Elsevier

International Journal of Cardiology

Volume 371, 15 January 2023, Pages 273-277
International Journal of Cardiology

Short communication
Does moderate hyperkalemia influence survival in HF? Insights from the MECKI score data base

https://doi.org/10.1016/j.ijcard.2022.09.030Get rights and content

Highlights

  • Hyperkalemia affects up to 18% of HFrEF patients leading to therapy down-titration.

  • The prognostic role of moderate hyperkalemia is still controversial.

  • We discovered that moderate hyperkalemia in HF is not associated to worst outcome.

Abstract

Background

The prognostic role of moderate hyperkalemia in reduced ejection fraction (HFrEF) patients is still controversial. Despite this, it affects the use of renin–angiotensin–aldosterone system inhibitors (RAASi) with therapy down-titration or discontinuation.

Objectives

Aim of the study was to assess the prognostic impact of moderate hyperkalemia in chronic HFrEF optimally treated patients.

Methods and results

We retrospectively analyzed MECKI (Metabolic Exercise test data combined with Cardiac and Kidney Indexes) database, with median follow-up of 4.2 [IQR 1.9–7.5] years. Data on K+ levels were available in 7087 cases. Patients with K+ plasma level ≥ 5.6 mEq/L and < 4 mEq/L were excluded. Remaining patients were categorized into normal >4 and < 5 mEq/L (n = 4826, 68%) and moderately high ≥5.0 and ≤ 5.5 mEq/L (n = 496, 7%) K+. Then patients were matched by propensity score in 484 couplets of patients. MECKI score value was 7% [IQR 3.1–14.1%] and 7.3% [IQR 3.4–15%] (p = 0.678) in patients with normal and moderately high K+ values while cardiovascular mortality events at two years follow-up were 41 (4.2%) and 33 (3.4%) (p = 0.333) in each group respectively.

Conclusions

Moderate hyperkalemia does not influence patients' outcome in a large cohort of ambulatory HFrEF patients.

Introduction

In reduced ejection fraction (HFrEF) heart failure patients, hyperkalemia has been reported up to 18% of cases with a higher incidence in patients with more severe HF [1].

Several mechanisms have been advocated as causes of hyperkalemia including both pathophysiological alterations and iatrogenic factors [2]. Moreover, some frequently observed HF comorbidities, such as diabetes and renal failure, by reducing K+ elimination in the kidney, are reported as hyperkalemia causes [3,4]. Finally, renin angiotensin aldosterone system inhibitor (RAASi) therapy, which is recommended as a disease modifier HF therapy [5], may further increase the risk of hyperkalemia in HFrEF [1,6,7]. Consequently, in case of hyperkalemia RAASi therapy is usually down-titrated or discontinued [5,8].

However, the effect of moderate hyperkalemia in determining HFrEF prognosis is still controversial albeit a few studies suggest that hyperkalemia is associated with poor prognosis, arrhythmias, intensive care admission and death [[9], [10], [11]]. Specifically, the prognostic role of moderate hyperkalemia in well characterized HFrEF patients is basically unknown.

The aim of our study is to assess the prognostic role of moderate hyperkalemia in a large cohort of ambulatory optimally treated chronic HFrEF patients. We performed a post-hoc analysis of MECKI (Metabolic Exercise test data combined with Cardiac and Kidney Indexes) score database to investigate whether moderately elevated potassium levels, between 5.0 and 5.5 meq/L, independently affected long-term survival.

Section snippets

Methods

We retrospectively analyzed data from MECKI score database, which includes a cohort of patients with a history of HFrEF recruited between 1993 and 2020 and prospectively followed [12]. MECKI score inclusion/exclusion criteria and follow up modalities were previously reported in details [12]. In brief, MECKI score inclusion/exclusion criteria were: history of HFrEF [left ventricle (LV) EF < 40%], clinical stability and optimized HF treatment and ability to perform a cardiopulmonary exercise

Results

The studied population included 484 couplets of stable and optimally treated chronic HFrEF patients (Table 1). In normal K+ patients (K+ ≥ 4.0 and < 5.0 mEq/L) average daily diuretic dose was 50 [25.0–75.0] mg and carvedilol equivalent β-blockers dosage was 18.75 [12.5–25.0] mg while in high K+ patients (K+ ≥ 5and ≤5.5 mEq/L) diuretic dose was 50 [25.0–100.0] mg (p = 0.748) and equivalent β-blockers dosage was 12.5 [12.5–25.0] mg (p = 0.162). HF etiology was ischemic in around 50% of cases and

Discussion

Results of the present study spread some light on the field of moderate hyperkalemia in HF showing that per se moderate hyperkalemia is not associated to a worst outcome provided that patients have been properly matched for clinical characteristics, HF severity and treatment. Accordingly, our findings are similar to those of Beusekamp et al. [14] who, differently from several other reports [[9], [10], [11]] showed that hyperkalemia was not associated with adverse outcomes but associated to a

Declaration of Competing Interest

None to declare.

Acknowledgement

The present study was funded by the Italian Ministry of Health (Ricerca Corrente).

References (16)

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All authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.

1

see appendix.

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