Abstract P326: Progression of ECG Abnormalities through Young Adulthood and Early Cardiovascular Events: Coronary Artery Risk Development in Young Adults (CARDIA) Study

Abstract

Background: In older adults, ECG abnormalities are associated with significant independent risk for cardiovascular disease (CVD). However, the progression of ECG abnormalities from young adulthood to middle age and the implications of ECG progression as a risk marker for premature CVD events are poorly described. Methods: CARDIA is a NHLBI-funded longitudinal cohort study of black and white men and women aged 18-30 years at baseline (Year 0) in 1985. We included all CARDIA participants (ppts) who had resting 12-lead ECGs performed at the Year 0, 7 and 20 examinations. We classified ppts into one of 3 strata based on ECG findings (Minnesota code normal, minor, major) across time: 1) Always Normal at all 3 exams; 2) baseline minor or major abnormalities with Regression/No Progression over time; or 3) Progression of ECG from normal to minor or major, or minor to major, over time. We used Cox proportional hazards models to assess risk for adjudicated incident CVD events (MI, stroke, CHF) by ECG stratum during 25 years’ follow up. Results: There were 2193 ppts: 63.0% were Always Normal, 14.2% had Regression/No Progression, and 22.8% showed Progression. Those with Progression were more likely to be black and to smoke and had a slightly higher BMI. Baseline ECG abnormalities (major or minor) were not associated with increased risk for CVD. Among the Always Normal, Regression/No Progression and Progression groups, CVD incidence rates (per 1000 p-y) were 0.73, 0.13 and 1.85, respectively. In unadjusted models, those with Progression were 2.5 times more likely than those with Always Normal ECGs to develop incident CVD; these findings were attenuated by adjustment for demographics and clinical risk factors (Table). Those with Regression/No Progression were at lower risk. Conclusions: Progression of ECG findings from normal to abnormal or from minor to major abnormalities during young adulthood may be a useful marker of risk, identifying those destined to develop premature CVD events.