Comparison of medical therapy dosing in outpatients cared for in cardiology practices with heart failure and reduced ejection fraction with and without device therapy: report from IMPROVE HF.

BACKGROUND: Few data exist to characterize the delivery of evidence-based medical therapy for outpatients with heart failure who have received implantable cardioverter-defibrillators or cardiac resynchronization therapy (CRT) for systolic dysfunction. METHODS AND
RESULTS: IMPROVE HF is a prospective study characterizing the management of 15 381 outpatients with systolic heart failure (left ventricular ejection fraction ≤35%) enrolled from 167 US cardiology practices. Data were abstracted for dose, type, and daily frequency for angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, and aldosterone antagonists. Target doses for each medication class were based on current guidelines. Patients with devices (implantable cardioverter-defibrillators, CRT with defibrillators, or CRT with pacemakers) more frequently received evidence-based medical therapy than did those without such devices, although treatment at or above target doses was low for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (implantable cardioverter-defibrillators 32.6%, CRT with pacemaker 30.7%, CRT with defibrillator 32.0%, no device 34.6%) and β-blockers (20.2%, 17.4%, 20.4%, and 15.3%, respectively). Fewer patients received aldosterone antagonists, although when used, doses were more frequently within the target dosing range (70.1%, 72.1%, 72.7%, and 76.5%, respectively). Multivariable models showed that use of CRT with defibrillators and CRT with pacemakers was significantly associated with delivery of β-blockers at or above target doses, but no device therapies were associated with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or aldosterone antagonist dosing.
CONCLUSIONS: Patients treated with heart failure devices received evidence-based medical therapy at similar or greater frequency than did those without such devices. Patients with CRT with defibrillator or CRT with pacemaker devices were more likely to be treated with target doses of β-blockers than were patients not treated with device therapy. Doses of evidenced-based therapies remain significantly lower in clinical practice than in clinical trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00303979.