Amlodipine in Residual Stable Exertional Angina Pectoris after Coronary Artery Bypass Surgery: A Randomised, Placebo-Controlled, Double-Blind, Crossover Study

Because of the long half-life (35 to 50 hours) of amlodipine, a calcium antagonist belonging to the dihydropyridine group, once-daily administration has been proposed. The aim of this study was to compare the effects of amlodipine and placebo on symptoms and exercise tolerance in patients with residual exertional angina after myocardial revascularisation. 16 patients (13 males, 3 females; mean age 61.9 ± 7.3 years) with chronic stable angina despite a previous myocardial revascularisation (more than 3 attacks per week after at least 3 months of pharmacological treatment) were enrolled. All patients had reproducible angina and >1mm horizontal or down-sloping ST-segment depression during two consecutive maximal exercise tests at the end of 2 weeks of a single-blind placebo period. A double-blind crossover study followed, in which 2 weeks on placebo were alternated with 2 weeks on amlodipine 10mg/day. An exercise cycloergometric test was performed 24 hours after the end of each treatment period. Concomitant antianginal treatment, with the exception of nitroglycerin, was not allowed. After administration of amlodipine, patients showed a significant increase in pressurerate product at ischaemic threshold (238 ± 27 vs 212 ± 29mm Hg • beats/min • 10⁻²; p