was implanted. Primary patency for ipsilateral and contralateral access was 20.2 and 22.2 months, respectively. With secondary interventions, ipsilateral and contralateral mean patency was 39 and 48.8 months, respectively. Six-month and 1-year primary patency for arteriovenous fistula or arteriovenous graft on patients with ipsilateral access was 69.2% and 53.8%, respectively. Ipsilateral 1-year cumulative patency was 39 months. CONCLUSIONS: CIED may lead to stenosis or occlusion to one's AV access; however, primary assisted and secondary patency rates are still acceptable at 6 months and 1 year compared to Kidney Disease Outcomes Quality Initiative guidelines. Despite a CIED, a surgeon's algorithm should not lead to the abandonment of an ipsilateral access if the central venous system is patent.

Cost-effectiveness analysis of asymptomatic peripheral artery disease screening with the ABI test.

Screening for asymptomatic peripheral artery disease (aPAD) with the ankle-brachial index (ABI) test is hypothesized to reduce disease progression and cardiovascular (CV) events by identifying individuals who may benefit from early initiation of medical therapy. Using a Markov model, we evaluated the cost effectiveness of initiating medical therapy (e.g. statin and ACE-inhibitor) after a positive ankle-brachial index (ABI) screen in 65-year-old patients. We modeled progression to symptomatic PAD (sPAD) and CV events with and without ABI screening, evaluating differences in costs and quality-adjusted life years (QALYs). The cost of the ABI test, physician visit, new medication, CV events, and interventions for sPAD were incorporated in the model. We performed sensitivity analysis on model variables with uncertainty. Our model found an incremental cost of US $338 and an incremental QALY of 0.00380 with one-time ABI screening, resulting in an incremental cost-effectiveness ratio (ICER) of $88,758/QALY over a 35-year period. The variables with the largest effects in the ICER were aPAD disease prevalence, cost of monthly medication after a positive screen and 2-year medication adherence rates. Screening high-risk populations, such as tobacco users, where the prevalence of PAD may be 2.5 times higher, decreases the ICER to $24,092/QALY. Our analysis indicates the cost effectiveness of one-time screening for aPAD depends on prevalence, medication costs, and adherence to therapies for CV disease risk reduction. Screening in higher-risk populations under favorable assumptions about medication adherence results in the most favorable cost effectiveness, but limitations in the primary data preclude definitive assessment of cost effectiveness.

Stabilization of the Abdominal Aorta During the Cardiac Cycle with the Sac-Anchoring Nellix Device.

The Nellix device uses polymer-filled endobags to stabilize the abdominal aortic aneurysm (AAA) sac which is described as endovascular aneurysm sealing (EVAS). We analyzed cardiac-gated computed tomography angiography scans of repaired AAA with EVAS in 4 patients to evaluate the geometry and cardiac pulsatility-induced deformation. Graft translation and aortic curvature changes were found to be minimal during the cardiac cycle. The mean ± standard deviation changes in renal-aorta angles (1.0 ± 0.9°) were less than the changes in the superior mesenteric artery-aorta angle (4.0 ± 2.1°) (P < 0.01), during the cardiac cycle, demonstrating greater stabilization of the visceral branches closer to the device. These findings confirm stabilization of the abdominal aorta during the cardiac cycle using EVAS.

Acute Type B Dissection Causing Collapse of EVAR Endograft and Iliac Limb Occlusion.

