The association of comorbid depression with mortality and amputation risk in patients with chronic limb-threatening ischemia.

OBJECTIVE: There is increasing evidence that depression is a risk factor for worse outcomes in patients with peripheral artery disease. The association of depression in patients with chronic limb-threatening ischemia (CLTI) is not well described, nor is the impact of medical treatment for depression in this patient population. The objective of this study was to investigate the prevalence of depression in patients with CLTI, its association on major amputation and all-cause mortality, and whether medical antidepressant treatment is associated with improvement in these outcomes in patients with depression. METHODS: A retrospective review of all adult patients (≥18 years old) diagnosed with CLTI from January 1, 2007, to December 31, 2018, at a single academic medical center was performed. Collected data included patient demographics, comorbidities, and diagnosis of depression within 6 months of initial CLTI diagnosis. We also collected data on use of antidepressant medications. Outcomes evaluated were need for major lower extremity amputation and all-cause mortality. Multivariable logistic regression models estimated the adjusted effects of comorbid depression and antidepressant medication use on major amputation and all-cause mortality. Kaplan-Meier survival curves illustrated the probabilities of survival and limb salvage over time, stratified by diagnosis of comorbid depression. Multivariable Cox proportional hazards models estimated the adjusted effects of comorbid depression on time to major amputation and all-cause mortality, and the adjusted effect of antidepressant treatment on time to all-cause mortality. RESULTS: A total of 2987 patients with CLTI were identified. Mean age was 68.6 years (standard deviation, 12.9 years); 56.5% were male, and 43.5% were female. Comorbid depression within 6 months of CLTI diagnosis was present in 7.1% of the cohort (212 patients). In multivariable analysis, comorbid depression was associated with a 68% increase in the odds of major amputation (adjusted odds ratio [aOR], 1.68; 95% confidence interval [CI], 1.19-2.37; P < .01), a 164% increase in the odds of all-cause mortality among patients not taking antidepressants (aOR, 2.64; 95% CI, 1.31-5.32; P = .03), and only a 6% increase in the odds of all-cause mortality among patients taking antidepressants (aOR, 1.06; 95% CI, 0.72-1.55; P = .99). The effect of comorbid depression on mortality varied significantly by whether or not the patient was taking an antidepressant medication (P = .02). CONCLUSIONS: Comorbid depression in the patient population with CLTI is associated with a worse prognosis for major lower extremity amputation overall, and a worse prognosis for all-cause mortality among patients not taking an antidepressant. Furthermore, antidepressant treatment in the presence of comorbid depression in this patient population is associated with an improvement in the odds of all-cause mortality, illustrating the potential importance of medical management of depression.

Dynamic perioperative platelet activity and cardiovascular events in peripheral artery disease.

OBJECTIVE: Patients with peripheral artery disease (PAD) undergo lower extremity revascularization (LER) for symptomatic relief or limb salvage. Despite LER, patients remain at increased risk of platelet-mediated complications, such as major adverse cardiac and limb events (MACLEs). Platelet activity is associated with cardiovascular events, yet little is known about the dynamic nature of platelet activity over time. We, therefore, investigated the change in platelet activity over time and its association with long-term cardiovascular risk. METHODS: Patients with PAD undergoing LER were enrolled into the multicenter, prospective Platelet Activity and Cardiovascular Events study. Platelet aggregation was assessed by light transmission aggregometry to submaximal epinephrine (0.4 µmol/L) immediately before LER, and on postoperative day 1 or 2 (POD1 or POD2) and 30 (POD30). A hyperreactive platelet phenotype was defined as >60% aggregation. Patients were followed longitudinally for MACLEs, defined as the composite of death, myocardial infarction, stroke, major lower extremity amputation, or acute limb ischemia leading to reintervention. RESULTS: Among 287 patients undergoing LER, the mean age was 70 ± 11 years, 33% were female, 61% were White, and 89% were on baseline antiplatelet therapy. Platelet aggregation to submaximal epinephrine induced a bimodal response; 15.5%, 16.8%, and 16.4% of patients demonstrated a hyperreactive platelet phenotype at baseline, POD1, and POD30, respectively. Platelet aggregation increased by 18.5% (P = .001) from baseline to POD1, which subsequently returned to baseline at POD30. After a median follow-up of 19 months, MACLEs occurred in 165 patients (57%). After adjustment for demographics, clinical risk factors, procedure type, and antiplatelet therapy, platelet hyperreactivity at POD1 was associated with a significant hazard of long-term MACLE (adjusted hazard ratio, 4.61; 95% confidence interval, 2.08-10.20; P < .001). CONCLUSIONS: Among patients with severe PAD, platelet activity increases after LER. Platelet hyperreactivity to submaximal epinephrine on POD1 is associated with long-term MACLE. Platelet activity after LER may represent a modifiable biomarker associated with excess cardiovascular risk.

