Prospective Randomised Investigation of the Safety and Efficacy of Micardis® vs Ramipril Using ABPM

Secondary objectives will compare telmisartan (80 mg) (MICARDIS® and ramipril (5 mg and 10 mg) on: 1) the reduction in the last 6-hour ABPM mean pulse pressure (PP) relative to dosing, 2) the reductions in the 24-hour ABPM mean DBP, SBP and PP relative to dosing, 3) reductions in ABPM mean DBP, SBP and PP during other periods of the 24-hour dosing interval (i.e., morning, daytime, and nighttime) relative to clock time, 4) change from baseline in systolic and diastolic blood pressure load during the 24-hour dosing interval, 5) reductions in the mean seated trough DBP and SBP measured using a manual in-clinic cuff sphygmomanometer, 6) responder rates as determined by both ABPM and manual in-clinic cuff measurements and 7) Health-Related Quality of Life (HRQL).

Study Hypothesis:

It is hypothesised that the rise of blood pressure (BP) during the last hours of the sleeping period is a cause of the high incidence of cardiovascular events in the morning. The purpose of the present study is to demonstrate that telmisartan (MICARDIS®) is not inferior to ramipril in lowering blood pressure in patients with mild-to-moderate hypertension. Blood pressure will be assessed by ambulatory blood pressure monitoring (ABPM) as this will allow comparison of the full 24-hour effects of both treatments without artefacts (e.g., white-coat hypertension) introduced by measurement of blood pressure in the clinic. This will measure diastolic blood pressures over the entire 24-hour dosing interval, with primary attention focused on the last six hours of the dosing interval.

NULL AND ALTERNATIVE HYPOTHESES In order to test the multiple hypotheses (e.g., non-inferiority and superiority of telmisartan compared to ramipril), multiple dosages (i.e., telmisartan 80mg (MICARDIS®) versus ramipril 5mg and ramipril 10mg after 8 and 14 weeks of treatment, respectively), and the two endpoints (i.e., reduction in DBP and SBP during the last 6 hours of the 24-hour dosing interval) as measured by ABPM, a completely hierarchical, closed testing procedure will be used.

Hierarchical Closed Testing Procedure:

1. Non-inferiority of telmisartan 80 mg (MICARDIS®) compared to ramipril 5 mg at the end of the 8 week treatment period in the reduction of DBP during the last 6 hours of the 24 hour dosing interval; if significant then,
2. Superiority of telmisartan 80 mg (MICARDIS®) compared to ramipril 5 mg at the end of the 8-week treatment period in the reduction of DBP during the last 6 hours of the 24-hour dosing interval; if significant then,
3. Superiority of telmisartan 80mg (MICARDIS®) compared to ramipril 5 mg at the end of the 8-week treatment period in the reduction of SBP during the last 6 hours of the 24-hour dosing interval; if significant then,
4. Non-inferiority of telmisartan 80mg (MICARDIS®) compared to ramipril 10 mg at the end of an 14 week treatment period in the reduction of DBP during the last 6 hours of the 24-hour dosing interval; if significant then,
5. Superiority of telmisartan 80mg (MICARDIS®) compared to ramipril 10 mg at the end of an 14-week treatment period in the reduction of DBP during the last 6 hours of the 24-hour dosing interval; and if significant then,
6. Superiority of telmisartan 80mg (MICARDIS®) compared to ramipril 10mg at the end of an 14-week treatment period in the reduction of SBP during the last 6 hours of the 24-hour dosing interval.

A difference of 2 mmHg was determined to be the maximum difference between the mean reductions in DBP during the last 6 hours of the 24-hour dosing interval for the two treatments which would be considered to have no clinical importance (i.e., the limit for non inferiority). Thus non-inferiority of telmisartan compared to ramipril will be tested using the following set of hypotheses:

Null Hypothesis:

The overall mean reduction from baseline in ABPM mean DBP during the last 6 hours of the 24-hour dosing interval for telmisartan 80 mg (MICARDIS®) is inferior to that for ramipril by at least 2 mmHg.

Alternative Hypothesis: The overall mean reduction from baseline in ABPM mean DBP during the last 6 hours of the 24-hour dosing interval for telmisartan 80mg (MICARDIS®) is less than 2 mmHg smaller than that for ramipril.

These hypotheses can be stated as:

H0: dT - dR less than or equal to -2 mmHg versus HA: dT - dR > -2 mmHg where dT and dR represent the overall mean reduction from baseline in ABPM mean DBP during the last 6 hours of the 24-hour dosing interval for telmisartan and ramipril, respectively, adjusted for any other factors included in the statistical model.

If the lower limit of the two-sided 95% confidence interval for the difference between the least square means of both treatments (telmisartan - ramipril) lies above -2 mmHg, then it will be concluded that telmisartan 80mg (MICARDIS®) is at least as effective as ramipril (5mg after 8 weeks of treatment or 10mg after 14 weeks of treatment, depending upon the comparison) in reducing DBP during the last 6 hours of the 24-hour dosing interval.

Superiority of telmisartan (MICARDIS®) compared to ramipril will be tested using the following set of hypotheses:

Null Hypothesis:

The overall mean reduction from baseline in the ABPM mean during the last 6 hours of the 24-hour dosing interval for telmisartan 80mg (MICARDIS®) is less than or equal to that for ramipril.

Alternative Hypothesis: The overall mean reduction from baseline in the ABPM mean during the last 6 hours of the 24-hour dosing interval for telmisartan 80mg (MICARDIS®) is greater than that for ramipril.

These hypotheses can be stated as:

H0: dT - dR less than or equal to 0 mmHg versus HA: dT - dR > 0 mmHg where dT and dR represent the overall mean reduction from baseline in ABPM mean DBP during the last 6 hours of the 24-hour dosing interval for telmisartan and ramipril, respectively, adjusted for any other factors included in the statistical model.

If the lower limit of the two-sided 95% confidence interval for the difference between the least square means of both treatments (telmisartan (MICARDIS®) - ramipril) is greater than zero, then it will be concluded that telmisartan 80mg (MICARDIS®) is statistically superior to ramipril (5mg after 8 weeks of treatment or 10mg after 14 weeks of treatment, depending upon the comparison) in reducing blood pressure (DBP or SBP, depending upon the comparison) during the last 6 hours of the 24-hour dosing interval.

Comparison(s):

Reductions in blood pressure during the last 6 hours of the 24-hour dosing interval as measured by ABPM in patients treated with telmisartan (MICARDIS®) compared to patients treated with ramipril. The primary analysis will consist of a closed testing procedure first testing for non-inferiority of telmisartan 80mg (MICARDIS®) compared to ramipril 10mg after fourteen weeks of treatment in the reduction in diastolic blood pressure (DBP); if significant, testing for superiority of telmisartan 80 mg (MICARDIS®) compared to ramipril 10 mg in the reduction in DBP; if significant, testing for superiority of telmisartan 80 mg (MICARDIS®) compared to ramipril 10 mg in the reduction of systolic blood pressure (SBP); if significant, testing for non-inferiority of telmisartan 80 mg (MICARDIS®) compared to ramipril 5 mg after eight weeks of treatment in the reduction in DBP; if significant, testing for superiority of telmisartan 80 mg (MICARDIS®) compared to ramipril 5 mg in the reduction in DBP; and if significant, testing for superiority of telmisartan 80mg (MICARDIS®) compared to ramipril 5mg in the reduction in SBP.