Prognostic implications of hypo and hyperkalaemia in acute heart failure with reduced ejection fraction. Analysis of cardiovascular mortality and hospital readmissions.

Background And Objectives: Potassium alterations constitute a major clinical problem in decompensated heart failure (HF). This study aims to assess the prognostic implications of hypo and hyperkalaemia on admission for acute HF in cardiovascular mortality and hospital readmissions.

Material And Method: From January 2016 to June 2020, 1,397 cases with a diagnosis of acute HF were admitted. Admission programmed for study, elective therapies, and patients with LVEF> 40% were excluded. The study was carried out on 689 patients, 45 with K <3.5 mmol/L, 49K >5.0 mmol/L and 595K+3.5-5.0 mmol/L. Medical history, baseline clinical profile, drug therapy, and potassium levels obtained upon admission were analysed.

Results: Annual mortality due to hypokalaemia (K+<3.5mmol/L) was 37.8% (HR 2.4; 95% CI: 1.3-4.7; P<.007); for hyperkalaemia 40.8% (HR: 1.9; 95% CI: 0.98-3.51; P<.055). Creatinine level and age were variables associated with mortality in both the hyperkalaemic and hypokalaemic cohorts. Hospital readmissions did not show statistical association with these electrolyte disorders.

Conclusions: In patients admitted for decompensated HF, both hyperkalaemia and hypokalaemia determined at admission have a negative prognostic impact on survival. Creatinine and age are other independent factors associated with mortality. The effect on the probability of hospital readmission at one year is not demonstrated in this study.