Long-term patient-reported outcomes among patients undergoing revascularization vs medical therapy for intermittent claudication.

OBJECTIVE: Society for Vascular Surgery guidelines recommend revascularization for patients with intermittent claudication (IC) if it can improve patient function and quality of life. However, it is still unclear if patients with IC achieve a significant functional benefit from surgery compared with medical management alone. This study examines the relationship between IC treatment modality (operative vs nonoperative optimal medical management) and patient-reported outcomes for physical function (PROMIS-PF) and satisfaction in social roles and activities (PROMIS-SA). METHODS: We identified patients with IC who presented for index evaluation in a vascular surgery clinic at an academic medical center between 2016 and 2021. Patients were stratified based on whether they underwent a revascularization procedure during follow-up vs continued nonoperative management with medication and recommended exercise therapy. We used linear mixed-effect models to assess the relationship between treatment modality and PROMIS-PF, PROMIS-SA, and ankle-brachial index (ABI) over time, clustering among repeat patient observations. Models were adjusted for age, sex, diabetes, Charlson Comorbidity Index, Clinical Frailty Score, tobacco use, and index ABI. RESULTS: A total of 225 patients with IC were identified, of which 40% (n = 89) underwent revascularization procedures (42% bypass; 58% peripheral vascular intervention) and 60% (n = 136) continued nonoperative management. Patients were followed up to 6.9 years, with an average follow-up of 5.2 ± 1.6 years. Patients who underwent revascularization were more likely to be clinically frail (P = .03), have a lower index ABI (0.55 ± 0.24 vs 0.72 ± 0.28; P < .001), and lower baseline PROMIS-PF score (36.72 ± 8.2 vs 40.40 ± 6.73; P = .01). There were no differences in patient demographics or medications between treatment groups. Examining patient-reported outcome trends over time; there were no significant differences in PROMIS-PF between groups, trends over time, or group differences over time after adjusting for covariates (P = .07, P = .13, and P =.08, respectively). However, all patients with IC significantly increased their PROMIS-SA over time (adjusted P = .019), with patients managed nonoperatively more likely to have an improvement in PROMIS-SA over time than those who underwent revascularization (adjusted P = .045). CONCLUSIONS: Patient-reported outcomes associated with functional status and satisfaction in activities are similar for patients with IC for up to 7 years, irrespective of whether they undergo treatment with revascularization or continue nonoperative management. These findings support conservative long-term management for patients with IC.

Trends in patient characteristics and mortality among Medicare patients diagnosed with peripheral artery disease.

INTRODUCTION: Peripheral artery disease (PAD) is a well-described risk factor for mortality, but few studies have examined secular trends in mortality over time for patients with PAD. We characterized trends in mortality in patients with PAD in recent years among Medicare patients. METHODS: We used Medicare claims to identify patients with a new diagnosis code for PAD between January 1, 2006 and December 31, 2018 using International Classification of Diseases (ICD) diagnosis codes. The primary outcome of interest was the 1-year all-cause age-adjusted mortality rate. Our secondary outcome was the 5-year all-cause mortality rate. Multivariable regression was used to identify factors which predict mortality at 1 year. RESULTS: We identified 4,373,644 patients with a new diagnosis code for PAD during the study period. Between 2006 and 2018, 1-year all-cause age-adjusted mortality declined from 12.6% to 9.9% (p < 0.001). One-year crude all-cause mortality also declined from 14.6% to 9.5% (p < 0.001). Similar results were observed for 5-year age-adjusted mortality rates (40.9% to 35.2%, p < 0.001). Factors associated with increased risk of death at 1 year included age ⩾ 85 years (hazard ratio [HR] 3.030; 95% CI 3.008-3.053) and congestive heart failure (HR 1.86; 95% CI 1.85-1.88). Patients who were regularly dispensed statins, ace-inhibitors, beta-blockers, antithrombotic agents, and anticoagulants all had lower mortality (range OR 0.36; CI 0.35-0.37 for statins to OR 0.60; CI 0.59-0.61 for anticoagulants; all p < 0.001). CONCLUSION: Among US Medicare patients diagnosed with PAD between 2006 and 2019, 1-year age-adjusted mortality declined by 2.7%. This decline in mortality among PAD patients occurred in the context of a younger mean age of diagnosis of PAD and improved cardiovascular prevention therapy.

