Prognostic Impact of Baseline Potassium Abnormalities in Patients with Heart Failure with Reduced Ejection Fraction:...

Abnormal serum potassium levels are a common issue in patients with heart failure with reduced ejection fraction (HFrEF), limiting the use of prognostically beneficial therapies. The primary aim of this study was to characterise the HFrEF population according to baseline potassium levels and to assess their impact on medium- to long-term prognosis.

A retrospective study was conducted on a cohort of consecutive patients with HFrEF recruited at our centre. Patients were classified according to baseline serum potassium levels into: Group 1 (<3.5 mEq/L), Group 2 (3.5-5.0 mEq/L), and Group 3 (>5.0 mEq/L). Prognostic impact was assessed in terms of HF readmissions, HF mortality and all-cause mortality.

A total of 409 patients were analysed. The median age was 69 years [IQR 59-77], with a predominance of male patients (74.1%). There were 26 patients (6.36%) with hypokalaemia, 365 (89.24%) with normokalaemia, and 18 (4.4%) with hyperkalaemia. Group 1 showed a higher prevalence of diabetes mellitus (69.2% vs. 47.4% vs. 33.4%; p = 0.043) and a greater proportion of patients with ≥2 previous admissions for HF (25% vs. 10.5% vs. 0%; p = 0.008). No differences were observed regarding echocardiographic parameters, markers of congestion, or HFrEF treatment. After a median follow-up of 60 months, no significant differences were found between groups in rates of HF readmissions, HF mortality and all-cause mortality.

Patients with hypokalaemia exhibited a higher prevalence of diabetes mellitus and previous HF admissions. In our population, no differences were observed between groups in the use of prognostically beneficial therapies or in outcomes in terms of HF rehospitalisations and mortality.