Targeted Potassium Levels for Prevention of ICD Therapy

Phase 4

Active, not recruiting

• Conditions: Ventricular Arrhythmias and Cardiac Arrest; Implantable Defibrillator User; Hypokalemia; Atrial Fibrillation; Hyperkalemia; Ventricular Tachycardia
• Interventions: Combination Product: Targeted serum potassium level

• Registration Number: NCT03833089
• Lead Sponsor: Rigshospitalet, Denmark

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.

Detailed Description

There is solid evidence that potassium-sparing drugs increase survival and ameliorates symptoms in heart failure patients and post-hoc studies have suggested that high-normal levels of blood potassium levels (p-K) markedly decreases the risk of malignant arrhythmias in cardiovascular patients.

This trial will randomize patients implanted with implantable cardioverter defibrillators (ICDs), who remain at high risk of life-threatening cardiac arrhythmias, to a standard therapy or standard therapy plus a regimen to keep high-normal p-K levels. The study will enroll 1,000 patients from the outpatient pacemaker clinics at Rigshospitalet and Gentofte hospital. Using a planned regime to increase p-K using inexpensive drugs and potassium supplements, the patients enrolled and followed with regular controls as well as continuous monitoring using existing home monitoring systems over a period of 4 years for the primary endpoint of appropriate ICD therapy and all cause mortality. Including analysis, the trial will be running for 5 years

Study Timeline

• Study First Submitted: 2019-02-01
• Study First Submitted QC: 2019-02-04
• Study First Posted: 2019-02-06
• Study Start: 2019-03-01
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-08
• Primary Completion: 2025-05-09
• Last Update Posted: 2025-05-09
• Study Completion: 2035-04-01

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 1200

Inclusion Criteria

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

Exclusion Criteria

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Targeted serum potassium levels	Targeted serum potassium level	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.

Primary Outcome Measures

Name	Time	Method
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	Total 291 events, expected 6 years	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.

Secondary Outcome Measures

Name	Time	Method
Time to first incidence of supraventricular arrhythmias as documented by ECG or the ICD	6 years	Any supraventricular tahcycardia documented on ECG, telemetry or as monitored/treated event on the ICD
Proportion of patients experiencing <92 % CRT-pacing for > 2 weeks (only CRT-D patients)	6 years	CRT-D home monitoring systems allow temporal evaluation of percentage of CRT pacing.
Time to first hospitalization for heart failure	6 years	Hospitalization with symptoms of heart failure and with a diagnosis of heart failure where treatment with i.v. diuretics was initiated.
Time to first hospitalization for cardiac arrhythmias	6 years	Hospitalization were records indicate that supraventricular or ventricular arrhythmias were implicated in the cause of the hospitalization
Time to hospitalization for electrolyte disturbances or kidney failure	6 years	Hospitalization were records indicate that kidney failure or disturbances in the potassium or sodium plasma leves were implicated in the cause of the hospitalization
First occurrence of appropriate ICD therapy for ventricular tachycardia or ventricular fibrillation irrespective of outcome.	6 years	Ventricular tachy-arrhythmia therapy, which will be obtained from home monitoring systems or interrogation of the ICD devices during in-clinic visits. All ICD therapy is routinely adjudicated as appropriate or in-appropriate by electrophysiologists at the study sites.
Time to first occurence of inappropriate ICD therapy	6 years	Any cause of inappropriate shock including atrial fibrillation, other supraventricular arrhythmias, ICD lead problems etc.

Trial Locations

Locations (3)

Gentofte University Hospital; 🇩🇰 Gentofte, Hellerup, Denmark

Roskilde University Hospital; 🇩🇰 Roskilde, Region Zealand, Denmark

Rigshospitalet; 🇩🇰 Copenhagen, Denmark