Prognostic Value of Coronary Sinus Flow and Aortic Pressure Gradient Quantified by 4D Flow CMR in AMI

This study aimed to investigate the prognostic value of 4D Flow CMR-derived coronary sinus flow (CS Flow) and pressure gradients across the aortic valve in patients with acute myocardial infarction (AMI).

We retrospectively enrolled 103 AMI patients who underwent CMR prior to PCI. CS Flow (normalized to left ventricular mass), supra- and sub-aortic valve peak pressure gradients (Supra-APGmax, Sub-APGmax) were quantified using 4D Flow CMR. The composite endpoint comprised all-cause death, unplanned revascularization, recurrent myocardial infarction, rehospitalization for heart failure, and stroke. After univariable screening, three stratified multivariate Cox regression models were constructed. Model performance was evaluated using the likelihood ratio test, Akaike Information Criterion (AIC), and Harrell's C-index. Kaplan-Meier curve analysis with the log-rank test was employed to evaluate survival estimates.

Patients with events (n=21) showed lower standardized CS Flow and lower Supra-APGmax than event-free patients (all P < 0.001). Across the three stratified multivariate Cox regression models constructed, all models incorporating 4D Flow CMR-derived parameters consistently demonstrated that CS Flow and Supra-APGmax remained independent predictors (all P < 0.05). Kaplan-Meier curves demonstrated the poorest event-free survival when CS Flow < 0.59 mL/min/g and Supra-APGmax < 4.01 mmHg (log-rank P < 0.001).

CS Flow and Supra-APGmax were independently associated with adverse cardiovascular outcomes after AMI. Their combined application demonstrated potential incremental prognostic information over conventional clinical markers and provided preliminary evidence for individualized risk assessment in patients with AMI.