The acute and chronic effects of losartan in heart failure

Background: Losartan is a novel, orally active, non-peptide angiotensin II receptor antagonist which specifically blocks the angiotensin II (AT1 receptor. It is postulated that losartan will have beneficial haemodynamic effects in heart failure similar to angiotensin converting enzyme inhibitors Recent findings: In patients with heart failure a single dose of losartan resulted in increased angiotensin II and decreased aldosterone levels. Systemic vascular resistance and systemic blood pressure were reduced. A 12 week study in similar patients found a persisting effect on systemic vascular resistance and systemic blood pressure after 12 weeks. Pulmonary capillary wedge pressure and heart rate were reduced and cardiac index increased after 12 weeks despite little acute effect on these parameters Conclusions: Losartan resulted in favourable and persisting haemodynamic effects in patients with heart failure. Further studies will be required to fully define the role of this drug in heart failure