Comparison of Mortality and Amputation after Lower Extremity Bypass vs. Peripheral Vascular Intervention in Patients with Chronic Limb-Threatening Ischemia and Comorbid Chronic Kidney Disease.

OBJECTIVE: Comorbid chronic kidney disease (CKD) is associated with worse outcomes for patients with chronic limb-threatening ischemia (CLTI). However, comparative effectiveness data is limited for lower extremity bypass (LEB) vs. peripheral vascular intervention (PVI) in patients with CLTI and CKD. We aimed to evaluate 1) 30-day all-cause mortality and amputation and 2) 5-year all-cause mortality and amputation for LEB vs. PVI in patients with comorbid CKD. METHODS: Individuals undergoing LEB and PVI were queried from the Vascular Quality Initiative with Medicare claims-linked outcomes data. Propensity scores were calculated using 13 variables, and a 1:1 matching method was used. The mortality risk at 30 days and 5 years in LEB vs. PVI by CKD was assessed using Kaplan-Meier and Cox proportional hazards models, with interaction terms added for CKD. For amputation, cumulative incidence functions and Fine-Gray models were used to account for the competing risk of death, with interaction terms for CKD added. RESULTS: Of 4084 patients (2042 per group), the mean age was 71.0 ± 10.8 years, 69.0% were male. Irrespective of CKD status, 30-day mortality (HR 0.94, 95% CI 0.63-1.42, p=0.78) was similar for LEB vs. PVI, but LEB was associated with a lower risk of 30-day amputation (sHR 0.66, CI 0.44-0.97, p=0.04). CKD status, however, did not modify these results. Similarly, LEB vs. PVI was associated with a lower risk of 5-year mortality (HR 0.79, 95% CI 0.71-0.88, p<0.001), but no difference in 5-year amputation (sHR 1.03, 95% CI 0.89-1.20, p=0.67). CKD status did not modify these results. CONCLUSION: Regardless of CKD status, patients had a lower risk of 5-year all-cause mortality and 30-day amputation with LEB vs. PVI. Results may help inform preference-sensitive treatment decisions on LEB vs. PVI for patients with CLTI and CKD, who may commonly be deemed too high risk for surgery.

Inter-Rater Reliability for the Amputation Endpoint in the National Vascular Quality Initiative.

BACKGROUND: National quality reporting efforts after revascularization for peripheral artery disease (PAD) are ongoing. Validation of endpoints are necessary in national quality registries. OBJECTIVES: This study sought to examine the interrater reliability for the endpoint of major amputation at 1 year in the Vascular Quality Initiative (VQI) registry and the Medicare-linked Vascular Quality Initiative registry (VQI-VISION) against electronic health record (EHR) review. METHODS: Surgical or endovascular revascularization procedures between January 1, 2010, and December 31, 2017, in the VQI registry and VQI-VISION for 2 academic health systems were queried. Major amputation data were abstracted by trained data collectors for the VQI and derived from Current Procedural Terminology codes for VQI-VISION. Cases underwent protocolized adjudication for the endpoint of major amputation by EHR review. Paired tests were used to evaluate the sensitivity and specificity. Spearman's ρ and Cohen's κ were used to evaluate interrater reliability. RESULTS: Amputation endpoints for 1,936 revascularizations were examined. Compared with major amputation data in EHR review, the sensitivity for the VQI registry was 35.9% and the specificity was 99.4% (ρ = 0.53; κ = 0.48). For VQI-VISION, sensitivity was 67.7% and specificity was 98.9% (ρ = 0.75; κ = 0.74). For any amputation in VQI data, sensitivity was 35.3% and specificity was 99.3% (ρ = 0.53; κ = 0.46), and for VQI-VISION, they were 71.6% and 97.7%, respectively (ρ = 0.75; κ = 0.74). CONCLUSIONS: Almost two-thirds of the amputations in the VQI registry and one-third of amputations in VQI-VISION were missing at 1 year compared against adjudicated EHR review. In preparing for national reporting systems for major amputation tracking, data collection system reform is needed.

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.

Variability in guideline-directed medical therapy across sites and operators and long-term mortality and amputation outcomes risk in patients undergoing peripheral vascular interventions.

