Cardiac ArrythmiasPhase 3TightKNCT03195647
Pilot Study for the Tight K Study
A Phase 3 study testing Potassium in people with Cardiac Arrythmias, run by Barts & The London NHS Trust at 2 sites in United Kingdom.
Trial summary
The primary purpose of this pilot study will be feasibility of recruitment. However, in order to further inform a full randomised controlled trial (RCT), information on the incidence of atrial fibrillation (AF) and other arrhythmias, hospital length of stay, resource use and morbidity will be collected. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiac Arrythmias
- What is being tested?
- Potassium
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 160 participants
- Where
- 2 sitesUnited Kingdom
- Study dates
- 1 Aug 2017to 29 May 2018
- Phase
- Phase 3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 1. All patients undergoing isolated elective coronary artery bypass graft (CABG)
Who cannot join
- Age less than 18 years
- Previous AF
- Concurrent patient involvement in another clinical study assessing post-operative interventions
- On-going infection/sepsis at the time of operation
- Pre-op high-degree atrioventricular (AV) block
- Pre-op serum K+ greater than 5.5 mEq/L
- Current or previous use of medication for the purposes of cardiac rhythm management
- Dialysis dependent end stage renal failure
Trial locations and contacts
2 sites in 1 country.
United Kingdom2 sites
Barts Health NHS Trust
London, EC1A 7DN
St George's University Hospital London
London
About this study
Official title: PILOT STUDY for the Tight K TRIAL. Arrhythmias on the Cardiac Intensive Care Unit - Does Maintenance of High-normal Serum Potassium Levels Matter?
The primary purpose of this pilot study will be feasibility of recruitment. However, in order to further inform a full randomised controlled trial (RCT), information on the incidence of atrial fibrillation (AF) and other arrhythmias, hospital length of stay, resource use and morbidity will be collected.
Read the detailed description
Arrhythmias are common in critical care, with atrial tachyarrhythmias (and especially AF) being the most prevalent. This is especially true after cardiac surgery, with approximately 1 in 3 patients affected. The occurrence of new-onset post-operative AF is associated with increased short and long-term mortality, intensive care unit (ICU) and hospital stay and costs of care. This association appears causal, even after correction for confounding factors.
Potassium (K+) plays an important role in cardiac electrophysiology and abnormal levels may cause arrhythmias. Hypokalaemia, defined as a serum K+ <3.6 milliequivalents per litre (mEq/L) is thus associated with an increased incidence of ventricular arrhythmia after myocardial infarction. Low K+ levels are common following cardiac surgery, and appear marginally lower in those suffering atrial arrhythmias in this context. Despite an absence of proof that this association is causal, efforts to maintain serum [K+] in the 'high-normal' range (4.5 - 5.5 mEq/L) are considered 'routine practice' for AF prevention worldwide. The efficacy of such intervention remains unproven and data supporting this practice is extremely limited, being derived from observational rather than interventional studies. Indeed, no data exist to demonstrate that maintaining a high-normal potassium level is beneficial, or that aggressive replenishment of potassium in patients with heart disease necessarily leads to a better clinical outcome.
Furthermore, the method of potassium supplementation may be problematic. Oral replacement is not possible immediately post-operatively. Central venous administration is thus generally utilised in the early post-operative period. However, this practice is both time-consuming and costly: the intravenous administration of potassium carries recognised clinical risk, and is now prescribed in pre-diluted doses, stored securely for a safety purposes. Oral replacement is commonly associated with profound nausea, and is very poorly tolerated by patients. The investigators have estimated that the annual spending on potassium in cardiothoracic patients at Barts Health National Health Service (NHS) Trust is £100,000, compared to £16,500 for Milrinone (perceived as a high cost drug (2011-2012 prices). Additional costs relating to nursing time, drug checks, and intravenous connection and charting are also accrued. Central venous catheters may also be routinely left in situ solely for the purposes of parenteral potassium replacement; leading to an increased risk of line-related sepsis.
The routine maintenance of serum K+ in the high-normal range is thus a costly and unproven practice.
- Conditions
- Cardiac Arrythmias
- Being tested
- Potassium
- Keywords
- cardiovascular, potassium supplementation, coronary artery by pass surgery
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PotassiumDrug
The trial treatment will start when patients are admitted to the intensive care unit after their surgery. The patient will undergo regular blood investigations, as per current practice. The frequency of K+ monitoring while on ICU will be according to clinician / nursing staff preference.
