Abstract 5895: The Impact of Response to Cardiac Resynchronization Therapy on Ventricular Arrhythmic Events
Background: It’s well known that cardiac resynchronization therapy (CRT) is effective to reduce heart failure hospitalization. However, the impact of response to CRT on ventricular arrhythmic events is not well established.
Methods: We investigated 216 pts received CRT in two institutions (age 69.3+/−10.8 years, NYHA class 3.1+/−0.5, LVEF 25.8+/−7.4%, LVEDD 62.1+/−8.3mm, pre QRS duration 158+/−32ms, AF 19.4%, ischemic heart disease 33.3%, CRT-D 51.3%) and divided into two groups, Responders (n=145, 67.1%) and Non-responders (n=71, 32.9%). CRT responder was defined as improvement of LVEF > or =5%, or reduction of LVEDD > or = 5mm at 3–6 month echo data. Long-term ventricular arrhythmic events (ventricular tachycardia: VT, ventricular fibrillation: VF and sudden cardiac death: SCD) were obtained. Kaplan-Meier curve were draw and Long-Rank test was used to compare event rates of two groups.
Results: Mean follow up periods was 19.3 +/−12.7 months. Event free survival rates from ventricular arrhythmic events (VT, VF and SCD) were all significantly higher in Responders compared to Non-responders (VT: 89.2% vs. 77.8% at 2 year, Log-rank p=0.031, VF: 99.2% vs. 89.9% at 2 year, Log-rank p=0.0031, SCD: 98.6% vs. 89.2% at 2 year, Log-rank p=0.0038) and event free survival rate from combined VT, VF and SCD was also significantly higher in Responders (87.8% vs. 76.5% at 2 year, Log-rank p=0.0013).
Conclusion: Response to CRT seems to reduce not only heart failure events, but also ventricular arrhythmic events.