Three-year clinical course after fluoropolymer-based drug-eluting stent implantation for femoropopliteal lesions.

BACKGROUND: Although the 1-year clinical outcomes of fluoropolymer-based drug-eluting stents (FP-DES) were favorable for the treatment of real-world femoropopliteal lesions in symptomatic peripheral artery disease (PAD), their performance beyond 1 year remained unknown. The current study determined the 3-year clinical course of FP-DES implantation for real-world femoropopliteal lesions. METHODS: This multicenter, prospective, observational study evaluated 1204 limbs (chronic limb-threatening ischemia, 34.8%; mean lesion length, 18.6 ± 9.9 cm, chronic total occlusion: 53.2%) of 1097 patients with PAD (age, 75 ± 9 years; diabetes mellitus, 60.8%) undergoing FP-DES implantation for femoropopliteal lesions. The primary outcome measure was 3-year restenosis. The secondary outcome measures included 3-year occlusive restenosis, stent thrombosis, target lesion revascularization (TLR), and aneurysmal degeneration. RESULTS: The 3-year cumulative occurrence of restenosis was 27.3%, whereas that of occlusive restenosis, stent thrombosis, and TLR was 16.1%, 7.3%, and 19.6%, respectively. The annual occurrence of restenosis decreased by 12.0%, 9.5%, and 5.8% in the first, second, and third year, respectively (p < 0.001). Similarly, the rates of occlusive restenosis and stent thrombosis decreased (p < 0.001 and p = 0.007, respectively), whereas the rate of TLR remained unchanged for 3 years (p = 0.15). The incidence of aneurysmal degeneration at 3 years (15.7%) did not significantly differ from that at 1 and 2 years (p = 0.69 and 0.20, respectively). CONCLUSIONS: This study highlights the favorable long-term clinical course of FP-DES in real-world practice, emphasizing the importance of monitoring for occlusive restenosis and stent thrombosis while considering the potential onset of aneurysmal degeneration.

Alleviating iatrogenic effects of paclitaxel via antiinflammatory treatment.

BACKGROUND: Paclitaxel (PTX) is touted as an essential medicine due to its extensive use as a chemotherapeutic agent for various cancers and an antiproliferative agent for endovascular applications. Emerging studies in cardio-oncology implicate various vascular complications of chemotherapeutic agents. METHODS: We evaluated the inflammatory response induced by the systemic administration of PTX. The investigation included RNAseq analysis of primary human endothelial cells (ECs) treated with PTX to identify transcriptional changes in pro-inflammatory mediators. Additionally, we used dexamethasone (DEX), a well-known antiinflammatory compound, to assess its effectiveness in counteracting these PTX-induced changes. Further, we studied the effects of PTX on monocyte chemoattractant protein-1 (MCP-1) levels in the media of ECs. The study also extended to in vivo analysis, where a group of mice was injected with PTX and subsequently harvested at different times to assess the immediate and delayed effects of PTX on inflammatory mediators in blood and aortic ECs. RESULTS: Our RNAseq analysis revealed that PTX treatment led to significant transcriptional perturbations in pro-inflammatory mediators such as MCP-1 and CD137 within primary human ECs. These changes were effectively abrogated when DEX was administered. In vitro experiments showed a marked increase in MCP-1 levels in EC media following PTX treatment, which returned to baseline upon treatment with DEX. In vivo, we observed a threefold increase in MCP-1 levels in blood and aortic ECs 12 h post-PTX administration. Similar trends were noted for CD137 and other downstream mediators like tissue factor, vascular cell adhesion molecule 1, and E-selectin in aortic ECs. CONCLUSION: Our findings illustrate that PTX exposure induces an upregulation of atherothrombotic mediators, which can be alleviated with concurrent administration of DEX. Considering these observations, further long-term investigations should focus on understanding the systemic implications associated with PTX-based therapies and explore the clinical relevance of DEX in mitigating such risks.

Association of health status and hospitalization risk for peripheral artery disease in the PORTRAIT registry.

