Vasopeptidase inhibition: a novel approach to cardiovascular therapy.

Omapatrilat was designed to inhibit simultaneously angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The ubiquitous involvement of the renin-angiotensin-aldosterone system, originally conceived as an axis of sodium and fluid metabolism in inflammation, thrombosis and cardiac and smooth muscle hypertrophy, is a major factor in disease progression for conditions as diverse as hypertension, heart failure, coronary artery disease and diabetes. Interruption of angiotensin II generation and bradykinin degradation by ACE inhibition is a major therapeutic advance in the management of these diseases. NEP metabolizes both bradykinin and the natriuretic peptides (atrial natriuretic peptide, brain natriuretic peptide, c-type natriuretic peptide and adrenomedullin). These peptides counter the adverse effects of angiotensin II by their vasodilator, natriuretic, diuretic and autonomic neural actions; by their antitrophic effects; and by suppressing plasma renin activity. These two systems can be considered key components of a cardiorenal axis that maintains blood pressure and cardiopulmonary blood volume within a stable range. This balance is compromised in the setting of heart failure and primary hypertension. The combination of ACE and NEP inhibition should augment the beneficial hemodynamic and tissue effects of bradykinin and the natriuretic peptides. Vasopeptidase inhibition, therefore, is a novel approach to cardiovascular therapy, with implications for hypertension, heart failure, renal function and ischemic heart disease.