Long-term outcomes of initial thoracic endovascular repair versus medical therapy in acute uncomplicated type B aortic dissection: real-world evidence from a nationwide claims database in Japan - a retrospective cohort study.

Abstract

Objectives: To compare the long-term outcomes of initial thoracic endovascular aortic repair (TEVAR) versus initial medical therapy (iMT) in patients with acute uncomplicated type B aortic dissection (uTBAD), using real-world evidence from a nationwide claims database in Japan. This study aligns with stage 4 of the Idea, Development, Exploration, Assessment, and Long-term Study (IDEAL) framework for surgical innovation.

Design: A retrospective cohort study using propensity score matching (PSM) to balance baseline characteristics.

Setting: Japanese nationwide health insurance claims database, between 1 January 2015 and 31 December 2023.

Participants: Among 40 229 cases with tentative codes for aortic dissection (International Classification of Diseases-10: I71.0), 4995 met all eligibility criteria for acute uTBAD. Among these patients, 96 underwent TEVAR in the subacute phase (15-90 days post diagnosis), while 4899 were managed with iMT. After PSM, 96 TEVAR cases were matched to 480 iMT cases in a 1:5 ratio.

Main outcome measures: The primary outcomes were aorta-related events and all-cause mortality. The secondary outcome was the frequency of follow-up CT imaging every year.

Results: After PSM, the baseline characteristics of both groups were balanced. Median age was 56 years (IQR: 50-62 years) in both groups, and follow-up duration was similar (TEVAR: 31 months; iMT: 28 months, p=0.84).At 60 months, Kaplan-Meier estimates showed an aorta-related event rate of 21.9% (95% CI: 12.6% to 36.4%) for TEVAR and 19.9% (95% CI: 15.6% to 25.2%) for iMT (p=0.99).All-cause mortality was 4.4% (95% CI: 1.4% to 13.6%) for TEVAR and 6.6% (95% CI: 4.0% to 10.6%) for iMT (p=0.70). No significant differences were observed.

Conclusions: While aorta-related events accumulated steadily in the crude iMT group, no survival benefit was observed for subacute TEVAR. These findings support ongoing randomized controlled trials and show the utility of claims-based analyses in IDEAL Stage 4.