We describe a rare case of acute type B dissection (ATBDs) causing collapse of a previously placed infrarenal stent graft, resulting in acute limb ischemia due to left iliac limb thrombosis in a 59-year-old male. The patient presented with acute back and abdominal discomfort radiating to his back, bilateral buttock stabbing discomfort and left > right thigh and calf rest pain. CT angiography showed a spiral type B dissection with collapse of the proximal portion of the endovascular repair of aortic aneurysm (EVAR) device and left limb occlusion. Urgent treatment with thoracic endovascular aortic repair distal to the left subclavian covered the entry tear and redirected the majority of the flow to the true lumen leading to near immediate expansion of the proximal portion of the EVAR device. After surgical femoral control, balloon embolectomy of the occluded iliac limb was performed and the limb relined. His lower extremity ischemic symptoms resolved, and his abdominal and back pain dissipated. At latest 6-month follow-up, CT angiography shows an intact thoracic endovascular aortic repair stent graft and a widely patent EVAR stent graft, and the patient has no further abdominal, back, or leg symptoms. ATBD causing proximal abdominal EVAR collapse is an extremely rare presentation of false lumen pressurization and can be treated similarly to complicated type B dissection with the goal of restoring true lumen patency.

Natural history of gutter-related type Ia endoleaks after snorkel/chimney endovascular aneurysm repair.

OBJECTIVE: Alternative endovascular strategies using parallel or snorkel/chimney (chimney endovascular aneurysm repair [ch-EVAR]) techniques have been developed to address the lack of widespread availability and manufacturing limitations with branched/fenestrated aortic devices for the treatment of complex abdominal aortic aneurysms. Despite high technical success and midterm patency of snorkel stent configurations, concerns remain regarding the perceived increased incidence of early gutter-related type Ia endoleaks. We aimed to evaluate the incidence and natural history of gutter-related type Ia endoleaks following ch-EVAR. METHODS: Review of medical records and available imaging studies, including completion angiography and serial computed tomographic angiography, was performed for all patients undergoing ch-EVAR at our institution between September 2009 and January 2015. Only procedures involving ≥1 renal artery with or without visceral snorkel stents were included. Primary outcomes of the study were presence and persistence or resolution of early gutter-related type Ia endoleak. Secondary outcomes included aneurysm sac shrinkage and need for secondary intervention related to the presence of type Ia gutter endoleak. RESULTS: Sixty patients (mean age, 75.8 ± 7.6 years; male, 70.0%) underwent ch-EVAR with a total of 111 snorkel stents (97 renal [33 bilateral renal], 12 superior mesenteric artery, 2 celiac). A mean of 1.9 ± 0.6 snorkel stents were placed per patient. Early gutter-related type Ia endoleaks were noted on 30.0% (n = 18) of initial postoperative imaging studies. Follow-up imaging revealed spontaneous resolution of these gutter endoleaks in 44.3%, 65.2%, and 88.4% of patients at 6, 12, and 18 months postprocedure, respectively. Long-term anticoagulation, degree of oversizing, stent type and diameter, and other clinical/anatomic variables were not significantly associated with presence of gutter endoleaks. Two patients (3.3%) required secondary intervention related to persistent gutter endoleak. At a mean radiologic follow-up of 20.9 months, no difference in mean aneurysm sac size change was observed between those with or without early type Ia gutter endoleak (-6.1 ± 10.0 mm vs -4.9 ± 11.5 mm; P = .23). CONCLUSIONS: Gutter-related type Ia endoleaks represent a relatively frequent early occurrence after ch-EVAR, but appears to resolve spontaneously in the majority of cases during early to midterm follow-up. Given that few ch-EVAR patients require reintervention related to gutter endoleaks and the presence of such endoleak did not correlate to increased risk for aneurysm sac growth, its natural history may be more benign than originally expected.

Lower extremity computed tomography angiography can help predict technical success of endovascular revascularization in the superficial femoral and popliteal artery.

