Quantitative assessment of cardiac mechanical dyssynchrony and prediction of response to cardiac resynchronization therapy in patients with non-ischaemic dilated cardiomyopathy using equilibrium radionuclide angiography

Abstract

Aims The aim of this study was to evaluate equilibrium radionuclide angiography (ERNA) in prediction of response to cardiac resynchronization therapy (CRT) in non-ischaemic dilated cardiomyopathy (DCM) patients. Methods and results Thirty-two patients (23 males, 57.5±12.1 years) were prospectively included. Equilibrium radionuclide angiography and clinical evaluation were performed before and 3 months after CRT implantation. Standard deviation of left ventricle mean phase angle (SD LVmPA) and difference between LV and right ventricle mPA (LV-RVmPA) expressed in degrees (8) were used to quantify left intraventricular synchrony and interventricular synchrony, respectively. Left ventricular ejection fraction (LVEF) was also evaluated. At the baseline, mean NYHA class was 3.3±0.5, LVEF 22.5±5.6%, mean QRS duration 150.3±18.2 ms, SD LVmPA 43.5±188, and LV-RVmPA 30.4±15.68. At 3-month follow-up, 22 patients responded to CRT with improvement in NYHA class ≥1 and EF .5%. Responders had significantly larger SD LVmPA (51.2±13.9 vs. 26.5±148) and LV-RVmPA (35.8±13.7 vs. 18.4±138) than non-responders. Receiver-operating characteristic curve analysis demonstrated 95% sensitivity and 80% specificity at a cut-off value of 308 for SD LVmPA, and 81% sensitivity and 80% specificity at a cut-off value of 238 for LV-RVmPA in prediction of response to CRT. Conclusion Baseline SD LVmPA and LV-RVmPA derived from ERNA are useful for prediction of response to CRT in non-ischaemic DCM patients. Published on behalf of the European Society of Cardiology. All rights reserved.