Prevention of stroke: new evidence

Treatment of hypertension may represent the most cost-effective strategy for reducing the burden of stroke for patients as well as for healthcare systems. In large clinical trials, angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors have demonstrated potential for preventing both primary and secondary stroke in addition to their blood-pressure-lowering effects. An important question is whether these anti hypertensive classes exhibit differential effects on stroke risk. Recently, the ONTARGET study showed that the ARB telmisartan trended towards reduced risk of primary stroke by 9% compared with the ACE inhibitor ramipril. Further evidence of the comparative efficacy of ARBs and ACE inhibitors in the prevention of stroke comes from a meta-analysis of six randomized comparative trials, which showed an 8% difference in primary stroke risk favouring ARBs over ACE inhibitors. Telmisartan may have greater potential to reduce stroke risk than other ARBs because of its highly lipophilic nature, which allows it to cross the blood-brain barrier to inhibit centrally mediated angiotensin II effects. In the PRoFESS study, early telmisartan treatment did not reduce the overall recurrent stroke rate vs. placebo. Analysis of the PRoFESS study post-6-month data showed potential for a significant later benefit with telmisartan compared with placebo (5.3 vs. 6.0%; hazard ratio 0.88; 95% confidence interval 0.78-0.99).