Use of β-Blockers in Patients with an Implantable Cardioverter Defibrillator

Abstract

Implantable cardioverter defibrillators (ICDs) are indicated for both primary and secondary prevention of sudden cardiac arrest. beta-Blockers are also indicated in most patients who have an indication for an ICD; however, their use in this population is not well described. Some clinicians may be unaware of the recommendation for beta-blockers in this population. To explore beta-blocker use among ICD recipients. Adults who received their first ICD at Duke Hospital between July 1999 and July 2004 for primary or secondary prevention of sudden cardiac arrest were identified. Using hospital data, beta-blocker use was determined at time of discharge, and characteristics of users were compared with those of nonusers. Continued use of beta-blockers after ICD implant was explored in the subset of patients included in the Duke Databank for Cardiovascular Disease (DDCD). The study cohort comprised 804 patients, 652 (81%) with ICD for secondary prevention of sudden cardiac arrest and 152 (19%) for primary prevention. The median age was 65 years and 75% of the patients were men. A total of 544 (68%) received a beta-blocker at time of ICD implant. There were no substantial changes in the proportion of patients with beta-blocker use from 1999 through 2004, overall or within the primary or secondary prevention groups. However, beta-blocker use was higher in the secondary prevention group than in the primary prevention group (69% vs 60%; p = 0.02). A higher proportion of beta-blocker users versus nonusers had ischemic heart disease (82% vs 68%; p < 0.0001), heart failure (84% vs 71%; p < 0.0001), previous myocardial infraction (51% vs 44%; p = 0.05), and ventricular arrhythmias (82% vs 76%; p = 0.04). Of the 425 patients included in the DDCD, only 241 (57%) were receiving beta-blockers at time of implant and during clinical follow-up. Lower than optimal use of beta-blockers suggests the need for new methods of including evidence-based medications in clinical practice, especially for complex patients for whom numerous clinical practice guidelines may apply.