Aims: Right ventricular (RV) failure is known to be the main cause of mortality and is closely related to prognosis in patients with pulmonary arterial hypertension (PAH). A decrease in the duration of tricuspid regurgitation corrected for heart rate (TRDc) has recently been shown to be associated with advanced RV failure and poor clinical outcomes. The aim of the present study was to investigate whether TRDc correlates with RV parameters assessed using cardiovascular magnetic resonance (CMR) and has prognostic significance in patients with PAH.
Methods and results: Thirty-seven consecutive patients with PAH (28 females, age 46 ± 14 years) underwent a 6 min walk test, right heart catheterization, echocardiography, and CMR within a 48 h period. Tricuspid regurgitation duration corrected for heart rate, tricuspid annular plane systolic excursion (TAPSE), Tei index, and tricuspid valve lateral annular systolic velocity were measured on echocardiography, and RV end-systolic and end-diastolic volumes and ejection fraction were measured on CMR. Tricuspid regurgitation duration corrected for heart rate was positively correlated with RV ejection fraction as measured on CMR (r = 0.400, P = 0.014). On multivariate regression analysis, TRDc was also significantly correlated with RV ejection fraction even after adjusting for the eccentric index, Tei index, and TAPSE (P = 0.034). During a median follow-up period of 487 days, there were seven events (19%) including two cardiac deaths and five inpatient admissions for heart failure. The event-free survival rate was significantly higher for patients with TRDc >400 ms than those with TRDc ≤400 ms (P = 0.040).
Conclusion: Tricuspid regurgitation duration corrected for heart rate correlated with CMR-derived RV ejection fraction, and decreased TRDc was associated with cardiovascular mortality and rehospitalization in patients with PAH. Therefore, TRDc could be a useful echocardiographic surrogate marker for predicting RV dysfunction and prognosis in patients with PAH.
Keywords: Prognosis; Pulmonary arterial hypertension; Right ventricular function.