Irbesartan Improves Hemodynamics And Slows Progression In Heart Failure

	April 1, 1999 - The ACE 2 antagonist - irbesartan - shows long-term benefit in the treatment of heart failure. Dr. Edward Havranek, of the University of Colorado Health Sciences Center and investigators for the Irbesartan Heart Failure Group examined the effects of 4 doses of irbesartan on blood flow in more than 200 patients with symptomatic heart failure and EF of 40% or less.
	After 12 weeks of once-daily irbesartan at 75mg and 150 mg doses, pulmonary capillary wedge pressure was reduced by 5-6mm Hg and heart failure did not worsen. "Irbesartan also caused reductions in pulmonary arterial pressure."
	The drug was well-tolerated, had no significant neurohormonal effects and did not cause tachycardia, cough or kidney failure. "Irbesartan appears to be a promising new therapy for CHF patients," Dr. Havranek concludes.
	Although the study did not compare irbesartan with any ACE inhibitors, several "theoretical considerations" suggest that the ACE 2 blocker may be more appropriate for CHF, said Dr. Havranek. "About 15% of patients treated with ACE inhibitors develop a cough which is severe enough to require stopping the ACE inhibitor. This side-effect did not occur in patients treated with irbesartan," Dr. Havranek said.
	ACE 2 blockers "might cause better blockade of the angiotensin system than ACE inhibitors." Selective blockade of the ACE 2 receptor but not the ACE receptor "may produce better long-term remodeling of the heart," Dr. Havranek said.
	Also, ACE inhibitors interact with bradykinin but ACE 2 blockers do not.
	Based on this, Dr. Havranek believes that a randomized trial comparing ACE 2 blockers to ACE inhibitors in patients with heart failure is needed.

J Am Coll Cardiol 1999;33:1174-1181