Myocardial Work by Speckle-Tracking Echocardiography in Heart Transplant Recipients: Association Between Global Work Efficiency and Coronary Allograft Vasculopathy

Abstract

Coronary allograft vasculopathy (CAV) is a leading cause of morbidity and mortality following heart transplantation. CAV is often diagnosed in later stages or during routine screening in asymptomatic subjects. Myocardial work (MW), calculated using left-ventricular global longitudinal strain (LV-GLS) and systemic blood pressure, may be associated with the presence of CAV and outperform conventional echocardiographic parameters. In this retrospective observational study, heart transplant recipients undergoing regular follow-up at our Institution between May 2022 and September 2023 were enrolled. All included patients underwent speckle tracking echocardiography, including MW indices. CAV was classified according to invasive coronary angiography or computed tomography performed within 12 months of index echocardiography. We collected all available clinical and echocardiographic parameters and evaluated potential association with CAV. CAV was detected in 29/93 (31%) patients (CAV+). Of the MW indices, mean global work efficiency (GWE) was 90±6%, and was significantly lower in CAV+ than CAV- subjects (86±7% vs 91±4%, p<0,001). GWE (OR 0.86; CI 0.77-0.94, p=0.002), E/e’ ratio (OR 1.27; CI 1.08-1.52, p=0.006) and LVEF (OR 0.90; CI 0.81-0.98, p=0.017) were independently associated with the presence of CAV. GWE (GWE vs LV-GLS, delta AUC 0.154, p=0.047) and the proposed model (GWE+E/e’ vs LV-GLS, delta AUC 0.198, p=0.004) were significantly superior in stratifying incremental risk for CAV compared to LV-GLS. In conclusion GWE was observed to be independently associated with the presence of CAV. MW could represent a novel non-invasive screening method for CAV in heart transplant recipients. Larger and prospective studies are needed to confirm this hypothesis.