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
Cardiac output is the amount of blood the heart pumps into the circulation per minute. In patients scheduled for cardiac (heart) surgery, cardiac output is measured using a catheter (tube) in the pulmonary artery. This is an invasive method. This study aims to compare the invasive method with a completely non-invasive method of cardiac output measurement. The non-invasive method uses a single air-inflatable cuff around one of the fingers. The non-invasive measurement has no potential harmful side effects.

Who can participate?
Patients aged over 18 scheduled for cardiac surgery.

What does the study involve?
The cuff will be applied directly before the operation starts, but before you are being anesthetized. We compare the new method against the standard method of measuring cardiac output during operations. The standard method involves placement of a special central venous line. In patients undergoing cardiac surgery, the latter method is used as the standard of care. Therefore the only procedure the this study involves is the extra measurement using the finger cuff.

What are the possible benefits and risks of participating?
Participation in this study has no potential benefits for you as a patient. Because the new method is completely non‐invasive, participation to this study has very little associated risks. The only adverse effect of the finger cuff is a temporarily blue‐coloring of the fingertip. This is completely harmless and the color of the finger immediately normalizes when the cuff is removed.

Where is the study run from?
Academic Medical Center (Netherlands), VU Medical Center (Netherlands), Cooper University Hospital (USA).

When is the study starting and how long is it expected to run for?
November 2013 to February 2015.

Who is funding the study?
Edwards Lifesciences (USA).

Who is the main contact?
Dr Niek Sperna Weiland

Trial website

Contact information



Primary contact

Dr Niek Sperna Weiland


Contact details

Meibergdreef 9

Additional identifiers

EudraCT number number

Protocol/serial number

Protocol Revision C/ METC 2013_068 / NL44270.018.13

Study information

Scientific title

A prospective, nonrandomized, noninterventional study to compare Nexfin CO-trek cardiac output with thermodilution cardiac output


Study hypothesis

The primary objective of this study is to show the accuracy of Cardiac Output measurement with the ccNexfin by assessment of agreement between ccNexfin and Cardiac Output measurement by pulmonary thermodilution using a Pulmonary Artery Catheter. To demonstrate this, the difference between the two methods must be smaller than the minimum difference considered as clinically significant (within 0.6 liters per minute difference).

Ethics approval

Medisch Ethische Toetsingscommissie Academisch Medisch Centrum, internal reference number METC 2013_068

Study design

Observational multicenter study

Primary study design


Secondary study design

Prospective nonrandomized noninterventional

Trial setting


Trial type


Patient information sheet

Not available in web format. Please contact the details below to request a patient information sheet


Cardiac output measurement


The standard pre‐evaluation will include:
1. Informed consent
2. Screening for inclusion and exclusion criteria
3. Basic medical history.
4. Baseline information, findings, and results will be entered in the eCRFs from the source documents including:
4.1. General Information (subject ID number, date & time of consent, age/gender/height/weight)
4.2. Clinical Information (ASA class, relevant medical history, use of medication, cardiac rhythm, reason for surgery)
For subjects who are enrolled in the study (signed an informed consent) but who do not undergo the required measurements, the eCRFs will not be completed. The site must retain the subject’s informed consent. Verification that the subject signed the consent will occur during an on‐site monitoring visit.

The CO comparison will be made in the period before the extracorporeal circulation and preferably in baseline as well as in Trendelenburg/reverse Trendelenburg position as clinically required. The following items will be performed:
1. The measurements are performed in the OR during anesthesia
2. ccNexfin cuff application to the appropriate finger of the arm with the arterial line
3. Start of ccNexfin measurement
4. The Investigator will perform intermittent TD measurements as required. Pre‐loading status (baseline, [reverse] Trendelenburg) will be noted.
5. Marking of this period on the ccNexfin recording in order to be able to pair TD measurements with beats recorded with the ccNexfin. Pairing of the cardiac cycles for the analyses is described in Appendix 6.
6. General Information (subject ID number, time of surgery start, study/reference device information and measurement sites)
7. Clinical Information as available (fluid administration, fluid loss, fluid balance, vasoactive/inotropic medications administered, mechanical ventilation settings [tidal volume, PEEP & FiO2]; all with time instants).

Study is complete when cardiopulmonary bypass is initiated or when the heart or vascular system is physically manipulated. Devices will be removed from the patients at the end of the surgical procedure

Intervention type



Drug names

Primary outcome measures

The primary study endpoint is the acquisition of the cardiac output values of the two devices to meet an acceptance criterion of Bias < 0.6 liters per minute.

Secondary outcome measures

The secondary study endpoints (and acceptance criteria) are:
1. The comparability of both methods as determined by Bland-Altman analysis (Bias < 0.6, Percentage Error < 40.4)
2. The precision of Nexfin CO-trek versus TD (no acceptance criterion)
3. The Pearson correlation coefficient of the CO pairs of the two methods (no acceptance criterion)

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Subjects must be at least 18 years of age
2. Subjects must give signed written informed consent
3. Subjects' height and weight must be accurately obtained prior to study start

Participant type


Age group




Target number of participants

Maximally 60

Participant exclusion criteria

1. Aortic or tricuspid valve regurgitation
2. Aortic stenosis or aneurysms
3. History of uncontrolled cardiac arrhythmia
4. Any peripheral vascular disease or conditions such as Raynaud's disease or Buerger's disease
5. Insufficient perfusion of the digits
6. Inability to place the finger cuff appropriately due to subject anatomy or condition
7. Known pregnancy
8. Patients being treated with an intra-aortic balloon pump
9. Patient is currently participating in an investigational drug or another device study that clinically interferes with the study endpoints

Recruitment start date


Recruitment end date



Countries of recruitment

Netherlands, United States of America

Trial participating centre

Academic Medical Center
Meibergdreef 9
1105 AZ

Trial participating centre

VU Medical Center
De Boelelaan 1117
1081 HV

Trial participating centre

Cooper University Hospital
1 Cooper Plaza
Camden, NJ
United States of America

Sponsor information


Edwards Lifesciences LLC

Sponsor details

One Edwards Way
92614 USA
United States of America

Sponsor type




Funder type


Funder name

Edwards Lifesciences

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype



United States of America

Results and Publications

Publication and dissemination plan

To be confirmed at a later date

Intention to publish date


Participant level data

Available on request

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes