Heart failure & cardiomyopathiesSecondary analysis
Serum Magnesium and the Effect of Empagliflozin in Heart Failure With Reduced Ejection Fraction
- Secondary analysis of the EMPEROR-Reduced randomised trial
Authors' conclusion
In EMPEROR-Reduced, low serum magnesium levels were modestly associated with poor HF and kidney outcomes. Empagliflozin increased serum magnesium levels and was associated with a more pronounced reduction of HF events among patients with low magnesium levels at baseline.
Study context
- Population
- Patients with heart failure with reduced ejection fraction (HFrEF)
- Participants
- 3,730 patients
- Comparison
- Empagliflozin vs placebo, by baseline serum magnesium quintile
- Primary endpoint
- CV death or HF hospitalization
- Follow-up
- Median 16 months
Primary result
As reported in the abstract
CV death or HF hospitalization, by baseline magnesium quintile
Empagliflozin vs PlaceboHazard ratio (95% CI)
Q1 (0.68 ± 0.07 mmol/L, n = 878)
0.54(0.41–0.71)
Q2 (0.79 ± 0.02, n = 724)
0.69(0.50–0.96)
Q3 (0.84 ± 0.01, n = 668)
0.82(0.58–1.15)
Q4 (0.88 ± 0.02, n = 733)
0.99(0.72–1.37)
Q5 (0.97 ± 0.05, n = 727)
0.87(0.65–1.17)
Further findings
Baseline serum magnesium
- Mean serum magnesium
- 0.83 ± 0.11 mmol/L
Association of magnesium with outcomes
- Lower magnesium modestly associated with higher risk of heart failure (HF) and kidney events; attenuated with full covariate adjustment
Effect of empagliflozin on serum magnesium
- Empagliflozin rapidly increased magnesium levels
- 0.05 mmol/L
- Relative odds of lower magnesium levels reduced with empagliflozin
Original publication
Serum Magnesium and the Effect of Empagliflozin in Heart Failure With Reduced Ejection Fraction. JACC Heart Fail. Published 31 October 2025. doi:10.1016/j.jchf.2025.102751
Summarised from the published abstract; every number is checked against it