Gradient Between Radial and Central Aortic Pressure After Cardiopulmonary BypassGARPNCT07857811
Evaluation of Aortic-Radial Blood Pressure Gradient in Pediatric Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass
An observational study of Gradient Between Radial and Central Aortic Pressure After Cardiopulmonary Bypass, run by Pontificia Universidad Catolica de Chile at 2 sites in Chile.
Trial summary
Invasive blood pressure monitoring is essential during heart surgery. Usually, doctors measure blood pressure using a small tube (a catheter) placed in an artery, typically in the wrist or arm. Read more about this study
- Who is it for?
- Ages 0 to 3 years
- Conditions the study is for
- Gradient Between Radial and Central Aortic Pressure After Cardiopulmonary Bypass
- What is being tested?
- Placement of a pressure transducer at the accessory port of the CPB arterial cannula
- How many people
- 100 participants
- Where
- 2 sitesChile
- Study dates
- 20 Apr 2026to 21 Apr 2028
- How long will I take part?
- 2 Days
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 0 to 3 years
- All sexes
- No healthy volunteers
- Child
Study population: Pediatric patients from 0-3 years of age
Who may be able to join
- Patients from 0 to 3 years old
- Cardiac surgery with cardiopulmonary bypass (CPB)
- Invasive blood pressure monitoring via radial artery
Who cannot join
- Patients in whom radial cannulation is not achieved
- Significant vascular malformations that may interfere with or contraindicate invasive radial blood pressure measurement
- Emergency surgeries
- Reinterventions during the same hospital stay
- Technical complications preventing reliable direct aortic pressure measurement
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Chile2 sites, 2 recruiting
- Recruiting
Pontificia Universidad Católica de Chile
Santiago, Santiago Metropolitan, 8320000
- Recruiting
Red de Salud UC Christus
Santiago, Santiago Metropolitan, 8320000
About this study
Invasive blood pressure monitoring is essential during heart surgery. Usually, doctors measure blood pressure using a small tube (a catheter) placed in an artery, typically in the wrist or arm. During surgeries that require a heart-lung machine (cardiopulmonary bypass), doctors can also measure blood pressure directly near the heart in the main artery (the aorta). This is done using a tube already in place for the machine, so no extra procedure is needed.
In adult patients, doctors have noticed that blood pressure readings taken at the arm can sometimes be significantly different from readings taken near the heart right after coming off the heart-lung machine. This difference could lead to unnecessary or incorrect treatments if medical teams rely only on arm readings. However, it is still unknown whether this same difference occurs in children.
The goal of this study is to measure and compare blood pressure from both the arm and near the heart in children aged 3 years and younger as they come off the heart-lung machine during heart surgery. This research will help medical teams make safer, more accurate treatment decisions for children undergoing heart surgery.
Read the detailed description
Accurate arterial blood pressure monitoring is essential during and after cardiopulmonary bypass (CPB) in pediatric cardiac surgery. However, a significant gradient between radial and central aortic pressure has been reported, which could lead to erroneous clinical decisions if radial pressure is overestimated. Although this phenomenon has been studied in adults, its incidence, associated factors, and clinical implications in pediatric patients under 3 years of age remain to be clearly established.
This study proposes a prospective observational cohort design including 100 patients under 3 years of age undergoing cardiac surgery with CPB and invasive radial arterial monitoring. The study will evaluate the incidence of a significant radial-to-aortic gradient (defined as a >20% difference in SBP or >10% in MAP sustained for more than 5 minutes), alongside biometric and surgical risk factors, and its relationship with clinical outcomes such as vasoactive drug requirements, blood transfusions, and duration of mechanical ventilation.
Statistical analysis will be performed using descriptive statistics, bivariate testing, and multivariate LASSO logistic regression. This study is expected to identify a pediatric risk profile for developing a significant pressure gradient, thereby optimizing decision-making regarding arterial monitoring sites and post-CPB hemodynamic management. Ultimately, this research aims to address a clinically relevant knowledge gap and enhance perioperative safety in this highly vulnerable population.
- Being tested
- Placement of a pressure transducer at the accessory port of the CPB arterial cannula
- Keywords
- Pressure gradient, Radial Aortic pressure gradient, cardiopulmonary bypass, Pediatric cardiac surgery
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Placement of a pressure transducer at the accessory port of the CPB arterial cannulaOther
Placement of a pressure transducer at the accessory port of the cardiopulmonary bypass (CPB) arterial cannula during the final phase of CPB and the immediate post-CPB period.
| Study group | Role | What they receive |
|---|---|---|
| Study group | Patients under 3 years of age undergoing cardiac surgery with cardiopulmonary bypass (CPB) at the UC-Christus Clinical Hospital. Receives: Other: Placement of a pressure transducer at the accessory port of the CPB arterial cannula |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the occurrence of a significant radial-to-aortic (R-Ao) pressure gradient during the immediate post-cardiopulmonary bypass (CPB) period
A significant radial-to-aortic (R-Ao) pressure gradient is defined as a >20% difference in SBP or >10% difference in MAP sustained for >5 minutes) during the immediate post-cardiopulmonary bypass (CPB) period
Measured: within 15 minutes from the weaning of the CBP
Secondary outcomes (6)
To determine the incidence of the R-Ao gradient in pediatric patients undergoing cardiac surgery with CPB and compare it with reported rates in the adult literature.
