Abstract 3574: Comparative Study Between De novo and Upgrade Cardiac Resynchronization Therapy patients on Echocardiographic and Clinical Outcomes
Background: Cardiac resynchronization therapy (CRT) has been shown to significantly benefit patients (pts) with moderate to severe heart failure and electro-mechanical dyssynchrony. However, clinical and echocardiographic outcomes between pts with de novo CRT and pts with upgrade to CRT from RV apex pacing are not well established. Methods: We investigated 47 patients received CRT (age 68±10years, NYHA class 3.2±0.4, LVEF 24±6%, QRS duration 174±28ms) and divided into two groups, 27 pts with de novo CRT (DN group) and 20 pts with upgraded CRT from RV apex pacing (UG group). Long-term clinical and echocardiographic data were obtained.
Results: Baseline clinical and echocardiographic characteristics were similar between two groups without QRS duration (161±21ms in DN group vs. 190±29ms in UP group, p=0.0003), LVEDD (66.4±5.9mm in DN group vs. 62.8±5.7mm in UP group, p=0.04) and LVESD (58.4±5.8mm in DN group vs. 52.7±6.5mm in UP group, p=0.003). All echocardiographic parameters (LVEF, LVEDV, LVESV, LVEDD, LVESD, MR grade) were equally improved in both groups after 6 months. On the other hand, after mean follow-up of 407±249days, event free survival rates from combined death and heart failure hospitalization were significantly higher in UP group compared to DN group (87% vs.61% at 1 year, Log-rank p=0.019). After adjusted QRS duration, LVEDD and LVESD, UP group was still significantly associated with better clinical outcomes (HR 0.15, 95%CI 0.03– 0.87, p=0.03).
Conclusion: CRT pts with upgrading from RV apex pacing to bi-ventricular pacing had equal effects of left ventricular reverse remodeling and better clinical outcomes compared to de novo CRT pts.