Lessons learned from the ONTARGET and TRANSCEND trials.

Cardiovascular disease (CVD) accounts for one of every three deaths in the United States. In recent years, a greater understanding of the renin-angiotensin-aldosterone system's (RAAS) contribution to CVD, particularly in the area of blood pressure regulation, has emerged. Thus, interrupting or blocking the RAAS has become a key component in the treatment of hypertension and other cardiovascular conditions. The role of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in reducing CVD in high-risk populations has been demonstrated by two recently completed major trials: the Ongoing Telmisartan Alone and in Combination with Ramipril Global endpoint Trial (ONTARGET) and the Telmisartan Randomized Assessment Study in ACE-Intolerant Subjects with Cardiovascular Disease (TRANSCEND). This article describes these key studies and their outcomes and identifies critical issues that they raise for clinical practice in terms of choosing the most effective therapy for patients with existing CVD.