R-Ao Gradient Incidence: percentage of positive finding to the total of recruited patients in the study.
Reported Rates in adult population: As per an exhaustive review of previous literature.
Measured: Within the first 15 minutes after CPB weaning.
To identify risk factors associated with a higher R-Ao gradient, based on patient biometric parameters and surgical variables
Patient variables: age, body surface area [BSA], radial artery diameter Surgery variables: CPB duration and use of hypothermia Outcome Measure: Odds Ratio
Measured: From enrollment to 48 hours after surgery
To compare vasoactive drug requirements/dosages between patients with and without a significant arterial gradient
The comparison will be made using VIS score, as:
VIS = dopamine + dobutamine + (100 × epinephrine) + (100 × norepinephrine) + (10 × milrinone) + (10,000 × vasopressin)
It will be measured at three time periods: 30 mins post CPB, Postoperative Day 1 and Postoperative Day 2
Measured: within 30 minutes from the weaning of the CBP, up to 48 hours after surgery.
To compare the duration of invasive mechanical ventilation between patients with and without a significant arterial gradient.
Measured: within the first 48 hours following weaning of the CBP
To compare the incidence of post-CPB blood transfusion between patients with and without a significant arterial gradient.
Measured: within the first 48 hours following weaning of the CBP
To compare the incidence of renal dysfunction between patients with and without a significant arterial gradient.
Measured: within 48 hours following weaning of the CBP
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Oct 2026
- Study start20 Apr 2026
- Primary completion20 Apr 2026
- Study completion21 Apr 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Gradient Between Radial and Central Aortic Pressure After Cardiopulmonary BypassStudies of the same condition, open and under way.
- More trials run by Pontificia Universidad Catolica de ChileThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
- Target duration
- 2 Days
Sponsor and investigators
- Lead sponsor
- Pontificia Universidad Catolica de Chile
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Santiago Arze, MD, Principal investigator, División de Anestesiología, Pontificia Universidad Católica de Chile
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07857811
- Sponsor's protocol ID
- 250425011
- Acronym
- GARP
- Status last verified
- Jun 2026
- First submitted
- 29 Sep 2026
- Last updated
- 5 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Stern DH, Gerson JI, Allen FB, Parker FB. Can we trust the direct radial artery pressure immediately following cardiopulmonary bypass? Anesthesiology. 1985 May;62(5):557-61. doi: 10.1097/00000542-198505000-00002.
PubMed 3994020Jacquet-Lagreze M, Costescu A, Denault A. Can we trust radial artery pressure monitoring for cardiac surgery? Can J Anaesth. 2022 Nov;69(11):1319-1326. doi: 10.1007/s12630-022-02321-1. Epub 2022 Oct 5. No abstract available.
PubMed 36198991Bouchard-Dechene V, Kontar L, Couture P, Perusse P, Levesque S, Lamarche Y, Denault AY; Montreal Heart Institute Research Team. Radial-to-femoral pressure gradient quantification in cardiac surgery. JTCVS Open. 2021 Aug 5;8:446-460. doi: 10.1016/j.xjon.2021.07.031. eCollection 2021 Dec.
PubMed 36004190Dhanyee AS, Parida S, Thangaswamy CR, Jha AK, Rajappa M, Munuswamy H, Mishra SK. Relationship between difference of preoperative and cardiopulmonary bypass mean arterial pressure, and acute kidney injury in cardiac surgical patients undergoing valve surgery. Perfusion. 2025 Jan;40(1):164-173. doi: 10.1177/02676591231226161. Epub 2024 Jan 5.
PubMed 38182129Oh AR, Hong KY, Park J, Her S, Lee JH. Risk factors for femoral-to-radial artery pressure gradient after weaning from cardiopulmonary bypass: a historical cohort study. Can J Anaesth. 2022 Nov;69(11):1330-1339. doi: 10.1007/s12630-022-02320-2. Epub 2022 Oct 6.
PubMed 36203041Pauca AL, Hudspeth AS, Wallenhaupt SL, Tucker WY, Kon ND, Mills SA, Cordell AR. Radial artery-to-aorta pressure difference after discontinuation of cardiopulmonary bypass. Anesthesiology. 1989 Jun;70(6):935-41. doi: 10.1097/00000542-198906000-00009.
