The study recruited 16,492 patients with type 2 diabetes who had a history of or were at risk of cardiovascular event. The participants were randomly assigned saxagliptin or placebo and followed them for a median of 2.1 years. All other therapies for the management of the patient could be adjusted at the discretion of the physicians managing the patient; this included drugs for the treatment of diabetes. The primary outcome of the study was a composite cardiovascular outcome consisting of cardiovascular death, myocardial infarction or stroke.
7.3% (613/8280) of the patients who received saxagliptin experienced the primary outcome compared to 7.2% (609/8212) in those who received placebo. There was a statistically significant increase in the rate of hospital admission for heart failure in the saxagliptin group with a hazard ratio 1.27 (95% CI 1.07–1.51, p=0.007).
The authors propose several explanations for the apparent lack of benefit in terms of cardiovascular outcomes including a relatively short period of follow up (2 years), small differences in the levels of glycated haemoglobin in the treatment and placebo arms of the study (7.5% versus 7.8% at the end of the study), and large proportions of patient in the trial received statins, antiplatelet therapy and blood-pressure–lowering agents which may have mitigated any cardiovascular benefit.
The authors conclude that, "saxagliptin did not increase or decrease the rate of ischemic events" and they recommend that "other approaches are necessary to reduce cardiovascular risk in patients with diabetes".
Action: The absence of a cardiovascular benefit leaves no compelling reason to use saxagliptin ahead of other second line oral hypoglycaemic agents. Clinicians should continue to follow the existing NICE guideline for Type 2 Diabetes.