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

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Mr David Jenkins


Contact details

Department of Cardiothoracic Surgery
Papworth Hospital NHS Foundation Trust
Papworth Everard
United Kingdom
+44 (0)1480 364806

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title



Study hypothesis

Please note that as of 25/04/2008 this record was extensively updated. All updates to this record can be found in the relevant field, under the update date of 25/04/2008. Please note that the anticipated start and end dates of this trial have also been updated. The previous start and end dates of this trial were:
Anticipated start date: 01/09/2006
Anticipated end date: 30/11/2009

Current hypothesis as of 25/04/2008:
In order that an accurate pulmonary endarterectomy (PEA) may be performed, good visibility of the pulmonary artery tree, by way of a dry (bloodless) operative field, is required by the surgeon. Two alternative techniques may be used to obtain a bloodless field; deep hypothermic circulatory arrest (DHCA) involves the draining of blood from the entire circulation into the cardiopulmonary bypass (CPB) reservoir for short periods of time and selective antegrade cerebral perfusion (SACP) maintains blood flow to the brain, but blood flow to the lungs is reduced allowing adequate vision for dissection.

Null Hypothesis:
The two methods of obtaining a bloodless field for performing PEA are:
1. Equivalent in maintaining brain function, and
2. Equivalent in their surgical success, i.e. improvement in lung function

Alternative hypothesis: Studies by Ergin et. al. in 1994 and 1999, where 19% and 28% of patients, respectively, undergoing DHCA showed temporary neuropsychological dysfunction. In comparison, Eusanio et. al. in 2002 showed a dysfunction in 5.1% of patients undergoing SACP. We therefore hypothesise that although surgical success will not differ between the two techniques, SACP will be superior to DHCA in maintaining (or improving) pre-operative brain function.

Previous hypothesis:
To determine whether maintaining blood flow around the brain during pulmonary endarterectomy (PEA), as opposed to total circulatory arrest, improves three-month post-operative brain function.

Ethics approval

Added 25/04/2008:
Ethics approval received from the Peterborough and Fenland Local Research Ethics Committee (now known as Cambridgeshire 3 Research Ethics Committee) on the 29 March 2006.

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet




Minor additions made to interventions on 25/04/2008 (noted in text):
We propose to perform a prospective, single centre, randomised study to include all patients referred to Papworth Hospital for PEA to determine the impact of DHCA versus SACP on brain function and surgical success. Patients will be randomly allocated into either DHCA or SACP groups.

Cognitive (or neuropsychological) testing will be used to assess subject brain function pre- and post-operatively (3 and 12 months). Cognitive testing aims to detect slight changes in intellectual function and personality, and has traditionally been done using 'pen and paper' tests. Consensus statements published in 1995 and 1997 recommend four tests (Rey auditory verbal learning test, Trail-making A and B, and the grooved pegboard) to be used as a minimum to enable comparisons to be made across different studies. Computerised tests may also be useful, as they are more user friendly for both test administrator and subject, and are less susceptible to human error. We therefore propose to administer the consensus battery of four conventional tests alongside a series of computerised tests (CAmbridge Neuropsychological Test Automated Battery [CANTAB]). The patient and member of the research team administering the cognitive function tests will be blind to the randomisation group. Scores for depression, anxiety and pain will be used to check for their effects on test results. The national adult reading test will also be administered to subjects in order to determine baseline intelligence quotient (IQ) levels. The total length of time spent by each subject on the cognitive testing will be 4.5 hours (1.5 hours at each of the pre-operative and follow-up visits).

Cognitive testing will be carried out in a dedicated quiet room (added as of 25/04/2008 - previously 'quiet area of the ward'), by the same test administrator on each occasion, without interruptions and allowing for rest breaks if required by the subject. Blood samples will be collected before the operation, and also at one time point post-operatively. These samples will be stored until an appropriate test for oxygen deprivation has been identified, up to a maximum of ten years (added as of 25/04/2008 - previously two years).

