The potential benefit of dual antiplatelet therapy beyond 1 year after a myocardial infarction has not been established.
Researchers have investigated the efficacy and safety of Ticagrelor ( Brilique, Brilinta ), a P2Y12 receptor antagonist with established efficacy after an acute coronary syndrome, in this context.
Investigators randomly assigned, in a double-blind 1:1:1 fashion, 21,162 patients who had had a myocardial infarction 1 to 3 years earlier to Ticagrelor at a dose of 90 mg twice daily, Ticagrelor at a dose of 60 mg twice daily, or placebo.
All the patients were to receive low-dose Acetylsalicylic acid ( Aspirin ) and were followed for a median of 33 months.
The primary efficacy end point was the composite of cardiovascular death, myocardial infarction, or stroke.
The primary safety end point was Thrombolysis in Myocardial Infarction ( TIMI ) major bleeding.
The two Ticagrelor doses each reduced, as compared with placebo, the rate of the primary efficacy end point, with Kaplan-Meier rates at 3 years of 7.85% in the group that received 90 mg of Ticagrelor twice daily, 7.77% in the group that received 60 mg of Ticagrelor twice daily, and 9.04% in the placebo group ( hazard ratio for 90 mg of Ticagrelor vs placebo, 0.85; 95% confidence interval [CI], 0.75 to 0.96; P=0.008; hazard ratio for 60 mg of Ticagrelor vs placebo, 0.84; 95% CI, 0.74 to 0.95; P=0.004 ).
Rates of TIMI major bleeding were higher with Ticagrelor ( 2.60% with 90 mg and 2.30% with 60 mg ) than with placebo ( 1.06% ) ( P less than 0.001 for each dose vs placebo ); the rates of intracranial hemorrhage or fatal bleeding in the three groups were 0.63%, 0.71%, and 0.60%, respectively.
In conclusion, in patients with a myocardial infarction more than 1 year previously, treatment with Ticagrelor has significantly reduced the risk of cardiovascular death, myocardial infarction, or stroke and increased the risk of major bleeding. ( Xagena )
Bonaca MP et al, N Engl J Med 2015; 372:1791-1800