Identify those patients who are likely to benefit most from reperfusion strategies.

Multiple studies have shown that patients who present within 12 hours of the onset of symptoms benefit the most from reperfusion strategies (i.e., percutaneous coronary intervention (PCI) or thrombolytic therapy). While consideration for reperfusion should be given for up to 12 hours, the risk:benefit ratio declines after the first 6 hours. Thus, clinical judgment should be used in the decision to give reperfusion therapy, such as ongoing ischemia, size and location of the MI.

The speed with which coronary blood flow is reestablished following the onset of AMI symptoms relates directly to overall patient mortality. Survival rates increase, both in the short term (i.e., within six weeks of presentation) and longer term (i.e., more than six months), if thrombolytic agents are given within at least 12 hours from the onset of symptoms. This benefit is most marked in patients receiving thrombolytic agents within three hours of the onset of symptoms. A nearly 45% greater survival rate is seen in patients treated with thrombolytic agents within 2 hours after onset of symptoms, as compared with patients treated more than six hours from symptom onset (FTT, 1994).

In general, patients who benefit most from thrombolytic agents are patients who have a BBB, an acute anterior wall or right ventricular MI, diabetes, or low systolic blood pressure (i.e., <100 mm Hg), tachycardia, or who present within six hours from onset of symptoms.