Implications of Atrial Fibrillation in Patients with Myocardial Infarction with Non-obstructive Coronary Arteries.

Background: Myocardial Infarction with non-obstructive 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 ICD-10-CM 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% 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).

Conclusion: AF in MINOCA is associated with worse in-hospital outcomes, including mortality, heart failure, acute kidney injury, and cardiogenic shock. AF may be a key prognostic marker in this population, warranting further research.