Targeted Potassium Levels for Prevention of ICD Therapy

NCT03833089 | Active Not Recruiting Phase 4 DMC

• 1 other identifier: 3589
• Study Type: interventional
• Target: 1,200
• Locations: 1 country
• Sites: 3

Brief Summary

This study evaluates whether a rigorously controlled high-normal level of serum-potassium (4.5-5.0 mEq/L) using dietary recommendations, potassium supplements and mineralocorticoid receptor antagonists will results in a lower incidence of cardiac arrhythmias in patients with an ICD. Patients will be randomized to this treatment or a control arm, where patients will receive usual guideline recommended follow-up.

Conditions

Ventricular Arrhythmias and Cardiac Arrest; Implantable Defibrillator User; Hypokalemia; Hyperkalemia; Ventricular Tachycardia; Atrial Fibrillation

Outcome Measures

Primary Outcomes (1)

• Time to first occurrence of ECG documented ventricular tachycardia, appropriate ICD therapy, hospitalization > 24 hours due to arrhythmias and/or heart failure leading to a change in treatment and all cause mortality

  A combination of: * ECG documented ventricular tachycardia \> 125 bpm lasting \> 30 seconds * Any appropriate ICD therapy as documented by the ICD or ECG * Any unplanned hospitalizations \> 24 hours due to arrhythmias and/or heart failure leading to a change in treatment, e.g., administration of new drugs, or change in doses of already prescribed drugs or invasive or non-invasive treatment. * All-cause mortality The time period with regards to the Time-to-Event Outcome Measures starts with the randomization of the patient. ECG documented tachycardia from ECGs or ICD interrogations will be obtained from hospitalizations or outpatients clinic visits via electronic records after patient consent. Information of ventricular tachyarrhythmia therapy will be obtained from home monitoring systems or interrogation of the ICD devices during in-clinic visits. Mortality will be obtained from danish electronic hospital files or the danish death registry.

  Total 291 events, expected 6 years

Secondary Outcomes (7)

• Time to first incidence of supraventricular arrhythmias as documented by ECG or the ICD

  6 years

• Proportion of patients experiencing <92 % CRT-pacing for > 2 weeks (only CRT-D patients)

  6 years

• Time to first hospitalization for heart failure

  6 years

• Time to first hospitalization for cardiac arrhythmias

  6 years

• Time to hospitalization for electrolyte disturbances or kidney failure

  6 years

Study Arms (2)

Control

NO INTERVENTION

ICD recipients in optimal Medical treatment as per guidelines according to their comorbidity

Targeted serum potassium levels

EXPERIMENTAL

ICD recipients recipients in optimal Medical treatment as per guidelines according to their comorbidity. In addition to guideline recommended treatment, this cohort will be treated to increase serum potassium levels to 4.5-5.0 mEq/L.

Combination Product: Targeted serum potassium level

Interventions

Targeted serum potassium level COMBINATION_PRODUCT

In the following order, following advices end prescriptions will be provided: 1) Potassium rich dietary advice, 2) Mineralocorticoid receptor antagonists, 3) Potassium supplementation,

Targeted serum potassium levels

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Implantable cardioverter defibrillator (ICD) or cardiac resynchronization pacemaker with ICD (CRT-D).
• Age \>18 years

You may not qualify if:

• Estimated glomerular filtration rate (eGFR) \<30 ml/h
• Pregnancy
• Lack of ability to understand and sign informed consent

Sponsors & Collaborators

• Rigshospitalet, Denmark: lead
• Herlev and Gentofte Hospital: collaborator

Study Sites (3)

Gentofte University Hospital

Gentofte Municipality, Hellerup, 2900, Denmark

Location

Roskilde University Hospital

Roskilde, Region Sjælland, 4000, Denmark

Location

Rigshospitalet

Copenhagen, 2100, Denmark

Location

Related Publications (2)

• Jons C, Zheng C, Winslow UCG, Danielsen EM, Sakthivel T, Frandsen EA, Saffi H, Vakilzadeh-Hashemi SS, Haugan KJ, Bruun NE, Iversen KK, Bosselmann HS, Risum N, Bundgaard H; POTCAST Study Group. Increasing the Potassium Level in Patients at High Risk for Ventricular Arrhythmias. N Engl J Med. 2025 Nov 20;393(20):1979-1989. doi: 10.1056/NEJMoa2509542. Epub 2025 Aug 29.

  PMID: 40879429 DERIVED

• Winslow U, Sakthivel T, Zheng C, Bosselmann H, Haugan K, Bruun N, Larroude C, Iversen K, Saffi H, Frandsen E, Oturai P, Jensen HJ, Vinther M, Risum N, Bundgaard H, Jons C. Treatment-induced increase in total body potassium in patients at high risk of ventricular arrhythmias; a randomized POTCAST substudy. PLoS One. 2023 Jul 19;18(7):e0288756. doi: 10.1371/journal.pone.0288756. eCollection 2023.

  PMID: 37467227 DERIVED

MeSH Terms

Conditions

Heart Arrest; Hypokalemia; Hyperkalemia; Tachycardia, Ventricular; Atrial Fibrillation

Condition Hierarchy (Ancestors)

Heart Diseases; Cardiovascular Diseases; Water-Electrolyte Imbalance; Metabolic Diseases; Nutritional and Metabolic Diseases; Tachycardia; Arrhythmias, Cardiac; Cardiac Conduction System Disease; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Christian Joens, MD, PhD

  Dept of Cardiology, Rigshospitalet, Denmark

  PRINCIPAL INVESTIGATOR

• Niels Risum, MD, PhD

  Dept of Cardiology, Rigshospitalet, Denmark

  STUDY CHAIR

• Henning Bundgaard, Prof., DMSc

  Dept of Cardiology, Rigshospitalet, Denmark

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Staff Cardiologist, Electrophysiology, Principal investigator, PhD

Study Record Dates

• First Submitted: February 1, 2019
• First Posted: February 6, 2019
• Study Start: March 1, 2019
• Primary Completion: May 9, 2025
• Study Completion (Estimated): April 1, 2035
• Last Updated: May 9, 2025

Record last verified: 2025-05

Locations

DK (3)