OBJECTIVE: Preprocedural computed tomography angiography (CTA) assists in evaluating vascular morphology and disease distribution and in treatment planning for patients with lower extremity peripheral artery disease (PAD). The aim of the study was to determine the predictive value of radiographic findings on CTA and technical success of endovascular revascularization of occlusions in the superficial femoral artery-popliteal (SFA-pop) region. METHODS: Medical records and available imaging studies were reviewed for patients undergoing endovascular intervention for PAD between January 2013 and December 2015 at a single academic institution. Radiologists reviewed preoperative CTA scans of patients with occlusions in the SFA-pop region. Radiographic criteria previously used to evaluate chronic occlusions in the coronary arteries were used. Technical success, defined as restoration of inline flow through the SFA-pop region with <30% stenosis at the end of the procedure, and intraoperative details were evaluated. RESULTS: From 2013 to 2015, there were 407 patients who underwent 540 endovascular procedures for PAD. Preprocedural CTA scans were performed in 217 patients (53.3%), and 84 occlusions in the SFA-pop region were diagnosed. Ten occlusions were excluded as no endovascular attempt to cross the lesion was made because of extensive disease or concomitant iliac intervention. Of the remaining 74 occlusions in the SFA-pop region, 59 were successfully treated (80%) and 15 were unsuccessfully crossed (20%). The indications for revascularization were claudication in 57% of patients and critical limb ischemia in the remaining patients. TransAtlantic Inter-Society Consensus A, B, and C occlusions were treated with 87% success, whereas D occlusions were treated with 68% success (P = .047). There were nine occlusions with 100% vessel calcification that was associated with technical failure (P = .014). Longer lengths of occlusion were also associated with technical failure (P = .042). Multiple occlusions (P = .55), negative remodeling (P = .69), vessel runoff (P = .56), and percentage of vessel calcification (P = .059) were not associated with failure. On multivariable analysis, 100% calcification remained the only significant predictor of technical failure (odds ratio, 9.0; 95% confidence interval, 1.8-45.8; P = .008). CONCLUSIONS: Analysis of preoperative CTA shows 100% calcification as the best predictor of technical failure of endovascular revascularization of occlusions in the SFA-pop region. Further studies are needed to determine the cost-effectiveness of obtaining preoperative CTA for lower extremity PAD.

Outcomes of Endovascular Repair of Aortoiliac Aneurysms and Analyses of Anatomic Suitability for Internal Iliac Artery Preserving Devices in Japanese Patients.

BACKGROUND: Understanding that the common iliac arteries (CIA) are shorter in Asian patients, we investigated whether this anatomic difference affects the clinical outcomes of internal iliac artery (IIA) exclusion during endovascular aneurysm repair (EVAR) of aortoiliac aneurysm and thus limits the use of IIA-preserving devices in Japanese patients.Methods and Results:From 2008 to 2014, 69 Japanese patients underwent EVAR of aortoiliac aneurysms with 53 unilateral and 16 bilateral IIA exclusions. One patient had persistent buttock claudication during follow-up; however, colonic or spinal cord ischemia was not observed. Anatomic suitability was investigated for the iliac branch device (IBD) by Cook Medical and the iliac branch endoprosthesis (IBE) by WL Gore: 87 aortoiliac segments were analyzed, of which 17% met the criteria for the IBD, 25% met the criteria for the IBE and 40% met the criteria for either. Main exclusions for the IBD were IIA diameter >9 mm or <6 mm (47%) and CIA length <50 mm (39%). Main exclusions for the IBE were proximal CIA diameter <17 mm (44%) and aortoiliac length <165 mm (24%). CONCLUSIONS: EVAR with IIA exclusions in Japanese patients showed low incidence of persistent buttock claudication and no major pelvic complications. Aorto-iliac morphology demonstrated smaller proximal CIA diameters and shorter CIA lengths, limiting the use of IIA-preserving devices.

SPY technology as an adjunctive measure for lower extremity perfusion.

