Antithrombotic Therapy in Coronary Artery Aneurysm, Ectasia, and Slow Flow: A Systematic Review

BACKGROUND: Coronary artery aneurysm (CAA), coronary artery ectasia (CAE), and coronary slow flow phenomenon (CSFP) are coronary pathologies associated with altered hemodynamics and increased thrombotic risk. However, optimal antithrombotic management remains uncertain because of limited and heterogeneous evidence. OBJECTIVES: This systematic review aimed to synthesize data on the efficacy and safety of antiplatelet and anticoagulant therapies in patients with CAA, CAE, and CSFP. METHODS: Following PRISMA 2020 guidelines, PubMed, Scopus, Web of Science, and ProQuest were searched through September 2025 for randomized and observational studies evaluating antithrombotic therapy in adults with these conditions. Outcomes included major adverse cardiovascular events and major bleeding. Narrative synthesis was conducted using the SWiM framework. Risk of bias was assessed using ROBINS-I and RoB 2.0, and certainty of evidence using GRADE. RESULTS: Eleven studies comprising 3271 participants were included: six on CAE (n = 895), four on CAA (n = 2356), and one on CSFP (n = 20). In CAE, dual antiplatelet therapy (DAPT) and oral anticoagulation (OAC) were associated with fewer ischemic events than no therapy, although direct comparisons were inconsistent. The only randomized trial in CAE showed numerically lower recurrent myocardial infarction and cardiovascular death with single antiplatelet therapy (SAPT) plus direct oral anticoagulant (DOAC) versus DAPT, but findings were nonsignificant and based on few events. Evidence for CAA and CSFP remains limited and inconclusive. CONCLUSIONS: Intensified antithrombotic therapy may benefit patients with CAE, but evidence remains inconclusive for CAA and CSFP. Large, multicenter randomized trials are warranted to establish condition-specific treatment recommendations.