Can Pulmonary Vascular Resistance Predict Response to Cardiac Resynchronization Therapy in Patients with Heart Failure

Background To evaluate if pulmonary vascular resistance (PVR) calculated by echocardiography can be a novel criterion to predict the response to cardiac resynchronization therapy (CRT). Methods Forty-five patients with heart failure who underwent CRT were retrospectively analyzed. Based on CRT response, which was defined by a decrease of left ventricular end-systolic volume by at least 15% after 6 months, the patients were assigned to the responder or nonresponder groups. The peak tricuspid regurgitant velocity (TRV) and time velocity integral of the right ventricular outflow tract (TVIRVOT) were obtained. The relation between TRV, PVR, and CRT response were analyzed using univariate and multivariate analyses. Results Twenty-seven patients (60%) were responders and 18 patients (40%) were nonresponders to CRT. At baseline, responders had lower PVR (3.57±1.65 vs 2.32 ± 1.28 wood; P = 0.01), or lower PVR1 (3.26 ± 1.32 vs 1.83 ± 0.79 wood; P = 0.01) compared with nonresponders. Multivariate analysis has shown that PVR and PVR1 were independent factors for CRT response. The optimal cutoff point of PVR to predict nonresponse to CRT was 2.39 wood, with a sensitivity of 0.78 and a specificity of 0.81 (95% confidence interval [CI]: 53.4–88.2). The optimal cutoff point of PVR1 calculated by the other model was 3.55 wood, determined at a sensitivity of 0.72 and a specificity of 0.82 (95%CI: 56.7–90.7). In nonresponders, patients demonstrated higher PVR, TVIA, and TVIRVOT, and decreased TRV. Conclusions PVR could be used to predict response to CRT after 6 months as a novel criterion, and higher PVR may indicate nonresponse.