Primary Outcome of the ONTARGET Trial
The primary outcome of the ONTARGET trial was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, or hospitalization for heart failure. 1, 2, 3
Trial Design and Endpoints
The ONTARGET (Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial) was designed to compare three treatment strategies in high-risk patients: telmisartan 80 mg daily, ramipril 10 mg daily, and the combination of both medications. 2, 3
Primary Composite Endpoint Components:
- Cardiovascular death 1, 2
- Non-fatal myocardial infarction 1, 2
- Non-fatal stroke 1, 2
- Hospitalization for heart failure 1, 2
The trial defined the primary endpoint as the time to first event, and in cases of multiple simultaneous events, all individual events were considered. 1
Key Trial Results
Telmisartan demonstrated non-inferiority to ramipril for the primary composite outcome, with no significant differences between the three treatment groups (telmisartan, ramipril, or combination therapy). 1, 4
Specific Findings:
- Event rates were 16.7% for telmisartan versus 16.5% for ramipril (HR 1.01,97.5% CI 0.93-1.10) 1
- Combination therapy did not provide superior cardiovascular protection compared to monotherapy, but was associated with increased adverse events including hypotension, syncope, and renal dysfunction 1, 4
- Telmisartan was better tolerated than ramipril, with less cough and angioedema 4
Secondary Outcomes
The trial also evaluated a secondary composite outcome of cardiovascular death, myocardial infarction, or stroke (without hospitalization for heart failure), which showed similar results across treatment groups: 13.9% for telmisartan versus 14.1% for ramipril (HR 0.99,95% CI 0.90-1.08). 1
Clinical Context
The ONTARGET trial enrolled 25,620 high-risk patients with vascular disease or diabetes with end-organ damage, followed for a median of 56 months (approximately 4.7 years). 5, 1, 2 The study population was similar to the HOPE trial, with patients having coronary, peripheral, or cerebrovascular disease, confirming they were at high cardiovascular risk. 2, 3
The trial definitively established that telmisartan provides cardiovascular protection equivalent to ramipril in high-risk patients, supporting the use of ARBs as an alternative to ACE inhibitors, particularly in patients who cannot tolerate ACE inhibitors. 5, 6, 1