Following myocardial infarction, one drawback of several reperfusion strategies is the potential to activate platelet and inflammatory mechanisms, which exacerbates micro-vascular dysfunction. Several studies have indicated that abciximab, a potent antiplatelet agent, can contribute to myocardial salvage. Kastrati and colleagues compared the two leading reperfusion strategies of stenting and fibrinolysis when each was combined with abciximab.
They studied patients presenting within 12 hours of onset of symptoms of proven myocardial infarction as demonstrated by ST segment changes of at least 0.1 mV in two or more limb leads, or at least 2.0 mV in two or more contiguous precordial leads, or complete left bundle branch block of new onset. Patients with contraindications to reperfusion or anticoagulation were excluded. More than 160 patients were randomly assigned to intravenous fibrinolysis or stenting, each plus abciximab. All patients also received aspirin and clopidogrel. Scintigraphy was performed on admission and repeated after seven to 14 days to document the extent of myocardial damage. The primary end point was the salvage index, defined as the proportion of the initial perfusion defect salvaged by reperfusion therapy. The study also monitored clinically significant events in patients for six months after the acute myocardial infarction.
The 81 patients assigned to stenting were similar in all significant variables to the 81 patients receiving alteplase. The initial perfusion defect was similar in size in the two groups. The stent was not necessary in three cases. The left anterior descending coronary artery was the target vessel in 48 percent of cases. Five patients assigned to fibrinolysis required rescue stenting, but no patients in the stenting group required more than one intervention. At discharge, the two groups of patients were receiving similar treatment based on aspirin, beta blockers, angiotensin-converting enzyme inhibitors, and statins. Follow-up scintigraphy was performed in 88 percent of patients in the stent group and 94 percent of those receiving alteplase. The salvage index was significantly greater in the stent group, and this group also had fewer deaths within six months (5 percent compared with 9 percent). The groups were similar in bleeding complications, but four alteplase patients experienced recurrent myocardial infarction, and three required urgent coronary artery surgery. At six months, the combined rate of death and recurrent myocardial infarction was 7.4 percent in the stent group compared with 17.3 percent in the fibrinolysis group.
The authors conclude that stenting plus abciximab resulted in greater myocardial salvage than alteplase plus abciximab. They call for larger studies to confirm this advantage.