BACKGROUND: Healthcare utilization for patients with peripheral artery disease (PAD) is high, but stratifying patients' risk of hospitalization at initial evaluation is challenging. We examined the association between health status at PAD presentation and risk of (1) combined all-cause hospital admissions and emergency department (ED) visits and (2) all-cause hospital admissions. METHODS: Patients with claudication enrolled at US sites in the PORTRAIT registry were included. Health status was assessed using the Peripheral Artery Questionnaire (PAQ), a PAD-specific patient-reported outcome measure. Crude overall and cause-specific hospital admissions and ED visits were reported by PAQ overall summary score (PAQ-OS) ranges (0-24, 25-49, 50-74, and 75-100). Kaplan-Meier survival and unadjusted and adjusted Cox proportional hazards models examined the association between baseline PAQ scores and (1) combined all-cause hospital admissions or ED visits and (2) all-cause hospital admissions over 12 months. RESULTS: Of 796 patients, 349 (44%) had a hospital admission or ED visit over 12 months. Patients in the lowest (PAQ-OS = 0-24) versus the highest range (PAQ-OS = 75-100) had higher rates of 12-month (53.3% vs 22.4%) hospital admission and ED visits. In the adjusted model, each 10-point decrease in PAQ-OS was associated with a higher risk of all-cause hospital admission and ED visits (HR = 1.1, 95% CI 1.1-1.2, p < 0.0010) and all-cause hospital admission (HR = 1.1, 95% CI 1.1-1.2, p < 0.0010) at 12 months. CONCLUSION: PAD-specific health status is associated with an increased risk of healthcare utilization. Baseline health status may help stratify risk in patients with PAD, although replication and further validation of results are necessary.

Urinary vanin-1 as a novel biomarker for survival in peripheral artery disease.

BACKGROUND: Chronic kidney disease is associated with increased rates of incidence, morbidity, and mortality in lower-extremity peripheral artery disease (PAD). No specific marker for a functional risk assessment of kidney disease in PAD is known, especially at the early stages. Thus, we speculated that urinary vanin-1 (uVNN1), a marker of oxidative stress even in early kidney injury, could further stratify outcome assessment in patients with PAD. METHODS: Patients with stable PAD (n = 304) of the Vienna medical cohort were followed up for up to 10 years and the outcome was assessed by central death database queries. uVNN1 was measured by enzyme-linked immunosorbent assay (ELISA) at study inclusion and normalized to urinary creatinine (uVNN1/Cr). During the observation time (9.3, 7.0-9.8 years), 104 patients died, 54.8% of which were due to cardiovascular causes. RESULTS: uVNN1/Cr was associated with a urine albumin-creatinine ratio (UACR) (R = 0.166, p = 0.004) but not with an estimated glomerular filtration rate (R = 0.102, p = 0.077). Levels of uVNN1/Cr did not differ between asymptomatic and symptomatic PAD (p = 0.406). Kaplan-Meier curves showed a clear-cut association with higher all-cause (log-rank p = 0.034) and cardiovascular mortality (log-rank p = 0.032) with higher uVNN1/Cr levels. Similarly, significant associations for all-cause (hazard ratio [HR] 1.34, 95% CI [1.08-1.67], p = 0.009) and cardiovascular mortality (HR 1.45, 95% CI [1.06-1.99], p = 0.020) could be seen in multivariable Cox regression models. CONCLUSIONS: uVNN1/Cr showed an independent association with both all-cause and cardiovascular mortality in patients with PAD and was associated with early kidney disease. Thus, uVNN1 could be a useful marker for risk stratification of kidney disease in PAD.

Quantifying patients' preferences on tradeoffs between mortality risk and reduced need for target vessel revascularization for claudication.

BACKGROUND: In 2019, the US Food and Drug Administration issued a warning that symptomatic relief from claudication using paclitaxel-coated devices might be associated with an increase in mortality over 5 years. We designed a discrete-choice experiment (DCE) to quantify tradeoffs that patients would accept between a decreased risk of clinically driven target-vessel revascularization (CDTVR) and increased mortality risk. METHODS: Patients with claudication symptoms were recruited from seven medical centers to complete a web-based survey including eight DCE questions that presented pairs of hypothetical device profiles defined by varying risks of CDTVR and overall mortality at 2 and 5 years. Random-parameters logit models were used to estimate relative preference weights, from which the maximum-acceptable increase in 5-year mortality risk was derived. RESULTS: A total of 272 patients completed the survey. On average, patients would accept a device offering reductions in CDTVR risks from 30% to 10% at 2 years and from 40% to 30% at 5 years if the 5-year mortality risk was less than 12.6% (95% CI: 11.8-13.4%), representing a cut-point of 4.6 percentage points above a baseline risk of 8%. However, approximately 40% chose the device alternative with the lower 5-year mortality risk in seven (20.6%) or eight (18.0%) of the eight DCE questions regardless of the benefit offered. CONCLUSIONS: Most patients in the study would accept some incremental increase in 5-year mortality risk to reduce the 2-year and 5-year risks of CDTVR by 20 and 10 percentage points, respectively. However, significant patient-level variability in risk tolerance underscores the need for systematic approaches to support benefit-risk decision making.