Potassium supplementation will be according to local hospital protocols. This can be either via an intravenous infusion or as a tablet. Patients will otherwise be treated as per current hospital protocol.
| Study group | Role | What they receive |
|---|---|---|
| Relaxed control | Experimental | Those randomised to the 'Relaxed' Group will receive potassium supplementation only if their serum potassium drops below or equals 3.6 mEq/L. Receives: Drug: Potassium |
| Tight Control | Active comparator | Patients randomised to the 'Tight' group will receive potassium supplementation if their serum potassium falls below 4.5 mEq/L (current practice). Receives: Drug: Potassium |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total number of patients recruited over a 6 month period
The pilot study is being conducted to assess if it is feasible to recruit the required patient population into the study. The aim of the pilot is to recruit 160 patients over 6 months from two different centres.
Measured: 6 months
Number of patients successfully randomised into the study to receive standard either usual care or control of potassium at the lower limit of the normal range
The pilot study will investigate if it is feasible to randomised patients between the control and intervention arms of the study
Measured: 6 months
Protocol violation rate
Feasibility of ensuring that protocol violation rate is no more than 10%
Measured: 6 months
Number of patient with outcome data at 28 days
This is a feasibility and one of the main outcome will be to assess the number of participants with outcome data at 28 days. The study will aim to follow up 90% of the patients randomised.
Measured: 6 months
Secondary outcomes (7)
Incidence of new onset atrial fibrillation
Episode of AF lasting at least 30 seconds that is clinically detected and/or electrocardiographically confirmed post surgery until day 5
Measured: Maximum of 5 days
Mean critical care length of stay
Average time patients are treated on critical care ward
Measured: Maximum 28 days
Mean hospital length of stay
Average time patients are inpatients in all hospital wards
Measured: Maximum 28 days
Incidence of all other arrhythmias, defined using standard diagnostic criteria
All other arrhythmias detected clinically and/or review of holter monitor data
Measured: Maximum of 5 days
Incidence of in-patient mortality
Number of patients deceased during their hospital stay
Measured: 28 days from randomisation
Incidence of mortality
All incidence of mortality during hospital stay and follow up
Measured: 28 days from randomisation
Cost-effectiveness
Measured: 28 days from randomisation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jun 2017
- Study start1 Aug 2017
- Primary completion24 Apr 2018
- Study completion29 May 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Cardiac ArrythmiasStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 160 participants (actual)
Sponsor and investigators
- Lead sponsor
- Barts & The London NHS Trust
- Sponsor type
- University, hospital or other
- Collaborators
- London School of Hygiene and Tropical Medicine
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03195647
- Sponsor's protocol ID
- 011660
- Acronym
- TightK
- Status last verified
- Jun 2018
- First submitted
- 23 May 2017
- Last updated
- 16 Jul 2020
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Campbell NG, Allen E, Sanders J, Swinson R, Birch S, Sturgess J, Al-Subaie N, Elbourne D, Montgomery H, O'Brien B. The impact of maintaining serum potassium >/=3.6 mEq/L vs >/=4.5 mEq/L on the incidence of new-onset atrial fibrillation in the first 120 hours after isolated elective coronary artery bypass grafting - study protocol for a randomised feasibility trial for the proposed Tight K randomized non-inferiority trial. Trials. 2017 Dec 28;18(1):618. doi: 10.1186/s13063-017-2349-x.
PubMed 29282098
Study at a glance
From the registry record, last updated by the sponsor on 16 Jul 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- PILOT STUDY for the Tight K TRIAL. Arrhythmias on the Cardiac Intensive Care Unit - Does Maintenance of High-normal Serum Potassium Levels Matter?
- ClinicalTrials.gov ID
- NCT03195647
- Acronym / sponsor ID
- TightK / 011660
- Conditions
- Cardiac Arrythmias
- Keywords
- cardiovascular, potassium supplementation, coronary artery by pass surgery
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 160 participants (actual)
- Lead sponsor
- Barts & The London NHS TrustUniversity, hospital or other
- Collaborators
- London School of Hygiene and Tropical Medicine
- Study start
- 1 Aug 2017 (actual)
- Primary completion
- 24 Apr 2018 (actual)
- Study completion
- 29 May 2018 (actual)
- First posted
- 22 Jun 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The primary purpose of this pilot study will be feasibility of recruitment. However, in order to further inform a full randomised controlled trial (RCT), information on the incidence of atrial fibrillation (AF) and other arrhythmias, hospital length of stay, resource use and morbidity will be collected.
Detailed description
Arrhythmias are common in critical care, with atrial tachyarrhythmias (and especially AF) being the most prevalent. This is especially true after cardiac surgery, with approximately 1 in 3 patients affected. The occurrence of new-onset post-operative AF is associated with increased short and long-term mortality, intensive care unit (ICU) and hospital stay and costs of care. This association appears causal, even after correction for confounding factors.
