Abstract 19151: Clinical Predictors of Response to Beta-Blocker Therapy in Patients with Heart Failure and Reduced Ejection Fraction due to Non-Ischemic Cardiomyopathy
Background: Beta-blocker therapy is the mainstay of evidence-based therapy for heart failure with reduced ejection fraction (HFrEF). It is estimated that about a third of HFrEF patients may not respond to beta-blockers. Whereas, patients with ischemic cardiomyopathy (ICMP) receive beta-blockers for both coronary artery disease and HFrEF, this is not the case with non-ischemic cardiomyopathy (NICMP) patients. Thus, in the current analyses, we examined clinical predictors of response to beta-blockers among NICMP patients.
Methods: We analyzed data from the Beta-Blocker Evaluation of Survival Trial (BEST) in which HFrEF patients (left ventricular ejection fraction<35%) were randomized to bucindolol or placebo for the primary end point of all-cause mortality during 24 months of mean follow-up. Of the 2708 patients, 1120 had NICMP. We used Cox Proportional hazard model with interaction analyses to assess response to bucindolol. We also used factor analyses for dimension reduction in order to evaluate the effect of multiple variables on heterogeneity in response to bucindolol therapy.
Results: Patients had a mean age of 55±13 years, 33% were women and 32% were African American. There was significant interaction between right ventricular ejection fraction (RVEF) and systolic blood pressure (SBP), and bucindolol therapy (p=0.04 and 0.01, for interaction with RVEF and SBP, respectively). Using factor analyses, we combined SBP and RVEF into 1 variable (SBP_RVEF) and divided the database into 4 quartiles of SBP_RVEF (Figure). Only patients in the 4th quartile who had the highest SBP (136±18) and RVEF (46±11) had a significant reduction in mortality with bucindolol therapy (Figure).
Conclusion: Among the subgroup of patients with NICMP in BEST trial, patients who had SBP above 130 mm Hg and RVEF above 40% appeared to benefit from bucindolol therapy.
Author Disclosures: S. Ather: None. N.S. Bajaj: None. V. Bhatia: None. C. Morgan: None. S.D. Prabhu: Research Grant; Significant; NIH and VA grants. P. Deedwania: None. G.C. Fonarow: None. R. Kheirbek: None. W. Aronow: None. S. Anker: None. R. Fletcher: None. A. Ahmed: None.
- © 2014 by American Heart Association, Inc.