Can the ECG be used to estimate age-related survival?

Abstract

Summary Background There are few reports of the relationship between electrocardiogram (ECG) findings and the age-related survival of acutely ill patients. Aim This study compared the 1-year survival curves of patients attending two Danish emergency departments (EDs) with normal and abnormal ECGs. Patients were divided into age groups from 20 to 90 years of age, and an abnormal ECG was defined as low QRS voltage (i.e. lead I + II <1.4 mV) or QTc interval prolongation >434 ms. Methods A retrospective register-based observational study on 35 496 patients attending two Danish EDs, with 100% follow-up for 1 year. Results ECG abnormality increases linearly with age, and between 30 and 70 years of age. Patients aged 20–29 years with ECG abnormalities are more than four times more likely to die within a year than patients of the same age with a normal ECG. An individual with an abnormal ECG has the same risk of dying within a year as an individual with a normal ECG who is 10 years older. After 70 years of age this tight relationship ends, but for younger individuals with an abnormal ECG the increase in mortality is even higher. Conclusion An ECG may be a simple practical estimate of age-related survival. For a patient under 70 years, an abnormal QRS voltage or a prolonged QTc interval may increase 1-year mortality to that of a patient ∼10 years older.