Efficacy of Right Ventricular Free-Wall Longitudinal Speckle-Tracking Strain for Predicting Long-Term Outcome in Patients With Pulmonary Hypertension

BACKGROUND: The development of right ventricular (RV) dysfunction in pulmonary hypertension (PH) patients is associated with adverse outcome, so that the assessment of RV function has become increasingly important in the management of such patients. The present objective was to test the hypothesis that RV free-wall longitudinal speckle-tracking strain (RV-free), an independent echocardiographic predictor of hemodynamic RV performance, can predict long-term outcome. METHODS AND RESULTS: Forty-two PH patients were studied. RV-free was calculated by averaging the 3 regional peak systolic strains for the RV free wall. For comparison, tricuspid annular plane systolic excursion (TAPSE), RV fractional area change, RV index of myocardial performance, and tissue Doppler-derived tricuspid lateral annular systolic velocity were also studied. Long-term follow-up was performed for 4 years after adding PH-specific drugs. Receiver operating characteristic curve analysis identified RV-free ≤ 19.4% as the best predictor of cardiovascular events with 90% sensitivity, 69% specificity, and area under the curve of 0.819 (P=0.0001). Furthermore, the Kaplan-Meier curve indicated that patients with RV-free >19.4% experienced fewer cardiovascular events than those with RV-free ≤ 19.4% (log-rank P=0.0008). Importantly, the co-occurrence of RV-free ≤ 19.4% and TAPSE <16 mm was associated with the highest frequency of cardiovascular events. CONCLUSIONS: RV-free may serve as a non-invasive predictor of cardiovascular events for PH patients. Combining RV-free with TAPSE may be more effective for predicting long-term cardiovascular events.