The HERO-2 ECG sub-studies in patients with ST elevation myocardial infarction: implications for clinical practice

The ECG studies of the international HERO-2 trial in ST elevation myocardial infarction (STEMI) patients evaluated the prognostic value of ECGs systematically recorded at baseline and at 60-min post-administration of fibrinolytic therapy. Patients were overall managed conservatively with a low percentage undergoing angiography. Many of the analyses were pre-specified. While modern management of STEMI has improved, particularly with the widespread use of primary angioplasty, the HERO-2 database documents the prognostic relationship between ECG findings in STEMI patients managed with fibrinolytic therapy and 30-day mortality. This article describes the history of the HERO-2 ECG sub-studies, discloses new information in the project development and summarizes its findings. The strength of having serial ECG recordings is discussed as is the weakness of lacking angiographic correlation. The paper discusses with take-home points (Table 1) the prognostic implications of bundle branch blocks, QRS duration, Q waves in infarct leads, V1 ST elevation during inferior STEMI, lead aVR ST changes and new ST depression in the infarct leads after fibrinolysis. With the ever increasing emphasis on early (including pre-hospital) therapies for STEMI, a diagnosis based on the 12-lead ECG, the current summary article provides helpful hints to fully extract ECG information, and a vision for future STEMI diagnosis and management.