Incremental Prognostic Value of Coronary Hyper-intensity Plaque on Non-contrast Cardiac Magnetic Resonance with Global Longitudinal Strain for Major Adverse Cardiac Events in Patients with Acute Coronary Syndrome.

Rationale And Objectives: This study aims to determine the long-term prognostic value of coronary hyper-intensity plaques and left ventricular (LV) myocardial strain for major adverse cardiac events (MACEs).

Materials And Methods: The study prospectively recruited 71 patients with acute coronary syndrome (ACS). All patients underwent CMR before PCI to determine the plaque-to-myocardium signal intensity ratio and LV strains. The MACEs included all-cause death, reinfarction, and new congestive heart failure. Mann-Whitney U test and chi-square test to compare patients with and without MACE, Kaplan-Meier survival analysis, Cox proportional hazards regression and C-statistics to assess prognosis, Receiver-operating characteristic (ROC) curve analysis to define the cutoff value. A P value of < 0.05 was considered statistically significant.

Results: Cox proportional hazard analysis showed that plaque-to-myocardium signal intensity ratio and global longitudinal strain (GLS) were independently associated with MACEs (plaque-to-myocardium signal intensity ratio: hazard ratio (HR) 2.80, 95% CI, 1.25-6.26, P = 0.01; GLS: HR1.21, 95% CI, 1.07-1.38, P＜0.01). ROC showed that a plaque-to-myocardium signal intensity ratio of 1.65 and a GLS of -10% were the best cutoff values for MACEs. The C-statistic values for plaque-to-myocardium signal intensity ratio, GLS, and plaque-to-myocardium signal intensity ratio+GLS for MACEs were 0.691, 0.792, and 0.825, respectively. Compared to GLS alone, the addition of plaque-to-myocardium signal intensity ratio to GLS increased the net reclassification index by 0.664 (P = 0.017).

Conclusion: Plaque-to-myocardium signal intensity ratio and GLS were significantly associated with MACEs. Adding plaque-to-myocardium signal intensity ratio to GLS substantially improved the prediction for MACEs. Our findings indicate that plaque-to-myocardium signal intensity ratio combined with GLS provides incremental prognostic value for MACEs.