Low serum potassium, diabetes worsen cardiac outcomes in HFpEF

The combination of diabetes and low serum potassium in heart failure patients with preserved ejection fraction (HFpEF) is tied to the risk of adverse outcomes, a recent study has found.

The study included 363 HFpEF patients (median age, 73.0 years; 70.3 percent female) who at baseline underwent a clinical examination, submaximal exercise testing, transthoracic echocardiography and other imaging procedures, and routine laboratory testing. The study outcome was a composite between HF hospitalization and/or cardiac death.

Over a median follow-up of 23.0 months, 114 endpoint events were reported, most of which (n=106) were HF hospitalizations. Only eight cardiac deaths were reported. Researchers found a threshold serum potassium concentration of 3.71 mmol/L, at or below which the risk of the composite endpoint was significantly elevated (hazard ratio [HR], 1.83, 95 percent confidence interval [CI], 1.14–2.94; p=0.0118).

Other independent predictors of the composite adverse outcome included a history of HF hospitalizations (HR, 2.77, 95 percent CI, 1.82–4.21; p<0.0001), higher log N-terminal pro-B-type natriuretic peptide (HR 1.93, 95 percent CI, 1.82–4.21; p=0.0084), and type 2 diabetes mellitus (HR, 1.57, 95 percent CI, 1.05–2.34; p=0.0027).

Further stratifying the participants according to type 2 diabetes status, the researchers found that the outcome was worst in those with diabetes and with serum potassium ≤3.71 mmol/L. Multivariate analysis showed that in this group, the risk of the combined endpoint was more than thrice that in patients without diabetes and with serum potassium >3.71 mmol/L.

Further studies are needed to determine whether serum potassium management, through supplementation or other therapies, may help improve cardiac outcomes in HFpEF patients.