011 Cardiac Magnetic Resonance Derived Left Atrial Strain Predicts Major Adverse Cardiovascular Events After ST-Elevation Myocardial Infarction

Abstract

To assess the relationship between cardiac magnetic resonance (CMR) derived left atrial (LA) strain, ejection fraction (LAEF) and volumes (LAVImax and LAVImin), and major adverse cardiovascular events (MACE) within 2 years after STEMI. We prospectively recruited 213 consecutive STEMI patients who underwent CMR at median day 4. 202 patients had complete CMR data for feature tracking assessment. MACE was a composite of all-cause mortality, reinfarction, new or worsening heart failure, stroke and sustained ventricular arrhythmias. The cohort included 174 (86.1%) males, median age 56 years (IQR 50-65 years). MACE occurred in 35 (17.3%) patients. Patients with MACE had lower median reservoir strain (18.9 vs 29.4%, p<0.001), booster strain (9.4 vs 13.0%, p=0.002) and LAEF (41.5 vs 49.2%, p<0.001), and higher LAVImax (43.5 vs 38.6ml/m2, p=0.019) and LAVImin (23.7 vs 19.3ml/m2, p<0.001) than patients without MACE. AUC analyses showed reservoir strain (AUC 0.769; 95% CI: 0.676-0.861, p<0.001), booster strain (AUC 0.684; 95% CI 0.558-0.810, p=0.002) and LAEF (AUC 0.698; 95% CI: 0.596-0.800, p<0.001) predicted MACE. Kaplan Meier analyses showed a difference in MACE between high- and low-risk groups for reservoir strain (cutoff 21%, p<0.001), booster strain (cutoff 9.6%, p<0.001) and LAEF (cutoff 41%, p<0.001). Univariate Cox regression analyses showed all LA parameters had a significant effect on MACE, while multivariate analyses found additional prognostic utility using reservoir strain (HR 0.937; 95% CI 0.886-0.990, p=0.02). LA reservoir strain provided incremental prognostic value beyond established clinical and CMR parameters for predicting MACE after STEMI.