Publications by Year: 2023

BACKGROUND: There is a paucity of real-world data on the in-hospital (IH) and post-discharge outcomes in patients undergoing lower extremity peripheral vascular intervention (PVI) with adjunctive atherectomy.

AIMS: In this retrospective, registry-based study, we evaluated IH and post-discharge outcomes among patients undergoing PVI, treated with or without atherectomy, in the National Cardiovascular Data Registry PVI Registry.

METHODS: The IH composite endpoint included procedural complications, bleeding or thrombosis. The primary out-of-hospital endpoint was major amputation at 1 year. Secondary endpoints included repeat endovascular or surgical revascularisation and death. Multivariable regression was used to identify predictors of atherectomy use and its association with clinical endpoints.

RESULTS: A total of 30,847 patients underwent PVI from 2014 to 2019, including 10,971 (35.6%) treated with atherectomy. The unadjusted rate of the IH endpoint occurred in 524 (4.8%) of the procedures involving atherectomy and 1,041 (5.3%) of non-atherectomy procedures (p=0.07). After adjustment, the use of atherectomy was not associated with an increased risk of the combined IH endpoint (p=0.68). In the 6,889 (22.4%) patients with out-of-hospital data, atherectomy was associated with a reduced risk of amputation (adjusted hazard ratio [aHR] 0.67, 95% confidence interval [CI]: 0.51-0.85; p<0.01) and surgical revascularisation (aHR 0.63, 95% CI: 0.44-0.89; p=0.017), no difference in death rates (p=0.10), but an increased risk of endovascular revascularisation (aHR 1.21, 95% CI: 1.06-1.39; p<0.01) at 1 year.

CONCLUSIONS: The use of atherectomy during PVI is common and is not associated with an increase in IH adverse events. Longitudinally, patients treated with atherectomy undergo repeat endovascular reintervention more frequently but experience a reduced risk of amputation and surgical revascularisation.

Several studies have shown that women and racial and ethnic minority patients are at increased risk of developing lower extremity peripheral artery disease and suffering adverse outcomes from it, but a knowledge gap remains regarding the underlying causes of these increased risks. Both groups are more likely to be underdiagnosed, have poorly managed contributory comorbidities, and incur disparities in treatment and management postdiagnosis. Opportunities for improvement in the care of women and racial and ethnic minorities with peripheral artery disease include increased rates of screening, higher rates of clinical suspicion (particularly in the absence of typical symptoms of intermittent claudication), and more aggressive risk factor management before and after the diagnosis of peripheral artery disease.

PURPOSE OF REVIEW: Peripheral artery disease (PAD) is an increasingly prevalent but frequently underdiagnosed condition that can be associated with high rates of morbidity and mortality. While an initial noninvasive approach is the cornerstone of management, revascularization is often pursued for patients with treatment-refractory claudication or chronic limb-threatening ischemia (CLTI). In this review, we discuss the current state of endovascular interventions for PAD and explore the many new emerging technologies.

RECENT FINDINGS: The last decade has resulted in numerous advances in PAD interventions including the ongoing evolution of drug-coated devices, novel approaches to complex lesions, and contemporary evidence from large clinical trials for CLTI. Advances in endovascular management have allowed for increasingly complex lesions to be tackled percutaneously. Future directions for the field include the continued evolution in device technology, continued development of state-of-the-art techniques to revascularization of complex lesions, and increased collaboration between a largely multidisciplinary field.

Several observational studies have compared apixaban with rivaroxaban in patients with non-valvular atrial fibrillation (NVAF), but these analyses may be confounded by unmeasured characteristics. This study used provider prescribing preference (PPP) as an instrumental variable (IV) to assess the association between prescriber choice of rivaroxaban vs. apixaban and the study outcomes of stroke/systemic embolism (SE), major bleeding, and death in a retrospective cohort of NVAF patients in the US. Initiators of either medication were linked to their prescribers and followed until the first of the study outcome, the end of rivaroxaban/apixaban use, or 365 days after initiation. PPP for each patient was the percent of rivaroxaban initiations issued by the provider for the prior 10 NVAF patients. Cox regression models tested associations between quintiles of PPP and each outcome. A total of 61,155 patients and 1726 providers were included. The IV was a strong predictor of rivaroxaban prescription (OR = 17.9; 95% CI: 16.6, 19.3). There were statistically significant associations between increasing preference for rivaroxaban and rates of major bleeding (ptrend = 0.041) and death (ptrend = 0.031), but not stroke/SE (ptrend = 0.398). This analysis provides evidence of the relative safety of apixaban over rivaroxaban for the risk of major bleeding and death.

BACKGROUND: After the Centers for Medicare and Medicaid Services modified reimbursement rates for outpatient peripheral vascular intervention in 2008 with the intent of improving access to care, providers began to increasingly perform peripheral vascular interventions in privately owned office-based clinics. Little is known about the characteristics of patients treated in this setting and their long-term outcomes as compared with those treated in hospital-based centers.

METHODS: In this retrospective cohort study, Medicare beneficiaries ≥66 years undergoing outpatient femoropopliteal peripheral vascular interventions in office-based clinics and hospital-based centers from 2015 to 2017 were identified. Sociodemographics, comorbidities, and institutional characteristics were compared across sites. Multivariable Cox proportional hazards models were used to estimate the adjusted associations between practice site location and outcomes. The primary outcome was the composite of major amputation or death analyzed through the end of follow-up.

