Potassium-increasing regimens in patients at high risk of ventricular arrhythmias: a prespecified observational analysis of the randomized POTCAST trial.
4 affiliations
- 1Department of Cardiology, The Heart Centre, Copenhagen University Hospital-Rigshospitalet, Blegdamsvej 9, Copenhagen Ø 2100, Denmark.
- 2Department of Cardiology, Copenhagen University Hospital-Herlev and Gentofte, Herlev Ringvej 75, Herlev 2730, Denmark.
- 3Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, Copenhagen N 2200, Denmark.
- 4Department of Cardiology, Zealand University Hospital-Roskilde, Sygehusvej 10, Roskilde 4000, Denmark.
Abstract
Aims
The POTCAST trial (n = 1200) 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.Methods
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 (i) mineralocorticoid-receptor antagonists (MRAs) monotherapy, (ii) potassium-supplement monotherapy, or (iii) 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.Results
After 6 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 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).Conclusion
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.
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BibTeX
@article{danielsen2026potassiumincreasing,
title = {{Potassium-increasing regimens in patients at high risk of ventricular arrhythmias: a prespecified observational analysis of the randomized POTCAST trial.}},
author = {Elisabeth Margrethe Danielsen and Emil Anton Frandsen and Ulrik Christian Gudbrand Winsløw and Chaoqun Zheng and Tharsika Sakthivel and Kasper Karmark Iversen and Helle Skovmand Bosselmann and Niels Risum and Henning Bundgaard and Christian Jøns},
journal = {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},
year = {2026},
month = oct,
doi = {10.1093/europace/euag272},
url = {https://europepmc.org/article/MED/42834820},
note = {CC BY},
}
RIS
TY - JOUR
TI - Potassium-increasing regimens in patients at high risk of ventricular arrhythmias: a prespecified observational analysis of the randomized POTCAST trial.
AU - Elisabeth Margrethe Danielsen
AU - Emil Anton Frandsen
AU - Ulrik Christian Gudbrand Winsløw
AU - Chaoqun Zheng
AU - Tharsika Sakthivel
AU - Kasper Karmark Iversen
AU - Helle Skovmand Bosselmann
AU - Niels Risum
AU - Henning Bundgaard
AU - Christian Jøns
PY - 2026
DA - 2026/10/01
JO - 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
DO - 10.1093/europace/euag272
UR - https://europepmc.org/article/MED/42834820
AB - Aims The POTCAST trial (n = 1200) 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.Methods 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 (i) mineralocorticoid-receptor antagonists (MRAs) monotherapy, (ii) potassium-supplement monotherapy, or (iii) 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.Results After 6 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 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).Conclusion 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.
SN - 1099-5129
SN - 1532-2092
ER -