Impaired glucose tolerance and future cardiovascular risk after coronary revascularization: a 10-year follow-up report

Aims: Practical management guidelines for impaired glucose tolerance (IGT) have not been established. Although IGT is a potent marker of cardiovascular disease (CVD), it is still controversial whether its magnitude of CVD risk is comparable to that of frank diabetes. Moreover, information on long-term clinical outcomes of IGT patients undergoing coronary revascularization is limited. The aim of the present work was to investigate the 10-year prognostic impact of IGT in comparison with diabetes in patients with CAD undergoing coronary revascularization. Methods: This cohort recruited from two Japanese clinical sites included patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI) between 2004 and 2008. Patients were categorized into previously known diabetes (PKD, n = 197), newly diagnosed diabetes (NDD, n = 51), and IGT (n = 50) groups according to oral glucose tolerance test results except for PKD. The primary end point was defined as a composite of cardiovascular death, myocardial infarction, stroke, repeat revascularization, and heart failure hospitalization. Results: The cumulative risk of the primary outcome was significantly higher in the PKD and IGT than in the NDD (log-rank test p = 0.017). A Cox proportional hazards model demonstrated that IGT (hazard ratio [HR], 7.91; 95% confidence interval [CI], 1.84–27.58) and creatinine clearance (HR, 7.89, 95% CI, 2.73–19.10) were predictors of long-term CVD risk, while NDD and PKD were not. Conclusions: IGT significantly increased the long-term risk of developing CVD in patients with CAD after PCI compared with diabetes.