Amlodipine in patients with stable angina pectoris treated with beta-blockers. Double-blind comparison with placebo

In order to assess additional anti-ischaemic effects of amlodipine (AML) on coronary artery disease (CAD) treated with beta-blockers, 32 patients with CAD, verified on angiograms, and stable angina were randomized to receive 5 mg/day of AML or placebo, increasing to 10 mg/day after 2 weeks. Baseline recording of 24-h ambulatory ECG and blood pressure, echocardiography and bicycle exercise test was repeated after treatment for 2 weeks and for 6 weeks. Reduction of ambulatory ischaemia was not significantly greater with AML than with placebo. In exercise tests the time to 0.1 mV ST segment depression and the total exercise time remained unaltered. Blood pressure was reduced by 10 mg AML. The total variability and the very low frequency component of heart rate were reduced after both doses. The clinical significance of the possible unfavourable change in autonomic modulation of the heart in CAD patients is not known.