Association of Guideline-Based Medical Therapy with Malignant Arrhythmias and Mortality among Heart Failure Patients Implanted with Cardioverter Defibrillator (ICD) or Cardiac Resynchronization-Defibrillator Device (CRTD)

Aim: Evaluate prevalence of heart failure (HF) medications and their association with ventricular arrhythmia (VA) and survival among patients implanted with primary prevention implantable cardiac defibrillator (ICD)/cardiac resynchronization therapy + defibrillator (CRTD) devices. Methods: Association of treatment and dose (% guideline recommended target) of beta-adrenergic receptor antagonist (BB), angiotensin-antagonists (AngA), and mineralocorticoid-antagonists (MRA), after ICD/CRTD implant with VA and mortality was retrospectively analyzed. Results: Study included 186 HF patients; 42.5% and 57.5% implanted with ICD and CRTD, respectively. During 3.8 (2.1;6.7) years; 52 (28%) had VA and 77 (41.4%) died. Treatment (% of patients) included: BB (83%), AngA (87%), and MRA (59%). Median doses were 25(12.5;50)% of target for all medications. BB treatment >25% target dose was associated with reduced VA incidence. In the multivariable model including age, gender, diabetes, heart rate, and medication doses, increased BB dose was associated with reduced VA (hazard ratio (HR) 0.443 95% CI 0.222–0.885; p = 0.021). In the multivariable model for overall mortality including age, gender, renal disease, VA, and medical treatment, VA was associated with increased mortality (HR 2.672; 95% CI 1.429–4.999; p = 0.002) and AngA treatment was associated with reduced mortality (HR 0.515; 95% CI 0.285–0.929; p = 0.028). Conclusions: In this cohort of real-life HF patients discharged after ICD/CRTD implant, prevalence of guideline-based HF medications was high, albeit with low doses. Higher BB dose was associated with reduced VA, while AngA was associated with improved survival.