Right Ventricular Function in Patients with Pulmonary Hypertension: Correlation between Myocardial Performance Index measured by Conventional Pulsed Wave Doppler and Tissue Doppler Imaging

Background and aim: Myocardial performance index (MPI) measured by conventional pulse-wave Doppler is invariably used to evaluate right ventricular (RV) systolic function in patients with pulmonary hypertension (PH). The primary objective of this study was to assess the degree of agreement between MPI measured by conventional pulsed-wave Doppler (PWMPI) and tissue Doppler imaging (TDMPI) in patients with PH. Secondary objective was to correlate MPI measured by these two methods with other RV systolic function related echocardiographic measures. Methods: It was a hospital-based, cross-sectional, observational study involving 100 consecutive patients with PH. Different echocardiographic parameters were used to evaluate RV systolic function. In all patients, conventional pulsed-wave Doppler and tissue Doppler imaging were used as a tool to calculate MPI. Results: Bland-Altman analysis showed moderate agreement between PWMPI and TDMPI (the mean difference was-0.14 at 95% intervals of agreement, absolute difference =-0.39 to 0.11; 95% intervals of agreement, percentage of average =-32.6 to 27.7). We found significant correlation of PWMPI with S'-wave velocity (r=-0.57, p = <0.0001),RVEF (r =-0.245, p = 0.013), RVFAC (r =-0.385, p = 0.0001), RV dp/dt (r =-0.295, p = 0.002), and TAPSE (r =-0.39, p = 0.0001).With regards to TDMPI, we found significant correlation with RVEF (r =-0.527, p = <0.0001),RVFAC (r =-0.53, p = <0.0001),RV dp/dt (r =-0.557, p = <0.0001),TAPSE (r =-0.50, p = <0.0001),and S'-wave velocity (r =-0.583, p = <0.0001).Conclusion: Our findings proved that MPI measured by tissue Doppler is a safe, effective, and accurate method to evaluate global RV function in patients with chronic PH.