Angiotensin receptor blockers provide better stroke protection than angiotensin converting enzyme inhibitors -a hypothesis with clinical and experimental support

Hippokratia 2005, 9(3):99-105

S.G. Chrysant
Oklahoma Cardiovascular and Hypertension Center University of Oklahoma, Oklahoma City, OK, USA


Stroke is a major cause of death and disability and its incidence increases linearly with age and the level of systolic and diastolic blood pressure. Stroke, besides being a cause of long-term disability for the affected person, also imposes a significant burden on society and healthcare costs. Although good blood pressure control is very critical for stroke prevention, angiotensin receptor blockers (ARBs) may be superior to angiotensin converting enzyme inhibitors (ACEIs) for the same degree of blood pressure control. This hypothesis has clinical and experimental support. ARBs prevent stroke incidence by blocking the angiotensin II (AII), AT1 receptors preventing brain ischemia and allowing AII to stimulate the unoccupied AT2 receptors which improve brain ischemia. ACEIs, by reducing AII generation, are less effective in preventing stroke. This hypothesis provides evidence that AII plays an important role in the prevention of stroke. Certain ARBs like losartan and telmisartan possess additional properties which may play a role in stroke prevention, which is independent of AII. However, the most critical factor in stroke prevention is good blood pressure control irrespective of drug used.