CRT-D non-responders have worse cardiovascular outcome than patients after primary ICD implantation with similar baseline left ventricular ejection fraction

Abstract

Abstract Background Cardiac resynchronisation therapy (CRT) fails to improve echocardiographic parameters and outcome in 20–40% of heart failure (HF) patients with reduced ejection fraction (EF) referred to as CRT non-responders (CRT-NR). The aim of this study was to compare the outcomes of CRT-NR patients who received a CRT defibrillator (CRT-D) device with patients after primary implantable cardioverter-defibrillator (ICD) implantation for impaired left ventricular (LV) function. Methods CRT-NR status was defined as no or less than 10% improvement in LV EF 12 months post implantation. CRT-NR patients and those after primary ICD implantation for LV EF<35% were identified in our database between 2010 and 2019. CRT-NR patients were further categorized as progressors (decrease in LV EF ≥5%) or non-progressors (LV EF change between +9 to −5%). Primary endpoint was all-cause mortality or the need for heart transplantation during follow-up. Statistical significance was assessed by Log-rank test of Kaplan-Meier survival analysis. Results 151 CRT-NR patients and 219 patients after primary ICD implantation were identified with a mean ± SEM follow-up of 43.7±2.5 and 47.3±2.2 months, respectively. Baseline (preoperative) LV EFs were higher (p<0.05) for the overall CRT-NR group (EF = 27.4±0.4%) than for the ICD group (EF = 25.2±0.3%) Further, both CRT-NR subgroups of progressors (n=49; EF = 28.6±0.7%) and non-progressors (n=102; EF = 26.9±0.5%) had also significantly higher baseline LV EF as compared to ICD patients (p<0.05). No statistical significance was found between the two CRT-NR subgroups. Event free median survival for the overall CRT-NR group (55.6 months) was significantly worse than for the ICD group (79.6; p<0.05). This difference was driven by progressor patients who had a significantly worse event free survival (37.8 months, p<0.05) than ICD patients, while vent free survival in non-progressors (60.8 months) was comparable to ICD patients (p=0.18). Conclusion Progressor subgroup of CRT-NR have worse outcome as compared to non-progressors and also to those after primary prevention ICD implantation. The poor prognosis of these patients should have implications for timely decision regarding all therapeutic measures currently available for the management of heart failure. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Project no. TKP2021-EGA-18 has been implemented with the support provided from the National Research, Developement and Innovation Fund of Hungary, financed under the TKP2021-EGA funding scheme