TRIMETAZIDINE - A NEW CONCEPT IN THE TREATMENT OF ANGINA - COMPARISON WITH PROPRANOLOL IN PATIENTS WITH STABLE ANGINA

1 Trimetazidine has a direct anti-ischaemic effect on the myocardium without altering the rate x pressure product or coronary blood flow. 2 The effects of trimetazidine (20 mg three times daily) were compared with those of propranolol (40 mg three times daily) in a double-blind parallel group multicentre study in 149 men with stable angina. 3 Reproducibility of exercise performance was verified during a 3 week run-in placebo washout period. All patients had > 1 mm ST-depression on exercise test. 4 After 3 months, similar anti-anginal efficacy was observed between the trimetazidine (n = 71) and propranolol (n = 78) groups. No significant differences were observed between trimetazidine and propranolol as regards anginal attack rate per week (mean difference P - TMZ: -2; 95% CI: -4.4, 0.5) and exercise duration (mean difference P - TMZ: 0 s; 95% CI: -33, 34) or time to 1 mm ST segment depression (mean difference P - TMZ: 13 s; 95% CI: -24, 51). Heart rate and rate x pressure product at rest and at peak exercise remained unchanged in the trimetazidine group but significantly decreased with propranolol (P < 0.001 in all cases). With both drugs there was a trend to decreased ischaemic episodes in the 46% patients who experienced ambulatory ischaemia on Holter monitoring. Six patients stopped trimetazidine and 12 propranolol. Of these, five in each group were withdrawn because of deterioration in cardiovascular status. 5 The results suggest that trimetazidine and propranolol at the doses studied have similar efficacy in patients with stable angina pectoris. The unchanged rate x pressure product suggests that the mechanism of action of trimetazidine is not primarily reduction in energy demand.