Prognostic implications of left ventricular torsion measured by feature-tracking cardiac magnetic resonance in patients with ST-elevation myocardial infarction

AIMS: The prognostic implication of left ventricular (LV) torsion on ST-elevation myocardial infarction (STEMI) is unclear. METHODS AND RESULTS: We analysed cardiovascular magnetic resonance (CMR) findings of 420 patients from a registry study (NCT03768453). These patients received CMR examination within 1 week after timely primary percutaneous coronary intervention. LV torsion and other CMR indexes were measured. Compared with healthy control subjects, STEMI significantly decreased patients' LV torsion (1.04 vs. 1.63°/cm, P < 0.001). During follow-up (median, 52 months), the reduction of LV torsion was greater in patients with than without composite major adverse cardiac and cerebrovascular events (MACCEs, 0.79 vs. 1.08°/cm, P < 0.001). The risk of MACCEs would increase to 1.125- or 1.092-fold, and the risk of 1-year LV remodelling would increase to 1.110- or 1.082-fold for every 0.1°/cm reduction in LV torsion after adjustment for clinical or CMR parameters respectively. When divided dichotomously, patients with LV torsion≤ 0.802°/cm had significantly higher risk of MACCEs (40.2 vs. 12.3%, P < 0.001) and more remarkable LV remodelling (46.1 vs. 11.9%, P < 0.001) than patients with better LV torsion. The addition of LV torsion to conventional prognostic factors such as the LV ejection fraction and infarction size led to a better risk classification model of patients for both MACCEs and LV remodelling. Finally, tobacco use, worse post-PCI flow, and greater microvascular obstruction size were presumptive risk factors for reduced LV torsion. CONCLUSION: LV torsion measured by CMR is closely associated with the prognosis of STEMI and would be a promising indicator to improve patients' risk stratification. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT03768453.