165 Antithrombotic Therapy for Aortic and Peripheral Artery Aneurysms: A Systematic Review and Meta-Analysis

Abstract Aim This systematic review and meta-analysis aimed to assess the impact of antithrombotic agents on extracranial aneurysms under surveillance or undergoing intervention. Method Medline, Embase, and CENTRAL databases were searched. Randomised-controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with aortic or extracranial peripheral arterial aneurysms were included. Aneurysm growth rate, major adverse cardiovascular or limb events, mortality, endoleaks, re-intervention rates, and other outcomes were captured. Results Fifty-seven studies involving 121,451 patients were included (26 antiplatelets, 12 anticoagulants, 16 any antithrombotic agent(s), 2 intra-operative heparin). Aspirin reduced growth rates of aortic aneurysms under surveillance (mean difference -0.9mm/y, 95%CI -1.74 to -0.07, p=0.03; GRADE certainty: moderate). For aortic aneurysms undergoing intervention, antithrombotics increased 30-day mortality (odds ratio [OR] 2.30, 95%CI 1.51 to 3.51, p<0.001; GRADE certainty: moderate). Antiplatelets reduced long-term all-cause mortality (hazard ratio [HR] 0.84, 95%CI 0.76 to 0.92, p<0.001; GRADE certainty: moderate), whilst anticoagulants increased this risk (HR 1.64, 95%CI 1.14 to 2.37, p=0.008; GRADE certainty: very low). Anticoagulants increased incidence of endoleaks under 3 years, and re-intervention rates (p<0.05 for all). Antithrombotic agents did not significantly affect rupture rates in aortic aneurysms. Meta-analysis was not possible for ruptured aneurysms and popliteal aneurysms. Conclusions There is moderate quality evidence that aspirin reduces aneurysm growth rates. Antiplatelet agents reduced all-cause mortality in aneurysms after intervention; whilst anticoagulants increased this risk, along with endoleaks and re-interventions. Well-designed trials are required to determine therapeutic benefits of antithrombotic agents for patients with aneurysms.