Comparison of right versus left ventricular strain analysis as a predictor of outcome in patients with systolic heart failure referred for heart transplantation

Abstract

The aim of the present study was to explore the relation between right ventricular (RV) and left ventricular (LV) echocardiographic parameters with clinical outcome in patients with advanced heart failure referred for cardiac transplantation. Ninety-eight consecutive patients with advanced systolic heart failure, referred for cardiac transplant evaluation, were enrolled. All patients were prospectively followed for the development of new outcome events, which included hospitalization for acute heart failure, cardiovascular death, heart transplantation, intra-aortic balloon pump implantation, and ventricular assist device implantation. Conventional transthoracic echocardiography was performed in all subjects. RV longitudinal strain (RVLS) by speckle-tracking echocardiography was assessed by averaging all segments in apical 4-chamber view (global RVLS) and by averaging RV free-wall segments (free-wall RVLS). LV global longitudinal and global circumferential strains were also calculated. Of the 98 subjects at baseline, 46 had 67 new events during a mean follow-up of 1.5 ± 0.9 years. Free-wall RVLS, global RVLS, N-terminal fragment of the prohormone brain natriuretic peptide, RV fractional area change, and LV end-diastolic volume were independently predictive of combined outcomes (all p <0.0001). The overall performance for the prediction of cardiovascular events was greatest for free-wall RVLS (area under the curve free-wall RVLS: 0.87; global RVLS: 0.67; RV fractional area change: 0.60; N-terminal fragment of the prohormone brain natriuretic peptide, 0.62; global circumferential strain: 0.55; global longitudinal strain: 0.35; and LV ejection fraction: 0.26). Free-wall RVLS showed the highest adjusted hazards ratio. A graded association between the grade of RV dysfunction and the risk of cardiovascular events was only evident for free-wall RVLS and global RVLS. In conclusion, in patients referred for heart transplantation, RVLS is a stronger predictor of outcome than LV longitudinal strain and other conventional parameters, providing a stronger prognostic stratification.