Predicting sudden cardiac death in a general population using an electrocardiographic risk score

Objective We investigated whether combining several ECG abnormalities would identify general population subjects with a high sudden cardiac death (SCD) risk. Methods In a sample of 6830 participants (mean age 51.2 +/- 13.9 years; 45.5% male) in the Mini-Finland Health Survey, a general population cohort representative of the Finnish adults aged >= 30 years conducted in 1978-1980, we examined their ECGs, following subjects for 24.3 +/- 10.4 years. We analysed the association between individual ECG abnormalities and 10-year SCD risk and developed a risk score using five ECG abnormalities independently associated with SCD risk: heart rate >80 beats per minute, PR duration >220 ms, QRS duration >110 ms, left ventricular hypertrophy and T-wave inversion. We validated the score using an external general population cohort of 10 617 subjects (mean age 44.0 +/- 8.5 years; 52.7% male). Results No ECG abnormalities were present in 4563 subjects (66.8%), while 96 subjects (1.4%) had >= 3ECG abnormalities. After adjusting for clinical factors, the SCD risk increased progressively with each additional ECG abnormality. Subjects with >= 3ECG abnormalities had an HR of 10.23 (95% CI 5.29 to 19.80) for SCD compared with those without abnormalities. The risk score similarly predicted SCD risk in the validation cohort, in which subjects with >= 3ECG abnormalities had HR 10.82 (95% CI 3.23 to 36.25) for SCD compared with those without abnormalities. Conclusion The ECG risk score successfully identified general population subjects with a high SCD risk. Combining ECG risk markers may improve the risk stratification for SCD.