Abstract 12432: Midterm Super-Response After Cardiac Resynchronization Therapy: Characterization and its Relation with Long-Term Prognosis
Introduction: Left ventricular (LV) volumetric improvement differs among heart failure (HF) patients receiving cardiac resynchronization therapy (CRT). Recently, a portion of patients who demonstrated a dramatic improvement after CRT were referred as super-responders. However, the characteristics and impact on long-term prognosis are not fully understood.
Methods: Assessments were performed in a cohort of 120 patients (64±13yrs, 75% male) at baseline and 3-month after CRT. Midterm super-response was defined as a reduction of LV end-systolic volume (LVESV) ≥10% with a lower-third tertile of LVESV (<80ml) at 3-month. A reduction of LVESV ≥10% but with a LVESV ≥80ml was classified as normal-response, whereas a reduction of LVESV <10% as non-response. Long-term prognosis included cardiovascular mortality and/or HF hospitalization during a 3-year follow up.
Results: Super-response was observed in 33 (27.5%), normal-response in 38 (31.7%) and non-response in 49 (40.8%) patients. When compared with the other 2 groups, super-responders had a smaller LVESV (93±24 vs. 164±53 vs. 148±71ml), a higher ejection fraction (EF) (30.2±5.5 vs. 23.9±7.3 vs. 25.2±7.6%) and a larger LV dyssynchrony index by echocardiography (46.9±10.0 vs. 39.4±10.4 vs. 29.4±11.3ms) at baseline (all p<0.05). At 3-month, the degree of reduction in LVESV (-38.9±13.8 vs. -26.5±12.2 vs. -1.9±8.8%) and increase in EF (absolute points: 13.2±6.7 vs. 9.1±5.6 vs. 2.1±3.4%) were the highest in super-responders (all p<0.05). During the follow up of 853±312 (100-1100) days, cardiovascular death was found in 21 (17.5%) and HF hospitalization in 45 (37.5%) patients. Patients with super-response showed a better event-free survival than the other 2 groups (Figure).
Conclusion: Midterm super-response occurred in about one-quarter of CRT candidates, which was related to a less dilated LV and greater extent of mechanical dyssynchrony before implantation. Super-responders had the best long-term outcome.
- © 2011 by American Heart Association, Inc.