446-P: Antihyperglycemic Medication Initiation after Cardiovascular Hospitalization in Older Adults with Diabetes Increases Hypoglycemia without Improving Survival

Background: The short-term safety and long-term cardiovascular benefits of initiating new antihyperglycemic medications at hospital discharge are unclear, especially for elderly patients with acute cardiovascular disease. This study aimed to determine if initiation of a new diabetes medication is associated with differences in outcomes in this patient population.

Methods: This was a population-based cohort study of individuals ≥65 years with diabetes on antihyperglycemic medication who were discharged from a hospitalization for heart failure, acute myocardial infarction, or stroke in Ontario, Canada from April 2011 to March 2019. We categorized individuals based on initiation of a new diabetes medication (initiators) within 30 days of discharge. Primary outcome was a composite of death or cardiovascular hospitalization. Secondary outcome was rate of hypoglycemia. We performed a Cox-regression on a propensity matched cohort.

Results: A total of 54,117 individuals were included, with 5,129 (9.5%) initiators and 48,988 (90.5%) non-initiators. Median age was 78 years (IQR 71-84) and 56.7% were male. Matched pair analysis included 4,844 pairs of initiators and non-initiators with standardized differences of ≤0.05 for all baseline variables. Median follow-up was near 2.2 years in both groups. There were no significant differences in the hazard of the composite of death/cardiovascular hospitalization (HR 0.97, 95% CI 0.92-1.02, p=0.18) or the hazard of death (HR 0.98, 95% CI 0.93-1.04, p=0.56). There was a higher risk of hypoglycemia among initiators (113 [2.3%] vs 76 [1.6%]) within one year of follow-up (HR: 1.49, 95% CI 1.12-1.98, p=0.007).

Conclusion: Starting a new antihyperglycemic medication in patients with diabetes who are discharged after hospitalization for a cardiovascular event is associated with an increased risk of hypoglycemia but does not reduce mortality or cardiovascular events.