Utility of Right Ventricular Tei Index in the Noninvasive Evaluation of Chronic Thromboembolic Pulmonary Hypertension Before and After Pulmonary Thromboendarterectomy

Abstract

We evaluated the utility of tissue Doppler-derived right ventricular (RV) Tei (or myocardial performance) index in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after pulmonary thromboendarterectomy (PTE) and assessed correlations with mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and cardiac output (CO). The assessment of RV function is limited with 2-dimensional echocardiography. The RV Tei index, an indicator of RV myocardial performance, is derived by Doppler measurements and is unaffected by RV geometry. The use of tissue Doppler imaging (at the lateral tricuspid annulus) for RV Tei index calculation is simple and eliminates the need for pulsed-wave Doppler recordings of both RV inflow and outflow. Ninety-three patients with CTEPH were prospectively studied along with 13 control patients. Right ventricular tissue Doppler imaging and right heart catheterization were performed before and after PTE. Right ventricular Tei index was compared with values of mPAP, PVR, and CO with the use of linear regression. Right ventricular Tei index was 0.52 +/- 0.19 in patients with CTEPH and 0.27 +/- 0.09 in control patients (p < 0.0001). After PTE, RV Tei index decreased to 0.33 +/- 0.10 (p < 0.0001). Pulmonary vascular resistance correlated well with RV Tei index before (r = 0.78, p < 0.0001) and after (r = 0.67, p < 0.0001) surgery. Also, the absolute change in Tei index in each patient after PTE correlated well with the concomitant change in PVR (r = 0.75, p < 0.0001). RV Tei index did not correlate as well with mPAP (pre-operatively: r = 0.55, p < 0.0001; post-operatively: r = 0.26, p = 0.03) or CO (pre-operatively: r = 0.57, p < 0.0001; post-operatively: r = 0.43, p < 0.0001). These results demonstrate a correlation between RV Tei index and right heart hemodynamics (particularly PVR) in CTEPH. Because PVR is difficult to estimate noninvasively -- and yet correlates with disease severity -- the RV Tei index may be a valuable noninvasive parameter for monitoring disease severity in CTEPH and outcome after PTE.