Right ventricular longitudinal strain measured using feature-tracking cardiac magnetic resonance is an independent predictor of all cause mortality in patients with severe tricuspid regurgitation

Abstract

Abstract Introduction Tricuspid regurgitation imposes a volume overload on the right ventricle (RV) that can lead to progressive RV dilation and dysfunction. Overt RV dysfunction is associated with poor prognosis and increased operative risk. Abnormalities of myocardial strain may provide the earliest evidence of ventricular dysfunction. CMR feature-tracking techniques now allow assessment of strain from routine cine-images, without specialized pulse sequences. Whether abnormalities of RV strain measured using CMR feature-tracking have prognostic value in patients with tricuspid regurgitation is unknown Purpose To evaluate the prognostic value of CMR feature-tracking derived RV free wall longitudinal strain (RVFWLS) in a large multicenter population of patients with severe tricuspid regurgitation. Methods Consecutive patients with severe tricuspid regurgitation undergoing CMR at four US medical centers were included in this study. Feature-tracking RVFWLS was calculated from 4 chamber cine-views (Figure-left panel). The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the independent association between RVFWLS and death. The incremental prognostic value of RVFWLS was assessed in nested models. Results Of the 406 patients in this study,115 died during a median follow-up of 8.8 years. By Kaplan-Meier-analysis, patients with RVFWLS ≥median (−16%) had significantly reduced event free survival compared to those with RVFWLS < median (log-rank p<0.001) (Figure-right panel). By Cox multivariable regression modeling, each 1% worsening in RVFWLS was associated with a 13% increased risk-of-death after adjustement for clinical and imaging risk factors (HR=1.13 per %; p<0.001). Addition of RVFWLS in this model resulted in significant-improvement in the global-chi-square (26 to 65; p<0.0001). Conclusions CMR feature-tracking derived RVFWLS is an independent predictor of mortality in patients with severe tricuspid regurgitation, incremental to common clinical and imaging risk factors. Funding Acknowledgement Type of funding source: None