ONTARGET: ONgoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial
Angiotensin II (A-II) is a potent vasoconstrictor that can cause myocardial hypertrophy and vascular pathology.
Angiotensin converting enzyme inhibitors (ACE-I) have been shown to prevent death, recurrent myocardial infarction,
and heart failure in patients with left ventricular dysfunction after myocardial infarction.
Recently, the HOPE trial showed that ramipril, a tissue-specific ACE-I, prevented cardiovascular events
(death, heart attack, and stroke) in patients at high risk for atherosclerosis but without left ventricular
dysfunction or heart failure. In HOPE, the mechanism of benefit was attributed to a vascular protective effect.
Despite their proven benefit ACE-I have limitations. About 20% of patients exposed to ACE-I have
intolerable adverse effects that lead to drug discontinuation and ACE-I do not completely block the generation of A-II.
More recently, angiotensin receptor blockers (ARB) have been developed and shown to be effective for treatment of
hypertension and have anti-inflammatory properties.
The two primary goals of ONTARGET are: (1) to show that telmisartan, an ARB, is as effective
as ramipril, an ACE-I, for preventing cardiovascular events and (2) that the combination of telmisartan and
ramipril is more effective than ramipril alone. Secondary goals are to determine whether combined telmisartan
and ramipril is better than ramipril or telmisartan alone for preventing heart failure, diabetes, cognitive
decline, and atrial fibrillation.
Study Participants: Men and women over the age of 55 years with a high risk of cardiovascular events,
patients with coronary or cerebrovascular atherosclerosis, peripheral vascular disease, or diabetes.
ONTARGET is a multicenter, randomized, double-blind trial that will be
conducted in approximately 40 countries and 800 clinical centers (125 in the United States of
American). Approximately 7,800 patients will be randomized to each of three groups: (1) ramipril,
(2) telmisartan, or (3) ramipril and telmisartan (a total of 23,400 participants). Patients will
be recruited over a 25-month period and followed 3.5 to 5.5 years for the composite primary endpoint
of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure. ONTARGET
started recruiting in the Clinical Trials Network in January 2002.