Acute Myocardial Infarction with Non-Obstructive Coronary Arteries - Stratifying the Risk of a "new" Clinical Entity using an "Old" Tool

ABSTRACT

Abstract Background Some of the patients admitted for acute myocardial infarction have non-obstructive coronary artery disease (MINOCA). Their prognosis is not always benign, making it necessary the development of tools for risk stratification of these patients. Objectives To describe the characteristics of a sample of patients admitted for suspected MINOCA and to evaluate the prognostic value of GRACE score in this population. Methods This was a retrospective, observational, single-center, cohort study involving 56 consecutive patients with MINOCA. During one-year follow-up, patients were assessed for mortality and major adverse cardiovascular events (MACE) - a composite of all-cause mortality and hospitalization due to acute myocardial infarction, heart failure, ischemic stroke, and acute limb ischemia. Statistical analysis was performed using a non-parametric approach, with the Mann-Whitney U test for quantitative variables and ROC curves for assessing the discriminatory power of the Grace score in predicting cardiovascular events. The level of significance was set at 5%. Results Of the 56 MINOCA patients included in the study (median age 67 years), 55.4% were female. During the one-year follow-up, mortality rate was 5.5% and 9.1% of patients had MACE. A higher GRACE score was associated with mortality (p = 0.019; AUC 0.907; 95%CI 0.812-1.000; cut off 138) and MACE (p =0.034; AUC 0.790; 95%CI 0.632-0.948; cutoff 114). Conclusion The definition of MINOCA includes various diagnoses and prognoses, and the GRACE score is useful for risk stratification of patients with this condition.