All patients return to Papworth Hospital for an inpatient stay of 2 - 4 days at 12 weeks and and a minimum of 1 day at 1 year post-operatively as part of their routine care (added as of 25/04/2008 - previously there was no mention of 'minimum of 1 day'). Lung function testing, six-minute walk test, New York Heart Association (NYHA) scores and the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) quality of life assessment (a disease specific questionnaire developed at Papworth Hospital) are routinely carried out during the 12 week and 1 year visits and this data will be collected. A right heart catheter is routinely performed at 12 weeks to measure changes in pulmonary artery pressures. These routine assessments will provide the measures of surgical success for our study. No additional clinical assessments will be carried out as part of the study.

Safety and recourse use data will also be collected for each participant, including all adverse events, details on the operative procedure, concomitant medications, and length of critical care and hospital stay.

Project timetable:
Months 0 - 2: trial literature will be produced and Ethics Committee approval will be sought
Months 3 - 32: recruitment of patients into the study. A total of 110 will be required. If 1 patient is recruited per week, for 48 weeks/year, recruitment will be complete in 27 months.
Months 6 - 44: follow-up period. Patients will be followed up for 1 year post-operatively.
Months 45 - 47: closedown period to ensure data complete and prepare final report.

Risks and inconvenience for participants:
There are no additional risks involved with completing the cognitive tests. However, the additional time necessary to complete the tests may be considered an inconvenience by some participants.

Joint Principal Investigator:
Dr Alain Vuylsteke
Department of Anaesthesia
Papworth Hospital NHS Foundation Trust
Papworth Everard
Cambridge CB23 8RE
United Kingdom
Tel: +44 (0)1480 364675

Intervention type



Not Specified

Drug names

Primary outcome measure

The proportion of patients demonstrating a decline in cognitive function, compared to baseline, 12 weeks after PEA in DHCA versus SACP groups. Cognitive function will be assessed using the consensus battery of conventional pen and paper tests.

Secondary outcome measures

Added as of 25/04/2008:
1. The number of patients with clinically significant cognitive function deficit at twelve weeks, defined as a drop in a patient's postoperative score of greater than or equal to 1 SD from their pre-operative score in two or more tests
2. Mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) at baseline and 12 weeks post-surgery
3. NYHA, CAMPHOR and six-minute walk test at baseline, 12 weeks, and 1 year
4. Cognitive function in patients 12 months after PEA assessed as detailed above
5. CANTAB system of computerised cognitive tests at baseline, 12 weeks and 1 year
6. Extubation time
7. Length of stay in the Intensive Care Unit and in hospital
8. Intra-operative cerebral oxygen saturation as measured by near infrared spectroscopy (NIRS)

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Current inclusion criteria as of 25/04/2008:
1. Patients referred for PEA
2. Aged between 18 and 80, either sex
3. Written informed consent obtained

Previous inclusion criteria:
All patients referred to Papworth hospital for PEA

Participant type


Age group

Not Specified


Not Specified

Target number of participants


Participant exclusion criteria

Added 25/04/2008:
1. Anticipated difficulty with completion of cognitive function tests (e.g. sight or hearing impairments, physical barriers)
2. Not fluent in the English language
3. Unable to obtain informed consent
4. Patients having other concomitant surgery, e.g. coronary artery bypass grafting, valve surgery
5. Past medical history of stroke or psychiatric disorder
6. Repeat PEA
7. Patients having unacceptable risk as per investigator judgement or where a specific request for either DHCA or SACP has been made by the surgeon

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Department of Cardiothoracic Surgery
United Kingdom

Sponsor information


Papworth Hospital NHS Foundation Trust (UK)

Sponsor details

Papworth Everard
CB23 8RE
United Kingdom

Sponsor type




Funder type


Funder name

Cambridge Consortium - Papworth Hospital NHS Trust (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Papworth Hospital Own Account (UK) - Time only

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

NHS R & D Support Funding (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Added as of 25/04/2008:

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

The Moulton Charitable Foundation (UK)

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

Basic results (scientific)

Publication list

2011 results in

Publication citations

  1. Results

    Vuylsteke A, Sharples L, Charman G, Kneeshaw J, Tsui S, Dunning J, Wheaton E, Klein A, Arrowsmith J, Hall R, Jenkins D, Circulatory arrest versus cerebral perfusion during pulmonary endarterectomy surgery (PEACOG): a randomised controlled trial., Lancet, 2011, 378, 9800, 1379-1387, doi: 10.1016/S0140-6736(11)61144-6.

Additional files

Editorial Notes