Risk of ventricular arrhythmia in patients with myocardial infarction and non-obstructive coronary arteries and normal ejection fraction

AIM To assess the arrhythmic determinants and prognosis of patients presenting with myocardial infarction and nonobstructive coronary arteries(MINOCA)with normal ejection fraction(EF).METHODS This is an observational analysis of 131 MINOCA patients with normal EF.Three cardiac magnetic resonance(CMR)diagnosis classes were recognized according to the late gadolinium enhancement(LGE)pattern:Myocardial infarction(MI)(n=34),myocarditis(n=47),and"no LGE"(n=50).Ventricular events occurring during hospitalization were recorded and the entire population was followed-up at 1 year.RESULTS Ventricular arrhythmia was observed in 18(13.8%)patients during hospitalization.The"no LGE"patients experienced fewer ventricular events than the MI and myocarditis patients[4.0%vs 26.5%and 14.9%,respectively(P=0.013)].There was no significant difference between the MI and myocarditis groups.On multivariate analysis,LGE transmural extent[OR=1.52(1.08-2.15),P=0.017]and ST-segment elevation[OR=4.65(1.61-13.40),P=0.004]were independent predictors of ventricular arrhythmic events,irrespective of the diagnosis class.Finally,no patient experienced sudden cardiac death or ventricular arrhythmia recurrence at 1-year.CONCLUSION MINOCA patients with normal EF presented no 1-year cardiovascular events,irrespective of the CMR diagnosis class.LGE transmural extent and ST segment elevation at admission are risk markers of ventricular arrhythmia during hospitalization.