Potassium-Increasing Regimens in Patients at High Risk of Ventricular Arrhythmias: A Prespecified Observational Analysis of the Randomized POTCAST Trial.

Authors

Elisabeth Margrethe Danielsen, Emil Anton Frandsen, Ulrik Christian Gudbrand Winsløw, Chaoqun Zheng, Tharsika Sakthivel, Kasper Karmark Iversen, Helle Skovmand Bosselmann, Niels Risum, Henning Bundgaard, Christian Jøns

Published in

Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. Oct 06, 2026. Epub Oct 06, 2026.

Abstract

The POTCAST trial (n=1,200) showed that targeting high-normal plasma potassium levels reduced ventricular arrhythmias in patients with Implantable Cardioverter-Defibrillators (ICDs). We compared changes in plasma potassium and described outcomes across the three regimens used to increase plasma potassium.
We studied 600 control participants and 572 intervention participants who completed potassium up-titration in POTCAST. Participants in the intervention arm were categorized according to treatment after plasma-potassium up-titration into: a) mineralocorticoid-receptor antagonists (MRAs) monotherapy, b) potassium-supplement monotherapy, or c) combination-therapy with both. The primary endpoint was a composite of sustained ventricular arrhythmia, appropriate ICD-therapy, hospitalization for arrhythmia or heart-failure or all-cause mortality. Safety outcomes included death and electrolyte/renal disturbances.
After six months, plasma potassium increased from 4.12 to 4.27 mmol/L (p=0.004) with MRA, from 3.99 to 4.24 mmol/L (p<0.001) with potassium-supplements, and from 3.98 to 4.34 mmol/L (p<0.001) with combination-therapy. The primary endpoint occurred in 29% (n=175) of controls, 22% (n=16) in the MRA group, 21% (n=31) in the potassium-supplements group and in 22% (n=72) in the combination-therapy group (p=0.8 between regimens). Hypokalemia occurred in 13% of controls and in 3%, 9%, and 5% of participants receiving MRA, potassium-supplements and combination-therapy, respectively. Hyperkalemia occurred in 0.2% of controls and in 0%, 3%, and 4% of participants receiving MRA, potassium-supplements, and combination-therapy (p>0.1 between regimens).
Treatment with MRA, potassium-supplements or both increased potassium levels. All regimens were associated with numerically lower endpoint rates than controls. We detected no statistically significant differences in endpoints or safety between regimens.

PMID:
42834820
Bibliographic data and abstract were imported from PubMed on 06 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.