Electrocardiography-defined silent CHD and risk of cardiovascular events among diabetic patients in a Middle Eastern population

Background: We assessed the clinical outcomes of symptomatic and asymptomatic coronary heart disease (CHD) with type 2 diabetic patients. Design: Population-based cohort study. Methods: The study sample consisted of 380 men and 546 women, aged ≥30 years. Silent CHD was defined using Minnesota coding criteria on baseline electrocardiogram (ECG), in the absence of a history of CHD and symptoms of angina. Participants were categorized into four groups: group 1, participants with no CHD symptoms and with normal ECG; group 2, silent CHD; group 3, participants with symptomatic CHD but with normal ECG; group 4, participants with symptomatic CHD and ECG-determined CHD. Cox regression analysis was used to estimate the hazard ratios (HRs) of cardiovascular disease (CVD) and CHD events for these groups, with group 1 as the reference.Results: During median follow up of 9.2 years, we ascertained 226 CVD events (202 CHD). In the multivariable-adjusted model, among men, HRs (95% CI) of CVD events were 2.32 (1.29-4.16), 2.56 (1.47-4.46), and 3.97 (2.24-7.02) for groups 2, 3, and 4, respectively; the corresponding figures among women were 1.19 (0.65-2.18), 1.90 (1.24-2.92), and 1.92 (1.02-3.62) respectively. Similar results were achieved for CHD events. Conclusion: In both sexes, symptomatic CHD was an independent predictor of recurrent CVD/CHD, regardless of ECG results. In diabetic men with asymptomatic CHD, ECG could be of prognostic value for incident CVD/CHD. The present study provides evidence-based support only in men for the ADA recommendation of 'further cardiac testing for diabetic patients with an abnormal resting ECG'.