Mechanistic Insights of Empagliflozin in Nondiabetic Patients With HFrEF: From the EMPA-TROPISM Study

Effects of the sodium-glucose cotransporter 2 inhibitor empagliflozin on vascular function in patients with chronic heart failure

AIMS

Impairment of vascular function contributes to the progression of chronic heart failure (HF) by increasing the afterload. Treatment with selective sodium-glucose cotransporter 2 (SGLT2) inhibitors improves the prognosis of HF, but the precise mechanisms remain unclear. The aim of this study was to analyse the effect of empagliflozin on vascular function in patients with HF.

METHODS AND RESULTS

In an investigator initiated, double-blind, randomized, placebo-controlled, parallel-group, clinical study, patients with HF NYHA II-III and an ejection fraction of 49% or less were randomized 2:1 to receive empagliflozin 10 mg once daily or placebo for 3 months. A total of 74 patients (15% female), aged 66 ± 9 years, with a mean ejection fraction of 39 ± 8% and a median NTproBNP of 558 pg/mL (IQR 219-1051 pg/mL), were included. Vascular parameters such as central systolic blood pressure (cSBP), central pulse pressure (cPP), forward (FPH), and reflected pressure pulse height (RPH) decreased under resting conditions after 1 and 3 months (1 month: cSBP -6.4 ± 8.3 mmHg, P < 0.001, cPP -3.0 ± 6.6 mmHg, P = 0.004, FPH -2.5 ± 4.5 mmHg, P = 0.001, RPH -1.6 ± 3.0 mmHg, P = 0.001; 3 months: cSBP -4.6 ± 8.4 mmHg, P = 0.001, cPP -3.1 ± 4.8 mmHg, P < 0.001, FPH -1.7 ± 3.7 mmHg, P = 0.004, RPH -1.4 ± 2.5 mmHg, P = 0.001) in patients treated with empagliflozin (n = 45). In accordance, cSBP and cPP decreased in patients with empagliflozin treatment under 24 h ambulatory conditions after 1 and 3 months (1 month: cSBP -4.8 ± 10.1 mmHg, P = 0.003, cPP -2.0 ± 5.7 mmHg, P = 0.026; 3 months: cSBP -4.7 ± 9.0 mmHg, P = 0.002, cPP -2.1 ± 6.4 mmHg, P = 0.044). In the placebo group, there was no significant change after 1 and 3 months. The decrease in cSBP under resting conditions (-5.7 ± 2.4 mmHg, P = 0.019) after 1 month and in cSBP (-6.0 ± 2.6, P = 0.027) as well as in pulse wave velocity (-0.5 ± 0.2 m/s, P = 0.021) under 24 h ambulatory conditions after 3 months was greater in the empagliflozin group than in the placebo group.

CONCLUSIONS

We found an improvement of vascular function after treatment with empagliflozin that indicates decreased afterload of the left ventricle and may contribute to the beneficial effects of SGLT2 inhibition in HF.

The Interplay between Myocardial Fibrosis, Strain Imaging and Collagen Biomarkers in Adults with Repaired Tetralogy of Fallot

Background: We sought to assess the interplay between right ventricle (RV) fibrosis, biventricular dysfunction based on global longitudinal strain (GLS) analysis, and biomarkers such as Galectin-3 (Gal-3), procollagen type III (PCIII), and NTproBNP. Methods: We studied 35 adult patients with rToF. All patients underwent a cardiac magnetic resonance (CMR) scan including feature tracking for deformation imaging. Blood biomarkers were measured. Results: LGE RV was detected in all patients, mainly at surgical sites. Patients with the highest RV LGE scoring had greater RV dilatation and dysfunction whereas left ventricular (LV) function was preserved. LV GLS correlated with RV total fibrosis score (p = 0.007). A LV GLS value of −15.9% predicted LGE RV score > 8 (AUC 0.754 (p = 0.02)). Neither RV GLS nor biomarker levels were correlated with the extent of RV fibrosis. A cut-off value for NTproBNP of 145.25 pg/mL predicted LGE RV score > 8 points (AUC 0.729, (p = 0.03)). A cut-off value for Gal-3 of 7.42 ng/mL predicted PR Fraction > 20% [AUC 0.704, (p = 0.05)]. Conclusions: A significant extent of RV fibrosis was mainly detected at surgical sites of RV, affecting RV performance. CMR-FT reveals subtle LV dysfunction in rToF patients, due to decreased performance of the fibrotic RV. Impaired LV function and elevated NTproBNP in rToF reflect a dysfunctional fibrotic RV.

Empagliflozin protects the heart against ischemia/reperfusion-induced sudden cardiac death

BACKGROUND

Empagliflozin is a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor used to lower blood sugar in adults with type 2 diabetes. Empagliflozin also exerts cardioprotective effects independent from glucose control, but its benefits on arrhythmogenesis and sudden cardiac death are not known. The purpose of this study was to examine the effect of empagliflozin on myocardial ischemia/reperfusion-provoked cardiac arrhythmia and sudden cardiac death in vivo.

METHODS

Male Sprague Dawley rats were randomly assigned to sham-operated, control or empagliflozin groups. All except for the sham-operated rats were subjected to 5-min left main coronary artery ligation followed by 20-min reperfusion. A standard limb lead II electrocardiogram was continuously measured throughout the experiment. Coronary artery reperfusion-induced ventricular arrhythmogenesis and empagliflozin therapy were evaluated. The hearts were used for protein phosphorylation analysis and immunohistological assessment.

RESULTS

Empagliflozin did not alter baseline cardiac normal conduction activity. However, empagliflozin eliminated myocardial vulnerability to sudden cardiac death (from 69.2% mortality rate in the control group to 0% in the empagliflozin group) and reduced the susceptibility to reperfusion-induced arrhythmias post I/R injury. Empagliflozin increased phosphorylation of cardiac ERK1/2 after reperfusion injury. Furthermore, inhibition of ERK1/2 using U0126 abolished the anti-arrhythmic action of empagliflozin and ERK1/2 phosphorylation.

CONCLUSIONS

Pretreatment with empagliflozin protects the heart from subsequent severe lethal ventricular arrhythmia induced by myocardial ischemia and reperfusion injury. These protective benefits may occur as a consequence of activation of the ERK1/2-dependent cell-survival signaling pathway in a glucose-independent manner.