QRS narrowing predicts left ventricular reverse remodelling after resynchronization therapy in patients with end-stage heart failure. (14th October 2021) - Neves Pereira, M
Abstract: Introduction: Cardiac resynchronization therapy (CRT) is an established treatment for heart failure (HF) patients, however one-third of the patients fail to benefit from CRT. The relationship between the QRS duration, severity of mechanical dyssynchrony and efficacy of CRT is not completely understood. We determined if QRS duration shortening after CRT implantation was predictive of left ventricular reverse remodelling. Methods: We retrospectively enrolled 227 patients undergoing CRT implantation between 2013 and 2020 according to the guidelines. 88 patients were included in our analysis, from whom all data were available, and these represent our sample. Clinical, electrocardiographic and echocardiographic parameters were evaluated at baseline and after 6 months of CRT implantation. Response to CRT was defined as a reduction in left ventricular end-diastolic volume (LVEDV) >15%. Linear regression models were used. Results: 88 patients were included (mean age 69±10 years, 62.5% males, 36.4% ischemic etiology). Baseline left ventricular ejection fraction (LVEF) was 27, 5±5, 8% and LVEDV was 181±69 ml. After 6 months of CRT, 52 patients (59.1%) were considered responders. Baseline LVEDV was superior in responders when compared with non responders (199±85 ml vs 168±53 ml, p=0.038). No significant differences were noted in male gender (p=0.823), ischemic cardiomyopathy (p=0.065), LVEF (p=0.853), atrial fibrillation (p=0.390), left bundle branch block (p=0.950) or biventricular pacing (p=0.154) between them. QRS duration at baseline was similar between responders and non-responders (165±17 ms vs 163±17 ms, p=0.620). After 6 months of CRT, the reduction of QRS duration in responders was significantly higher than non-responders (p<0.001). QRS duration was reduced from 165±17 ms to 136±15 ms in responders vs 163±17 ms to 160±17 ms in non-responders, (p<0.001). The change in QRS duration positively correlated with the change in LVEDV (0. 654; p<0.001). Multi-linear regression analysis suggested that QRS duration shortening had a significant effect on LVEDV (y = 14, 375 + 1.354 X, R2 0.337, p<0.001) Conclusion: QRS duration shortening after CRT implantation was predictive of LV reverse remodelling in end-stage heart failure patients. Further prospective studies should be conducted to assess the prognostic value of QRS narrowing in response to CRT. Funding Acknowledgement: Type of funding sources: None.