[Side effects of vasodilator therapy in heart failure: risk of hypotension with ACE inhibitors].

The role of ACE-inhibition for the treatment of congestive heart failure has been established over the last decade. In patients with moderate and severe congestive heart failure long-term beneficial effects on symptoms may be achieved in 60-70%. Mortality is significantly improved in patients with congestive heart failure functional class NYHA IV. Therefore, ACE-inhibitors are superior to other vasodilators. Hypotension represents an important side effect of ACE-inhibitors. It is predominantly due to either inhibition of systemic and/or local angiotensin II formation or to reduce degradation of bradykinin. If the activity of the renin-angiotensin system is stimulated, as in severe congestive heart failure and/or by diuretic pretreatment, the risk for the occurrence of hypotension is therefore increased. With respect to these risk factors, small doses of ACE-inhibitors should be administered initially, e.g. captopril 6.25 mg or enalapril, 2.5 mg. Recently, two large trials demonstrated the safety of enalapril, a long-acting ACE-inhibitor, regarding the occurrence of hypotension in patients with congestive heart failure. The overall incidence of hypotension is about 2-4% in mild to moderate and about 5-8% in severe heart failure. Reduction of the dosage of the ACE-inhibitor or the diuretic drug usually results in normalization of blood pressure, allowing continuation of therapy with ACE-inhibitors.