DPP4 and type 2 diabetes mellitus: Another open observational non-crossover retrospective cohort study which was conducted between June 2012 and December 2013, and which compared the cardiovascular efficacy and safety of linagliptin, another DPP-4 inhibitor, also did not show any significant increase in cardiovascular events with the drug in these patients with T2DM and acute coronary syndrome [15].