Sex-related differences in clinical outcomes among patients with myocardial infarction with nonobstructive coronary artery disease: A systematic review and meta-analysis.

BACKGROUND

Among patients who present with acute myocardial infarction (MI), 2-6% are found to have non-obstructive coronary arteries (NOCA). Patients with MINOCA are more commonly women and present at a younger age (51-59 years). The influence of sex on adverse event rates remains unclear.

METHODS

PubMed, MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), EMBASE, EBSCO, Web of Science and CINAHL databases were searched for trials comparing gender differences in clinical outcomes among patients with MINOCA from inception through April 10, 2022. The primary endpoint of the study was composite major adverse clinical events (MACE) including all-cause mortality, non-fatal MI, stroke, and cardiovascular readmissions, and secondary endpoints were the individual components of the MACE.

RESULTS

Seven studies with a total of 28,671 MINOCA patients were included (n = 11,249 men and n = 17,422 women) over a mean follow-up of 2 years. Women had more MACE than men (10.1% vs. 9.1%, OR 1.15, 1.04-1.23, I2 = 44.7%). Among secondary endpoints, only the incidence of stroke was higher in women (3.5% vs. 2.2%, OR 1.3, 1.01-1.68, I2 = 0%). All-cause mortality, non-fatal MI, and cardiovascular readmissions were not significantly different between the two groups.

CONCLUSIONS

We hypothesize that small vessel disease associated with MINOCA drives MACE in women and the diminishing influence of estrogen, hypercoagulability and underprescribing could contribute to the differences sex-related outcomes.