A simple method to predict impaired right ventricular performance and disease severity in chronic pulmonary...

The evaluation of right ventricular (RV) function is clinically important in pulmonary hypertension (PH) because of prognostic implications. Conventional echocardiography has been used to predict adverse outcomes in chronic PH, but there were certain limitations arising from the complexity of RV anatomy. We used strain rate imaging (SRI) to evaluate RV function in PH patients.

Study population consisted of 50 patients (mean age 46 ± 13 years; 39 females) with chronic PH who underwent echocardiography including SRI within 24h of right heart catheterization. Mean value of peak systolic longitudinal strain obtained from basal and mid RV free wall were calculated. Reduced RV systolic contraction (fractional area change <32%) and cardiac index (CI) <2.0 L/min/m(2) were defined as impaired RV performance.

Pulmonary vascular resistance (PVR) averaged 1195 ± 522 dyn · s · cm(-5). RV strain correlated closely with pulmonary artery systolic pressure (r = 0.53; p < 0.001) and PVR (r = 0.68; p < 0.001). RV strain best correlated with CI (r = -0.70; p < 0.001) among the invasive variables. After adjusting for various parameters that could influence the CI, this correlation remained robust (r = -0.63, p < 0.001). In a multivariate model, RV strain (odds ratio 1.65; 95% confidential interval 1.06-2.57; p = 0.028) was independently associated with impairment of RV performance. A cutoff value of -15.5% discriminated cases of impaired RV performance from those of preserved RV performance with a sensitivity of 100%, specificity of 84% and accuracy of 92%.

RV strain correlates well with hemodynamic variables indicative of disease severity and help identify the cases of impaired RV performance in PH patients.