Non-Invasive Myocardial Work Detects Extensive Coronary Disease in Orthotopic Heart Transplant Patients

Cardiac allograft vasculopathy (CAV) remains a prevalent and serious long-term complication following orthotopic heart transplantation (OHT), contributing substantially to graft failure and patient mortality. Given the adverse prognostic impact of extensive coronary artery involvement, this study investigates whether myocardial work (MW) indices can serve as a non-invasive tool to detect OHT recipients with a high burden of coronary disease.

In this prospective study, 55 OHT recipients underwent paired evaluations with coronary computed tomography angiography (CCTA) and transthoracic echocardiography (TTE) during routine follow-up. From the echocardiograms, global longitudinal strain (GLS) of the left ventricle (LV) and myocardial work (MW) indices were derived. Patients were classified into two groups according to CCTA findings: those without extensive coronary artery disease (disease affecting fewer than four coronary segments or none, OHT < 4) and those with extensive disease (disease of four or more coronary artery segments, OHT ≥ 4).

CCTA revealed extensive coronary disease in 38 OHT recipients, while 17 had involvement of fewer than four segments or none. Between-group comparisons showed significant differences in global wasted work (GWW, energy expended without generating forward flow) and global work efficiency (GWE, the percentage of constructive work relative to total work). Using the Youden Index, the optimal thresholds for identifying extensive disease were GWW > 88 mmHg% and GWE < 94%. Patients exceeding these thresholds had a markedly higher probability of having ≥ 4 affected segments, with ORs of 4.61 for pathological GWW and 3.68 for pathological GWE compared to those with normal values.

GWW and GWE demonstrated the strongest performance for identifying OHT recipients with extensive coronary disease. If confirmed in larger cohorts, these indices could offer a practical, non-invasive approach for detecting extensive CAV.