Right ventricular global longitudinal strain by cardiac magnetic resonance feature tracking is associated with outcome in patients with a systemic right ventricle

Abstract Introduction It is well known, that patients with a systemic (sub-aortic) right ventricle (sRV) for congenitally-corrected transposition of the great arteries (TGA) or with complete TGA after atrial switch operation are more threatened to develop RV dysfunction, relevant supra- and ventricular tachycardia and have a reduced life expectancy. While the randomized, placebo-controlled, double-blinded, multi-centre SERVE trial to investigate the effect of phosphodiesterase-5 inhibitor tadalafil in sRV patients showed negative results on the primary end-point RV endsystolic volume (RVESV), aim of this sub-analysis was to evaluate RV global longitudinal strain (GLS), a more sensitive measure of RV function, by cardiac magnetic resonance (CMR) feature tracking (FT) over time, for treatment effect and to investigate whether RV GLS predicts clinical outcome in sRV patients. Methods CMR volumetric RV and FT parameters were analysed (blinded for patient and assessment time and treatment) at baseline and compared to follow-up (FU) after 3 years, or after 1 year in case of withdrawal of the study drug. FT was performed using appropriate software. Treatment effect was analysed using ANCOVA with baseline values and FU-time as covariates. Values of > 4th quartile of RV GLS were used as cut-off for Kaplan-Meier analysis on the primary outcome, defined as a composite of all-cause death, clinically relevant arrhythmias and hospitalisation for heart failure. Results CMR exams were available for 78 patients at baseline (40±11 years, 33% females) and for 71 patients at FU. No treatment effect of tadalafil compared to the placebo was discovered for RV GLS (p=0.26), RVESVi (p=0.63) and RV ejection fraction (RVEF, p=0.6). Over a 3 years FU-time, RV GLS mildly increased (p=0.0023, figure 1). During FU, 14 patients experienced a clinical outcome: 1 death, 4 hospitalisations for heart failure, and 12 clinically relevant arrhythmic events. An RV GLS > -13.4% was associated with adverse clinical outcome (p=0.003, figure 2). Conclusion In patients with a systemic RV, treatment with Tadalafil had no effect on CMR-derived RV global longitudinal strain compared to placebo. RV GLS changed significantly over the 3 years FU-time. A RV GLS value of > -13.4% is associated with adverse clinical outcome in these patients.Figure 1Figure 2