Abstract 13675: Impact of Antithrombotic Therapy on Clinical Outcomes in Patients With Type B Acute Aortic Syndrome

Introduction: In type B acute aortic syndrome (B-AAS), degree of false lumen thrombosis is known to affect clinical outcome. Antithrombotic therapy might have impact on prognosis through affecting false lumen thrombosis.We aimed to assess the impact of antithrombotic therapy on clinical outcomes in patients with B-AAS. Methods: A total of 429 patients with acute B-AAS admitted to our hospital and discharged alive were retrospectively analyzed. The primary outcome was aorta-related adverse events, defined as a composite of aorta-related death, aortic rupture, surgical or endovascular aortic repair and progressive aortic dilation. Results: Of the 429 patients, 72 patients (17 %) were discharged with antithrombotic therapy and 357 (83 %) without antithrombotic therapy. 254 patients (59 %) presented with intramural hematoma with complete thrombosis of false lumen, and 175 (41 %) presented with classic aortic dissection. Reasons for prescription were coronary artery disease (n=25), cerebral ischemia (n=17) and others (n=30). In the antithrombotic group, patients were significantly older than no-antithrombotic group (73 ± 13 vs 67 ± 13 years, P= 0.001) and had more comorbidities such as dyslipidemia (40 % vs 26 %, P= 0.011), diabetes mellitus (22 % vs 11 %, P= 0.007) and coronary artery disease (36 % vs 5 %, P< 0.001). During a mean follow-up of 4.8 ± 5.2 years, 37 patients (51 %) in the antithrombotic group and 98 patients (27 %) in the no-antithrombotic group had a primary outcome event. Event-free survival rate among antithrombotic versus no-antithrombotic group was 36 % vs 73 % at 5 years (P< 0.001). Multivariate Cox regression analysis adjusted for age, sex, comorbidity and medication revealed that antithrombotic therapy was a significant risk factor for aorta-related adverse events (hazard ratio 2.08, 95% confidence interval 1.247-3.463; P= 0.005). Conclusion: In B-AAS, antithrombotic therapy was associated with an increased risk of aorta-related events. For patients with indispensable need of antithrombotic therapy, careful follow-up should be provided.