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 after 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 who underwent regular follow-up at our institution between May 2022 and September 2023 were enrolled. All included patients underwent speckle-tracking echocardiography, including MW indexes. 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 the potential association with CAV. CAV was detected in 29 of 93 patients (31%) (CAV+). Of the MW indexes, the 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 to 0.94, p = 0.002), E/e' ratio (OR 1.27, CI 1.08 to 1.52, p = 0.006), and left ventricular ejection fraction (OR 0.90; CI 0.81 to 0.98, p = 0.017) were independently associated with the presence of CAV. GWE (GWE vs LV-GLS, delta area under the curve 0.154, p = 0.047) and the proposed model (GWE+E/e' vs LV-GLS, delta area under the curve 0.198, p = 0.004) were significantly superior in stratifying the incremental risk for CAV compared with LV-GLS. In conclusion, GWE was observed to be independently associated with the presence of CAV. MW could represent a novel noninvasive screening method for CAV in heart transplant recipients. Larger and prospective studies are needed to confirm this hypothesis.

Keywords: coronary allograft vasculopathy; heart transplantation; myocardial work; speckle-tracking echocardiography.