Long-term outcome and characteristics of patients with NSTEMI and non-obstructive coronary arteries

Abstract

Abstract Introduction Discordant data have been reported on the prognosis of myocardial infarction with nonobstructive coronary arteries (MINOCA). Purpose The objectives of this study were to assess characteristics and prognostic impact on the long-term follow-up of the diagnosis of MINOCA. Methods We included 274 consecutive patients with non–ST-segment elevation myocardial infarction (NSTEMI) who underwent coronary angiography between November 2015 and October 2016. MINOCA was classified according to angiographic findings as smooth coronary arteries, mild irregularities (< 30% stenosis), and moderate atherosclerosis (30%-49% stenosis). The primary endpoint was a composite of cardiovascular mortality, nonfatal myocardial infarction, and revascularization (MACE) at a median of 6 years of follow-up. Results A total of 74 patients (27.0%) showed no obstructive lesions. Patients with MINOCA are characterized by younger age, a predominance of females, less diabetes mellitus, dyslipidemia, and smoking, lower GRACE score at admission, less marked electrocardiographic and echocardiographic changes, and lower troponin levels. MINOCA was associated with a lower occurrence of MACE (P< 10-3; HR, 0.085; 95%CI, 0.031-0.231) and was confirmed as an independent factor in the multivariate analysis (P< 10-3; HR, 0.121; 95%CI, 0.042-0.354). On analysis of the separate components of the main endpoint, MINOCA was significantly associated with a lower rate of cardiovascular mortality, myocardial infarction, and revascularization. Conclusions MINOCA is characterized by a low-risk profile at admission except for the positivity of troponin and is associated with a lower rate of MACE at the long-term follow-up.Table:Characteristics6-year outcomes