Prognostic Value of Coronary Sinus Flow Quantification by Cardiac Magnetic Resonance Imaging in Patients With Acute Myocardial Infarction

BACKGROUND: This study aimed to evaluate the prognostic value of hyperemic coronary sinus flow (h‐CSF) and global coronary flow reserve (g‐CFR) obtained by phase‐contrast cine‐magnetic resonance imaging in patients with acute myocardial infarction (MI). METHODS AND RESULTS: This retrospective study analyzed patients with acute MI (n=523) who underwent primary (ST‐segment–elevation MI) or urgent (non–ST‐segment–elevation MI) percutaneous coronary intervention. Absolute coronary sinus blood flow (CSF) at rest and during vasodilator stress hyperemia was quantified at 30 days (24–36 days) after the index infarct‐related lesion percutaneous coronary intervention and revascularization of functionally significant non–infarct‐related lesions. We used Cox proportional hazards regression modeling to examine the association between h‐CSF, g‐CFR, and major adverse cardiac events defined as all‐cause death, nonfatal MI, hospitalization for congestive heart failure, and stroke. Finally, 325 patients with ST‐segment–elevation MI (62.1%) and 198 patients with non–ST‐segment–elevation MI (37.9%) were studied over a median follow‐up of 2.5 years. The rest CSF, h‐CSF, and g‐CFR were 0.94 (0.68–1.26) mL/min per g, 2.05 (1.42–2.73) mL/min per g, and 2.17 (1.54–3.03), respectively. Major adverse cardiac events occurred in 62 patients, and Cox proportional hazards analysis showed that h‐CSF and g‐CFR were independent predictors of major adverse cardiac events (h‐CSF: hazard ratio [HR], 0.64; 95% CI, 0.47–0.88; P=0.005; g‐CFR: HR, 0.62; 95% CI, 0.47–0.82; P=0.001). When stratified by h‐CSF and g‐CFR, cardiac event‐free survival was the worst in patients with concordantly impaired h‐CSF (<1.6 mL/min per g) and g‐CFR (<1.7) (P<0.001). CONCLUSIONS: Global coronary sinus flow quantification using phase‐contrast cine‐magnetic resonance imaging provided significant prognostic information independent of infarction size and conventional risk factors in patients with acute MI undergoing revascularization.