Implications of Atrial Fibrillation in Patients With Myocardial Infarction With Nonobstructive Coronary Arteries

BACKGROUND: Myocardial infarction with nonobstructive coronary arteries (MINOCA) is defined as myocardial infarction with <50% stenosis of coronary arteries. Atrial fibrillation (AF) is a common arrhythmia that may influence MINOCA outcomes. METHODS: We performed a retrospective analysis of the National Inpatient Sample (2016-2021), identifying MINOCA patients with and without AF using the International Classification of Diseases, Tenth Revision, Clinical Modification codes. Multivariable mixed-effects logistic regression and propensity score matching were applied to control for confounders and assess outcomes. RESULTS: Of 94,840 MINOCA patients, 28,270 (30%) had AF. AF was associated with higher in-hospital mortality (3.74% vs. 2.75%; P = 0.004), acute heart failure (38.33% vs. 34.97%; P < 0.001), sudden cardiac arrest (2.54% vs. 1.73%; P < 0.050), and cardiogenic shock (3.11% vs. 1.56%; P < 0.001). AF independently predicted in-hospital mortality [adjusted odds ratio (aOR), 1.3; 95% confidence interval (CI), 1.07-1.58; P < 0.001], heart failure (aOR, 1.48; 95% CI, 1.38-1.59; P < 0.001), cardiogenic shock (aOR, 1.85; 95% CI, 1.48-2.30; P < 0.001), and acute kidney injury (aOR, 1.15; 95% CI, 1.07-1.24; P < 0.001). There were no significant differences in percutaneous coronary intervention, mechanical circulatory support, or defibrillator use ( P > 0.050). CONCLUSIONS: AF in MINOCA is associated with worse in-hospital outcomes, including mortality, sheart failure, acute kidney injury, and cardiogenic shock. AF may be a key prognostic marker in this population, warranting further research.