Left ventricular (LV) dysfunction and/or heart failure (HF) are frequent complications of hypertension and myocardial infarction (MI), placing affected patients at increased risk of significant morbidity and premature death. Given that the renin-angiotensinaldosterone system (RAAS) is activated and of pathophysiological importance in such patients, a strong therapeutic rationale exists to target the main effector mechanism (that is, angiotensin II [Ang II]) in order to lessen the associated morbidity and mortality burden.

Angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce mortality and LV dysfunction and to slow disease progression in patients with HF, including high-risk, post-MI patients. However, ACE inhibitors (ACE-Is) may not provide optimal long-term RAAS blockade (a finding that is associated with a worse prognosis) and many patients are unable to tolerate such therapy (because of troublesome dry cough, for example). In contrast, Ang II receptor blockers (ARBs) may block the RAAS more completely than ACE-Is and appear to be better tolerated. Several large-scale trials have evaluated the efficacy of ARBs in patients with LV dysfunction and/or HF (including highrisk, post-MI patients), and have confirmed their utility as an efficacious and well-tolerated alternative to ACE-Is in this setting.