BACKGROUND: The use of guideline-directed medical therapy (GDMT) in patients undergoing peripheral vascular interventions (PVIs) decreases the risk of death and amputation and may decrease hospital readmissions. The variability of GDMT prescription across sites and operators and the proportionality of risk is not well understood. We aimed to study the association between variability of GDMT prescription at the site and operator level and outcomes (including 90-day readmissions and 24-month all-cause mortality and major amputation). METHODS: We examined GDMT discharge rates in PVIs performed between 2017 and 2018 using Medicare-linked Vascular Quality Initiative registry. GDMT included a statin, antiplatelet therapy, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACE-i/ARB) if hypertensive. Quartiles (Q1-4) of GDMT rates were documented by operators and sites and variability was quantified using median odds ratios (MOR) and intraclass correlation (ICC). The association between lower GDMT rates (per 10%) by sites and operators with 90-day readmission were calculated using logistic regression, and with 24-month mortality and major amputation using parametric survival model. Models were adjusted for patient-level factors and included sites and operators nested within sites as 2 random effects. RESULTS: GDMT rates for 17,147 patients across 223 sites and 1,263 operators ranged from 0% to 38% (Q1, MOR 1.43, 95%CI 1.39-1.47, P ≤ .001) to 57%-100% (Q4, MOR 1.48, 95%CI 1.44-1.51, P ≤ .001). Four percent of variance in GDMT use was explained by sites (ICC 3.9, 95%CI 2.9-5.3) and operators (ICC 4.1, 95%CI 3.1-5.4). A dose-response relationship was noted between lower GDMT rates and increased risk of 90-day readmission risk by sites (P = .021) and operators (P < .001). Lower GDMT prescription by site was associated with higher risk of 24-month mortality (HR = 1.07, 95%CI 1.02-1.13) and major amputation (HR = 1.08, 95%CI 1.01-1.15). Similar associations were found for GDMT use by provider (mortality HR = 1.05, 95%CI 1.02-1.08 and amputation HR = 1.04, 95%CI 1.00-1.08). CONCLUSION: Both at the operator and health system level, there was significant variability in GDMT prescription following PVI, proportionally translating into risk for readmission, mortality, and major amputation. Targeted quality efforts should prioritize both operator and site levels to improve GDMT use and outcomes for patients undergoing PVI.

Psychosocial and socioeconomic factors are most predictive of health status in patients with claudication.

BACKGROUND: As a key treatment goal for patients with symptomatic peripheral artery disease (PAD), improving health status has also become an important end point for clinical trials and performance-based care. An understanding of patient factors associated with 1-year PAD health status is lacking in patients with PAD. METHODS: The health status of 1073 consecutive patients with symptomatic PAD in the international multicenter PORTRAIT (Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) registry was measured at baseline and 1 year with the Peripheral Artery Questionnaire (PAQ). The association of 47 patient characteristics with 1-year PAQ scores was assessed using a random forest algorithm. Variables of clinical significance were retained and included in a hierarchical multivariable linear regression model predicting 1-year PAQ summary scores. RESULTS: The mean age of patients was 67.7 ± 9.3 years, and 37% were female. Variables with the highest importance ranking in predicting 1-year PAQ summary score were baseline PAQ summary score, Patient Health Questionnaire-8 depression score, Generalized Anxiety Disorder-2 anxiety score, new onset symptom presentation, insurance status, current or prior diagnosis of depression, low social support, initial invasive treatment, duration of symptoms, and race. The addition of 19 clinical variables in an extended model marginally improved the explained variance in 1-year health status (from R2 0.312 to 0.335). CONCLUSIONS: Patients' 1-year PAD-specific health status, as measured by the PAQ, can be predicted from 10 mostly psychosocial and socioeconomic patient characteristics including depression, anxiety, insurance status, social support, and symptoms. These characteristics should be validated and tested in other PAD cohorts so that this model can inform risk adjustment and prediction of PAD health status in comparative effectiveness research and performance-based care.

Examining Outcomes in Patients Admitted With Comorbid Peripheral Artery Disease and Microvascular Disease.

BACKGROUND: Peripheral artery disease (PAD) and microvascular disease (MVD) are highly prevalent conditions that share common risk factors. This observational study aimed to characterize patients with both conditions and determine the impact of comorbid PAD/MVD on outcomes. METHODS AND RESULTS: Patients admitted across 31 states January 2011 through December 2018 with a primary or secondary diagnosis of PAD or MVD were included from the National Readmissions Database and weighted to approximate a national sample. Those age <18 years or with nonatherosclerotic leg injuries were excluded. Patients were divided into 3 groups: PAD-only, MVD-only, or comorbid PAD/MVD. Multiple logistic regression was used to evaluate associations with major and minor amputations, major adverse cardiac events, and in-hospital mortality. Cox regression was used to evaluate associations with readmission within 1 year. The PAD group was used as reference. The final cohort included 33 972 772 admissions: 9.1 million with PAD, 21.3 million with MVD, and 3.6 million with both. Annual admissions for PAD/MVD increased to >500 000 in 2018. Major and minor amputations increased ≈50% for PAD/MVD between 2011 and 2018. Compared with PAD-only, PAD/MVD was associated with a higher risk for major amputation (odds ratio [OR], 1.30 [95% CI, 1.28-1.32]), minor amputation (OR, 2.15 [95% CI, 2.12-2.18]), major adverse cardiac events (OR, 1.04 [95% CI, 1.03-1.04]), in-hospital mortality (OR, 1.07 [95% CI, 1.05-1.09]), and readmission (hazard ratio, 1.02 [95% CI, 1.02-1.02]) after adjustment for baseline factors. CONCLUSIONS: Comorbid MVD is present in a large and growing number of patients with PAD and is associated with augmented risk for adverse outcomes. Further prospective research is merited to understand this vulnerable population.

