Effects of Teneligliptin on the Progressive Left Ventricular Diastolic Dysfunction in Patients with Type 2 Diabetes Mellitus in Open-Label, Marker-Stratified Randomized, Parallel-Group Comparison, Standard Treatment-Controlled Multicenter Trial (TOPLEVEL Study): Rationale and Study Design

Background and Aims Diabetes mellitus (DM) can cause left ventricular (LV) diastolic dysfunction, leading to heart failure with preserved ejection fraction (HFpEF). Dipeptidyl peptidase IV (DPP-IV) inhibitors have failed to reduce hospitalization due to HF in type 2 DM (T2D) patients in a large-scale clinical trial, despite their cardiovascular protective effects. Therefore, it is important to investigate whether DPP-IV inhibitors can improve LV diastolic dysfunction in T2D patients. The aim of the study was to evaluate whether teneligliptin, the strongest of the DPP-IV inhibitors, improves LV dysfunction or prevents the worsening of LV diastolic function in T2D patients. Methods The TOPLEVEL study is designed as an open-labeled, marker-stratified randomized, parallel-group comparison, standard treatment-controlled multicenter study. TOPLEVEL includes two marker-defined subgroups to give treatment recommendations for T2D patients with normal (E/e′ < 8) or impaired LV diastolic function (E/e′ ≥ 8), where E/e′ is the ratio of peak velocity of early transmitral diastolic filling by echocardiography to early diastolic mitral annular velocity by tissue Doppler echocardiography as LV diastolic function. Patients are randomly assigned to either teneligliptin (20 or 40 mg) or the standard treatment group. All patients are followed up for 2 years. The primary endpoint measure is the change in E/e′ from baseline and 2 years after enrollment. Conclusion and Perspectives TOPLEVEL is a clinical trial of teneligliptin targeting LV diastolic dysfunction in T2D patients. This study demonstrates the effectiveness of DPP-IV inhibitors on LV diastolic dysfunction, an important surrogate endpoint to predict the cardiovascular outcomes of HFpEF (UMIN000014589).