Abstract 4143007: Pericoronary fat attenuation index as a Novel Tool to predict the morbidity of new-onset atrial fibrillation in patients with myocardial infarction with nonobstructive coronary artery disease

Background: Myocardial infarction with nonobstructive coronary artery disease (MINOCA) is a special syndrome with clear evidence of myocardial ischemia, but no clear stenosis of coronary artery imaging sign. The pericoronary fat attenuation index (FAI) could reflect the local coronary inflammation as a novel imaging marker. This study focuses on the correlation between FAI and the morbidity of new-onset atrial fibrillation (NOAF) in MINOCA patients. Methods: This study was a single-center, observational clinical cohort study. Patients who underwent coronary angiography and diagnosed with MINOCA in Fuwai Hospital from January 2015 to December 2019 and met the inclusion criteria were enrolled. We mainly explored the correlation between the FAI of right coronary artery and left circumflex and morbidity of AF. Kaplan-Meier analyses and Cox regression analyses were performed to evaluated cumulative NOAF hazard ratio during a 77.2-month follow-up. ROC analyses were also adapted in this study to detect the best cut-off value for FAI in predicting NOAF. Results: A total of 592 MINOCA patients with coronary CT angiography were enrolled, including 40 (8.0%) with NOAF. CT was performed within two months before or after the onset of MI. Patients in higher median group of FAI had an apparently higher rate of NOAF (8.8% vs 4.7%; P<0.05) during the follow-up time. After adjusted for multiple clinically relevant variables, higher FAI was still associated with an increased risk of NOAF (HR=1.71; 95% CI: 1.23-2.39 P<0.001). Moreover, AMR had an AUC of 0.722 for NOAF prediction with the best cut-off value of -74.395 HU. Conclusions: FAI score of main atrial coronary artery (RCA and LCX ), which may capture the risk of inflammation, is closely related to the atrial function. Higher FAI was a risk factor for NOAF in patients with MINOCA, which had high specificity and sensitivity for predicting NOAF in MINOCA patients. Assessment of FAI score derived from CCTA may increase predictability for NOAF in this special population.