Use of the electrocardiogram in optimizing reperfusion for ST-elevation myocardial infarction: a new role for an old tool?

Abstract

Rapidly obtaining an electrocardiogram (ECG) is the critical first step in the evaluation of patients with chest pain. For >25 years, the ECG has been used to detect those patients with ST-elevation myocardial infarction (STEMI) who are eligible for reperfusion therapy with either fibrinolytic therapy or primary percutaneous coronary intervention (PCI).1,2 The ECG also has been instrumental in identifying those patients at highest risk for complications following STEMI and who may gain the most benefit from reperfusion therapy, based on features such as infarct location, the sum of ST-elevations, and the presence of reciprocal ST-depression or arrhythmias.3 Once patients with STEMI are identified, the decision to administer reperfusion therapy should be made as rapidly as possible and, ideally, it should be delivered within 12 h from symptom onset. Primary PCI is generally recognized as superior to fibrinolytic therapy due to its higher TIMI 3 (Thrombolysis In Myocardial Infarction) flow rates and lower rates of reinfarction, intracerebral haemorrhage, and mortality.4 However, primary PCI is not immediately available at many hospitals, and time delays in performing it may negate its advantages over fibrinolytic therapy.5 In fact, fibrinolytic therapy may actually be preferred when patients present very early after symptom onset and face potentially long delays to primary PCI.6 With these challenges in mind, risk stratification in STEMI has become increasingly important in selecting the optimal type of reperfusion therapy. The intent is to identify those patients who might benefit the most from primary PCI or, conversely, those who may be safely treated with fibrinolytic therapy. Using data from the landmark DANAMI-2 trial,7 for example, Thune et al. found that differences in mortality between primary PCI and fibrinolytic therapy were primarily driven by a high-risk subgroup of patients with TIMI risk scores of ≥5.8 … *Corresponding author. Tel:+1 734 936 8214; fax:+1 734 615 3326. E-mail address : ckasapis{at}med.umich.edu