Clinical and prognostic importance of strain echocardiograpy in patients under specific treatment for pulmonary hypertension

Background: Pulmonary arterial hypertension (PAH) is a devastating illness with progressive pulmonary vascular remodeling, right-sided heart failure, and limited survival. Although right ventricular (RV) dysfunction is a major determinant of outcome in patients with pulmonary hypertension (PH), the optimal assesment of RV function is poorly defined. The objectives of this study was first; to test the utility of RV free wall speckle-tracking strain as an assessment tool for RV function in patients with PAH under specific medical treatment and to compare with conventional echocardiographic parameters. Secondly; to investigate the relationship of the findings obtained with RV speckle-tracking strain with the hemodynamic parameters of RV performance. Methods: Prospective RV free wall longitudinal systolic strain (LS) measurement was performed on 92 PAH (62 women, mean age: 41.4 years, 49 with PAH associated with congenital heart disease, 21 idiopathic PAH, 11 PAH associated with connective tissue disease and 11 chronic thromboembolic pulmonary hypertension) patients who were followed-up at our PAH center. RV free wall longitudinal speckle-tracking strain was calculated by averaging each of three regional peak systolic strains along the entire right ventricle free wall. The mean interval of follow-up was 222 133 days. The conventional echocardiographic parameters-RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular peak systolic velocity, hemodynamic parameters (functional class, six minute walk test, and NT-proBNP levels) were also studied. Data were comparatively evaluated using appropriate statistical analyses. Results: Mean RV free LS was (%-13.16 6.3) in whole group. There w s signifi nt positive correlation between RV free wall LS and functional class (Rho = 0.312, p=0.01) and NT-proBNP (Rho = 0.423, p=0.0001) levels, whereas there was a significant negative correlation with FAC (Rho =-0.637, p=0.0001), TAPSE (Rho =-0.524, p=0.0001), Tricuspid annular peak systolic velocity (Rho =-0.450, p=0.0001), 6 minute walking test (Rho =-0.333, p=0.002). RV free wall LS was also associated with loop diuretic use (p = 0.0001). There was a significant relationship between RV free wall LS when correlated with all follow-up adverse events, death and clinical right heart failure (p=0.04, p=0.03, p=0.02, respectively). Conclusions: Noninvasive assessment of RV free wall LS is a feasible and powerful predictor of right-sided heart failure, clinical deterioration, and mortality in patients under PAH specific treatmen