Is the ECG useful in predicting outcome of heart disease?

This study aimed to determine whether the QRS duration from an ECG could be used to predict long term outcomes in patients with heart disease. The authors concluded that a QRS duration of 120ms or more was capable of predicting  the risk of a heart attack and also the risk of death from heart-related causes.

Electrocardiography (ECG) is a procedure used to measure the electrical activity of the heart. The QRS duration is a measurement recorded during the ECG procedure and is used in the management of heart disease. A QRS duration of less than 120 milliseconds (ms) is generally considered normal. It is suggested that the QRS duration could be used to predict outcomes of patients with coronary artery disease (build-up of substances in blood vessels). 

Patients with known or suspected coronary artery disease were recruited into the study.

512 patients underwent myocardial perfusion imaging (procedure to look at how blood flows through the heart). ECG was performed and the QRS duration was obtained. Patients were followed-up for an average of 8.6 years.

22% of patients had a QRS duration of 120 ms or more. An abnormal myocardial perfusion imaging was observed in 58% of patients.

Each year, 3% of patients with abnormal myocardial perfusion imaging and 2.1% of patients with normal myocardial perfusion imaging died due to heart-related causes. 2.2% of patients with QRS duration of less than 120 ms and 4.1% of patients with QRS duration greater than 120 ms died each year due to heart-related causes.  

QRS duration of more than 120 ms could predict heart-related death or heart attack, and gives more information on outcomes compared to myocardial perfusion imaging and clinical characteristics. In combination with myocardial perfusion imaging and clinical characteristics, patients with a QRS duration of 120 ms or more had a 1.93 times higher risk of death from heart-related causes. 

The authors concluded that a QRS duration of 120ms or more could predict the risk of a heart attack and also the risk of death from heart-related causes.

Both patients with known or suspected coronary artery disease were studied.