Prognostic Implications of Right Ventricular Free Wall Longitudinal Strain in Patients With Significant Functional Tricuspid Regurgitation

Background In patients with significant functional tricuspid regurgitation, timely detection of right ventricular (RV) dysfunction with conventional 2-dimensional echocardiography is challenging, whereas speckle-tracking echocardiography RV free wall longitudinal strain has been proposed as better prognosticator. We evaluated the prevalence and prognostic value of impaired RV free wall longitudinal strain in patients with significant functional tricuspid regurgitation, in comparison with tricuspid annular plane systolic excursion (TAPSE) and fractional area change (FAC). Methods Eight hundred ninety-six patients (51.3% men, 71 years [62-78 years]) with significant functional tricuspid regurgitation were divided according to the presence of RV dysfunction (defined as TAPSE <17 mm, FAC <35%, and RV free wall longitudinal strain >-23%) and were followed for the occurrence of all-cause mortality. Results RV free wall longitudinal strain identified the highest percentage of RV dysfunction (84.9%), in comparison to FAC (48.5%) and TAPSE (71.7%). During a median follow-up of 2.8 years (1.3-5.4 years), 443 (49.4%) patients died. Compared with survivors, nonsurvivors showed worse RV systolic dysfunction (FAC=36.5±12.7% versus 33.9±11.8%, P=0.001; TAPSE=15.4±5.0 versus 14.0±4.5 mm, P<0.001; RV free wall longitudinal strain=-15.9±7.5% versus -12.9±6.8%, P<0.001). Cumulative event-free survival was significantly worse in patients with decreased FAC, decreased TAPSE, and impaired RV free wall longitudinal strain. On multivariate analysis, RV free wall longitudinal strain was independently associated with all-cause mortality and incremental to FAC and TAPSE. Conclusions In significant tricuspid regurgitation, impaired RV free wall longitudinal strain identifies higher rates of RV dysfunction and is associated with worse outcome beyond conventional echocardiographic parameters of RV systolic function.