The problem of underdosing of angiotensin-converting enzyme inhibitors is markedly overrated: results from a study of patients discharged from hospital after an acute myocardial infarction.

Abstract

The use of angiotensin-converting enzyme (ACE) inhibitors has increased markedly during the last decade. It has been claimed that doses of ACE inhibitors prescribed in clinical practice are considerably lower than the target doses used in randomized clinical trials. The aim of the study was to investigate dosing of ACE inhibitors in patients discharged from the hospital after an acute myocardial infarction (AMI) and, furthermore, to compare these doses with the doses actually reached in clinical trials. From 16 hospitals, we drew a sample of patients who were discharged alive with the diagnosis of AMI during a 3-month period in 1999/2000. From medical records, physicians in each hospital obtained the observed rate of cardiovascular drugs at discharge, including type and doses of ACE inhibitors. The clinicians' main indication for ACE inhibitor use was also reported. Outcome variables, including deaths and drug utilization with dosing after 6 months, were collected. Of a total of 767 patients discharged alive, 274 patients received an ACE inhibitor. The daily mean doses of the four ACE inhibitors used in the study were as follows: captopril 69.8+/-36.9 mg (n=44), enalapril 13.6+/-8.1 mg (n=75), lisinopril 11.0+/-7.2 mg (n=114), and ramipril 8.4+/-4.5 mg (n=38). The doses were unchanged after 6 months except for captopril, which showed a rise in mean daily dose to 84.4+/-36.7 mg. Ramipril compared most favorably with clinical trial medications, while captopril deviated most. The indication of hypertension was associated with slightly higher doses than the indication of secondary prevention. AMI patients were discharged from the hospital with ACE inhibitor doses fairly close to the ones achieved in clinical trials showing survival benefits for ACE inhibitors. A distinction should be made between target doses and doses actually obtained in clinical trials.