ORal anticoagulation risks late aortic intervention in Conservatively managed type B Aortic dissection (ORCA study)

OBJECTIVES: Single-center retrospective cohort study to evaluate the impact of oral anticoagulation (OAC) on long-term outcomes of conservatively managed acute type B aortic dissection. METHODS: Clinical and morphological data of eligible patients from a high-volume vascular centre from 1 January 2003 through 31 December 2020 were evaluated. Patients were excluded for: type A or non-A-non-B dissection, isolated abdominal dissection, intramural haematoma and connective tissue disease. The primary outcome was freedom from late aortic events (intervention, rupture and mortality). Secondary outcomes included spinal cord ischaemia, bleeding, reno-visceral artery occlusion, ilio-femoral intervention, dissection propagation, aortic growth, aortic remodelling, deterioration of false lumen thrombosis as well as 30-day and overall mortality. Time to event was analysed using multivariable Cox proportional hazard models with OAC as time-varying covariate and mortality as a competing risk. The impact of OAC was adjusted for potential confounding factors. RESULTS: A total of 69 patients [50 males, median age 65 (interquartile range: 58-72) years] were enrolled. The median follow-up was 49.3 (28-92) months. A total of 47 patients (68%) received OAC at any time throughout the follow-up for a median length of 26 (11-61) months. Late aortic events occurred in 28 patients (41%) including intervention (n = 27, 39%) and rupture (n = 1, 1%). OAC was associated with more late aortic events (hazard ratio 3.94, 95% confidence interval 1.06-14.6, P = 0.040). Secondary outcomes were not associated with OAC. CONCLUSIONS: Our data suggest a relation of OAC therapy with an increased risk for late aortic interventions. Type B aortic dissection should not be the primary indication for OAC and patients with OAC for other indications require frequent follow-up imaging.

Automated summary

This study suggests a potential association between oral anticoagulation therapy and increased risk of late aortic events in patients with conservatively managed acute type B aortic dissection. It emphasizes that type B aortic dissection should not be the primary indication for oral anticoagulation, and patients on anticoagulation for other indications need close monitoring.