RESUMO
UNLABELLED: Efficacy of clopidogrel in acute myocardial infarction (AMI) was studied only in two trials. However efficacy and safety of loading dose of this drug and its long-term effectiveness were not studied in these trials. AIM: To assess effects of clopidogrel loading dose and long term therapy in addition to standard treatment on death, re-infarction, recurrence of angina and bleedings rate in patients with ST segment elevation acute coronary syndrome. METHODS: Patients (n=107) with AMI who met the criteria for thrombolytic therapy (TLT) were assigned randomly into either clopidogrel group A (n=51) or conventional therapy group B (n=56). Group A received loading dose of clopidogrel (300 mg) in addition to conventional therapy (TLT, aspirin, statin, ACE inhibitor and beta-blocker). Group B received only conventional therapy. The follow-up was 6 months after inclusion during which patients in group A continued to receive clopidogrel (75 mg/day after Day 2 of the study). Primary endpoint included death, re-infarction, recurrence of angina and bleedings. In addition, changes of ST segment after TLT and local contractility were assessed. RESULTS: During 30 days of follow-up rates of primary endpoint were 2.0 and 41.1% in groups A and B, respectively (p=0.003). Subgroup analyses showed that this difference depended on the rate of angina recurrence (2.4 and 36.1% in groups A and B, respectively, p=0.002). These differences were maintained during all follow-up period. Odds ratios for clopidogrel were 0.235 for primary endpoint (95% CI 0.104-0.528, p=0.0003), 0.078 for angina recurrence (95% CI 0.022-0.279, p=0,0001). No significant differences were obtained for mortality, re-infarction and bleeding rate. TLT in group A was more effective. ST depression 90 min after TLT was 86.23+/-4.38 and 61.00+/-6.97% (p=0.010), reperfusion arrhythmia rate - 72.6+/-3.27 and 33.9+/-2.78% (p=0.005) in groups A and B, respectively. CONCLUSION: The use of clopidogrel in addition to standard therapy for AMI is safe and effective. Long-term clopidogrel treatment decreases angina recurrence rate.
