Preoperative right ventricular strain predicts sustained right ventricular dysfunction after balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

Abstract

Balloon pulmonary angioplasty (BPA) improves hemodynamics and exercise tolerance in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, its diagnostic and predictive values remain unclear. We investigated the diagnostic and predictive values of BPA by assessing the mechanism of right ventricular (RV) dysfunction. Hemodynamic improvement was maintained over 6months in 99 patients with CTEPH who underwent BPA. Notably, 57 of 99 patients showed normalization of pulmonary vascular resistance (PVR) after BPA. The RV mid free wall longitudinal strain (RVMFS) was inversely correlated with the 6-min walk distance (r=-.35, P=.01) and serum levels of high-sensitivity cardiac troponin T (hs-cTNT) (r=-.39, P=.004) 6months post-BPA in the PVR-normalized group. Among all variables analyzed, only the pre-BPA RVMFS was correlated with the post-BPA RVMFS (r=.40, P=.001), and the pre-BPA RVMFS (<-15.8%) was the strongest predictor of post-BPA normalization of RVMFS (area under the curve 0.80, P=.01, sensitivity 89%, and specificity 63%). The immediate post-BPA RVMFS showed worsening over 6months after the procedure (-25.8% to -21.1%) in patients with high serum hs-cTNT levels (>0.0014ng/mL). In contrast, we observed an improvement in these values in those with low serum hs-cTNT levels (-23.6% to -24.4%). RVMFS of -15.8% may be a useful cutoff value to categorize the refractory and non-refractory stages of disease. Sustained serum hs-cTNT elevation post-BPA indicates subclinical RV myocardial injury, with resultant RVMFS deterioration and poor exercise tolerance.