Angiotensin-converting enzyme inhibitor compliance and dosing among patients with heart failure

Background: The efficacy of angiotensin-converting enzyme (ACE) inhibitors in treating heart failure is well established, but there is concern that these agents are underutilized. Proper treatment is contingent both on appropriate medication dosing by the physician and on patient compliance with therapy. This study examined dosing and compliance with ACE inhibitors in routine clinical practice. Methods and Results: Data were integrated medical and pharmacy claims from 869 patients with heart failure. Compliance and dosing of ACE inhibitors was examined for each patient over a 10- to 17-month period. Patients had ACE inhibitors available on 71% of the days assessed. At 180 days after their index prescription, 86% of patients continued to take an ACE inhibitor. The mean percentage of an adequate daily dose of ACE inhibitors dispensed per prescription was 79%, but only 34% of patients were dispensed ≥100% of an adequate daily dose. A number of variables were found to independently predict compliance and dosing levels in the multivariate analyses. Conclusions: Both physician-dependent and patient- dependent factors contributed significantly to ACE inhibitor underutilization. Each of these factors must be addressed to improve compliance and dosing of ACE inhibitors in routine clinical care.