Abstract 14098: Long-Term Outcomes of Upgrading From Chronic Right Ventricular Pacing to Cardiac Resynchronization Therapy in Patients With Heart Failure.
Backgrounds: Chronic right ventricular (RV) pacing may impose ventricular dyssynchrony leading to left ventricular (LV) remodeling, which is associated with increased morbidity and mortality.
Purpose: To determine the long-term outcome of upgrading from chronic RV pacing to cardiac resynchronization therapy (CRT) in patients with heart failure.
Methods: CUBIC study is a multi-center registry of Japanese patients undergoing CRT. A total of 650 patients from 11 centers were enrolled during 2004–2008 and analyzed after de novo CRT implantation (n=470) and upgrade from chronic RV pacing to CRT (n=180).
Results: A mean follow-up period was 663 days. Compared with the de novo CRT patients, the upgrade-to-CRT patients were older (71 years vs. 68 years, p=0.01) and more likely to be woman (39% vs. 27%, p=0.003) and non-diabetic (73% vs. 64%, p=0.03), and to have wide QRS width (174 msec. vs. 141 msec., p<0.0001), chronic atrial fibrillation or flutter (32% vs. 18%, p=0.0004) and non-ischemic etiology (82% vs. 63%, p<0.0001). CRT plus implantable cardioverter-defibrillator devices were more frequently indicated in the de novo CRT patients than in the upgrade-to-CRT patients (66% vs. 44%, p<0.0001). The prevalence of chronic kidney disease (de novo: 28% vs. upgrade: 27%) and severe mitral regurgitation (de novo: 14% vs. upgrade: 13%) were similar between the 2 groups. The crude survival rates were comparable between the de novo CRT group and the upgrade-to-CRT group (at 2 years, de novo: 81.5% vs. upgrade: 82.0%, log rank p=0.13). The rate of freedom from hospitalization for heart failure tended to be higher in the upgrade-to-CRT group, but the difference did not reach statistical significance (at 2 years, 80.4% vs. 67.2%, log-rank p=0.057). There was also no significant difference in the rate of reverse LV remodeling defined as LV end-systolic volume reduction ≥ 15% after 6 months (de novo: 56.0% vs. upgrade: 61.4%, p=0.27). Responder rate defined as an improvement (≥ 1 score) of NYHA class after 6 months was also similar between the 2 groups (de novo: 66.0 % vs. upgrade: 61.3%, p=0.28).
Conclusions: Long-term mortality was similar in patients upgraded to CRT after chronic RV pacing to patients undergoing de novo CRT. The degree of LV reverse remodeling was also comparable.
- © 2010 by American Heart Association, Inc.