The impact of the Affordable Care Act Medicaid Expansion in Medicare beneficiaries with peripheral artery disease.

Background: In 2014, the Affordable Care Act Medicaid Expansion (ME) increased Medicaid eligibility for adults with an income level up to 138% of the federal poverty level. In this study, we examined the impact of ME on mortality and amputation in patients with peripheral artery disease (PAD). Methods: The 100% MedPAR and Part-B Carrier files from 2011 to 2018 were queried to identify all fee-for-service Medicare beneficiaries with PAD using International Classification of Diseases codes. Our primary exposure was whether a state had adopted the ME on January 1, 2014. Our primary outcomes were the change in all-cause 1-year mortality and leg amputation. We used a state-level difference-in-differences (DID) analysis to compare the rates of the primary outcomes among patients who were in states (including the District of Columbia) who adopted ME (n = 25) versus those who were in states that did not (n = 26). We performed a subanalysis stratifying by sex, race, region, and dual-eligibility status. Results: Over the 8-year period, we studied 37,743,929 patients. The average unadjusted 1-year mortality decreased from 2011 to 2018 in both non-ME (9.5% to 8.7%, p < 0.001) and ME (9.1% to 8.3%, p < 0.001) states. The average unadjusted 1-year amputation rate did not improve in either the non-ME (0.86% to 0.87%, p = 0.17) or ME (0.69% to 0.69%, p = 0.65) states. Across the entire cohort, the DID model revealed that ME did not lead to a significant change in mortality (p = 0.15) or amputation (p = 0.34). Conclusion: Medicaid Expansion was not associated with reduced mortality or leg amputation in Medicare beneficiaries with PAD.

Impact of comorbid opioid use disorder and major depressive disorder on healthcare utilization outcomes in patients with peripheral artery disease: A National Readmission Database analysis.

BACKGROUND: Prior research has demonstrated that individuals with peripheral artery disease (PAD) often have comorbid opioid use disorder (OUD) and major depressive disorder (MDD), with limited data regarding their impact on readmission outcomes, length of stay, and cost. This study aimed to investigate these healthcare utilization outcomes in patients with PAD who have comorbid OUD and MDD. METHODS: Data were obtained from the National Readmission Database from 2011 through 2018. The study population included all hospitalizations with PAD as the primary or secondary diagnosis, from which hospitalizations with OUD and MDD were extracted using appropriate ICD-9/10 diagnosis codes. Primary outcomes were 30-day and 90-day readmission, total cost, and total length of stay within the calendar year. We created hierarchical multivariable logistic regression models examining OUD with and without MDD, with a random effect for healthcare facility location. RESULTS: From 2011 to 2018, 13,265,817 weighted admissions with PAD were identified. These admissions were segmented into four categories: No OUD/No MDD (12,056,466), OUD/No MDD (323,762), No OUD/MDD (867,641), and OUD/MDD (17,948). The group with No OUD/No MDD was used as the reference group for all subsequent comparisons. Regarding 30-day and 90-day readmissions, patients with OUD/MDD had odds of 1.14 (95% CI 1.10, 1.18) and 1.09 (95% CI 1.06, 1.13), respectively. Patients with OUD/No MDD bore the highest median cost of $64,354 (IQR $30,797-137,074), and patients with OUD/MDD marked the lengthiest median stay of 6.01 days (IQR 2.01-13.30). CONCLUSION: This study found a significant association between these comorbidities and outcomes and therefore calls for targeted interventions and pain management strategies.

Methods, design, and initial results of an angiographic core lab from VOYAGER-PAD.

