Condition category
Circulatory System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Having a heart operation can affect the functioning of other organs in the body and sometimes people suffer from damage to their kidneys as a result of their surgery. This is called acute kidney injury. The risk of acute kidney injury is greater in people having heart valve operations compared to other types of heart operation. Most people completely recover from heart surgery related acute kidney injury, but some people will experience long-term kidney disease, affecting their quality of life. Acute kidney injury can increase the length of time patients spend in hospital after their operation and therefore increase the cost of care. One of the reasons heart valve surgery patients suffer from acute kidney injury is because during the operation people are attached to a ‘heart-lung bypass’ machine. This machine takes over the job of pumping blood around the body whilst the heart is being operated on. The white blood cells circulating in the blood then react to the materials in the heart-lung bypass machine, which ‘activates’ them and causes inflammation throughout the body. This inflammation can damage the kidneys. This study is looking to see if removing the ‘activated’ white blood cells from the blood (through a special filter in the heart-lung bypass machine) during surgery will reduce damage to the kidneys.

Who can participate?
Males and females, aged between 18-89 years, having planned heart valve surgery.

What does the study involve?
Participants are randomly allocated to one of two groups. In the standard group a standard filter will be used in the heart bypass machine. This will filter the blood in the normal way but it won’t filter out the white blood cells. This is standard practice at the hospital where the study is being held. In the new group a new filter will be used in the heart bypass machine, which will filter the blood in the same way as the standard filter but will also filter out the white blood cells. Participants will be followed for 3 months to see if they develop acute kidney injury after surgery. We will also see how well participants recover in general.

What are the possible benefits and risks of participating?
Possible benefits for patients who have their surgery using the new filter may be reduced kidney damage after surgery. This may lead to reduced recovery times and improved health after surgery, although this cannot be guaranteed. Little is known in terms of risks or adverse effects associated with the new filter. In theory there is a small risk of contamination when the new filter in inserted into the heart-lung bypass machine and also a small risk of the filter clotting, but these are both thought to be negligible. Patients who have their surgery using the standard filter as part of the study will have no benefits or risks above those patients who do not take part in the study , as the standard filter is used routinely during heart surgery outside of the study.

Where is the study run from?
The study is being run from Blackpool, Fylde and Wyre Hospitals NHS Foundation Trust with the University of Bristol providing management support.

When is the study starting and how long is it expected to run for?
The study is expected to start in January 2014 and is expected to run until March 2015.

Who is funding the study?
National Institute for Health Research (NIHR), UK.

Who is the main contact?
Lucy Dreyer

Trial website

Contact information



Primary contact

Ms Lucy Dreyer


Contact details

Bristol Heart Institute
Level 7
Bristol Royal Infirmary
Marlborough Street
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The Renoprotective value of Leukodepletion in Heart Valve surgery: an external feasibility randomised controlled trial


Study hypothesis

That leukodepletion during cardiopulmonary bypass will reduce the incidence and severity of cardiac surgery related acute kidney injury (CSA-AKI) and therefore improve clinical outcomes in patients undergoing heart valve surgery.

Ethics approval

North West - Preston REC, 04/11/2013, ref: 13.NW.0728

Study design

Randomised; Interventional; Design type: Treatment

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Topic: Cardiovascular; Subtopic: Cardiovascular (all Subtopics); Disease: Cardiovascular


Control: Standard heart valve surgery will be carried out incorporating a Pall corporation standard 40 µm filter into the arterial line of the extracorporeal circuit downstream from the CPB pump.

Leukodepletion filter (LG6): Standard heart valve surgery will be carried out incorporating a Pall corporation LG6B leukocyte-depleting filter into the arterial line of the extracorporeal circuit downstream from the CPB pump.

Follow Up Length: 3 month(s)

Intervention type



Not Applicable

Drug names

Primary outcome measures

Primary outcome; Timepoint(s): Development of AKI in the period from surgery until 6 weeks post-op using KDIGO criteria

Secondary outcome measures

1. Evaluation of tubular kidney injury using the following biomarkers: urinary excretion ratio of Retinol Binding Protein (RBP) to Creatinine (RBP:Cr) and urinary excretion ratio of Kidney Injury Molecule-1 to Creatinine (KIM-1:Cr)
2. Evaluation of glomerular kidney injury using the following biomarkers: urinary excretion ratio of Albumin to creatinine (A:Cr) and serum Cystatin C measurement
3. Total diuretic dosage over first 5 postoperative days
4. Daily fluid balance (total input and output)
5. Adverse events including: in-hospital mortality, need for haemodialysis (CVVH) and infection rates
6. Length of post-operative stay in hospital (intensive care and ward days) and other resource use required for the economic evaluation
7. Health-related Quality of life (HRQoL) assessment: Minnesota Living with Heart Failure
Questionnaire (MLHFQ) and EQ-5D

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Adults aged 18-89 years having single or multiple heart valve repair or replacement as a first time or redo operation as an elective or urgent procedure (i.e. non-emergency procedure), who are able to give informed consent
2. Patients with or without concomitant procedures. Concomitant procedures may include but are not restricted to: coronary artery bypass graft (CABG), ascending aortic and/or root replacement, and ablation for atrial fibrillation
3. Baseline urea and creatinine levels are within normal range, defined as follows: urea 2.5 to 7.8 mmol/L; creatinine 45 to 90 µmol/L for women and 60 to 110 µmol/L for men. Patients taking medications that may influence renal function, such as aspirin, statins, beta adrenergic antagonists, calcium channel antagonists, ACE inhibitors, diuretics and other cardiac medications, can be included provided that baseline urea and creatinine levels are within the normal ranges given above
Target Gender: Male & Female; Upper Age Limit 89 years ; Lower Age Limit 18 years

Participant type


Age group




Target number of participants

Planned Sample Size: 108; UK Sample Size: 108; Description: Intervention (leukodepletion filter) = 54Control (standard filter) = 54

Participant exclusion criteria

1. Baseline eGFR <30 ml/min/1.73m2
2. Patients on renal replacement therapy
3. Planned deep hypothermic circulatory arrest with cardiopulmonary bypass switched off
4. Patients participating in any other interventional research study (until the end of the follow-up period of the study).
Participation in an observational study will not preclude participation in ROLO

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Bristol Heart Institute
United Kingdom

Sponsor information


Blackpool, Fylde and Wyre Hospitals NHS Trust (UK)

Sponsor details

Whinney Heys Road
United Kingdom

Sponsor type

Research council



Funder type


Funder name

NIHR (UK) - Research for Patient Benefit (RfPB); Grant Codes: PB-PG-0711-25090

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes

21/02/2017: No publications found in PubMed, verifying study status with principal investigator.