Antiplatelet Treatment Strategy in MINOCA Patients: Predictors of Decision Making in Clinical Practice and Prognostic Implications.

Background/Objectives: Large clinical trials have established the optimal antiplatelet strategy in the wide spectrum of coronary artery disease. However, data are scarce regarding MINOCA and the aim of our study is to present data from the current clinical practice. Methods: A total of 151 patients were included in this study after exclusion of 27 patients with myocarditis and other diagnoses. A cardiac magnetic resonance (CMR) performed at 123/151 patients demonstrated an ischemic pattern of late gadolinium enhancement (LGE) confirming the diagnosis of true acute myocardial infarction (AMI) in 42 cases (28%). Based on multimodality imaging and clinical judgement, Takotsubo syndrome (TTS) was diagnosed in 55 patients (36%), whereas CMR failed to reveal abnormal findings in 54 cases (36%), categorized as MINOCA of unknown origin. Results: Regarding antithrombotic prescriptions at discharge, 38% of patients received dual antiplatelet (DAPT) or dual antithrombotic therapy (DAT, 1 antiplatelet plus 1 anticoagulant), 49.7% received single antiplatelet (SAPT) or anticoagulant, and 12% received no antithrombotic treatment. Univariate analysis showed that the likelihood of prescribing DAPT or DAT was associated with left ventricular ejection fraction (LVEF) (r = 0.202, p = 0.013), atherosclerotic lesions on coronary angiography (r = 0.303, p < 0.001), prior use of anticoagulants (r = -0.258, p = 0.001), and marginally with the INTERTAK score (r = -0.198, p = 0.044). A multivariable model, adjusted for age, LVEF, ECG abnormalities, and history of anticoagulant use, confirmed the independent association between angiographic evidence of atherosclerosis and the decision for DAPT/DAT (OR: 0.334, 95% CI: 0.307-0.813, p < 0.001). However, the initial treatment decision did not seem to impact 2-year prognosis in our population. Conclusions: Our study results reveal that decision making in the antithrombotic strategy for MINOCA patients poses a challenge in clinical practice. More robust data are required for definite conclusions on the prognostic implications.