Comparison of trimetazidine with nifedipine in effort angina: A double-blind, crossover study
Trimetazidine has been shown to have an antianginal effect, increasing exercise capability without producing any significant change of heart rate or systolic blood pressure. The aim of this study was to compare trimetazidine efficiency to that of another classical antianginal drug. A double-blind crossover trimetazidine versus nifedipine trial was carried out in 39 male patients, mean age 58 years, with effort angina for 5 years on average, and a mean number of weekly attacks of 2.4. Thirteen patients had previous myocardial infarction. Nineteen patients received nifedipine (40 mg per day) then trimetazidine (60 mg per day), and 20 patients received the drugs in the opposite order. Each therapeutic period of 6 weeks was preceded by 1 week of washout with placebo. Drug efficacy was assessed by a bicycle exercise tolerance test, performed at the beginning and at the end of each therapeutic period, and by clinical symptoms observed with placebo or with treatment. The statistical analysis was performed according to a crossover design, with repeated measurements. The decrease of the number of weekly attacks was not significantly different with trimetazidine and nifedipine. Results on the exercise test showed no significant differences for maximum workload, the duration of exercise, ST-segment depression at peak exercise, and the time to 1-mm ST-segment depression. Heart rate and systolic blood pressure were not significantly different at rest and at peak exercise. However, the change in the rate-pressure product at the same workload differed significantly between the drugs: It decreased with nifedipine and remained unchanged with trimetazidine, indicating the difference to be in the mode of action of the drug. In conclusion, trimetazidine was as efficient as nifedipine in stable angina and had a lower incidence of side effects.