Association of myocardial infarction with nonobstructive coronary arteries with long-term outcomes

Abstract

Abstract Background Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA) is a disease classification that is not uncommonly encountered yet poorly characterized. The association of MINOCA with long-term cardiovascular (CV) outcomes has been inconsistently assessed with studies reporting conflicting results. The purpose of this meta-analysis is to evaluate the association of MINOCA with long-term cardiovascular outcomes. Methods A literature search was conducted for studies reporting on the association of MINOCA with clinical endpoints as compared to obstructive coronary artery disease (OCAD). The primary end-point was all-cause mortality. Secondary endpoints included CV mortality, need for revascularization, recurrence of acute coronary syndrome (ACS), CV rehospitalization, persistent angina after discharge, and major adverse cardiac events (MACE). Databases searched included Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. Results A total of 29 studies with 893134 patients with acute myocardial infarction (AMI) (48425 with MINOCA, 844709 with OCAD) met inclusion criteria. Mean follow-up was 39 months, mean age was 62, 66% were male. MINOCA was associated with significantly lower risk of all-cause mortality compared to OCAD (OR 0.69, 95% CI 0.60-0.78; p<0.01). The overall effect size was large (z=5.72). MINOCA was associated with significantly lower risk of CV mortality, need for revascularization, recurrent ACS, and persistent angina after discharge (OR 0.49, 95% CI 0.36-0.67; p<0.01; OR 0.09, 95% CI 0.03-0.31; p<0.01; OR 0.57, 95% CI 0.37-0.89; p=0.01; OR 0.23, 95% CI 0.11-0.51; p<0.01). MINOCA was not associated with a significant difference in risk of CV rehospitalization (OR 0.74, 95% 0.46-1.19; p=0.21). Conclusions In patients with AMI, MINOCA is associated with lower risk of all-cause mortality, CV mortality, need for revascularization, recurrent ACS, and persistent angina on long-term follow-up compared to OCAD. However, MINOCA is associated with similar risk of rehospitalization for CV events. Further studies are needed to determine the association between different medical therapies and clinical outcomes in patients with MINOCA.