Objectives: Older patients experience higher rates of cardiovascular disease than younger patients, but studies have suggested that relative risk reductions due to antihypertensive therapy are lower in older than younger patients. The Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA) allowed an evaluation of the efficacy and safety of an amlodipine versus an atenolol-based antihypertensive regimen among older (≥ 65 years) and younger (<65 years) patients.
Methods: In ASCOT-BPLA 19 257 patients (8137 aged ≥ 65 years and 11 020 <65 years) were randomly assigned to receive amlodipine or atenolol-based antihypertensive therapy. The primary endpoint (nonfatal myocardial infarction and fatal coronary heart disease) and seven secondary endpoints were consistent with the original trial design.
Results: All cardiovascular endpoints evaluated favoured the amlodipine-based regimen, significantly so in seven of the 16 age-stratified endpoints. Compared with the atenolol-based regimen, the amlodipine-based regimen reduced the relative risk of cardiovascular events by 17% in older and 15% in younger patients (P < 0.01). Overall, older patients experienced more cardiovascular events [n = 1625 (20%)] than younger patients [n = 1339 (12%)]. Discontinuations due to serious adverse events were low in both age groups and less frequent in the amlodipine-based versus atenolol-based regimen: 0.6 versus 1.1% among older patients and 0.4 versus 0.8% among younger patients.
Conclusions: The amlodipine-based regimen reduced the relative risk of cardiovascular events more effectively than the atenolol-based regimen in both older and younger patients. However, because event rates were higher among older patients, the absolute benefits were greater for older compared with younger patients.