A state-of-the-art review of quality-of-life assessment in venous disease.

OBJECTIVE: Chronic venous disease is a common condition and has a significant impact on patients' health status. Validated patient-reported outcome measures (PROMs) used to assess health status are needed to measure health status. This state-of-the-art review summarizes the current validation evidence for disease-specific PROMs for chronic venous disease and provides a framework for their use in the clinical setting. METHODS: A literature search in OVID Embase and Medline was conducted to identify relevant English-language studies of chronic venous disease that used disease-specific PROMs between January 1, 1993, and June 30, 2022. Abstracts and titles from identified studies were screened by four investigators, and full-text articles were subsequently screened for eligibility. Data on validation of disease-specific PROMs was abstracted from each included article. Classical test theory was used as a framework to examine a priori defined validation criteria for content validity, reliability (construct validity, internal reliability, and test-retest reliability), responsiveness, and expansion of the validation evidence base (use in randomized controlled trials and comparative effectiveness research, cultural or linguistic translations, predictive validity, or establishing the minimal clinically important difference threshold, defined as smallest amount an outcome or measure is perceived as a meaningful change to patients). The PROMs were categorized into three groups based on the manifestations of disease of the population for which they were developed. The overall validity of each PROM was assessed across three stages of validation including content validity (phase 1); construct validity, reliability, and responsiveness (phase 2); and expansion of the validation evidence base (phase 3). RESULTS: Of 2338 unique studies screened, 112 studies (4.8%) met inclusion criteria. The eight disease-specific PROMs identified were categorized into three groups: (1) overall chronic venous disease (C1 to C6); (2) C1 to C4 disease; and (3) C5 to C6 disease. Assessed by group, the Chronic Venous Insufficiency Questionnaire met criteria for validation at all three phases for patients with C1 to C4 disease, and the Charing Cross Venous Ulcer Questionnaire met criteria for validation at all three phases for patients with C5 to C6 disease. There were no PROMs that met all criteria for validation for use in overall chronic venous disease (C1 to C6). CONCLUSIONS: Of the eight PROMs assessed in this review, only two met prespecified criteria at each phase for validation. The Chronic Venous Insufficiency Questionnaire and Charing Cross Venous Ulcer Questionnaire should be considered for use in patients with chronic venous disease without venous ulcers and with venous ulcers, respectively.

Longitudinal Pathways Between Physical Activity, Depression, and Perceived Stress in Peripheral Artery Disease.

BACKGROUND: One-fifth of the patients with peripheral artery disease (PAD) experience depression and stress. Depression and stress may impact patients' abilities to be physically active, a key recommendation for supporting overall PAD management to improve symptoms and reduce the risk of cardiovascular events. We aimed to study interrelationships between 1-year longitudinal trajectories of depression, stress, and physical activity following a PAD diagnosis. METHODS: Patients with new or worsening PAD symptoms enrolled at 10 US PORTRAIT study (Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) vascular specialty clinics (CT, LA, MI, MO, NC, OH, and RI) were assessed at baseline, 3, 6, and 12 months between June 2, 2011 and December 3, 2015. Depressive symptoms were measured with the 8-item Patient Health Questionnaire, perceived stress with the 4-item Perceived Stress Scale and physical activity with items from the INTERHEART study. Path analysis was used to examine the longitudinal relationship between depression and physical activity and perceived stress and physical activity. RESULTS: A total of 766 patients were included (mean age of 68.2 [±9.4] years; 57.7% male). Overall, 17.8% reported significant depressive symptoms, 36.0% experienced increased perceived stress, and 44.1% were sedentary upon PAD diagnosis. A decrease in physical activity preceded a rise in subsequent depressive symptoms (ß ranges -0.45 [95% CI, -0.80 to -0.09]; -0.81 [95% CI, -1.19 to 0.42]) over the course of 1 year. Low physical activity scores at the initial presentation were followed by high perceived stress at 3 months (ß=-0.44 [95% CI, -0.80 to -0.07]). CONCLUSIONS: In symptomatic PAD, a decrease in physical activity was followed by an increased risk of depressive symptoms and perceived stress at subsequent intervals over the course of 1 year following PAD diagnosis and treatment. Integrated behavioral health approaches for PAD, addressing physical activity and managing depression or distress, are indicated as collective PAD treatment goals.

