Dapagliflozin improves Myocardial Flow Reserve in patients with Type 2 Diabetes: the DAPAHEART Trial

Abstract Objective Cardiovascular (CV) outcome trials have shown that in patients with type 2 diabetes (T2D), treatment with sodium-glucose cotransporter-2 inhibitors (SGLT-2i) reduces CV mortality and admission rates for heart failure (HF). However, the mechanisms behind these benefits are not fully understood. This study was performed to investigate the effects of the SGLT-2i dapagliflozin on whole body insulin sensitivity, myocardial perfusion, and metabolism in patients with T2D without HF. Research design and methods This was a single-center, prospective, randomized, double-blind controlled clinical trial including 16 patients with T2D randomized to SGLT-2i dapagliflozin (10 mg) or placebo. Whole body glucose uptake (WBGU) and myocardial glucose uptake (MGU) were measured with PET/CT with FDG during euglycemic hyperinsulinemic clamp. Stress (i.v. adenosine infusion) and resting myocardial blood flow (MBF) and myocardial flow reserve (MFR) were calculated by PET/CT with 13N-ammonia. Results 16 patients were randomized (8 dapagliflozin; 8 placebo). The groups were well-matched for baseline characteristics (age, diabetes duration, HbA1c, renal and heart function). Dapagliflozin significantly improved MFR (2.56±0.26 vs 3.59±0.35) compared with placebo group (2.34±0.21 vs 2.38±0.24; p for interaction =0.001) and was associated to a reduction of resting MBF corrected for cardiac workload (p=0.045). A trend toward an increase in stress MBF was also detected (p=0.058). Moreover, in dapagliflozin group we observed an increase of WBGU of borderline statistical significance (p=0.06) and no effects on MGU (p=0.41). Conclusions At the best of our knowledge, our study, for the first time, demonstrated that SGLT-2 inhibition increases MFR in T2D patients. The data presented provide a new potential explanation of cardiovascular benefits with SGLT-2i as they make patients more tolerant to the detrimental impact of obstructive coronary atherosclerosis on MFR. Funding Acknowledgement Type of funding sources: None.