Intracoronary compared with intravenous bolus tirofiban on the microvascular obstruction in patients with STEMI undergoing PCI: a cardiac MR study.

To investigate the potential effect of intracoronary administration of the glycoprotein IIb/IIIa inhibitor tirofiban on the microvascular obstruction (MVO) assessed by cardiac magnetic resonance (CMR) imaging compared to the intravenous route in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI). Two hundred eight patients were randomized into two groups (tirofiban i.v. and tirofiban i.c.). CMR was completed within 3-7 days after ST-segment-elevation myocardial infarction. One hundred thirty-two patients had a follow-up CMR at 6 months after discharge. The primary end point was the CMR measurements including myocardium strain, myocardial perfusion index, final infarct size, prevalence and extent of MVO, and the change of left ventricular end-diastolic volume (LVEDV) at six months follow-up. The second endpoint was major adverse cardiovascular events (composite of all-cause death, nonfatal reinfarction and congestive heart failure) in one year. The MVO prevalence and extent [56% versus 36%, p = 0.004; 2.08 (IQR: 1.18-5.07) g versus 1.68 (IQR: 0.30-3.28) g, p = 0.041] showed a significant difference between the intravenous and intracoronary groups. Global left ventricular peak longitudinal strain was significantly different in intracoronary groups compared to intravenous groups, - 12.5 [IQR: - 13.4 to - 10.9] versus - 12.3 [IQR: - 13.4 to - 10.4], respectively (P = 0.042). Infarcted myocardial perfusion index was significantly different in intracoronary groups compared to intravenous groups, 0.11 [IQR: 0.08 to 0.15] versus 0.09 [IQR: 0.07 to 0.14], respectively (P = 0.026). Intracoronary tirofiban was associated with a higher change in LVEDV compared with intravenous group (- 10.2% [IQR: - 13.7% to - 2.6%] versus 1.3% [IQR: - 5.6% to 6.1%], p < 0.001). Intracoronary tirofiban application showed no benefit on the occurrence of major adverse cardiovascular events during follow-up compared to intravenous administration. This CMR study in ST-segment-elevation myocardial infarction patients showed a benefit in MVO and left ventricular remodeling for intracoronary tirofiban administration compared to intravenous administration in patients undergoing PCI.