ECG abnormalities are strongly associated with incident heart failure events in low-risk individuals using the PREVENT HF risk equations

Background: Resting electrocardiogram (ECG) are associated with heart failure (HF) events, even though it is not currently recommended in risk assessment. Objective: To examine the association between ECG abnormalities and incident HF events according to the 2023 PREVENT HF equation. And identify a subgroup of individuals who are misclassified as being at low risk. Design: Secondary data analysis from the REasons for Geographic And Racial Differences in Stroke (REGARDS) prospective cohort, including study participants without baseline HF. Exposure: ECG abnormalities were classified by Minnesota Code (MC) as normal, only minor, or any major abnormality at baseline (2003-2007). Outcome: Participants were followed for expert adjudicated incident HF hospitalizations/ deaths through December 2021. Results: Among 20,923 participants (mean age at baseline 63.6 years, 53.7% female), 26.0% of the sample was classified as low risk (<3%), 17.5% as borderline risk (3-<5%), 27.5% as intermediate risk (5%-<10%), and 29.0% as high risk (10%). Compared to those without ECG abnormality, the adjusted HR for incident HF was 1.56 (95% CI 1.35-1.80) for any minor abnormality and 2.56 (2.18-3.00) for any major abnormality. 43.5% of the population were in the less than 5% risk by PREVENT among whom 45.8% had any ECG abnormalities. The fully adjusted HR for only minor ECG abnormalities in the <3% was 1.47 (95% CI 0.72-3.01), and the fully adjusted HR for any major ECG abnormality was 5.22 (95% CI 2.42-11.30). In the borderline risk group, the fully adjusted HR for only minor ECG abnormalities was 1.37 (95% CI 0.89 - 2.11), and the fully adjusted HR for any major ECG abnormality was stronger than the HR in the intermediate and high-risk groups; 3.05 (95% CI 1.85 - 5.03). Conclusion: ECG abnormalities were common and associated with HF events across all PREVENT risk groups, especially in the low/borderline risk groups with major ECG abnormalities.