A randomized trial assessing the impact of three different glycoprotein IIb/IIIa antagonists on glycoprotein IIb/IIIa platelet receptor inhibition and clinical endpoints in patients with acute coronary syndromes.

AIMS: To compare three glycoprotein IIb/IIIa receptor antagonists (GPIs) in terms of platelet inhibition and major adverse cardiac events (MACEs), and assess the rate of bleeding and MACEs between GPIs and coadministered P2Y12 agents. METHODS: Eighty-three acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) with planned GPI use were randomized to receive high-dose bolus tirofiban, double-bolus eptifibatide, or abciximab followed by a 12-hour infusion. Glycoprotein IIb/IIIa platelet receptor inhibition was measured at baseline and at 10 minutes, 1 hour, and 24 hours postbolus dose. Major adverse cardiac events and bleeding complications at 30 days were documented. The incidence of MACEs and bleeding in patients receiving ticagrelor or prasugrel were compared to those given clopidogrel. RESULTS: There were no statistically significant differences in platelet inhibition between GPIs at 10 minutes (P=.085) and 1 hour (P=.337). At 24 hours, abciximab achieved statistically significantly higher median [interquartile range] platelet inhibition (75 [65-88]%) compared to tirofiban (28 [3-56]%; P<.0001) and eptifibatide (44 [31-63]%; P=.007). There were no differences in bleeding or MACEs depending on GPI or P2Y12 inhibitor administered. CONCLUSIONS: Glycoprotein receptor inhibitors achieve similar levels of platelet inhibition at 10 minutes and 1 hour; however, abciximab maintains this benefit 24 hours after bolus dose. We did not witness an increased rate of bleeding in patients given new potent P2Y12 inhibitors and a GPI in the modern era.

Electrocardiographic measurement of infarct size compared to cardiac MRI in reperfused first time ST-segment elevation myocardial infarction.

BACKGROUND: Myocardial infarct size (IS) following ST-segment elevation myocardial infarction (STEMI) is an important prognostic factor. We assessed the Selvester 32-point QRS score from the 12-lead ECG for measurement of IS in STEMI patients receiving reperfusion therapy compared to cardiac magnetic resonance imaging (CMRI). Furthermore we sought to explore the impact of microvascular obstruction (MVO) on the scoring system, and determine factors contributing to discrepancies between CMRI IS and Selvester score. METHODS: We examined 70 patients (55 men, 15 women), mean age 57±10years with a first time STEMI (46 anterior, 24 non-anterior). QRS scores were calculated early and at follow-up (mean 2±1 and 59±14days post-STEMI). Myocardial core scar size (5SD) was measured at 5.3±3.3 and 57.8±13.5days post-infarction by CMRI. MVO was determined on initial MRI. Logistic regression analysis was performed to determine factors contributing to discordant scores, defined as a difference between CMRI and Selvester IS of >6% myocardium. RESULTS: QRS scoring of anterior infarcts correlated with CMRI IS both early (r=0.734, p<0.0001) and at follow-up (r=0.716, p<0.0001); however no correlation was seen among non-anterior infarcts. QRS scoring overestimated IS at all time points. There was better agreement between ECG and CMRI measured IS in patients without MVO at both time points. Anterior infarction was inversely predictive of discordant IS estimation acutely, and larger Selvester scores were predictive of inaccurate scoring at both time periods. CONCLUSIONS: Selvester QRS score correlates well with CMRI IS for anterior infarcts. MVO did not independently affect the score.