Effect of additional temporary glycoprotein IIb/IIIa receptor inhibition on troponin release in elective percutaneous coronary interventions after pretreatment with aspirin and clopidogrel (TOPSTAR trial).

OBJECTIVES: The Troponin in Planned PTCA/Stent Implantation With or Without Administration of the Glycoprotein IIb/IIIa Receptor Antagonist Tirofiban (TOPSTAR) trial investigated: 1) the amount of troponin T (TnT) release after nonacute, elective percutaneous coronary intervention (PCI) in patients pretreated with aspirin and clopidogrel; and 2) the effect of additional glycoprotein (GP) IIb/IIIa receptor inhibiton on postinterventional TnT release.

BACKGROUND: No data are available yet as to whether additional administration of a GP IIb/IIIa receptor antagonist might be beneficial in patients undergoing elective PCI already pretreated with aspirin and clopidogrel.

METHODS: After bolus application of the study medication (tirofiban [T] or placebo [P]), PCI was performed followed by an 18-h continuous infusion of T/P. Primary end point of the study was incidence and amount of TnT release after elective PCI after 24 h.

RESULTS: A total of 12 h after PCI troponin release was detected in 63% of the patients receiving P and in 40% of the patients receiving T (p < 0.05), after 24 h in 69% (P) and 48% (T) (p < 0.05) and after 48 h in 74% (P) versus 58% (T) (p < 0.08) of the patients. No differences were observed regarding major bleeding, intracranial bleeding or nonhemorrhagic strokes. After nine months a reduction of combined death/myocardial infarction/target vessel revascularization could be observed in the tirofiban group ([T] 2.3% vs. [P] 13.04%, p < 0.05).

CONCLUSIONS: Troponin T release occurs after successful intervention in 74% of the patients undergoing elective PCI after 48 h even after pretreatment with aspirin and clopidogrel. The GP IIb/IIIa receptor antagonist tirofiban is able to decrease the incidence of troponin release significantly in this patient population.