The Relationship Between Hospital Procedure Volume and Outcomes After Endovascular or Open Surgical Revascularisation for Peripheral Arterial Disease: An Analysis of Health Insurance Claims Data.

OBJECTIVE: There is a paucity of data on the relationship between hospital procedure volume and outcomes after inpatient treatment of symptomatic peripheral arterial disease (PAD). This study aimed to generate meaningful hypotheses to support the ongoing discussion. METHODS: Data derived from BARMER, Germany's second largest insurance provider, were linked with nationwide hospital procedure volumes from mandatory hospital quality reports. All endovascular (EVR) and open surgical revascularisations (OSR) provided to patients (≥ 40 years) with symptomatic PAD between 1 January 2013 and 31 December 2018 were included. Hospital volume was defined as the number of procedures performed by a hospital in the previous calendar year (in quartiles). Freedom from re-intervention, amputation, and overall mortality rate within 12 months after discharge were analysed using multivariable Cox proportional hazards models. In hospital mortality was determined by generalised estimating equations logistic regression models. RESULTS: There were 88 187 revascularisations (72.4% EVR; EVR: 72.7 years and 45.2% females; OSR: 71.9 years and 41.9% females) registered by 668 hospitals. No statistically significant association was found between 12 month freedom from re-intervention and hospital volume (EVR: 4; quartile HR 1.05; 95% CI 0.94 - 1.16. OSR: 4; quartile HR 1.05; 95% CI 0.92 - 1.21). Patients with OSR had a decreased hazard of 12 month mortality in a high volume hospital compared with a low volume hospital (HR 0.85; 95% CI 0.73 - 0.98), but not with EVR (HR 1.03; 95% CI 0.91 - 1.16). Patients who were treated in hospitals with highest volumes showed decreased hazards of 12 month freedom from amputation when compared with low volume hospitals (EVR: HR 0.72; 95% CI 0.52 - 0.99. OSR: HR 0.61; 95% CI 0.44 - 0.85). CONCLUSION: This large retrospective analysis of insurance claims suggests that higher procedure volume is associated with lower major amputation rates, although there is a need for standardisation of the definition of volume stratification. Future studies should address the impact of subsequent outpatient care and surveillance to further examine the complex interaction between treatment and outcomes.

How Does Female Sex Affect Complex Endovascular Aortic Repair? A Single Centre Cohort Study.

OBJECTIVE: There is growing evidence of a female patient disadvantage in complex endovascular aortic repair using fenestrated and branched endografts (FB-EVAR) primarily related to peri-procedural events including ischaemic and access vessel complications. This study aimed to determine the impact of sex differences on treatment patterns, and in hospital outcomes in a single centre cohort. METHODS: This was a retrospective cross sectional single centre cohort study of all consecutive FB-EVAR procedures provided to patients with asymptomatic pararenal and thoraco-abdominal aortic aneurysm (TAAA) between 1 January 2010 and 28 February 2021. Adjusted multivariable logistic regression models were developed using backward (Wald) elimination of variables to determine the independent impact of female sex on short term outcomes. RESULTS: In total, 445 patients (24.3% females, median age 73.0 years, IQR 66, 78) were included. Female patients had a smaller aneurysm diameter, less frequent coronary artery disease (29.6% vs. 44.8%, p = .007) and history of myocardial infarction (2.8% vs. 15.4%, p < .001) when compared with males. Females were more frequently treated for TAAA than males (49.1% vs. 25.2%, p < .001). The median length of post-procedural hospital stay was 10 days in females and 9 in males. In adjusted analyses, female sex was independently associated with higher mortality (odds ratio [OR] 10.135, 95% CI 2.264 - 45.369), post-procedural complications (OR 2.500, 95% CI 1.329 - 4.702), spinal cord ischaemia (OR 4.488, 95% CI 1.610 - 12.509), sepsis (OR 4.940, 95% CI 1.379 - 17.702), and acute respiratory insufficiency (OR 3.283, 95% CI 1.015 - 10.622) after pararenal aortic aneurysm repair during the hospital stay. CONCLUSION: In this analysis of consecutively treated patients, female sex was associated with increased in hospital mortality, peri-procedural complications, and spinal cord ischaemia after elective complex endovascular repair of pararenal aortic aneurysm, while no differences were revealed in the TAAA subgroup. These results suggest that sex related patient selection and peri-procedural management should be studied in future research.

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.

Sex Disparities in Long Term Outcomes After Open Surgery for Chronic Limb Threatening Ischaemia: A Propensity Score Matched Analysis of Health Insurance Claims.

OBJECTIVE: Several studies suggest a disadvantage for women in peri-operative morbidity and mortality after open surgery in peripheral arterial occlusive disease. In addition to their heterogeneity regarding design and analysed cohorts, long term data are mostly missing. This study aimed to determine sex disparities in outcomes after open revascularisation in chronic limb threatening ischaemia (CLTI). METHODS: Using health insurance claims data of the second largest insurance fund in Germany, BARMER, a large cohort of patients was sampled consecutively for analysis including index open surgical revascularisations of CLTI performed between 1 January 2010, and 31 December 2018. Propensity score matching was used to adjust for confounding. Sex related differences regarding overall survival, amputation free survival (AFS), and cardiovascular event free survival (CVEFS) during the five years after surgery were determined using Kaplan-Meier time to event curves, log rank test, logistic, and Cox regression. RESULTS: Among 9 526 patients (49.5% women) in the entire cohort, 6 502 patients were matched. Before matching, women were older at presentation (78.0 vs. 71.8 years, p < .001) and suffered more often from multiple comorbidities (van Walraven score > 9, 55.5% vs. 50.6%, p < .001). During the hospital stay, there were 692 (7.3%) deaths, while 4 631 deaths (48.6%) occurred during the follow up. In the matched cohort, the median follow up was 746 days for women and 871 days for men. In the matched analyses, female sex was significantly associated with better overall survival (hazard ratio, HR, 0.80, log rank p < .001), AFS (HR 0.81, log rank p < .0001), and CVEFS (HR 0.84, log rank p < .001) five years after the index treatment. CONCLUSION: In this largest propensity score matched analysis of health insurance claims to date from Germany, evidence was found for better long term outcomes in women after open surgical revascularisations for chronic limb threatening ischaemia. Future guidelines and studies should address the impact of sex on patient selection practice and outcomes to determine the underlying reasons for existing disparities.