Abstract
Abstract
Background and aims
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.
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: 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.
Results
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 (p0.1 between regimens).
Conclusions
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.