Glycoprotein IIb/IIIa antagonists

SummaryThe role of GP IIb/IIIa antagonists has been focused on patients with acute coronary syndromes undergoing PCI. In the ISAR-REACT 2 study abciximab given in patients with NSTEACS undergoing PCI already treated with 600 mg clopidogrel improved 30-day death and reinfarction rate in troponin positive patients. In the large EARLY-ACS trial upstream therapy with eptifibatide in high risk with NSTE-ACS did not improve ischaemic complications but was associated with an increase in bleeding complications. Therefore GP IIb/IIIa antagonists should be given after the initial angiography and the decision the perform PCI in troponin positive patients with NSTE-ACS.In patients with STEMI undergoing primary PCI the prehospital administration of tirofiban was associated with an improved myocardial reperfusion. In contrast in the BRAVE 3 trial abciximab in patients with pretreatment with 600 mg clopidogrel did not reduce infarct size or improve clinial outcome. Comparative trials evaluating the effectiveness of abciximab and the small molecules tirofiban and eptifibatide did not show any differences between the three GP IIb/IIIa antagoniosts.

Calcium-Channel Blockers in Acute Myocardial Infarction

The calcium-channel blockers are useful in treating a variety of cardiovascular disorders. Due to their antiischemic and spasmolytic properties, these agents have been studied in the prophylaxis and treatment of acute myocardial infarction. This article reviews this application with respect to reduction of mortality, infarct size, and reinfarction rate. Of the agents currently available for clinical use, nifedipine has been studied most extensively. This agent shows no beneficial effects in this setting and its use may in fact be harmful. Of the few trials that have been conducted with verapamil, none have shown decreased mortality. Verapamil may reduce infarct size although further confirmation is required. Diltiazem is the only agent that has been shown to have short- and long-term benefits in the patient with acute myocardial infarction. Proper patient selection is of utmost importance in ensuring successful therapy. In particular, those patients with non-Q-wave infarctions and/or normal left ventricular function can be expected to derive the most benefit in terms of reducing mortality and reinfarction rate associated with the acute event.

REDUCTION OF EARLY MORTALITY AND OF CARDIAC RUPTURE IN ACUTE TRANSMURAL MYOCARDIAL INFARCTION BY INTRAVENOUS STREPTOKINASE

Patients (Pts)≤ 70 years old with a first transmural AMI of ≤ 4h (164±55 min) were randomized to receive (Group I,GI n=105) or not (GII, n=102) i.v. streptokinase (SK, 840.000U in lh).Contrc ST segment elevation and at lh and 24h after admission were comparable in both groups. Coronary arteriography performed within 15 days showed a recanalization rate of 64% in GI and of 27% in GII (p<0.001)but an incidence of severe stenosis (≥90<100%) higher in GI (46 vs 22%, p<0.01).Recanalized Pts presented an earlier peak of MB creatin kinase in GI (12 vs 16h p<0.01) as well as in GII (15 vs 21h, p<0.002). The incidence of pericarditis was lower in GI (14 vs 35%, p<0.001). Although hospital mortality was comparable in the 2 groups (GI,8% vs GII,11%), early mortality, <5 days, was lower in GI (2 vs 10%, p<0.02). Sudden electromechanical dissociation was the mechanism of death in 12% of patients from GI and in 77% of those from GII and it was associated with left ventricular free wall rupture in each of the 5 autopsied cases but in none of the 5 autopsied cases who died without electromechanical dissociation During a follow-up of 20±11 months (1-36) , mortality an incidence of angina was similar in both groups but reinfarction rate was higher in GI (16 vs 1%, p<0.05).It is concluded that: 1) In contrast with the changes in ST .segment, an early MB creatin kinase peak is a reliable marker of reperfusion; 2) i.v. SK lowers the incidence of pericarditis and of early mortality reducing the incidence of cardiac rupture; and 3) It is conceivable that early treatment of critical residual stenosis will reduce in hospital mortality and reinfarction in these Pts.