Coronary Embolism in Atrial Fibrillation: A Distinct High-Risk Phenotype With Residual Thromboembolic Risk Despite Anticoagulation.

BACKGROUND

Coronary embolism (CE) is an underrecognized cause of acute myocardial infarction (AMI) in patients with atrial fibrillation (AF). Dedicated management guidelines are lacking because of limited evidence.

METHODS

This retrospective cohort study leveraged routinely collected electronic health records and regional death registry data from a tertiary hospital in China (2014-2023). Among 4777 patients with AMI, CE was diagnosed using a 3-stage validation process: modified Shibata criteria, blinded angiographic core laboratory assessment, and final adjudication. Patients were categorized into 3 groups: CE with AF (n=78), non-CE AMI with AF (n=205), and non-CE AMI without AF (n=3937). Overlap weighting based on propensity scores was used to balance baseline covariates, and weighted Cox proportional hazards models with competing-risk analysis were applied for comparative outcome analyses.

RESULTS

CE accounted for 1.6% (95% CI, 1.3%-2.0%) of all AMI cases and was present in 14.7% to 27.6% of AF-related AMI. Compared with non-CE AMI patients without AF, those with CE and AF had significantly higher risks of all-cause mortality (overlap-weighted hazard ratio [HR], 1.77 [95% CI, 1.15-2.71]) and ischemic stroke (overlap-weighted HR, 4.45 [95% CI, 2.34-8.45]), despite 79.2% receiving therapeutic anticoagulation.

CONCLUSIONS

CE complicating AF represents a high-risk phenotype characterized by high residual thromboembolic risk despite anticoagulation. An integrated management strategy is proposed for future investigation, incorporating multimodal imaging, embolism-targeted reperfusion, and optimization of antithrombotic therapy, including standard-dose direct oral anticoagulants.

REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT06845956.