Effects of tirofiban maintenance duration on myocardial perfusion defect severity in anterior myocardial infarction.

ABSTRACT

INTRODUCTION: Percutaneous coronary intervention (PCI) does not often produce optimal results, despite restoration of coronary blood flow at myocardial recovery, because of impaired microvascular perfusion. This study aimed to investigate and evaluate with (99m)Tc-sestamibi scan whether the results of PCI can be changed by maintenance infusion of tirofiban for 24 or 48 h in patients presenting with anterior ST-elevation myocardial infarction (STEMI). METHODS: The study included 84 patients with anterior STEMI who were candidates for primary PCI and whose occlusion was in the proximal or mid-left anterior descending artery. Patients were given 25 µg/kg/3 min tirofiban and randomized to receive maintenance infusion at 0.15 µg/kg/min for 24 or 48 h. A resting (99m)Tc sestamibi scan was performed on the 5th day post-procedure before discharge. The primary efficacy endpoint was a patient's score on a 5-point scoring system for perfusion defect severity. Major adverse cardiac events (MACE) were defined as death from any cause, re-infarction, and clinically driven target-vessel revascularization within the first 6 months. RESULTS: Baseline characteristics of the patients were similar in the two infusion groups (n = 42 per group). There was no significant difference in the symptom onset-to-presentation time or door-to-balloon time between the two groups. With the exception of basal anteroseptal and basal anterior segments, significant reductions were obtained on the 5-point scoring system for perfusion defect severity in segments and in the summed rest scores. No significant differences were observed between the two groups in the incidence of MACE at 6 months. The safety profile did not differ between 24 and 48 h infusions of tirofiban. CONCLUSION: The use of tirofiban, when administered at a high bolus dose and maintained for 48 h, was safe and significantly reduced perfusion defect severity in patients with anterior STEMI presenting early after symptom onset and undergoing primary PCI.