ONTARGET

ONTARGET
Name	ONTARGET
Full name	Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial
Acronym	ONTARGET
Phase	Phase III
Design	Randomized, double-blind, controlled trial
Conditions	Cardiovascular disease, hypertension, atherosclerosis
Interventions	Telmisartan, Ramipril, Combination therapy
Primary outcome	Composite of cardiovascular death, myocardial infarction, stroke, and hospitalisation for heart failure
Recruitment	2001–2004
Sample size	~25,000
Countries	Canada, United Kingdom, United States, Europe, Australia

ONTARGET

ONTARGET was a large international randomized clinical trial comparing the angiotensin II receptor blocker telmisartan, the angiotensin-converting enzyme inhibitor ramipril, and their combination for prevention of major cardiovascular events in high-risk patients. The trial enrolled tens of thousands of participants with established atherosclerotic disease or diabetes with end-organ damage and addressed competing strategies tested in landmark trials such as HOPE and LIFE. ONTARGET informed clinical practice on renin–angiotensin system blockade in contexts influenced by guidelines from bodies like the European Society of Cardiology and the American College of Cardiology.

Background

ONTARGET was conceived against a backdrop of evidence from trials including HOPE, which established benefit of ramipril, and comparative studies of angiotensin receptor blockers such as LIFE and VALIANT. Concerns addressed included whether angiotensin II receptor blockers would match or exceed outcomes seen with established angiotensin-converting enzyme inhibitors and whether combination therapy would provide additive protection beyond monotherapy — questions relevant to recommendations from the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure and committees shaping guidelines at the National Institute for Health and Care Excellence and the World Health Organization.

Study design

ONTARGET was an international, randomized, double-blind, noninferiority and superiority trial with three parallel arms: telmisartan, ramipril, and the combination of both. The design incorporated intention-to-treat principles similar to those used in PROGRESS and used a composite primary endpoint consistent with trials such as SAVE and PEACE. Randomisation was stratified by centre and baseline characteristics, and statistical planning included prespecified subgroup analyses reflecting prior subgroup work from HOPE and meta-analytic considerations promoted by consortia like the Cochrane Collaboration.

Participants and setting

Participants were adults with established atherosclerotic disease (history of coronary artery disease, peripheral arterial disease, or cerebrovascular disease) or diabetes mellitus with end-organ damage, recruited across multiple countries including centres in Canada, the United Kingdom, the United States, and various European and Australasian institutions. Inclusion and exclusion criteria paralleled contemporary trials such as ONTARGET-related studies and ensured enrolment of patients at elevated risk for myocardial infarction, stroke, and cardiovascular death. Baseline characteristics and risk profiles were analysed with reference to demographic cohorts described in publications from the Framingham Heart Study and registries like the European Society of Cardiology registries.

Interventions

Patients were randomised to receive telmisartan, ramipril, or combination therapy. The ramipril arm used doses established in HOPE, whereas telmisartan dosing reflected pharmacologic data and prior trials of angiotensin receptor blockers such as LIFE. The combination arm administered both agents concurrently to test hypotheses of additive blockade similar to the approach evaluated in smaller mechanistic studies and in trials like combination therapy investigations. Concomitant therapies (e.g., statins, antiplatelet agents, beta-blockers) were managed per local practice and contemporary guidance from organisations such as the European Society of Cardiology and the American Heart Association.

Outcomes and results

The primary composite endpoint combined cardiovascular death, myocardial infarction, stroke, and hospitalisation for heart failure. ONTARGET showed that telmisartan was noninferior to ramipril for the primary outcome, replicating and extending comparative findings from trials like LIFE and TRANSCEND. Combination therapy did not confer additional reduction in the primary composite outcome compared with ramipril alone and, in several analyses, offered no incremental benefit over monotherapy; these findings paralleled neutral results seen in other combination trials reporting on major adverse cardiovascular events in populations defined by trials such as ALLHAT and VALUE. Secondary endpoints, including renal outcomes and individual components of the composite, were reported in prespecified analyses and subgroup assessments consistent with methods used in CHARM publications.

Safety and adverse events

ONTARGET identified higher rates of adverse events with combination therapy, notably symptomatic hypotension, renal dysfunction, and hyperkalaemia, echoing safety signals described in pharmacovigilance reports and trials like VALIANT and CHARM. Rates of cough — a class effect associated with angiotensin-converting enzyme inhibitors such as ramipril and discussed in reviews by organisations like the European Medicines Agency — were higher in the ramipril arm. The trial emphasised monitoring strategies for serum creatinine and potassium in line with recommendations from the National Kidney Foundation and safety monitoring committees typical of multicentre trials such as those overseen by the Clinical Trials Network.

Interpretation and impact

ONTARGET influenced guideline recommendations by clarifying that angiotensin II receptor blockade with telmisartan offers comparable cardiovascular protection to ramipril, while combination blockade increases adverse events without improving major outcomes. The findings were integrated into practice statements from the European Society of Cardiology, the American College of Cardiology, and other professional bodies, and informed prescribing decisions in the context of evidence synthesized by entities like the Cochrane Collaboration and health technology assessment agencies such as NICE. ONTARGET remains cited in discussions on optimal renin–angiotensin system blockade and for framing subsequent trials addressing blood pressure, renal protection, and cardiovascular prevention strategies.

Category:Clinical trials