Putative protective effects of sodium-glucose cotransporter 2 inhibitors on atrial fibrillation through risk factor modulation and off-target actions: potential mechanisms and future directions

Sodium-glucose co-transporter-2 inhibitors for the prevention of atrial fibrillation: a systemic review and meta-analysis

AIMS

Sodium-glucose co-transporter-2 (SGLT2) inhibitors are reported to have cardiac benefits. The effects of SGLT2 inhibitors on the prevention of atrial fibrillation (AF) remain inconclusive. We aimed to investigate whether SGLT2 inhibitors can prevent AF occurrence in patients with cardiometabolic diseases.

METHODS AND RESULTS

We searched MEDLINE, EMBASE, and the Cochrane CENTRAL database up to 1 July 2023. Randomized, placebo-controlled trials of SGLT2 inhibitors in patients with diabetes, heart failure, chronic kidney diseases (CKDs), or cardiometabolic risk factors were included. The primary outcome was AF occurrence. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated in the overall population and selected subgroups. Forty-six trials comprising 101 100 patients were included. Overall, no significant risk reduction of AF occurrence was observed with SGLT2 inhibitors, although there was a favourable trend (RR 0.90, 95% CI 0.80-1.01). In trials with follow-up durations of over 1 year, a similar result was achieved (RR 0.90, 95% CI 0.80-1.01). The results were consistent across different SGLT2 inhibitors, with RRs (95% CIs) of 0.82 (0.60-1.12) for canagliflozin, 0.87 (0.73-1.03) for dapagliflozin, 0.97 (0.78-1.22) for empagliflozin, 0.99 (0.66-1.50) for sotagliflozin, and 0.87 (0.58-1.29) for ertugliflozin. Analyses in different doses of SGLT2 inhibitors yielded similar results. The associations between SGLT2 inhibitors and AF occurrence were also absent in patients with diabetes, heart failure, and CKDs.

CONCLUSION

For patients with cardiometabolic diseases or risk factors, SGLT2 inhibitors did not decrease the risk of AF occurrence, regardless of follow-up duration, type or dose of the drug, or the patient population.

SGLT2 inhibition, circulating metabolites, and atrial fibrillation: a Mendelian randomization study

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown promise in reducing the risk of atrial fibrillation (AF). However, the results are controversial and the underlying metabolic mechanism remains unclear. Emerging evidence implied that SGLT2 inhibitors have extra beneficial metabolic effects on circulating metabolites beyond glucose control, which might play a role in reducing the risk of AF. Hence, our study aimed to investigate the effect of circulating metabolites mediating SGLT2 inhibition in AF by Mendelian randomization (MR).

METHODS

A two-sample and two-step MR study was conducted to evaluate the association of SGLT2 inhibition with AF and the mediation effects of circulating metabolites linking SGLT2 inhibition with AF. Genetic instruments for SGLT2 inhibition were identified as genetic variants, which were both associated with the expression of SLC5A2 gene and glycated hemoglobin level (HbA1c). Positive control analysis on type 2 diabetes mellitus (T2DM) was conducted to validate the selection of genetic instruments.

RESULTS

Genetically predicted SGLT2 inhibition (per 1 SD decrement in HbA1c) was associated with reduced risk of T2DM (odds ratio [OR] = 0.63 [95% CI 0.45, 0.88], P = 0.006) and AF (0.51 [0.27, 0.97], P = 0.039). Among 168 circulating metabolites, two metabolites were both associated with SGLT2 inhibition and AF. The effect of SGLT2 inhibition on AF through the total concentration of lipoprotein particles (0.88 [0.81, 0.96], P = 0.004) and the concentration of HDL particles (0.89 [0.82, 0.97], P = 0.005), with a mediated proportion of 8.03% (95% CI [1.20%, 14.34%], P = 0.010) and 7.59% ([1.09%, 13.34%], P = 0.011) of the total effect, respectively.

CONCLUSIONS

This study supported the association of SGLT2 inhibition with a reduced risk of AF. The total concentration of lipoprotein particles and particularly the concentration of HDL particles might mediate this association. Further mechanistic and clinical studies research are needed to understand the mediation effects of circulating metabolites especially blood lipids in the association between SGLT2 inhibition and AF.

Benefits of SGLT2 inhibitors in arrhythmias

Some studies have shown that sodium-glucose cotransporter (SGLT) 2 inhibitors can definitively attenuate the occurrence of cardiovascular diseases such as heart failure (HF), dilated cardiomyopathy (DCM), and myocardial infarction. With the development of research, SGLT2 inhibitors can also reduce the risk of arrhythmias. So in this review, how SGLT2 inhibitors play a role in reducing the risk of arrhythmia from the perspective of electrical remodeling and structural remodeling are explored and then the possible mechanisms are discussed. Specifically, we focus on the role of SGLT2 inhibitors in Na+ and Ca2 + homeostasis and the transients of Na+ and Ca2 +, which could affect electrical remodeling and then lead to arrythmia. We also discuss the protective role of SGLT2 inhibitors in structural remodeling from the perspective of fibrosis, inflammation, oxidative stress, and apoptosis. Ultimately, it is clear that SGLT2 inhibitors have significant benefits on cardiovascular diseases such as HF, myocardial hypertrophy and myocardial infarction. It can be expected that SGLT2 inhibitors can reduce the risk of arrhythmia.