Publications

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.

In this part 1 of a 2-part continuing medical education series, we review the epidemiology and pathophysiology of cardiovascular disease, its association with cutaneous symptoms, and the diagnosis and evaluation of cutaneous features of cardiovascular syndromes, including infective endocarditis, acute rheumatic fever, Kawasaki disease, cholesterol embolization syndrome, lipid disorders, cardiac amyloidosis, and cardiac myxomas. As the incidence and prevalence of cardiovascular diseases increase, dermatologists play an essential role in recognizing the cutaneous manifestations of cardiovascular diseases in order to appropriately connect patients with follow-up care.

OBJECTIVE: Intravascular ultrasound (IVUS) is an important adjunctive tool for patients with lower extremity peripheral arterial disease (PAD) undergoing endovascular therapy (EVT). The evidence regarding the advantages of IVUS use is evolving, and recent studies have reported conflicting results. We aimed to perform a meta-analysis to evaluate the efficacy of IVUS during angiography-guided EVT for patients with PAD.

METHODS: MEDLINE and EMBASE were searched through April 2023 to identify studies that investigated the outcomes of IVUS with angiography-guided EVT versus angiography-alone guided EVT. The primary outcome was restenosis/occlusion rate; secondary outcomes were target lesion revascularization (TLR), major amputation, and mortality.

RESULTS: One randomized controlled trial and 14 observational studies, largely of moderate quality, were included, yielding a total of 708 808 patients with 709 189 lesions that were treated with IVUS-guided EVT (n = 101 405) versus angiography-alone (n = 607 784). Compared to angiography-alone, IVUS-guided EVT was associated with a non-significant trend towards decreased restenosis/occlusion (relative risk (RR) [95% Confidence interval (CI)] = 0.74 [0.54-1.00], I2 = 60%). Although the risk of TLR and mortality were comparable (RR [95% CI] = 0.85 [0.65-1.10], I2 = 70%, RR [95% CI] = 1.01 [0.79-1.28], I2 = 43%, respectively), the use of IVUS was also associated with significantly lower risk of major amputation (RR [95% CI] = 0.74 [0.67-0.82], I2 = 47%). Subgroup analysis focusing on femoropopliteal disease demonstrated significantly higher patency (RR [95% CI] = 0.72 [0.52-0.98], I2 = 73%). However, superiority with major amputation was not observed.

CONCLUSIONS: IVUS-guided EVT for PAD may possibly be associated with a lower major amputation rate compared to angiography-alone guided EVT, although the difference in patency remained an insignificant trend in favor of IVUS-guided EVT. Adjunctive use of IVUS during EVT may be beneficial, and further prospective studies are warranted to delineate this relationship and the applicability of this technology in routine practice.

BACKGROUND: Persons living with human immunodeficiency virus (HIV, PLWH) have an increased risk of peripheral artery disease (PAD) in comparison to the general population. However, a gap remains in understanding optimal management for this condition. This study assesses longitudinal outcomes associated with peripheral endovascular intervention (PVI) for PAD among PLWH.

METHODS: All Medicare fee-for-service patients undergoing femoropopliteal artery PVI between April 1, 2015 and December 31, 2018 were identified and stratified by HIV serostatus. The primary outcome was major adverse limb events (MALE), defined as major amputation or arterial embolism/thrombosis following an index procedure. The subdistribution hazard was used to evaluate the association between HIV serostatus and MALE, accounting for the competing risk of death. Results were adjusted for sociodemographics and major comorbidities.

RESULTS: Of 168,553 patients who underwent PVI, 357 (0.21%) were PLWH. The average age was 77.0 ± 7.6 years; 80.3% had hypertension, 70.3% had hyperlipidemia, and 24.6% had tobacco use disorder. Compared to those without HIV, PLWH were younger and had a higher burden of cardiovascular risk factors. MALE were substantially more frequent among PLWH, with a cumulative incidence of 24.6%, compared to 14.5% among those without HIV. The adjusted subdistribution hazard ratio was 1.26 (95% CI 1.00-1.58, p = 0.05). The use of guideline-directed statin therapy was low in both groups in the 90 days following revascularization (57.9% in PLWH vs 58.1% in those without HIV, p = 0.95).

CONCLUSION: Among US Medicare beneficiaries, PLWH had poorer long-term outcomes following PVI. Greater attention to the management of symptomatic PAD is warranted for the HIV population, particularly following revascularization.

Background Frailty is rarely assessed in clinical trials of patients who receive dual antiplatelet therapy (DAPT) after percutaneous coronary intervention. This study investigated whether frailty defined using claims data is associated with outcomes following percutaneous coronary intervention, and if there is a differential association in patients receiving standard versus extended duration DAPT. Methods and Results Patients ≥65 years of age in the DAPT (Dual Antiplatelet Therapy) Study, a randomized trial comparing 30 versus 12 months of DAPT following percutaneous coronary intervention, had data linked to Medicare claims (n=1326), and a previously validated claims-based index was used to define frailty. Net adverse clinical events, a composite of all-cause mortality, myocardial infarction, stroke, and major bleeding, were compared between frail and nonfrail patients. Patients defined as frail using claims data (12.0% of the cohort) had higher incidence of net adverse clinical events (23.1%) compared with nonfrail patients (10.7%; P<0.001) at 18-month follow-up and increased risk after multivariable adjustment (adjusted hazard ratio [HR], 2.24 [95% CI, 1.38-3.63]). There were no differences in effects of extended duration DAPT on net adverse clinical events for frail (HR, 1.42 [95% CI, 0.73-2.75]) and nonfrail patients (HR, 1.18 [95% CI, 0.83-1.68]; interaction P=0.61), although analyses were underpowered. Bleeding was highest among frail patients who received extended duration DAPT. Conclusions Among older patients in the DAPT Study, claims-defined frailty was associated with higher net adverse clinical events. Effects of extended duration DAPT were not different for frail patients, although comparisons were underpowered. Further investigation of how frailty influences ischemic and bleeding risks with DAPT are warranted. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00977938.