Comparing the Prognostic Impact of Prediabetes with Diabetes in a Nationwide Cohort of Patients with Chronic Coronary Syndromes: An Analysis of the START Registry

Aims: Using data from the nationwide prospective START registry that enrolled a large cohort of patients with chronic coronary syndromes (CCS), we aimed to investigate whether the presence of diabetes mellitus (DM) and pre-DM independently affected the risk of cardiovascular events at 1-year follow-up. Methods: We assessed the impact of DM and pre-DM on all-cause mortality and a composite of all-cause mortality and hospitalization for cardiovascular causes at 1-year follow-up. Results: Among the 3,778 patients with available fasting plasma glucose data at study entry, 37% were classified as DM, 25% as pre-DM, and 38% as no DM. At 1 year, patients with DM had higher rates of all-cause death (p = 0.004) and death/cardiovascular hospitalization (p = 0.003) than those with pre-DM or without DM. Conversely, no significant differences in the adverse event rate were found between patients with pre-DM and those without DM. At unadjusted Cox analysis, DM resulted as a predictor of both death for any cause (hazard ratio [HR]: 2.41; 95% confidence intervals [CI]: 1.34–4.34; p = 0.003) and all-cause death/hospitalization for cardiovascular causes (HR: 1.29; 95% CI: 1.02–1.62; p = 0.03). However, DM did not result as an independent predictor of either endpoint at multivariate analysis. Conclusions: The risk of 1-year major events among patients with CCS and pre-DM is comparable to that of patients with CCS and normoglycemic status and is lower than that of patients with DM.