Background: Anatomy is critical in risk stratification and therapeutic decision making in coronary disease. The relationship between anatomy and outcomes is not well described in PAD. We sought to develop an angiographic core lab within the VOYAGER-PAD trial. The current report describes the methods of creating this core lab, its study population, and baseline anatomic variables. Methods: Patients undergoing lower-extremity revascularization for symptomatic PAD were randomized in VOYAGER-PAD. The median follow up was 2.25 years. Events were adjudicated by a blinded Clinical Endpoint Committee. Angiograms were collected from study participants; those with available angiograms formed this core lab cohort. Angiograms were scored for anatomic and flow characteristics by trained reviewers blinded to treatment. Ten percent of angiograms were evaluated independently by two reviewers; inter-rater agreement was assessed. Clinical characteristics and the treatment effect of rivaroxaban were compared between the core lab cohort and noncore lab participants. Anatomic data by segment were analyzed. Results: Of 6564 participants randomized in VOYAGER-PAD, catheter-based angiograms from 1666 patients were obtained for this core lab. Anatomic and flow characteristics were collected across 16 anatomic segments by 15 reviewers. Concordance between reviewers for anatomic and flow variables across segments was 90.5% (24,417/26,968). Clinical characteristics were similar between patients in the core lab and those not included. The effect of rivaroxaban on the primary efficacy and safety outcomes was also similar. Conclusions: The VOYAGER-PAD angiographic core lab provides an opportunity to correlate PAD anatomy with independently adjudicated outcomes and provide insights into therapy for PAD. (ClinicalTrials.gov Identifier: NCT02504216).

Role of noninvasive ocular imaging as a biomarker in peripheral artery disease (PAD): A systematic review.

This study aimed to review the current literature exploring the utility of noninvasive ocular imaging for the diagnosis of peripheral artery disease (PAD). Our search was conducted in early April 2022 and included the databases Medline, Scopus, Embase, Cochrane, and others. Five articles were included in the final review. Of the five studies that used ocular imaging in PAD, two studies used retinal color fundus photography, one used optical coherence tomography (OCT), and two used optical coherence tomography angiography (OCTA) to assess the ocular changes in PAD. PAD was associated with both structural and functional changes in the retina. Structural alterations around the optic disc and temporal retinal vascular arcades were seen in color fundus photography of patients with PAD compared to healthy individuals. The presence of retinal hemorrhages, exudates, and microaneurysms in color fundus photography was associated with an increased future risk of PAD, especially the severe form of the disease. The retinal nerve fiber layer (RNFL) was significantly thinner in the nasal quadrant in patients with PAD compared to age-matched healthy individuals in OCT. Similarly, the choroidal thickness in the subfoveal region was significantly thinner in patients with PAD compared to controls. Patients with PAD also had a significant reduction in the retinal and choroidal circulation in OCTA compared to healthy controls. As PAD causes thinning and ischemic changes in retinal vessels, examination of the retinal vessels using retinal imaging techniques can provide useful information about early microvascular damage in PAD. Ocular imaging could potentially serve as a biomarker for PAD. PROSPERO ID: CRD42022310637.

Impact of preexisting coronary artery and peripheral artery disease on outcomes in diabetic patients after kidney transplant.

BACKGROUND: Atherosclerotic cardiovascular disease is highly prevalent in patients with end-stage kidney disease (ESKD). Kidney transplant (KT) improves patient survival and cardiovascular outcomes. The impact of preexisting coronary artery disease (CAD) and peripheral artery disease (PAD) on posttransplant outcomes remains unclear. METHODS: This is a retrospective study utilizing the United States Renal Data System. Adult diabetic dialysis patients who underwent first KT between 2006 and 2017 were included. The study population was divided into four cohorts based on presence of CAD/PAD: (1) polyvascular disease (CAD + PAD); (2) CAD without PAD; (3) PAD without CAD; (4) no CAD or PAD (reference cohort). The primary outcome was 3-year all-cause mortality. Secondary outcomes were incidence of posttransplant myocardial infarction (MI), cerebrovascular accidents (CVA), and graft failure. RESULTS: The study population included 19,329 patients with 64.4% men, mean age 55.4 years, and median dialysis duration of 2.8 years. Atherosclerotic cardiovascular disease was present in 28% of patients. The median follow up was 3 years. All-cause mortality and incidence of posttransplant MI were higher with CAD and highest in patients with polyvascular disease. The cohort with polyvascular disease had twofold higher all-cause mortality (16.7%, adjusted hazard ratio (aHR) 1.5, p < 0.0001) and a fourfold higher incidence of MI (12.7%, aHR 3.3, p < 0.0001) compared to the reference cohort (8.0% and 3.1%, respectively). There was a higher incidence of posttransplant CVA in the cohort with PAD (3.4%, aHR 1.5, p = 0.01) compared to the reference cohort (2.0%). The cohorts had no difference in graft failure rates. CONCLUSIONS: Preexisting CAD and/or PAD result in worse posttransplant survival and cardiovascular outcomes in patients with diabetes mellitus and ESKD without a reduction in graft survival.

