Survival after Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) – A Comprehensive Systematic Review and Meta-Analysis from MINOCA Global Collaboration

Background: This systematic review and meta analysis evaluates the 12-month all-cause mortality in patients with Myocardial Infarction (MI) with Non-Obstructive Coronary Arteries (MINOCA); comparing this to those with MI and obstructive coronary artery disease (MI-CAD), and those without a prior MI (No-MI). Methods: Using PRISMA guidelines, the terms ‘MI’, ‘non-obstructive’, ‘angiography’ and ‘prognosis” were searched in literature databases, including original, English language MINOCA studies with >100 consecutive patients. Publications with a heterogenous cohort, unreported coronary stenosis, or exclusively focussing on MINOCA-mimicking conditions, were excluded. Unpublished data were obtained from the MINOCA Global Collaboration. The Paule-Mandel, the Hartung, Knapp, Sidik and Jonkman and restricted maximum-likelihood random-effects meta-analysis methodology. The primary outcome was 12-month all-cause mortality in MINOCA. PROSPERO Registration: CRD42020145356. Findings: The 23 eligible studies yielded 55,369 suspected MINOCA, 485,382 MI-CAD and 33,074 No-MI patients. Pooled meta-analysis of MINOCA studies revealed an unadjusted 12-month all-cause mortality rate of 3.4% (95% CI, 2.6% – 4.2%) and re-infarction in 2.6% (95% CI, 1.7% – 3.5%). MINOCA had a lower 12-month all-cause mortality than those with MI-CAD (3.3% [95% CI, 2.5%-4.1%] vs 5.6%; [95% CI, 4.1% – 7.0%]; OR=0.60; 95% CI: 0.52 – 0.70, p<0.001). In contrast, there was a trend towards increased 12-month all-cause mortality in patients with MINOCA (2.6% [95% CI, 0% – 5.9%]) compared with No-MI (0.7% [95% CI, 0.1% – 1.3%]; OR=3.71; 95% CI: 0.58 – 23.61, p=0.09). Interpretation: In the largest contemporary meta-analysis to-date, patients with suspected MINOCA had a favourable prognosis compared to MI-CAD, but a guarded prognosis compared to those with No-MI. Funding Statement: The hospital Research Foundation Basil Hetzel Translational Grant. Declaration of Interests: The authors declare no competing interests.