2389Survival after myocardial infarction with non-obstructive coronary arteries (MINOCA) - A comprehensive systematic review and meta-analysis
Authors: Pasupathy S , Lindahl B , Litwin P , Tavella R , Williams M , Air T , Marfella R , Bainey K , Alzuhairi K , Reynolds H , Johnston N , Kerr A , Beltrame J 
Published: October 2019

Abstract

Introduction
Myocardial Infarction (MI) with Non-Obstructive Coronary Arteries (MINOCA) is now a recognised MI subtype. A 2013 systematic review of MINOCA literature indicated that MINOCA prognosis is favourable compared to those with MI and obstructive coronary artery disease (MICAD), but healthy controls were not included. With the growth of recent literature and evaluation of MINOCA prognosis, we performed an in-depth analysis of MINOCA prognosis, in relation to 1-year all-cause mortality and 1-year re-infarction compared with MICAD patients and a healthy cohort.

Methods
An unrestricted literature search was conducted on the terms “MI”, “non-obstructive”, “angiography” and “prognosis” using PubMed and Embase. Publications with non-consecutive recruitment, less than 100 MINOCA patients or selection bias (i.e. restricted age group) were excluded. MINOCA & MICAD were defined as the presence of an MI (as per the universal criteria) in the absence & presence of CAD (i.e. epicardial vessel with a stenosis ≥50% on angiography), respectively. The healthy cohort was defined as those with no history of cardiovascular diseases. Unpublished data were accumulated via the MINOCA Global Collaboration. Data from the included studies were pooled and analysed using DerSimonian-Laird random-effects meta-analysis. Heterogeneity was assessed using Cochran's Q and I2 statistics. Odds ratios (ORs), mean differences and 95% confidence intervals (CI) were calculated for proportion and continuous data respectively.

Results
The search identified 2889 unique publications, of which 27 included prognosis data. Of the 563660 consecutive MI patients, the overall pooled prevalence of MINOCA wasat 8.7% (95% CI: 7.5%-9.9%). The 1-year mortality and 1-year re-infarction data by diagnosis are presented in the table.
Prognosis comparison by diagnosis MINOCA (n=41658) MINOCA vs MICAD MINOCA vs Healthy % (95% CI) MINOCA (n=16642) MICAD (n=174461) Mean difference or OR 95% CI MINOCA (n=8465) Healthy (n=33074) Mean difference or OR 95% CI Years or % (95% CI) Years or % (95% CI) Years or % (95% CI) Years or % (95% CI) Age 61 (60–62) 61 (59–63) 64 (63–66) 3.2 (2.2–4.2) 62 (57–66) 60 (58–63) 1.6 (−5–8.6) Female 51 (48–53) 51 (48–55) 28 (26–30) 2.8 (2.5–3.1) 56 (48–64) 38 (24–52) 2.2 (1.3–3.7) 1 year mortality 3.4 (2.9–4) 3.4 (2.9–3.9) 5.5 (4.7–6.2) 0.6 (0.5–0.7) 2.6 (1.2–4) 0.7 (0.5–1) 3.7 (1.7–8.2) 1 year Re-MI 2.7 (2.1–3.3) 2.8 (1.8–3.7) 5.7 (3.9–7.5) 0.5 (0.4–0.7) 3.5 (0–7) 0.3 (0–0.6) 14.1 (9.5–21.2)

Conclusions
This pooled analysis shows that MINOCA accounts for almost one in ten MI presentations. The risks of re-infarction and death among MINOCA patients are much higher than in healthy controls, but lower than for MICAD patients. Efforts are needed to improve understanding of the optimal management and secondary prevention strategies in this unique and heterogeneous population.