A retrospective cohort study on the provision and outcomes of pharmacological therapy after revascularisation for peripheral arterial occlusive disease: a study protocol

Antithrombotic Treatment Patterns of Patients with Symptomatic Peripheral Arterial Occlusive Disease in Germany: Evidence from Health Insurance Claims Data

Objectives: Patients with peripheral arterial occlusive disease (PAOD) are at risk of worsening limb symptoms, major adverse cardiovascular events and exhibit an impaired life expectancy. There is a lack of evidence on the extent of pharmacological secondary prevention in PAOD patients. This study assesses treatment patterns of antithrombotic agents in symptomatic PAOD patients. Methods: This is a retrospective cohort study using data from the second largest insurance fund in Germany, BARMER. We included symptomatic PAOD patients undergoing in-hospital treatment with an index admission between 1 January 2010 and 31 December 2017. Outcomes were proportions of single antiplatelets (SAPT), dual antiplatelets (DAPT), vitamin-K antagonists (VKA), or direct oral anticoagulants (DOAC) in the 12 months prior and 6 months after the index hospitalization. Non-parametric cumulative incidence for competing risks was estimated to account for censoring and death after discharge from hospital stay. Patient flows were visualised by alluvial diagrams. All analyses were stratified by intermittent claudication (IC) and chronic limb-threatening ischaemia (CLTI). The protocol was registered to ClinicalTrials.gov (NCT03909022). Results: A total of 80,426 unique patient encounters were identified. Mean age was 72.7 (46.3% female). Amongst all patients, 25.6% were on SAPT, 4.1% on DAPT, 9.1% on VKA, 3.9% on DOAC, 3.9% on both antiplatelets and oral anticoagulation, and 53.3% without any antithrombotic therapy during the 12 months before index stay. The estimated cumulative incidence was 37.9% SAPT, 14.8% DAPT, 7.5% VKA, 4.3% DOAC, 7.4% both, and 28.1% without any antithrombotic therapy during the 6 months after index stay. The considerable increases in antiplatelet therapy were mainly driven by the group of patients without antithrombotics before index stay. As compared with IC, patients who suffered from CLTI received less often antiplatelets but more often anticoagulants both before and after index stay. Conclusions: Utilisation rates of antithrombotic therapy increased considerably after in-hospital treatment for PAOD. Yet, remarkably high rates of symptomatic patients without any blood-thinning therapy constitute a major concern with respect to adequate secondary prevention of PAOD patients.

Sex Disparities in Long-Term Mortality after Paclitaxel Exposure in Patients with Peripheral Artery Disease: A Nationwide Claims-Based Cohort Study

BACKGROUND

Randomized controlled trials have reported excess mortality in patients treated with paclitaxel-coated devices versus uncoated devices, while observational studies have reported the opposite. This study aims to determine the underlying factors and cohort differences that may explain these opposite results, with specific focus on sex differences in treatment and outcomes.

METHODS

Multicenter health insurance claims data from a large insurance fund, BARMER, were studied. A homogeneous sample of patients with an index of endovascular revascularization for symptomatic peripheral arterial occlusive disease between 2013 and 2017 was included. Adjusted logistic regression and Cox regression models were used to determine the factors predicting allocation to paclitaxel-coated devices and sex-specific 5-year all-cause mortality, respectively.

RESULTS

In total, 13,204 patients (54% females, mean age 74 ± 11 years) were followed for a median of 3.5 years. Females were older (77 vs. 71 years), and had less frequent coronary artery disease (23% vs. 33%), dyslipidemia (44% vs. 50%), and diabetes (29% vs. 41%), as well as being less likely to have a history of smoking (10% vs. 15%) compared with males. Mortality differences were mostly attributable to the female subgroup who were revascularized above the knee (hazard ratio, HR 0.78, 95% CI: 0.64-0.95), while no statistically significant differences were observed in males.

CONCLUSIONS

This study found that females treated above the knee benefited from paclitaxel-coated devices, while no differences were found in males. Ongoing and future registries and trials should take sex disparities into account.

A health insurance claims analysis on the effect of female sex on long-term outcomes after peripheral endovascular interventions for symptomatic peripheral arterial occlusive disease

OBJECTIVE

Several reports have addressed sex disparities in peripheral arterial occlusive disease (PAOD) treatment with inconclusive or even conflicting results. However, most previous studies have neither been sufficiently stratified nor used matching or weighting methods to address severe confounding. In the present study, we aimed to determine the disparities between sexes after percutaneous endovascular revascularization (ER) for symptomatic PAOD.