RESULTS: Among 134 869 patients, 29.9% were treated in office-based clinics and 70.1% in hospital-based centers. Patients treated in office-based clinics were more often Black (16.9% versus 11.9%), dually enrolled in Medicaid (26.3% versus 19.6%), and residents of lower-resourced regions (32.6% versus 25.6%). Over a median follow-up time of 800 days (interquartile range, 531-1119 days), patients treated in office-based clinics had reduced risks of major amputation or death compared with outpatients treated in hospital-based centers (hazard ratio, 0.92 [95% CI, 0.89-0.95]). They also had lower adjusted all-cause mortality (hazard ratio, 0.93 [95% CI, 0.90-0.96]), major lower extremity amputation (hazard ratio, 0.84 [95% CI, 0.79-0.89]), and all-cause hospitalization (hazard ratio, 0.86 [95% CI, 0.84-0.88]). These findings persisted after stratification by critical limb ischemia, race, dual enrollment, and regional socioeconomic status, as well as among operators treating patients in both clinical settings.

CONCLUSIONS: In this large nationwide analysis of Medicare beneficiaries, office-based clinics treated a more socioeconomically disadvantaged population compared with hospital-based centers. Long-term outcomes were comparable between locations. As such, these clinics appear to be selecting lower-risk patients for outpatient peripheral vascular interventions, although there remains the possibility of unmeasured confounding.

OBJECTIVES: The objective of this study was to assess the reliability the Social Security Administration Death Master File (SSADMF) for evaluating mortality in comparative peripheral vascular device studies.

METHODS: We leveraged 2 versions of an administrative claims data set that were identical except for the source of mortality data. The SSADMF was the primary source of mortality records in one version. The SSADMF was combined with mortality from Medicare beneficiary records in the other. Our study was set in the context of a comparative effectiveness analysis of recent Food and Drug Administration interest involving peripheral paclitaxel-coated devices. Mortality of patients with Medicare Advantage insurance coverage from 2015 to 2018 who underwent femoropopliteal artery revascularization with a drug-coated device (DCD) or non-DCD was assessed through 2019. Covariate differences between treatment groups were adjusted by inverse propensity treatment weighting. The hazard ratio of DCD to non-DCD mortality was estimated using Cox regression.

RESULTS: The cumulative incidences of mortality differed substantially between versions of the data. Nevertheless, we could not reject the null hypothesis that the hazard ratios of the SSADMF (1.05; 95% confidence interval 0.95-1.17) and the Master Beneficiary Summary File/SSADMF (1.03; 95% confidence interval 0.96-1.11) were the same (P = .63).

CONCLUSIONS: The SSADMF is a common source of mortality records in the United States that can be linked to real-world data sources but is known to underreport mortality rates. We find that the SSADMF provides a reliable source of all-cause mortality for a comparative study assessing the safety of peripheral vascular devices.

OBJECTIVE: To describe the incidence and predictors of acute limb ischemia (ALI) in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS).

METHODS: Patients with index hospitalizations for AMI complicated by cardiogenic shock from 2016 to 2019 in the US National Readmission Database were identified. We evaluated the incidence of ALI and its associated mortality, length of stay, and cost of hospitalization. We used multivariable logistic regression to determine independent predictors of ALI in this population.

RESULTS: A total of 84,615 patients had AMI complicated by cardiogenic shock and 1302 (1.54%) developed ALI. The rates of ALI increased from 1.29% in 2016 to 1.66% in 2019 (P ≤ .002). The use of microaxial mechanical circulatory support increased from 2.25% in 2016 to 13.36% in 2019 (P = .0001). The major predictors of ALI included peripheral arterial disease (odds ratio [OR], 7.34; 95% confidence interval [CI], 6.12-8.81), venoarterial extracorporeal membrane oxygenation (OR, 4.40; 95% CI, 3.19-6.07), and microaxial mechanical circulatory support (OR, 3.12; 95% CI, 2.74-3.55). ALI in patients with cardiogenic shock was associated higher mortality (39.20% vs 33.53%; P ≤ .0001).

CONCLUSIONS: This nationwide observational study shows that ALI is an important complication of AMI with cardiogenic shock. This complication is associated with higher mortality. In addition to peripheral artery disease, the use of mechanical circulatory devices was associated with significantly higher rates of ALI.

Drug-coated balloon (DCB) percutaneous interventional therapy allows for durable reopening of the narrowed lumen via physical tissue expansion and local anti-restenosis drug delivery, providing an alternative to traditional uncoated balloons or a permanent indwelling implant such as a conventional metallic drug-eluting stent. While DCB-based treatment of peripheral arterial disease (PAD) has been incorporated into clinical guidelines, DCB use has been recently curtailed due to reports that showed evidence of increased mortality risk in patients treated with paclitaxel (PTX)-coated balloons. Given the United States Food and Drug Administration's 2019 consequent warning regarding PTX-eluting DCBs and the subsequent marked reduction in clinical DCB use, there is now a critical need to better understand the compositional and mechanical factors underlying DCB efficacy and safety. Most work to date on DCB refinement has focused on designing both the enabling balloon catheter and alternate coatings composed of various drugs and excipients, followed by device evaluation in preclinical and clinical studies. We contend that improvement in DCB performance will require a better understanding of the biophysical factors operative during and following balloon deployment, and moreover that the elaboration and demonstrated control of these factors are needed to address current concerns with DCB use. This article provides a perspective on the biophysical interactions that govern DCB performance and offers new design strategies for the development of next-generation DCB devices.