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 degrees/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 degrees/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 degrees/cm reduction in LV torsion after adjustment for clinical or CMR parameters respectively. When divided dichotomously, patients with LV torsion <= 0.802 degrees/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.