EFFICACY OF AMLODIPINE IN THE TREATMENT OF STABLE EFFORT ANGINA - AN ECHOCARDIOGRAPHIC STRESS STUDY

The purpose of this double-blind placebo-controlled crossover study wa s to assess the antianginal efficacy of oral amlodipine (10mg once dai ly) in 16 patients with stable effort angina. After each 7-day treatme nt period, patients underwent symptom-limited exercise tests with elec trocardiographic and 2D-echocardiographic assessment. Under resting co nditions, systolic arterial pressure was significantly lower after tre atment with amlodipine compared with placebo (126.5 vs 132.8mm Hg). He art rate and the pressure rate product did not differ appreciably betw een amlodipine and placebo treatment. The stress test results showed a n increase in effort tolerance during amlodipine treatment compared wi th placebo (time to onset of angina = 6.8 vs 5.7 min), with a negative test in 25% of patients (4 of 16), These favourable effects may be at tributed to a reduction in myocardial oxygen consumption, as indicated by a slower increase in systolic blood pressure during exercise and t he delayed occurrence of ischaemia during amlodipine therapy (time to ST-segment depression of 1 mm = 4.5 vs 3.5 minutes). Moreover, the fac t that patients with negative tests during amlodipine were able to wor k above their ischaemic threshold during placebo, suggests a possible increase in myocardial blood flow with amlodipine. In conclusion, amlo dipine is effective in the treatment of stable angina pectoris. This d rug reduces myocardial oxygen consumption and, in some patients, may a lso increase myocardial blood flow.