Impact of antithrombotic therapy on clinical outcomes in patients with type B acute aortic syndrome.

Objective: Antithrombotic therapy has the potential to interfere with false lumen thrombosis. In type B acute aortic syndrome, the degree of false lumen thrombosis affects clinical outcomes. We aimed to explore the association of antithrombotic therapy with the prognosis of patients with type B acute aortic syndrome. Methods: We reviewed 406 patients with type B acute aortic syndrome who were discharged alive with and without antithrombotic therapy. The primary outcome was aorta-related adverse events, defined as a composite of aorta-related death, aortic rupture, aortic repair, and progressive aortic dilation. Results: Of the 406 patients, 64 (16%) were discharged with antithrombotic therapy and 342 (84%) were discharged without antithrombotic therapy. A total of 249 patients (61%) presented with intramural hematoma with complete thrombosis of the false lumen, and 157 patients (39%) presented with aortic dissection. During a median follow-up of 4.6 years, 32 patients (50%) in the antithrombotic group and 93 patients (27%) in the nonantithrombotic group had a primary outcome event. Cumulative incidence of aorta-related events at 1 and 3 years with death as the competing risk was higher in the antithrombotic group than in the nonantithrombotic group (19% ± 5% vs 9% ± 2% at 1 year and 40% ± 7% vs 17% ± 2% at 3 years, P < .001). Conclusions: Antithrombotic therapy might be associated with an increased risk of aorta-related events in patients with type B acute aortic syndrome.