MINOCA patients: the Portuguese reality from a multicentre national registry analysis

Abstract Background Myocardial infarction with nonobstructive coronary arteries (MINOCA) is defined by clinical symptoms compatible with acute myocardial infarction (AMI) but without significant stenosis in a major epicardial artery. Several gaps in evidence for MINOCA exist, particularly in diagnosis, management, and outcomes. Purpose To describe clinical characteristics and prognosis of Portuguese patients with a working diagnosis of MINOCA. Material and methods Retrospective multicentre analysis of patients clinically suspected of MINOCA included in the Portuguese Registry on Acute Coronary Syndromes between 2010 and 2022. Baseline characteristics/findings, treatment and a composite of in-hospital complications (death, stroke or AMI) and one-year death were analised. Results The authors studied 3668 patients (15% of AMI) with a mean age of 65 ± 13 years, of whom 65% were male. The diagnosis of MINOCA appears to be increasing in Portugal, especially in men, despite a decrease in 2019 and 2020. A high frequency of cardiovascular risk factors was observed, including high blood pressure (67%), dyslipidemia (55%), diabetes (27%), and smoking (25%). The most common symptom was chest pain (93%), and the admission diagnoses were non-ST-segment myocardial infarction (51%) and ST-segment myocardial infarction (48%) in Killip class 1 (88%). A composite of in-hospital complications occurred in 10%, and one-year mortality occurred in 2.9%. After multivariate analysis, age over 75 years (OR 2.889, 95% CI 1.131-7.378, p=0.027), Killip class above 1 (OR 3.920, 95% CI 1.59-9.66, p=0.003), and diuretics (OR 11.119, 95% CI 4.280-28.884, p<0.001) remained as independent predictors of in-hospital major adverse cardiac events. Conclusions This study highlights an increasing trend in MINOCA diagnoses in Portugal, possibly with an underrepresentation of women. Although some studies indicate better outcomes compared to AMI due to coronary artery disease, our research identified in-hospital complications and 1-year outcomes. Further investigation is crucial to advance our understanding and refine treatment options for this condition.