Are angiotensin-converting enzyme inhibitors and angiotensin receptor blockers especially useful for cardiovascular protection?

PURPOSE: This article seeks to objectively review the clinical trial evidence to determine whether angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin-receptor blockers (ARBs) have special cardiovascular protective effects.

METHODS: An objective review of the clinical trial evidence.

RESULTS: Clinical trials in hypertensive patients comparing ACEI and ARB with other drugs generally showed no difference in the primary cardiovascular outcome (United Kingdom Prospective Diabetes Study Group, Captopril Prevention Project, Swedish Trial in Old Patients with Hypertension 2, Japan Multicenter Investigation for Cardiovascular Diseases-B Randomized Trial, Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, Second Australian National Blood Pressure Study Group, Valsartan Antihypertensive Long-Term Use Evaluation). Where the primary, or major secondary, cardiovascular end-point favors one of the treatment arms, it was always the arm with the lower achieved blood pressure that saw the better clinical result as in Losartan Intervention For Endpoint Reduction in Hypertension Study, Captopril Prevention Project, Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, and Valsartan Antihypertensive Long-Term Use Evaluation. Trials comparing ACEI or ARB against placebo in patients at high risk of cardiovascular events have not showed a consistent result; cardiovascular outcomes were reduced in Heart Outcomes Prevention Evaluation, European Trial on Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease, and the Jikei Heart Study, but were not significantly reduced in Perindopril Protection Against Recurrent Stroke Study, Comparison of Arnlodipine vs Enalapril to Limit Occurrences of Thrombosis Trial, Prevention of Events with ACEIs Trial, Telmisartan Randomized Assessment Study in ACE-Intolerant Subjects with Cardiovascular Disease Trial, and Prevention Regimen for Effectively Avoiding Second Strokes Trial. In the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial, combining ACEIs with ARBs in high-risk patients did not reduce cardiovascular or renal outcomes compared with ACEI monotherapy alone. This absence of a reduction in cardiovascular outcome from the ACEI and ARB combination arm is further evidence suggesting that these drugs do not have any special cardiovascular protective effect. This objective review thus shows that the rennin-angiotensin antagonists do not have special cardiovascular protective properties.

CONCLUSION: The key to reducing cardiovascular outcome is to appropriately control blood pressure as well as to treat all other coronary risk factors.