Impact of Institutional Volume on Critical In-Hospital Complications Adjusted for Patient- and Limb-Related Characteristics: An Analysis of a Nationwide Japanese Registry of Endovascular Interventions for PAD

Purpose: To investigate the incidence and clinical predictors, including institutional annual case volume, of critical in-hospital complications after endovascular therapy (EVT) for peripheral artery disease (PAD). Materials and Methods: The data were extracted from the nationwide registry of peripheral interventions in Japan [Japanese EVT (J-EVT)] between 2012 and 2017. A total of 92,224 EVT cases either for chronic limb-threatening ischemia (CLTI) or intermittent claudication were included in the analysis. The primary outcome measure was critical in-hospital complications, which were defined as a composite of urgent surgery and in-hospital death within 30 days after EVT. The institutional volume was classified into quartiles. The association of institutional volume, as well as baseline characteristics, with the critical in-hospital complications was explored using a multivariable logistic regression model with multiple imputation for missing data. Results are presented as the adjusted odds ratio (OR) with the 95% confidence intervals (CI). Results: The estimated prevalence of critical in-hospital complications was 0.3% (95% CI 0.3% to 0.4%). The following 10 patient- and limb-related characteristics were identified as independent risk factors for critical in-hospital complications: (1) female sex (OR 1.75, 95% CI 1.36 to 2.25), (2) age ≥75 years (OR 1.60, 95% CI 1.06 to 2.40), (3) CLTI (OR 2.12, 95% CI 1.47 to 3.05), (4) nonambulatory status (OR 1.66, 95% CI 1.23 to 2.24), (5) regular dialysis (OR 1.35, 95% CI 1.02 to 1.77), (6) cerebrovascular disease (OR 1.76, 95% CI 1.33 to 2.33), (7) urgent revascularization (OR 5.10, 95% CI 3.64 to 7.13), (8) aortoiliac TASC II D lesion (OR 3.65, 95% CI 2.51 to 5.33), (9) femoropopliteal TASC II D lesion (OR 1.77, 95% CI 1.24 to 2.52), and (10) infrapopliteal TASC D lesion (OR 1.52, 95% CI 1.08 to 2.13). In addition, the 4th quartile of the institutional volume (≥158 cases/year), but not the 2nd or 3rd quartile, had a significantly and independently lower risk of critical in-hospital complications than the 1st quartile (OR 0.13, 95% CI 0.07 to 0.23). Conclusion: After EVT for symptomatic PAD, 0.3% of the population encountered critical in-hospital complications. A higher institutional volume was significantly associated with a lower risk of critical in-hospital complications.