Comparison of the effects of trimetazidine and diltiazem on exercise performance in patients with coronary heart disease. The Turkish trimetazidine study (TTS)

OBJECTIVE: A multicentre, double-blind comparative study was performed to compare the effects of trimetazidine with diltiazem on exercise performance in patients with stable angina pectoris. METHODS AND RESULTS: A total of 116 male patients with documented coronary artery disease at 11 centres were randomized into trimetazidine and diltiazem groups both including 58 men (mean age 55.1+/-8.6 years and 54.9+/-6.6 years, respectively) in a prospective, multicentre, double-blind active treatment trial. The study consisted of a two-week placebo washout period and a four-week active treatment phase. Clinical examinations and exercise tests were performed at the beginning (D0) and at the end (D28) of the active treatment. Laboratory investigations were also performed at the beginning of the washout period (D-14) and at D28. Holter recordings were done in the mid of the washout period (D-7) and D28. Both trimetazidine and diltiazem decreased the number of anginal attacks per week (p < 0.0001 for both drugs) and weekly nitrate consumption (p = 0.0008 and p < 0.0001, respectively). Both trimetazidine and diltiazem improved the recovery of anginal pain (p = 0.0188 and p = 0.0079, respectively) and maximal ST-segment depression (p = 0.0134 and p = 0.0214, respectively) but none of the drugs significantly changed the time to 1 mm ST-segment depression and ST recovery time on exercise test. Diltiazem caused a slight prolongation of PR and QRS durations (p = 0.039) on ambulatory ECG whereas trimetazidine did not change these parameters significantly. CONCLUSION: This study suggests that trimetazidine is an effective and safe alternative for diltiazem in the treatment of patients with stable angina pectoris. Although several other trials have shown that this drug can be used in combination with other antianginal drugs or instead of beta blockers or nifedipine in the symptomatic treatment of stable anginal syndromes, this study suggests that trimetazidine can be used instead of diltiazem, a well-known powerful antianginal drug.