Valsartan is an angiotensin II receptor antagonist (more commonly called an ARB, or angiotensin receptor blocker), with particularly high affinity for the type I (AT1) angiotensin receptor. By blocking the action of angiotensin, valsartan dilates blood vessels and reduces blood pressure. Whether angiotensin receptor blockers may or may not increase the risk of myocardial infarction (heart attack) was announced in BMJ and was debated in 2006 in the medical journal of the American Heart Association. In the VALUE trial, the angiotensin II receptor blocker valsartan produced a statistically significant 19% (p=0.02) relative increase in the prespecified secondary end point of myocardial infarction (fatal and non-fatal) compared with amlodipine. The CHARM-alternative trial showed a significant +52% (p=0.025) increase in myocardial infarction with candesartan (versus placebo) despite a reduction in blood pressure.