Prognostic Value and Determinants of High‐Sensitivity Cardiac Troponin T in Patients With a Systemic Right Ventricle: Insights From the SERVE Trial

Background The determinants and prognostic value of high‐sensitivity cardiac troponin T (hs‐cTnT) among patients with a systemic right ventricle are largely unknown. Methods and Results Ninety‐eight patients from the randomized controlled SERVE (Effect of Phosphodiesterase‐5 Inhibition With Tadalafil on Systemic Right Ventricular Size and Function) trial were included. The correlation between baseline hs‐cTnT concentrations and biventricular volumes and function quantified by cardiac magnetic resonance or cardiac multirow detector computed tomography was assessed by adjusted linear regression models. The prognostic value of hs‐cTnT was assessed by adjusted Cox proportional hazards models, survival analysis, and concordance statistics. The primary outcome was time to the composite of clinically relevant arrhythmia, hospitalization for heart failure, or all‐cause death. Median age was 39 (interquartile range, 32–48) years, and 32% were women. Median hs‐cTnT concentration was 7 (interquartile range, 4–11) ng/L. Coefficients of determination for the relationship between hs‐cTnT concentrations and right ventricular end‐systolic volume index and right ventricular ejection fraction (RVEF) were +0.368 (P=0.046) and −0.381 (P=0.018), respectively. The sex‐ and age‐adjusted hazard ratio for the primary outcome of hs‐cTnT at 2 and 4 times the reference level (5 ng/L) were 2.89 (95% CI, 1.14–7.29) and 4.42 (95% CI, 1.21–16.15), respectively. The prognostic performance quantified by the concordance statistics for age‐ and sex‐adjusted models based on hs‐cTnT, right ventricular ejection fraction, and peak oxygen uptake predicted were comparable: 0.71% (95% CI, 0.61–0.82), 0.72% (95% CI, 0.59–0.84), and 0.71% (95% CI, 0.59–0.83), respectively. Conclusions Hs‐cTnT concentration was significantly correlated with right ventricular ejection fraction and right ventricular end‐systolic volume index in patients with a systemic right ventricle. The prognostic accuracy of hs‐cTnT was comparable to that of right ventricular ejection fraction and peak oxygen uptake predicted. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03049540.