The subgroup analysis of heart failure risk by individual GLP-1 agonists agents suggested a possibility of differential treatment effect across individual agents (interaction p = 0.07), with liraglutide associated with a non-significant increased risk for heart failure (OR 4.85, 95 % CI 0.75 to 31.36); this finding was however based on a limited number of events (five in total) and characterized with very wide confidence interval. This evidence concerns the gene GCG and heart failure.