Interestingly, this study showed that the patients in the spironolactone group had a higher sK TTR than those in the placebo group, suggesting that spironolactone use may be closely related to more stable sK homeostasis in patients with HFpEF, and it reduced the incidence of hyperkalaemia or hypokalaemia throughout the follow-up period. This evidence concerns the gene TTR and Hypokalemia.