Survival in Type 1 and Type 2 Diabetes in a Population Referred for Invasive Evaluation of Coronary Disease

Abstract

Objectives: To evaluate long-term and time trends of survival in patients with a clinical diagnosis of type 1 and type 2 diabetes compared to patients without diabetes in a population referred for invasive treatment of coronary disease. Methods: Patients examined for heart disease at the Feiring LHL Clinics from March 1999 until December 2014 were followed for survival until 20 September, 2015. This yielded 43,872 patients with a known survival status including 1,326 (3.0%) patients with type 1 diabetes and 4,564 (10.9%) with type 2 diabetes. Results: Cox regression revealed a hazard ratio (HR) in type 1 and type 2 diabetes, respectively, of 1.78 (95% confidence interval [CI] 1.60-1.99) and 1.29 (95% CI 1.21-1.37). Comparing survival in the treatment periods before and after 2007, patients without diabetes and with type 2 diabetes had a reduced HR of 0.78 (95% CI 0.72-0.84) and 0.76 (95% CI 0.63-0.91), respectively, but there was no reduction in type 1 diabetes (HR 1.03; 95% CI 0.74-1.42). Conclusions: Type 1 and type 2 diabetes have excess long-term mortality. In the nondiabetic and type 2 diabetic patients, a reduction in mortality has been noted in recent years, but has not been observed in type 1 diabetic patients.