Identify patients who should be referred to direct percutaneous revascularization, who present late into a STEMI.

Patients who present with ongoing ischemic symptoms or cardiogenic shock more than 12 hours from onset of symptoms should be referred for direct percutaneous revascularization. If direct percutaneous revascularization is not available at the receiving facility, patients should be transferred to a facility with percutaneous revascularization capability.

DISCUSSION

The speed with which coronary blood flow is reestablished, following the onset of symptoms, relates directly to overall patient mortality. Only one prospective, placebo-controlled thrombolytic study has evaluated patients presenting more than 12 hours from onset of symptoms. When evaluating patients given alteplase 12 to 24 hours from onset of symptoms, the LATE trial found no significant mortality difference when compared to controls (8.7% versus 9.2%, p=0.14) (LATE, 1993). Though not a controlled trial, registry data from the MITRA Study Group suggests that direct percutaneous revascularization can be performed safely in patients who present late into their MI. When compared to patients who met standard criteria for thrombolytic trials, but underwent percutaneous revascularization, in-hospital mortality was similar (6% versus 6%), while the combined end points of death, reinfarction, heart failure, stroke, and post infarction angina was higher in the group treated late (33% versus 18%) (Zahn et al., 1999). The SHOCK trial randomized patients who developed cardiogenic shock within 36 hours of infarction and were randomized within 12 hours of the diagnosis of shock. In this study, emergent revascularization was associated with an improved 6-month mortality (50.3% versus 63%, p=0.027) (Hochman et al., 1999).