Abstract
BACKGROUND: Little is known about risk stratification in patients with myocardial infarction with nonobstructive coronary arteries (MINOCA). We investigated whether the age, creatinine, and ejection fraction (ACEF) score (age [years]/ejection fraction [%] + 1 [if creatinine >176 μmol/L]) might predict long-term outcomes after MINOCA. HYPOTHESIS: The ACEF score enables accurate risk prediction in patients with MINOCA. METHODS: A total of 1179 patients with MINOCA were enrolled and divided based on their ACEF score tertile levels. The primary endpoint was a composite of major adverse cardiovascular events (MACE), including all-cause death, nonfatal MI, nonfatal stroke, revascularization, and hospitalization for unstable angina or heart failure. Kaplan-Meier and Cox regression analyses were performed. Discrimination was defined as the area under the curve (AUC) using receiver operating characteristic analysis. RESULTS: During the median follow-up of 41.7 months, patients with MINOCA with higher ACEF score tertiles had a significantly higher incidence of MACE (6.3%, 12.5%, and 23.8%, respectively; p < .001). The adjusted risk of MACE increased with the rising ACEF score tertiles (1st tertile as reference; 2nd tertile: HR 2.70, 95% CI: 1.38-5.29, p = .004; and 3rd tertile: HR 5.35, 95% CI: 2.72-10.51, p < .001). Moreover, an elevated ACEF score was closely associated with an increased risk of MACE overall (HR 4.23, 95% CI: 3.37-5.30, p < .001) and in subgroups (all p < .05). The ACEF score also yielded a good predictive value (AUC 0.79) for MACE. CONCLUSION: Elevated ACEF scores were strongly associated with a poor prognosis after MINOCA. This simple and valid risk score may facilitate risk stratification and decision making in the population with MINOCA.