Dosing of ACE inhibitors in left ventricular dysfunction: does current clinical dosing provide optimal benefit?

In the present review, we discuss the role of clinical dosing of angiotensin converting enzyme (ACE) inhibitors in the treatment of left ventricular dysfunction. Although the precise mechanism of action of ACE inhibitors is still unresolved, the clinical efficacy of ACE inhibitors in the treatment of left ventricular dysfunction is well established. However, it is unclear whether the doses used in clinical trials translate directly into daily practice. Several reasons may cause differences between clinical practice and controlled trials: (1) clinical trials used higher doses than in normal practice; (2) some patients may be relatively 'resistant' to ACE inhibition; and/or (3) ACE activity increases during ACE inhibitor therapy and may provide escape mechanisms when the drug regimen is not strictly adhered to. Therefore, it is of interest that recent trials suggest that only the higher doses of ACE inhibition are clinically efficacious. In conclusion, it is suggested that optimal benefit from treatment with an ACE inhibitor in patients with left ventricular dysfunction requires sufficient and frequent dosing of the ACE inhibitor, e.g., enalapril 10 mg twice daily or captopril 25 mg three times daily.