Lead Investigator: João Sérgio Neves, Faculdade de Medicina da Universidade do Porto
Title of Proposal Research: Effect of Exenatide Across the Spectrum of Ejection Fraction An analysis from the EXSCEL trial
Vivli Data Request: 9286
Funding Source: None
Potential Conflicts of Interest: None
Summary of the Proposed Research:
Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RAs) are a type of medication used to treat diabetes (a condition where the body cannot control it’s own blood sugar levels) and obesity. This type of medication has been shown to have a number of cardiovascular benefits, such as reducing the risk of heart attack and stroke. However, concerns have been raised from previous studies regarding potential risks associated with the use of GLP-1 RAs in people with a specific type of heart condition called heart failure with reduced ejection fraction (when the heart’s lower left chamber (left ventricle) doesn’t pump blood out to the body as well as it should).
To better understand the effects of GLP-1 RAs among those with heart failure with reduced ejection fraction we will evaluate the data from the “Exenatide Study of Cardiovascular Event Lowering” (EXSCEL) trial, which investigated the effects of a GLP-1 RA called exenatide in people with diabetes. In our analysis, we will focus he impact of GLP-1 RAs on heart-related outcomes, such as the risk of being hospitalized due to heart failure, cardiovascular death, heart attacks, or strokes. We will examine, in patients with echocardiographic data available (data from a scan used to look at the heart and nearby blood vessels), how these heart-related outcomes vary based on the ejection fraction of the patients when they entered the study. The EXSCEL study is particularly suited for this analysis due to the high proportion of patients with available data on ejection fraction.
The safety of GLP-1 RAs in patients with heart failure with reduced ejection fraction is particularly relevant, considering that over 500 million people worldwide live with diabetes, and among them, 10 to 20 percent also have heart failure. This proposal aims to fill this gap in knowledge by studying the effects of exenatide on cardiovascular outcomes according to baseline left ventricle ejection fraction in patients with type 2 diabetes in the EXSCEL trial.
Statistical Analysis Plan:
Participants of the EXSCEL trial with echocardiographic data available will be divided into two subgroups according to baseline left ventricle ejection fraction (LVEF, <40% vs ≥40). Their clinical characteristics will be described as mean (standard deviation) or medians (percentile25-75) for continuous variables and number (%) for categorical variables and compared through Student’s t-test, Mann-Whitney and Chi2 tests, as appropriate. The effect of exenatide vs. placebo will be tested using Cox models for time-to-first event analyses with treatment group as explanatory variable and LVEF at baseline as stratification variable, with treatment-by-LVEF interaction term in the model. The results will be presented separately according to baseline left ventricle ejection fraction (LVEF, <40% vs ≥40), along with the respective interaction P-value. Analyses will be performed according to the intention-to-treat principle. The Kaplan-Meier method will be used to estimate event rates. Adverse events will be studied among patients who received at least one dose of the study drug using logistic regression models with treatment group as explanatory variable and LVEF at baseline as stratification variable, with treatment-by-LVEF at baseline interaction term in the model. Restricted cubic splines will be used to plot the flexible relationship between ejection fraction as a continuous variable and the incidence of each endpoint. An analysis restricted to participants with previous diagnosis of heart failure at baseline will also be performed. No adjustment for multiplicity will be performed given the exploratory nature of this analysis. Patients with missing data will be excluded from analysis for that specific variable but included in the analysis of other variables. A two-sided P-value <0.05 will be considered statistically significant for main effects, and a two-sided P-value <0.10 will be considered statistically significant for interaction tests, which have less statistical power. Analyses will be performed using Stata® (StataCorp. 2021. Stata Statistical Software: Release 17. College Station, TX: StataCorp LLC).
Requested Studies:
D5551C00003 – Exenatide Study of Cardiovascular Event Lowering Trial (EXSCEL): A Trial To Evaluate Cardiovascular Outcomes After Treatment With Exenatide Once Weekly In Patients With Type 2 Diabetes Mellitus
Data Contributor: AstraZeneca
Study ID: NCT01144338
Sponsor ID: N/A
Public Disclosure:
Neves, J.S., Leite, A.R., Mentz, R.J., Holman, R.R., Zannad, F., Butler, J., Packer, M. and Ferreira, J.P., 2024. Cardiovascular outcomes with exenatide in type 2 diabetes according to ejection fraction: The EXSCEL trial. European Journal of Heart Failure. Doi: 10.1002/ejhf.3478