Cardiovascular outcomes trial data from EMPA-REG OUTCOME, CAROLINA and CARMELINA: Assessment of a novel staging system for type 2 diabetes

Abstract

Aims: To apply the diabetes staging system (DSS), a novel disease staging system similar to what is used in oncology but designed to improve diabetes management, to three large type 2 diabetes (T2D) cardiovascular (CV) outcome trials to assess whether increasing DSS stage was associated with higher rates of all-cause mortality (ACM) and/or CV death. Materials and Methods: The DSS uses discrete CV events (none to ≥3: Stage 1 to 4), end-stage kidney disease (Stage 5) and microvascular complications (none to 3: A to D) to determine disease stage in individuals with T2D. The DSS stage for patients from the CAROLINA, EMPA-REG OUTCOME and CARMELINA trials was determined. Incidence rates for ACM/CV death were calculated across DSS stages and Cox regression analyses were performed. Results: The risk of ACM or CV death increased with increasing DSS (Stage 1 to 5; P for trend <0.0001) in all trials. In CAROLINA, the risk of ACM and CV death increased with increasing number of microvascular complications (A to D; both P for trend <0.0001), similar in CARMELINA (P for trend = 0.0020 and 0.0005, respectively). In EMPA-REG OUTCOME, having all three microvascular complications (Stage D), versus none, increased the risk of ACM and CV death (P = 0.0015 and 0.0010, respectively). Conclusions: Applying the DSS across T2D clinical trial populations with different CV risk revealed a significantly increased risk of ACM and CV death with higher DSS stage. The DSS may merit assessment in other T2D populations and evaluation of the impact of additional outcomes, such as heart failure, could also be worthwhile.