Effects of sodium-glucose cotransporter 2 inhibitors on cardiac metabolism, assessed by phosphorus magnetic resonance spectroscopy, in patients with heart failure
P Rubis, E Dziewiecka, R Banys, M Lisiecka, M Swieczewski, M Urbanczyk-Zawadzka, J Szachowicz-Jaworska, S Wisniowska-Smialek, M Winiarczyk, K Graczyk, N Przytula, A Stepien-Wroniecka, J G F ClelandAbstract
Background
Sodium-glucose co-transporter 2 inhibitors (SGLT2i) improve outcomes for patients with heart failure (HF), by diverse mechanisms with varying levels of evidence. One proposed mechanism is enhanced myocardial energy efficiency, but there is little clinical evidence to support this hypothesis.
Methods
In this prospective, single-centre observational study, 32 patients with HF [median age 60 (50 to 66) years), a left ventricular ejection fraction (LVEF) ≤50% and no prior exposure to SGLT2i] underwent comprehensive evaluation, including cardiac magnetic resonance imaging with phosphorus-magnetic resonance spectroscopy (31P-MRS) before and 6-months after initiation of SGLT2i and optimisation of other HF therapies.
Results
At baseline, patients exhibited altered myocardial energy metabolism compared to healthy controls, with lower PCr/ATP ratios [0.67 (0.46-0.89) vs. 1.11 (0.79-1.96), p=0.02]. No significant changes in 31P-MRS were detected six months after initiating SGLT2i [PCr/ATP 0.8 (0.5-1.3) vs. 0.7 (0.3-1.3), p=0.84; Pi/PCr 0.7 (0.4-0.9) vs. 0.6 (0.4-1.1), p=0.84; Pi/ATP 0.4 (0.3-0.7) vs. 0.3 (0.2-0.6), p=0.84; respectively] (Figure 1, Table 1).
Conclusions
Patients with HF have impaired myocardial energy metabolism but this does not improve after treatment with SGLT2 inhibitors. These findings suggest that direct effects on cardiac metabolism do not contribute to the well-established benefits of SGLT2i in patients with HF and a reduced LVEF.For image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.