CHICAGO (Reuters Health) – Results of a small study suggest that switching hypertensive patients from a beta-blacker to an angiotensin receptor blocker can improve endothelial function while maintaining good blood pressure control. The study was presented at the American Heart Association's 55th Annual Fall Conference of the Council for High Blood Pressure Research.
Dr. Ernesto L. Schiffrin from the Clinical Research Institute of Montreal and colleagues studied eleven men with essential hypertension who had been treated with atenolol and who had persistently altered resistance artery structure and impaired endothelium-dependent relaxation of small arteries. The men were switched to irbesartan and followed for 1 year. The mean age of the men was 51.
During treatment with irbesartan mean blood pressure was 131/85 mm Hg, which was identical to mean levels achieved with atenolol.
Resistance arteries were dissected from gluteal subcutaneous biopsies and studied using a pressurized myograph. Dr. Schiffrin said the media/lumen ratio of resistance arteries "decreased from 8.44 to 6.46 on irbesartan after a year." Similarly, acetylcholine-induced endothelium-dependent relaxation was "normalized after a year of treatment with irbesartan," he said.
Dr. Schiffrin concluded that this study and earlier studies that compared ACE-inhibitors to beta-blockers, suggest that either an angiotensin receptor blocker or an ACE-inhibitor treatment "results in correction of the structural remodeling" caused by hypertension.
"I think this explains why you can take a patient who has had a good response on a beta blocker and switch the patient to an ACE inhibitor or an angiotensin receptor blocker and get an even better response," Dr. Schiffrin concluded.