The prognostic impact of coronary anatomy in myocardial infarction with nonobstructive coronary artery disease: a seven-year longitudinal follow-up

Abstract

Abstract Background Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a common condition associated with major adverse events (MAE) that may occur presence of normal or nonobstructive coronary artery anatomy (NCAA and NOCAA, respectively). The prognostic impact presence of NOCAA on long-term outcomes of MINOCA patients remains unclear. Methods This is a retrospective study among consecutive MINOCA patients in a large referral medical center in Israel between the years 2005–2018. Patients with probable alternative cause for myocardial injury, as stress-induced cardiomyopathy and myocarditis, were excluded. Patients were classified according to their coronary angiography diagnosis into NCAA and NOCAA. The primary outcome was MAE, defined as the composite of all-cause mortality and recurrent acute coronary syndrome (ACS). We performed survival analyses using multivariable Cox regression, controlling for potential cofounders. Results Among 36,501 admitted with AMI during the study period, 1,544 patients (4.2%) had MINOCA. Among MINOCA patients, 651 (42%) had NCAA, and 893 (58%) had NOCAA. The mean age was 61.2±12.6 years, and 710 (46.0%) were females. The NOCAA group had more females and were older with higher rates of diabetes, hypertension, dyslipidemia, atrial fibrillation, and chronic renal failure (p<0.05 for all). At a median follow-up of 7 years, MAE occurred in 203 (22.7%) patients and 67 (10.3%) patients in the NOCAA and NCAA groups, respectively (p<0.01). In fully-adjusted multivariable model, NOCAA remained a significant risk factor for long-term MAE [adjusted-hazard-ratio (aHR) 1.67, 95% confidence-interval (95% CI) 1.25–2.23; p<0.001; figure]. Other factors associated with MAE were older age (aHR 1.05, 95% CI 1.03–1.06; p<0.001), left ventricular ejection fraction (LVEF) <40% (aHR 3.04, 95% CI 2.03–4.57; p<0.001) Conclusion Among MINOCA patients, NOCAA was associated with a worse long-term prognosis than NCAA. Other risk factors for long-term MAE were older age and LVEF <40%, while female sex and sinus rhythm at presentation were associated with lower MAE risk. Funding Acknowledgement Type of funding sources: None.