Prognostic impact of coronary artery ectasia after acute coronary syndrome: A systematic review and meta-analysis

Background Coronary artery ectasia (CAE) is associated with abnormal coronary flow, thrombus formation, and impaired reperfusion, but its prognostic significance after acute coronary syndrome (ACS) remains uncertain. Objectives To evaluate clinical outcomes among patients with versus without CAE presenting with ACS. Methods PubMed/MEDLINE and Scopus were searched from inception to April 2026 for studies comparing ACS patients with versus without CAE. Risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using random-effects models with restricted maximum likelihood estimation and Hartung-Knapp adjustment. Subgroup, leave-one-out, and Bayesian random-effects analyses were performed to assess robustness. Results Twelve observational studies comprising 13,540 patients were analyzed, including 1177 with CAE and 12,363 without CAE. Follow-up ranged from in-hospital assessment to 120 months. CAE was associated with a higher risk of recurrent myocardial infarction (RR, 1.96; 95% CI, 1.16–3.32; P = 0.022; I2 = 61.1%), corresponding to an estimated absolute excess of 58.6 events per 1000 patients and a descriptive number needed to harm of 17. For stroke, the prespecified Hartung-Knapp analysis yielded an RR of 2.40 (95% CI, 1.59–3.61), whereas conventional random-effects inference, used as the basis of interpretation, yielded an RR of 2.40 (95% CI, 1.08–5.31; P = 0.031). This estimate was based on 3 studies and was model-sensitive. CAE was not significantly associated with all-cause mortality, in-hospital mortality, cardiac death, repeat revascularization, or MACE. Stent thrombosis was not pooled because only 2 studies provided estimable stent-exposed comparisons. Bayesian analyses supported the recurrent myocardial infarction finding. Conclusions Among patients presenting with ACS, CAE identifies a higher-risk ischemic phenotype, with the most consistent association observed for recurrent myocardial infarction. Prospective studies are needed to define CAE-specific risk stratification and treatment strategies.