Uptake and outcomes of supervised exercise therapy for peripheral artery disease: The importance of vascular medicine specialists at a large midwestern health care system during the first 5 years of CMS reimbursement.

BACKGROUND: Supervised exercise therapy (SET) is the cornerstone of medical therapy for symptomatic peripheral artery disease (PAD). Despite the efficacy of SET, initial reports following the 2017 Centers for Medicare and Medicaid Services (CMS) reimbursement decision indicate low SET uptake, referral, and completion. Vascular medicine specialists are key to the success of such programs. We examined rates of SET referral, completion, and outcomes in a health system with a robust SET program during the first 5 years of CMS reimbursement. METHODS: A retrospective chart review of patients with PAD referred to SET between October 1, 2017 and December 31, 2022 was conducted. Patient demographic and medical characteristics, SET indication, referring provider specialty, SET participation (e.g., exercise modality, number of sessions, treadmill prescription), and outcomes were abstracted. Descriptive statistics, t-tests, and multiple linear regression were used to examine the sample, evaluate outcomes, and explore outcomes by relevant covariates (i.e., age, sex, referring provider specialty). RESULTS: Of 5320 patients with PAD, N = 773 were referred to SET; N = 415 enrolled and were included in the present study. Vascular medicine and vascular surgery specialists were the two primary sources of referrals (30.6% and 51.6%, respectively). A total of 207 patients (49.9%) completed SET. Statistically significant and clinically meaningful improvements were observed in all outcomes. CONCLUSION: SET referral and completion rates are low in the 5 years following CMS reimbursement, despite the advocacy of vascular medicine specialists. SET is effective in improving patient functional capacity and quality of life. Additional efforts are needed to increase both SET availability and referrals as part of comprehensive treatment of PAD.

The ankle-brachial index, gastrocnemius mitochondrial respirometry, and walking performance in people with and without peripheral artery disease.

Background: Mitochondrial abnormalities exist in lower-extremity peripheral artery disease (PAD), yet the association of the ankle-brachial index (ABI) with mitochondrial respiration in gastrocnemius muscle is unknown. The association of gastrocnemius mitochondrial respiration with 6-minute walk distance in PAD is unknown. Objective: To describe associations of the ABI with mitochondrial respiratory function in gastrocnemius muscle biopsies and associations of gastrocnemius mitochondrial respirometry with 6-minute walk distance in people with and without PAD. Methods: People with (ABI ⩽ 0.90) and without (ABI 1.00-1.40) PAD were enrolled. ABI and 6-minute walk distance were measured. Mitochondrial function of permeabilized myofibers from gastrocnemius biopsies was measured with high-resolution respirometry. Results: A total of 30 people with PAD (71.7 years, mean ABI: 0.64) and 68 without PAD (71.8 years, ABI: 1.17) participated. In non-PAD participants, higher ABI values were associated significantly with better mitochondrial respiration (Pearson correlation for maximal oxidative phosphorylation PCI+II: +0.29, p = 0.016). In PAD, the ABI correlated negatively and not significantly with mitochondrial respiration (Pearson correlation for PCI+II: -0.17, p = 0.38). In people without PAD, better mitochondrial respiration was associated with better 6-minute walk distance (Pearson correlation: +0.51, p < 0.001), but this association was not present in PAD (Pearson correlation: +0.10, p = 0.59). Conclusions: Major differences exist between people with and without PAD in the association of gastrocnemius mitochondrial respiration with ABI and 6-minute walk distance. Among people without PAD, ABI and walking performance were positively associated with mitochondrial respiratory function. These associations were not observed in PAD.

Competing risk analysis to estimate amputation incidence and risk in lower-extremity peripheral artery disease.

