Impact of Hospital Volume on Long-Term Outcomes After Endovascular Therapy for Peripheral Artery Disease.

To investigate the association between annual hospital volume of endovascular therapy (EVT) and long-term outcomes in patients with lower-extremity peripheral artery disease (PAD). We identified patients who underwent percutaneous endovascular transluminal angioplasty and thrombectomy of the extremities or percutaneous endovascular removal in the Japanese Diagnosis Procedure Combination inpatient database from April 2014 to March 2020 linked to the Survey of Medical Institutions data. A generalized linear model analysis was performed to assess 12-month amputation, all-cause death, composite outcome (amputation and death), and readmission. We also analyzed length of hospital stay and total health care costs during the first hospitalization. Among 127 486 eligible patients, 31 579, 31 913, 31 999, and 31 995 were in the first (1-27 cases/year), second (28-44 cases), third (45-67 cases), and fourth (68-289 cases) quartiles, respectively. There were no significant differences in 12-month amputation among the second (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.90-1.04), third (OR, 1.00; 95% CI, 0.93-1.07), and fourth (OR, 1.00; 95% CI, 0.93-1.07) quartile volumes compared with the first quartile. Significant differences were observed in 12-month death (OR for fourth quartile with reference to the first quartile, 0.71; 95% CI, 0.65-0.76), composite outcome (OR, 0.84; 95% CI, 0.80-0.89), and readmission (OR, 1.05; 95% CI, 1.02-1.09). We found that the annual hospital volume of EVT was not associated with decreased 12-month amputation in patients with lower-extremity PAD. In contrast, all-cause death and composite outcome were significantly decreased in hospitals with the highest volume. The association between hospital volume of endovascular therapy and long-term adverse clinical outcomes remains unclear. The present analyses showed no significant differences in 12-month amputation rates among the hospital volumes, whereas higher-volume quartiles were significantly associated with decreased 12-month all-cause death rates and composite outcome. There was also a positive association in the length of stay between the first quartile volume and the others, while no significant difference in total health care costs among the quartiles was observed. Further investigations are needed, including insights into operator volume and procedural characteristics, to clarify the relationship between hospital volume and long-term adverse outcomes.