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.

Community distress and risk of adverse outcomes after peripheral vascular intervention.

INTRODUCTION: Community distress is associated with adverse outcomes in patients with cardiovascular disease; however, its impact on clinical outcomes after peripheral vascular intervention (PVI) is uncertain. The Distressed Communities Index (DCI) is a composite measure of community distress measured at the zip code level. We evaluated the association between community distress, as measured by the DCI, and 24-month mortality and major amputation after PVI. METHODS: We used the Vascular Quality Initiative database, linked with Medicare claims data, to identify patients who underwent initial femoropopliteal PVI between 2017 and 2018. DCI scores were assigned using patient-level zip code data. The primary outcomes were 24-month mortality and major amputation. We used time-dependent receiver operating characteristic curve analysis to determine an optimal DCI value to stratify patients into risk categories for 24-month mortality and major amputation. Mixed Cox regression models were constructed to estimate the association of DCI with 24-month mortality and major amputation. RESULTS: The final cohort consisted of 16,864 patients, of whom 4734 (28.1%) were classified as having high community distress (DCI ≥70). At 24 months, mortality was elevated in patients with high community distress (30.7% vs 29.5%, P = .02), as was major amputation (17.2% vs 13.1%, P <.001). After adjusting for demographic and clinical characteristics, a 10-point higher DCI score was associated with increased risk of mortality (hazard ratio: 1.01; 95% confidence interval: 1.00-1.03) and major amputation (hazard ratio: 1.02; 95% confidence interval: 1.00-1.04). CONCLUSIONS: High community distress is associated with increased risk of mortality and major amputation after PVI.

Intravascular ultrasound analysis of intraplaque versus subintimal tracking in percutaneous intervention for coronary chronic total occlusions: One year outcomes.

OBJECTIVES: We sought to determine the 1-year outcomes of patients receiving successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) procedures comparing subintimal versus intraplaque wire tracking patterns. BACKGROUND: CTO PCI utilizes both intraluminal and subintimal wire tracking to achieve successful percutaneous revascularization. Intravascular ultrasound (IVUS) can be used to precisely determine the path of wire tracking. METHODS: From 2014 to 2016, data from patients undergoing CTO PCI were collected in a single-center database. The primary composite endpoint was target vessel failure (TVF) defined as cardiovascular death, target vessel myocardial infarction (MI), or target vessel revascularization (TVR). RESULTS: In total 157 patients with successful CTO PCI and concomitant IVUS imaging completed 1-year follow-up. Subintimal tracking was detected in 53.5% of cases and those patients had a higher incidence of prior PCI, prior coronary artery bypass grafting, and higher J-CTO score. At 1-year, the unadjusted rate of TVF in the subintimal tracking group was higher than the intraplaque group (17.9 vs. 6.9%, HR 2.74, 95% CI 1.00-7.54, P = 0.04), driven by numerically higher rates of TVR and peri-procedural MI. After multivariable adjustment, no significant differences in the rates of the TVF between subintimal vs. intraplaque groups were present at 1-year (TVF: HR 1.51, 95% CI 0.38-6.00, P = 0.55). Landmark analysis excluding in-hospital events showed no significant differences in TVF to 1-year. CONCLUSIONS: IVUS-detected subintimal tracking was observed in over half of successful CTO PCI cases and correlated with baseline and angiographic factors that contributed to the overall rate of TVF at 1-year.

Smooth Muscle Hypoxia-Inducible Factor 1α Links Intravascular Pressure and Atherosclerosis--Brief Report.

OBJECTIVE: We hypothesized that the hypoxia-inducible factor (HIF) 1α in vascular smooth muscle contributes to the development of atherosclerosis, and links intravascular pressure to this process. APPROACH AND RESULTS: Transverse aortic constriction was used to create high-pressure vascular segments in control, apolipoprotein E (ApoE)(-/-), smooth muscle-HIF1α(-/-), and ApoE(-/-)×smooth muscle-HIF1α(-/-) double-knockout mice. Transverse aortic constriction selectively induced atherosclerosis in high-pressure vascular segments in young ApoE(-/-) mice on normal chow, including coronary plaques within 1 month. Concomitant deletion of HIF1α from smooth muscle significantly reduced vascular inflammation, and attenuated atherosclerosis. CONCLUSIONS: HIF1α in vascular smooth muscle plays an important role in the pathogenesis of atherosclerosis, and may provide a mechanistic link between blood pressure, vascular inflammation, and lipid deposition.