Background: Patients with peripheral artery disease face high amputation and mortality risk. When assessing vascular outcomes, consideration of mortality as a competing risk is not routine. We hypothesize standard time-to-event methods will overestimate major amputation risk in chronic limb-threatening ischemia (CLTI) and non-CLTI. Methods: Patients undergoing peripheral vascular intervention from 2017 to 2018 were abstracted from the Vascular Quality Initiative registry and stratified by mean age (⩾ 75 vs < 75 years). Mortality and amputation data were obtained from Medicare claims. The 2-year cumulative incidence function (CIF) and risk of major amputation from standard time-to-event analysis (1 - Kaplan-Meier and Cox regression) were compared with competing risk analysis (Aalen-Johansen and Fine-Gray model) in CLTI and non-CLTI. Results: A total of 7273 patients with CLTI and 5095 with non-CLTI were included. At 2-year follow up, 13.1% of patients underwent major amputation and 33.4% died without major amputation in the CLTI cohort; 1.3% and 10.7%, respectively, in the non-CLTI cohort. In CLTI, standard time-to-event analysis overestimated the 2-year CIF of major amputation by 20.5% and 13.7%, respectively, in patients ⩾ 75 and < 75 years old compared with competing risk analysis. The standard Cox regression overestimated adjusted 2-year major amputation risk in patients ⩾ 75 versus < 75 years old by 7.0%. In non-CLTI, the CIF was overestimated by 7.1% in patients ⩾ 75 years, and the adjusted risk was overestimated by 5.1% compared with competing risk analysis. Conclusions: Standard time-to-event analysis overestimates the incidence and risk of major amputation, especially in CLTI. Competing risk analyses are alternative approaches to estimate accurately amputation risk in vascular outcomes research.

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.

Investigating the impact of suboptimal prescription of preoperative antiplatelets and statins on race and ethnicity-related disparities in major limb amputation.

BACKGROUND: Non-Hispanic Black and Hispanic patients with symptomatic PAD may receive different treatments than White patients with symptomatic PAD. The delivery of guideline-directed medical treatment may be a modifiable upstream driver of race and ethnicity-related disparities in outcomes such as limb amputation. The purpose of our study was to investigate the prescription of preoperative antiplatelets and statins in producing disparities in the risk of amputation following revascularization for symptomatic peripheral artery disease (PAD). METHODS: We used data from the Vascular Quality Initiative, a vascular procedure-based registry in the United States (2011-2018). We estimated the probability of preoperative antiplatelet and statin prescriptions and 1-year incidence of amputation. We then estimated the amputation risk difference between race/ethnicity groups that could be eliminated under a hypothetical intervention. RESULTS: Across 100,579 revascularizations, the 1-year amputation risk was 2.5% (2.4%, 2.6%) in White patients, 5.3% (4.9%, 5.6%) in Black patients, and 5.3% (4.7%, 5.9%) in Hispanic patients. Black (57.5%) and Hispanic patients (58.7%) were only slightly less likely than White patients (60.9%) to receive antiplatelet and statin therapy. However, the effect of antiplatelets and statins was greater in Black and Hispanic patients such that, had all patients received these medications, the estimated risk difference comparing Black to White patients would have reduced by 8.9% (-2.9%, 21.9%) and the risk difference comparing Hispanic to White patients would have been reduced by 17.6% (-0.7%, 38.6%). CONCLUSION: Even though guideline-directed care appeared evenly distributed by race/ethnicity, increasing access to such care may decrease health care disparities in major limb amputation.

Neutrophil-to-lymphocyte ratio as a prognostic biomarker in patients with peripheral artery disease: A systematic review and meta-analysis.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) is a simple and routinely obtained parameter reflecting systemic inflammation, including in peripheral artery disease (PAD). METHODS: This systematic review aimed to assess the role of NLR as a prognostic biomarker in patients with PAD. A systematic search was conducted across PubMed, ScienceDirect, Web of Science, Scopus, ProQuest, EBSCO, and Cochrane. Random-effects meta-analysis was used to pool risk ratios, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). A bivariate model was used to generate summary receiver operating characteristics with the corresponding area under the curve (AUC). RESULTS: This review included 5243 patients with PAD from nine eligible studies. High NLR corresponded to at least a twofold increased risk of all-cause mortality (ACM), major adverse limb events (MALE), and major adverse cardiovascular events (MACE). NLR's performance was good for predicting 1-year ACM (AUC 0.71 [95% CI: 0.59-0.79], sensitivity 58.2% [95% CI: 45.3-71.0], specificity 72.6% [95% CI: 65.6-79.62], PPV 41.0% [95% CI: 31.2-50.7], NPV 82.7% [95% CI: 74.1-91.3]) and 1-year MALE (AUC 0.78 [95% CI: 0.75-0.80], sensitivity 65.4% [95% CI: 41.6-89.2], specificity 77.7% [95% CI: 71.0-84.3], PPV 53.7% [95% CI: 47.3-60.1], NPV 83.91% [95% CI: 73.2-94.6]). However, these values tended to decrease as the follow-up duration extended, except for the pooled specificities, which exhibited the opposite pattern. CONCLUSION: NLR emerges as a simple and cost-effective prognostic biomarker with decent performance for poor outcomes in patients with PAD (PROSPERO Registration No.: CRD42023486607).