Electrocardiographic Abnormalities and Cardiovascular Disease Risk in Type 1 Diabetes: The Epidemiology of Diabetes Interventions and Complications (EDIC) Study

OBJECTIVE: We examined the association between the prevalence and incidence of electrocardiographic (ECG) abnormalities and the development of cardiovascular disease (CVD) in patients with type 1 diabetes, among whom these ECG abnormalities are common. RESEARCH DESIGN AND METHODS: We conducted a longitudinal cohort study involving 1,306 patients with type 1 diabetes (mean age 35.5 ± 6.9 years; 47.7% female) from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study. ECG abnormalities were defined by the Minnesota Code ECG classification as major, minor, or no abnormality. CVD events were defined as the first occurrence of myocardial infarction, stroke, confirmed angina, coronary artery revascularization, congestive heart failure, or death from any CVD. RESULTS: During a median follow-up of 19 years, 155 participants (11.9%) developed CVD events. In multivariable Cox proportional hazard models adjusted for demographics and potential confounders, the presence of any major ECG abnormalities as a time-varying covariate was associated with a more than twofold increased risk of CVD events (hazard ratio [HR] 2.10 [95% CI 1.26, 3.48] vs. no abnormality/normal ECG, and 2.19 [1.46, 3.29] vs. no major abnormality). Also, each visit (year) at which the diagnosis of major ECG abnormality was retained was associated with a 30% increased risk of CVD (HR 1.30 [95% CI 1.14, 1.48]). The presence of minor ECG abnormalities was not associated with a significant increase in CVD risk. CONCLUSIONS: The presence of major ECG abnormalities is associated with an increased risk of CVD in patients with type 1 diabetes. This suggests a potential role for ECG screening in patients with type 1 diabetes to identify individuals at risk for CVD.