Novel left and right ventricular strain analysis to detect subclinical myocardial dysfunction in cardiac allograft rejection

Abstract

Early detection of acute cellular rejection (ACR) by echocardiography shows potential clinical benefit as ACR remains a significant contributor to morbidity and mortality. This retrospective, longitudinal study sought to investigate the use of novel left (LV) and right ventricular (RV) strain analysis to detect biopsy proven ACR. 46 heart transplant patients (Mean age 46 ± 16 years) with biopsy proven ACR were grouped according to biopsy results: 1R-ACR (n = 36) and 2R-ACR (n = 10). Serial two-dimensional transthoracic echocardiography with strain analysis was performed. Echocardiographic parameters were serially measured: (1) rejection free period (0R-ACR); (2) pre-ACR period (pre-ACR); (3) during ACR (1R-ACR or 2R-ACR) and (4) post-ACR (Post-ACR). Significant reductions for LV Global Longitudinal Strain (LV GLS) and LV Early diastolic Strain rate (LV ESr) were observed between 0R-ACR and pre-ACR (LV GLS 0R-ACR: 17.3% vs Pre-2R ACR: 15.4%, p = 0.016; LV ESr 0R-ACR: 1.00/s vs Pre-2R ACR: 0.74/s, p = 0.007) with LV ESr demonstrating the highest sensitivity (92%) and specificity (81%) to predict ACR. LV ESr and the E/LV ESr ratio were significantly different (p = 0.0001; p = 0.016) during pre-1R ACR period vs 0R whereas LV GLS showed no significant differences for grade 1R-ACR. Diastolic mechanical dispersion showed significant increases in dispersion during ACR for the 1R-ACR group and early significant increases pre-2R ACR. Systolic and diastolic RV strain parameters showed a similar trend for both ACR groups. Systolic and diastolic strain parameters can detect myocardial dysfunction before biopsy confirmed 2R-ACR. Early diastolic strain rate parameters are most sensitive detecting subclinical myocardial dysfunction pre-ACR. Novel strain parameters are potentially useful clinical tool for prediction of early ACR in heart transplant.