METHODS

Health insurance claims data from the second-largest insurance fund in Germany, BARMER, were used. A large cohort of patients who had undergone index percutaneous ER of symptomatic PAOD from January 1, 2010 to December 31, 2018 were included in the present study. The study cohort was stratified by the presence of intermittent claudication, ischemic rest pain, and wound healing disorders. Propensity score matching was used to adjust for confounding through differences in age, treated vessel region, comorbidities, and pharmacologic treatment. Sex-related differences regarding cardiovascular event-free survival, amputation-free survival, and overall survival within 5 years of surgery were determined using Kaplan-Meier time-to-event curves, log-rank test, and Cox regression analysis.

RESULTS

In the present study, 50,051 patients (47.2% women) were identified and used to compose a matched cohort of 35,232 patients. Among all strata, female patients exhibited lower mortality (hazard ratio [HR], 0.69-0.90), fewer amputations or death (HR, 0.70-0.89), and fewer cardiovascular events or death (HR, 0.78-0.91). The association between female sex and improved long-term outcomes was most pronounced for the patients with intermittent claudication.

CONCLUSIONS

In the present propensity score-matched analysis of health insurance claims, we observed superior cardiovascular event-free survival, amputation-free survival, and overall survival during 5 years of follow-up after percutaneous ER in women with symptomatic PAOD. Future studies should address sex disparities in the open surgical treatment of PAOD to illuminate whether the conflicting data from previous reports might have resulted from insufficient stratification of the studies.

Long-Term Effectiveness and Safety of Initiating Statin Therapy After Index Revascularization In Patients With Peripheral Arterial Occlusive Disease

Background An increasing number of patients with a peripheral arterial occlusive disease were put on statins during the past years. This study assessed whether statin therapy was effective and safe for these new users. Methods and Results Using health insurance claims data from Germany's second-largest insurance fund, BARMER, we identified patients with peripheral arterial occlusive disease who had index revascularization between 2008 and 2018 without prior statin therapy. We compared patients with and without statin therapy in addition to antithrombotics during the first quarter after discharge (new users versus nonusers). Outcomes were all-cause mortality, cardiovascular events, and incident major amputation for effectiveness and incident diabetes mellitus and incident myopathy for safety. Propensity score matching was used to balance the study groups. All analyses were stratified into patients with chronic limb-threatening ischemia and intermittent claudication. A total of 22 208 patients (mean age 71.1 years and 50.3% women) were included in the study. In 10 922 matched patients, statin initiation was associated with lower all-cause mortality (chronic limb-threatening ischemia: hazard ratio [HR], 0.75 [95% CI, 0.68-0.84]; intermittent claudication: HR, 0.80 [95% CI, 0.70-0.92]), lower risk of major amputation in patients with chronic limb-threatening ischemia (HR, 0.73; 95% CI, 0.58-0.93) and lower risk of cardiovascular events (hazard ratio, 0.80; 95% CI, 0.70-0.92) in patients with intermittent claudication during 5 years of follow-up. Safety outcomes did not differ among the study groups. Conclusions Initiating statin therapy in patients with peripheral arterial occlusive disease after index revascularization is efficient and safe with an effect size comparable to earlier studies. Awareness campaigns for evidence-based optimal pharmacological treatment among patients are recommended.

Quality of care in surgical/interventional vascular medicine: what can routinely collected data from the insurance companies achieve?

The complexity and diversity of surgical/interventional vascular medicine necessitate innovative and pragmatic solutions for the valid measurement of the quality of care in the long term. The secondary utilization of routinely collected data from social insurance institutions has increasingly become the focus of interdisciplinary medicine over the years. Owing to their longitudinal linkage and pan-sector generation, routinely collected data make it possible to answer important questions and can complement quality development projects with primary registry data. Various guidelines exist for their usage, linkage, and reporting. Studies have shown good validity, especially for endpoints with major clinical relevance. The numerous advantages of routinely collected data face several challenges that require thorough plausibility and validity procedures and distinctive methodological expertise. This review presents a discussion of these advantages and challenges and provides recommendations for starting to use this increasingly important source of data.