OBJECTIVE: Lack of a reliable outcome measure often leads to excessive or insufficient interventions for critical limb ischemia (CLI). SPY technology (Novadaq Technologies Inc, Bonita Springs, Fla), widely adapted by plastic and general surgeons, uses laser-assisted fluorescence angiography (LAFA) to assess tissue perfusion. We sought to determine the role of SPY as an alternative, perhaps more reliable outcome measure for vascular interventions. METHODS: All patients undergoing elective or urgent revascularization for claudication and CLI were prospectively recruited from June 2012 to August 2014. LAFA using SPY technology was performed before and after revascularization procedures under a standard Institutional Review Board-approved protocol. Quantitative measures of perfusion at plantar surfaces were analyzed and compared with ankle-brachial index. RESULTS: A total of 93 patients with claudication or CLI underwent LAFA before and after a revascularization procedure in the study period. The mean preoperative ankle-brachial index increased from 0.60 to 0.84 (P < .001) after a revascularization procedure. Plantar perfusion as measured by LAFA also improved significantly after intervention. Ingress, defined as the rate at which fluorescence intensity increases on the plantar surface during LAFA, increased from 7.1 to 12.4 units/s (P < .001). Peak perfusion, defined as the difference between the baseline and the peak of fluorescence intensity, increased from 97.1 and 143.9 units (P < .001). Egress, defined as the rate at which intensity diminishes after reaching peak perfusion, increased from 1.0 to 1.9 units/s (P = .035). Procedure-related digital embolization was also observed in several patients despite lack of an angiographic finding. CONCLUSIONS: This is the largest prospective study evaluating SPY technology in peripheral vascular interventions. Our study shows that SPY is a valuable tool in visualizing real-time procedural outcomes and providing additionally useful information on regional tissue perfusion. Further investigation is warranted to standardize outpatient use and to determine threshold values that predict wound healing.

Use of a proactive duplex ultrasound protocol for hemodialysis access.

OBJECTIVE: Arteriovenous fistula (AVF) creation is the preferred approach for hemodialysis access; however, the maturation of AVFs is known to be poor. We established a proactive early duplex ultrasound (DUS) surveillance protocol for evaluating AVFs before attempted access. This study determined the effect of this protocol related to improving AVF maturation. METHODS: From 2008 to 2013, 153 patients received new upper extremity AVFs and an early DUS surveillance protocol at a single academic institution. The protocol involved an early DUS evaluation before hemodialysis cannulation of the AVF at 4 to 8 weeks after AVF creation. A positive DUS result was identified as a peak systolic velocity of >375 cm/s or a >50% stenosis on gray scale imaging, along with decreased velocity in the outflow vein. Patients with positive DUS findings underwent prophylactic endovascular or open intervention to assist with AVF maturation. Nature of secondary interventions, as well as AVF patency and maturation, were assessed. Overall clinical outcomes and fistula patency were investigated. RESULTS: During the study period, 183 upper extremity AVFs were created in 153 patients, including 82 radiocephalic, 63 brachiocephalic, and 38 brachiobasilic AVFs. A mortality rate of 43% (n = 66) was observed in a median follow-up period of 34.5 months (interquartile range, 19.6-46.9). A total of 164 early DUS were performed at a median of 6 weeks (interquartile range, 3.4-9.6 weeks) after the initial creation. Early DUS showed nine AVFs were occluded and were excluded from further analysis. Hemodynamically significant lesions were found in 62 AVFs (40%); however, only 17 (11%) were associated with an abnormal physical examination. Positive DUS finding prompted a secondary intervention in 81% of the patients. Among those with positive early DUS findings, AVF maturation was 70% in those undergoing a secondary intervention compared with 25% in those not undergoing a prophylactic intervention (P = .011). Primary-assisted patency for AVFs with early positive and negative DUS findings were 83% and 96% at 6 months, 64% and 89% at 1 year, and 52% and 82% at 2 years, respectively (P < .001). CONCLUSIONS: Early DUS surveillance of AVFs before initial access is reasonable to identify problematic AVFs that may not be reliably detected on clinical examination. Although DUS criteria for AVFs have yet to be universally accepted, proactive early postoperative DUS interrogation assists in the early detection of dysfunctional AVFs and improvement of fistula maturation. Despite improved patency in those with positive DUS findings who undergo prophylactic secondary intervention, overall patency remains inferior to those without an abnormality detected on early DUS imaging.