Valsartan in the treatment of heart failure or left ventricular dysfunction after myocardial infarction
The physiological role of the renin angiotensin aldosterone system (RAAS) is to maintain the integrity of the cardiovascular system. The effect of angiotensin II is mediated via the angiotensin type I receptor (AT1) resulting in vasoconstriction, sodium retention and myocyte growth changes. This causes myocardial remodeling which eventually leads to left ventricular hypertrophy, dilation and dysfunction. Inhibition of the RAAS with angiotensin converting enzyme (ACE) inhibitors after acute myocardial infarction has been shown to reduce cardiovascular morbidity and mortality. Angiotensin receptor blockers (ARBs) specifically inhibit the AT1 receptor. It has not been known until the performance of the VALIANT (valsartan in acute myocardial infarction trial) whether blockade of the angiotensin receptor with an ARB or combination of an ACE inhibitor and ARB leads to similar outcomes as an ACE inhibitor. The VALIANT trial demonstrated equal efficacy and non-inferiority of the ARB valsartan 160 mg bid compared with captopril 50 mg tds, when administered to high risk patients with left ventricular dysfunction or heart failure in the immediate post myocardial infarction period. The combination therapy showed no incremental benefit over ACE inhibition or an ARB alone and resulted in increased adverse effects. This review examines the role of valsartan in left ventricular dysfunction post myocardial infarction. We also discuss pharmacokinetics, dosing, side effects, and usage in the elderly.
Vascular Health and Risk Management