MICARDIS Rx

Two studies were conducted to support the use to reduce the risk of cardiovascular events. Both enrolled subjects age ≥55 years, at high cardiovascular risk as evidenced by coronary artery disease (75%), diabetes mellitus (27%) accompanied with end-organ damage (eg, retinopathy, left ventricular hypertrophy, and, in ONTARGET only, macro- or microalbuminuria), stroke (16%), peripheral vascular disease (13%), or transient ischemic attack (4%). 

Patients without a history of intolerance to ACE inhibitors entered ONTARGET, and those with such a history, usually cough (90%), entered TRANSCEND, but patients with >1+ proteinuria on dipstick were excluded from TRANSCEND. For both ONTARGET and TRANSCEND trials, the primary 4-component composite endpoint was death from cardiovascular causes, myocardial infarction, stroke, and hospitalization for heart failure.  The secondary 3-component composite endpoint was death from cardiovascular causes, myocardial infarction, and stroke.

ONTARGET was a randomized, active-controlled, multinational, double-blind study involving 25,620 patients who were randomized to telmisartan 80 mg, ramipril 10 mg, or their combination. Baseline therapy included acetylsalicylic acid (76%), lipid lowering agents (64%), beta-blockers (57%), calcium channel blockers (34%), nitrates (29%), and diuretics (28%). Mean blood pressure at randomization was 134/77 mmHg.  The mean duration of follow up was about 4 years and 6 months.  The results for the ONTARGET trial are summarized below:

Incidence of the Primary and Secondary Outcomes

Telmisartan (n=8542) vs. Ramipril (n=8576)

• Composite of CV death, myocardial infarction, stroke, or hospitalization for heart failure:
  • No. of  Events Telmisartan/Ramipril =  1423 (16.7%)/1412 (16.5%); HR 97.5% CI, 1.01 (0.93-1.10)
• Composite of CV death, myocardial infarction, or stroke:
  • No. of  Events Telmisartan/Ramipril =  1190 (13.90%)/1210 (14.1%); HR 97.5% CI, 0.99 (0.90-1.08)

TRANSCEND randomized patients to telmisartan 80 mg (n=2954) or placebo (n=2972). Baseline therapy included acetylsalicylic acid (75%), lipid lowering agents (58%), beta-blockers (58%), calcium channel blockers (41%), nitrates (34%) and diuretics (33%). Mean blood pressure at randomization was 135/78 mmHg. The mean duration of follow up was 4 years and 8 months. The results for the TRANSCEND trial are summarized below:

Incidence of the Primary and Secondary Outcomes

Telmisartan (n=2954) vs. Placebo (n=2972)

• Composite of CV death, myocardial infarction, stroke, or hospitalization for heart failure:
  • No. of  Events Telmisartan/Placebo =  465 (15.7%)/504 (17.0%); HR 95% CI, 0.92 (0.81-1.05); P =0.2129
• Composite of CV death, myocardial infarction, or stroke:
  • No. of  Events Telmisartan/Placebo =  384 (13.0%)/440 (14.8%); HR 95% CI, 0.87 (0.76-1.00); P = 0.0483

Individual components of the primary composite endpoint:

• All non-fatal MI:
  • No. of  Events Telmisartan/Placebo =  114 (3.9%)/145 (4.9%); HR 95% CI, 0.79 (0.62-1.01); P = 0.0574
• All non-fatal strokes:
  • No. of  Events Telmisartan/Placebo =  112 (3.8%)/136 (4.6%); HR 95% CI, 0.83 (0.64-1.06); P = 0.1365

Although the event rates in ONTARGET were similar on telmisartan and ramipril, the results did not unequivocally rule out that Micardis may not preserve a meaningful fraction of the effect of ramipril in reducing cardiovascular events. However, the results of both ONTARGET and TRANSCEND do adequately support Micardis being more effective than placebo would be in this setting, particularly for the endpoint of time to cardiovascular death, myocardial infarction, or stroke.

In ONTARGET, there was no evidence that combining ramipril and Micardis reduced the risk of death from cardiovascular causes, myocardial infarction, stroke, or hospitalization for heart failure greater than ramipril alone; instead, patients who received the combination of ramipril and telmisartan in ONTARGET experienced an increased incidence of clinically important renal dysfunction (eg, acute renal failure) compared to patients receiving Micardis or ramipril alone.

The antihypertensive effects of Micardis was shown in 6 principal placebo-controlled clinical trials, studying a range of 20 to 160 mg; one of these examined the antihypertensive effects of telmisartan and hydrochlorothiazide in combination. The studies involved a total of 1773 patients with mild to moderate hypertension (diastolic blood pressure of 95 to 114 mmHg), 1031 of whom were treated with telmisartan. After once daily administration of telmisartan, the magnitude of blood pressure reduction from baseline after placebo subtraction was approximately (SBP/DBP) 6-8/6 mmHg for 20 mg, 9-13/6-8 mmHg for 40 mg, and 12-13/7-8 mmHg for 80 mg. Larger doses (up to 160 mg) did not appear to cause a further decrease in blood pressure.

Upon initiation of antihypertensive treatment with telmisartan, blood pressure was reduced after the first dose, with a maximal reduction by about 4 weeks. With cessation of treatment with Micardis, blood pressure gradually returned to baseline values over a period of several days to one week. During long-term studies (without placebo control) the effect of telmisartan appeared to be maintained for up to at least one year. The antihypertensive effect of telmisartan is not influenced by patient age, gender, weight, or body mass index. Blood pressure response in black patients (usually a low-renin population) is noticeably less than that in Caucasian patients. This has been true for most, but not all, angiotensin II antagonists and ACE inhibitors.

In a controlled study, telmisartan was added to hydrochlorothiazide which produced an additional dose-related reduction in blood pressure that was similar in magnitude to the reduction achieved with telmisartan alone. Hydrochlorothiazide also had an added blood pressure effect when added to telmisartan.

The onset of antihypertensive activity occurs within 3 hours after administration of a single oral dose. At doses of 20, 40, and 80 mg, the antihypertensive effect of once daily administration of telmisartan is maintained for the full 24-hour dose interval. With automated ambulatory blood pressure monitoring and conventional blood pressure measurements, the 24-hour trough-to-peak ratio for 40 to 80 mg doses of telmisartan was 70% to 100% for both systolic and diastolic blood pressure. The incidence of symptomatic orthostasis after the first dose in all controlled trials was low (0.04%).

There were no changes in the heart rate of patients treated with telmisartan in controlled trials.