Potassium (K+) plays an important role in cardiac electrophysiology and abnormal levels may cause arrhythmias. Hypokalaemia, defined as a serum K+ <3.6 milliequivalents per litre (mEq/L) is thus associated with an increased incidence of ventricular arrhythmia after myocardial infarction. Low K+ levels are common following cardiac surgery, and appear marginally lower in those suffering atrial arrhythmias in this context. Despite an absence of proof that this association is causal, efforts to maintain serum [K+] in the 'high-normal' range (4.5 - 5.5 mEq/L) are considered 'routine practice' for AF prevention worldwide. The efficacy of such intervention remains unproven and data supporting this practice is extremely limited, being derived from observational rather than interventional studies. Indeed, no data exist to demonstrate that maintaining a high-normal potassium level is beneficial, or that aggressive replenishment of potassium in patients with heart disease necessarily leads to a better clinical outcome.
Furthermore, the method of potassium supplementation may be problematic. Oral replacement is not possible immediately post-operatively. Central venous administration is thus generally utilised in the early post-operative period. However, this practice is both time-consuming and costly: the intravenous administration of potassium carries recognised clinical risk, and is now prescribed in pre-diluted doses, stored securely for a safety purposes. Oral replacement is commonly associated with profound nausea, and is very poorly tolerated by patients. The investigators have estimated that the annual spending on potassium in cardiothoracic patients at Barts Health National Health Service (NHS) Trust is £100,000, compared to £16,500 for Milrinone (perceived as a high cost drug (2011-2012 prices). Additional costs relating to nursing time, drug checks, and intravenous connection and charting are also accrued. Central venous catheters may also be routinely left in situ solely for the purposes of parenteral potassium replacement; leading to an increased risk of line-related sepsis.
The routine maintenance of serum K+ in the high-normal range is thus a costly and unproven practice.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Relaxed control | Experimental | Drug: PotassiumThose randomised to the 'Relaxed' Group will receive potassium supplementation only if their serum potassium drops below or equals 3.6 mEq/L. |
| Tight Control | Active comparator | Drug: PotassiumPatients randomised to the 'Tight' group will receive potassium supplementation if their serum potassium falls below 4.5 mEq/L (current practice). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- 1. All patients undergoing isolated elective coronary artery bypass graft (CABG)
Key exclusion criteria (8 listed)
- Age less than 18 years
- Previous AF
- Concurrent patient involvement in another clinical study assessing post-operative interventions
- On-going infection/sepsis at the time of operation
- Pre-op high-degree atrioventricular (AV) block
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PotassiumThe trial treatment will start when patients are admitted to the intensive care unit after their surgery. The patient will undergo regular blood investigations, as per current practice. The frequency of K+ monitoring while on ICU will be according to clinician / nursing staff preference. Potassium supplementation will be according to local hospital protocols. This can be either via an intravenous infusion or as a tablet. Patients will otherwise be treated as per current hospital protocol. | Drug | Relaxed control, Tight Control |
Primary outcome
Total number of patients recruited over a 6 month period
Time frame: 6 months
The pilot study is being conducted to assess if it is feasible to recruit the required patient population into the study. The aim of the pilot is to recruit 160 patients over 6 months from two different centres.
Number of patients successfully randomised into the study to receive standard either usual care or control of potassium at the lower limit of the normal range
Time frame: 6 months
The pilot study will investigate if it is feasible to randomised patients between the control and intervention arms of the study
Protocol violation rate
Time frame: 6 months
Feasibility of ensuring that protocol violation rate is no more than 10%
Number of patient with outcome data at 28 days
Time frame: 6 months
This is a feasibility and one of the main outcome will be to assess the number of participants with outcome data at 28 days. The study will aim to follow up 90% of the patients randomised.
7 secondary outcomes
Incidence of new onset atrial fibrillation
Time frame: Maximum of 5 days
Mean critical care length of stay
Time frame: Maximum 28 days
Mean hospital length of stay
Time frame: Maximum 28 days
Incidence of all other arrhythmias, defined using standard diagnostic criteria
Time frame: Maximum of 5 days
Incidence of in-patient mortality
Time frame: 28 days from randomisation
Incidence of mortality
Time frame: 28 days from randomisation
Cost-effectiveness
Time frame: 28 days from randomisation
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jul 2020.
- Derived from this study: PubMed 29282098Campbell NG, Allen E, Sanders J, Swinson R, Birch S, Sturgess J, Al-Subaie N, Elbourne D, Montgomery H, O'Brien B. The impact of maintaining serum potassium >/=3.6 mEq/L vs >/=4.5 mEq/L on the incidence of new-onset atrial fibrillation in the first 120 hours after isolated elective coronary artery bypass grafting - study protocol for a randomised feasibility trial for the proposed Tight K randomized non-inferiority trial. Trials. 2017 Dec 28;18(1):618. doi: 10.1186/s13063-017-2349-x.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Potassium in people with Cardiac Arrythmias, run by Barts & The London NHS Trust at 2 sites in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 16 Jul 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total number of patients recruited over a 6 month period (time frame: 6 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03195647, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Jul 2020.