Mechanical Adaptation of the Right Ventricle to Secondary Tricuspid Regurgitation and Its Association With Patient Outcomes.

BACKGROUND

Data regarding right ventricular (RV) mechanical adaptation to secondary tricuspid regurgitation (STR) are scarce.

OBJECTIVES

The aim of this study was to investigate changes in RV contraction pattern in patients with different degrees of STR severity and etiologies and their association with outcomes.

METHODS

A total of 205 patients with STR (60% women; mean age, 77 ± 12 years) were enrolled in a single-center prospective observational study. Three-dimensional echocardiography was used to measure RV ejection fraction (RVEF); the absolute contributions of the longitudinal component of RVEF (LEF), the radial component of RVEF (REF), and the anteroposterior component of RVEF (AEF); and their relative contributions by indexing to global RVEF (LEF/RVEF, REF/RVEF, and AEF/RVEF, respectively). Patients were followed for a median of 9 months. The primary outcome was heart failure hospitalization or all-cause death.

RESULTS

Patients with different degrees of STR severity did not differ in terms of RVEF (mild vs moderate vs severe: 50 ± 11% vs 49 ± 9% vs 50 ± 10%, respectively, P = .085). However, LEF/RVEF was significantly lower in patients with severe STR (0.39 ± 0.08 vs 0.39 ± 0.09 vs 0.35 ± 0.10, respectively, P = .049). Patients with ventricular STR had lower global RVEF (48 ± 10% vs 53 ± 8%, P = .001), LEF (18 ± 6% vs 20 ± 5%, P = .043), REF (23 ± 9% vs 28 ± 8%, P = .002), and REF/RVEF (0.48 ± 0.012 vs 0.52 ± 0.09, P = .040) than patients with atrial STR. In a multivariable Cox regression model, REF/RVEF was a significant and independent predictor of outcomes in the entire cohort (hazard ratio, 0.980 [95% CI, 0.961-1.000] per 0.01-unit change, P = .047), whereas global RVEF was not.

CONCLUSIONS

Patients with STR demonstrate significant functional RV remodeling. Patients with severe STR show a significant decrease in RV longitudinal shortening. Apart from STR severity, STR etiology also influences the RV contraction pattern, which was associated with outcomes in our cohort.