The appropriate dose of angiotensin-converting-enzyme inhibitors or angiotensin receptor blockers in patients with dilated cardiomyopathy. The higher, the better?

Heart failure is a major public issue, and dilated cardiomyopathy (DCM) is one of the common etiologies of heart failure. DCM is generally progressive, and some patients with DCM need heart transplant despite optimal medical and mechanical therapy. Current guidelines recommend inhibitors of renin-angiotensin-aldosterone system, namely angiotensin-converting-enzyme (ACE) inhibitor, angiotensin receptor blocker (ARB), and mineralocorticoid receptor antagonist as well as beta-blockers for the medical treatment of heart failure with reduced ejection fraction, including DCM. Furthermore, because they have beneficial effects on the outcome of heart failure in a dose-related fashion, they should be titrated to the target dose. In clinical practice, the underuse and under-dose of these agents matter; however, the efficacy and safety of supramaximal dose of ACE inhibitor or ARB have never been investigated in the patients with DCM. In this issue of ESC Heart Failure, it is demonstrated that benazepril or valsartan at supramaximal dose improved left ventricular function and reduced cardiovascular events compared with each drug at low dose, respectively. In this editorial, the current evidence concerning the use of ACE inhibitor or ARB in patients with HF and future prospective will be discussed.