What can we learn from hyper-responders to cardiac resynchronisation therapy (CRT)? Characteristics and predictors of super response to CRT. An Algerian single centre experience

Abstract

In some patients with dilated cardiomyopathy (DCM) and left bundle branch block (LBBB), cardiac resynchronisation therapy (CRT) has been shown to reverse almost completely left ventricular (LV) function. Determine the proportion of super responders among patients with DCM and attempt to determine their profile. Consecutive patients with DCM (LV ejection fraction (LVEF) < 35%, LV end-diastolic diameter > 60 mm) and LBBB implanted with a CRT were prospectively followed. Patients were considered super-responders if they fulfilled two criteria: class NYHA I/II and LVEF ≥ 50%. Among the 98 DCM patients, 19 (19.5%) were found to be super-responders following CRT (LVEF increased from 29.89 ± 4.44 to 53.37 ± 3.76%, P < 0.001). In the 79 (81%) remaining patients, there was a significant increase in LVEF from 26.49 ± 4.67 to 37.27 ± 7.20, P < 0.001). At baseline, there were no significant differences between super-responders and other patients, except that super-responders were female, had no hospitalisation for heart failure before implantation and no renal deficiency. Super responders had also less severe LVEF and lower pulmonary artery systolic pressure. CRT-P (OR: 5.47; 95% CI: 1.48–20.27; P = 0.007), lower left ventricular end-diastolic dimension (OR: 0.97; 95% CI: 0.95–0.0.99; P = 0.0002) and lower pulmonary artery systolic pressure (OR: 0.92; 95% CI: 0.87, 0.96; P < 0.001) were independent predictors of super-response to CRT (see Table 1 ). Among patients with DCM and LBBB, Patients in earlier phases of the cardiomyopathy, with a less altered ventricular geometry, seem to have a greater probability of becoming super-responders.