Effect of ischaemic pre-conditioning on cardiac function during elective open abdominal aortic aneurysm repair

ISRCTN ISRCTN58848790
DOI https://doi.org/10.1186/ISRCTN58848790
Secondary identifying numbers N0544174260
Submission date
29/09/2006
Registration date
29/09/2006
Last edited
15/02/2013
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Surgery
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Vilas Navapurkar
Scientific

Box 17
Addenbrooke's Hospital
Cambridge
CB2 2QQ
United Kingdom

Phone +44
Email vilas.navapurkar@addenbrookes.nhs.uk

Study information

Study designRandomised controlled trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Not specified
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific title
Study objectivesTo measure the effect of a non-invasive technique called ischaemic preconditioning (IPC) on cardiac function during surgery to repair aortic aneurysms (an abnormal dilatation of the major artery in the body).
Ethics approval(s)Not provided at time of registration
Health condition(s) or problem(s) studiedSurgery: Open abdominal aortic aneurysm repair
InterventionThe technique of IPC temporarily reduces the blood flow to the patients legs in sequence for five minutes at a time. This causes the muscle in the patients legs to release various chemicals that can protect tissue against damage due to periods of reduced blood and oxygen supply. Once blood flow to the leg is fully restored, these substances enter the general circulation and can protect distant organs such as the heart, brain or kidneys from damage due to reduced blood flow. The Vascular Research Unit at Addenbrookes Hospital has shown that IPC reduces the levels of a protein in the blood called troponin I which is a marker of heart muscle damage.

We would like to investigate the effect of IPC on heart function by using established perioperative cardiovascular monitoring techniques.

IPC is not standard practice in major vascular surgery at present.

The Vascular Research Unit is undertaking a randomised controlled trial to look at the effect of IPC on renal function during AAA repair. We would like to use the monitoring techniques outlined below in the patients assigned to IPC in the randomised controlled trial to collect prospective data on how IPC effects heart function.

The patients assigned to the IPC group will have the blood flow to their legs reduced for two five minute periods by clamping the main artery to each leg in turn during the early stages of their operation. Cardiac output and allied haemodynamic data will be measured with a LiDCO monitor. This is a minimally invasive, continuous method of measuring cardiac output and deriving cardiac index, systemic vascular resistance and stroke volume variance. These are routine measures of cardiac function. This monitor uses clinically insignificant doses of intravenous lithium that are non toxic and do not harm or affect the patient in any way. The monitor is used routinely on patients in the Intensive Care Unit and HDU in Addenbrooke's hospital. The LiDCO is attached to an arterial drip. A central venous drip is also required as a port of injection for the lithium. Both of these drips are sited as routine monitors during such surgery and maintained in the post operative period. A 12 lead ECG monitor will be used to measure any cardiac ischaemia and serum troponin I levels to measure any cardiac injury.

No adverse events have been reported during IPC in previous trials by the Vascular Research Unit. The additional monitoring will not be in any way harmful to the patient and is routinely employed in many UK hospitals. Patients will be given an information sheet about the study when they attend outpatients about eight weeks before surgery. Contact details will be provided should they wish to discuss the study further. There will be opportunity to discuss any issues at the pre-admission clinic. All these patients are admitted the day before surgery. They will then be asked if they wish to participate in the study. Written informed consent will be obtained.
Intervention typeProcedure/Surgery
Primary outcome measureCardiac output measurement.
Secondary outcome measuresNot provided at time of registration
Overall study start date31/03/2006
Completion date31/03/2009

Eligibility

Participant type(s)Patient
Age groupAdult
SexNot Specified
Target number of participants40 - 9 patients as of July 2008
Key inclusion criteriaAny patient scheduled to undergo elective infra-renal aneurysm repair will be eligible for inclusion. The following entry criteria with respect to renal function shall apply:
1. No history of acute renal failure
2. No history of renal replacement therapy (haemodialysis, haemofiltration, peritoneal dialysis)
3. No previous renal transplant
4. No previous renal disease
5. Serum creatinine less than 150 micromols/L at pre-operative assessment
6. Serum urea less than 20 mmols/L at pre operative assessment
Key exclusion criteria1. Patients with aneurysms above the level of the renal arteries have a very high risk of renal damage during surgery. These aneurysms are relatively uncommon. Their inclusion could bias the trial.
2. Patients with lower limb amputations will be excluded as they have less muscle in their lower limbs. Thus, the IPC stimulus could be inadequate and bias the trial results.
3. Patients with ankle-brachial pressure index < 0.7 will be excluded as the IPC technique could trigger acute lower limb ischaemia.
4. Patients who have undergone previous endovascular repair of the aneurysm will be excluded.
Date of first enrolment31/03/2006
Date of final enrolment31/03/2009

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Box 17
Cambridge
CB2 2QQ
United Kingdom

Sponsor information

Record Provided by the NHSTCT Register - 2006 Update - Department of Health
Government

The Department of Health, Richmond House, 79 Whitehall
London
SW1A 2NL
United Kingdom

Phone +44 (0)20 7307 2622
Email dhmail@doh.gsi.org.uk
Website http://www.dh.gov.uk/Home/fs/en

Funders

Funder type

Government

Cambridge Consortium - Addenbrooke's (UK) - Own Account

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Abstract results p.4 01/01/2009 No No