PubMed 2729634
Study at a glance
From the registry record, last updated by the sponsor on 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Aortic-Radial Blood Pressure Gradient in Pediatric Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass
- ClinicalTrials.gov ID
- NCT07857811
- Acronym / sponsor ID
- GARP / 250425011
- Keywords
- Pressure gradient, Radial Aortic pressure gradient, cardiopulmonary bypass, Pediatric cardiac surgery
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Pontificia Universidad Catolica de ChileUniversity, hospital or other
- Study start
- 20 Apr 2026 (actual)
- Primary completion
- 20 Apr 2026 (actual)
- Study completion
- 21 Apr 2028 (estimated)
- First posted
- 5 Oct 2026 (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.
Invasive blood pressure monitoring is essential during heart surgery. Usually, doctors measure blood pressure using a small tube (a catheter) placed in an artery, typically in the wrist or arm. During surgeries that require a heart-lung machine (cardiopulmonary bypass), doctors can also measure blood pressure directly near the heart in the main artery (the aorta). This is done using a tube already in place for the machine, so no extra procedure is needed.
In adult patients, doctors have noticed that blood pressure readings taken at the arm can sometimes be significantly different from readings taken near the heart right after coming off the heart-lung machine. This difference could lead to unnecessary or incorrect treatments if medical teams rely only on arm readings. However, it is still unknown whether this same difference occurs in children.
The goal of this study is to measure and compare blood pressure from both the arm and near the heart in children aged 3 years and younger as they come off the heart-lung machine during heart surgery. This research will help medical teams make safer, more accurate treatment decisions for children undergoing heart surgery.
Detailed description
Accurate arterial blood pressure monitoring is essential during and after cardiopulmonary bypass (CPB) in pediatric cardiac surgery. However, a significant gradient between radial and central aortic pressure has been reported, which could lead to erroneous clinical decisions if radial pressure is overestimated. Although this phenomenon has been studied in adults, its incidence, associated factors, and clinical implications in pediatric patients under 3 years of age remain to be clearly established.
This study proposes a prospective observational cohort design including 100 patients under 3 years of age undergoing cardiac surgery with CPB and invasive radial arterial monitoring. The study will evaluate the incidence of a significant radial-to-aortic gradient (defined as a >20% difference in SBP or >10% in MAP sustained for more than 5 minutes), alongside biometric and surgical risk factors, and its relationship with clinical outcomes such as vasoactive drug requirements, blood transfusions, and duration of mechanical ventilation.
Statistical analysis will be performed using descriptive statistics, bivariate testing, and multivariate LASSO logistic regression. This study is expected to identify a pediatric risk profile for developing a significant pressure gradient, thereby optimizing decision-making regarding arterial monitoring sites and post-CPB hemodynamic management. Ultimately, this research aims to address a clinically relevant knowledge gap and enhance perioperative safety in this highly vulnerable population.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 2 Days
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Study group | – | Other: Placement of a pressure transducer at the accessory port of the CPB arterial cannulaPatients under 3 years of age undergoing cardiac surgery with cardiopulmonary bypass (CPB) at the UC-Christus Clinical Hospital. |
Who may qualify
- Ages
- 0 to 3 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
- Study population
- Pediatric patients from 0-3 years of age
Key inclusion criteria (3 listed)
- Patients from 0 to 3 years old
- Cardiac surgery with cardiopulmonary bypass (CPB)
- Invasive blood pressure monitoring via radial artery
Key exclusion criteria (5 listed)
- Patients in whom radial cannulation is not achieved
- Significant vascular malformations that may interfere with or contraindicate invasive radial blood pressure measurement
- Emergency surgeries
- Reinterventions during the same hospital stay
- Technical complications preventing reliable direct aortic pressure measurement
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 |
|---|---|---|
| Placement of a pressure transducer at the accessory port of the CPB arterial cannulaPlacement of a pressure transducer at the accessory port of the cardiopulmonary bypass (CPB) arterial cannula during the final phase of CPB and the immediate post-CPB period. | Other | Study group |
Primary outcome
To evaluate the occurrence of a significant radial-to-aortic (R-Ao) pressure gradient during the immediate post-cardiopulmonary bypass (CPB) period
Time frame: within 15 minutes from the weaning of the CBP
A significant radial-to-aortic (R-Ao) pressure gradient is defined as a >20% difference in SBP or >10% difference in MAP sustained for >5 minutes) during the immediate post-cardiopulmonary bypass (CPB) period
6 secondary outcomes
To determine the incidence of the R-Ao gradient in pediatric patients undergoing cardiac surgery with CPB and compare it with reported rates in the adult literature.
Time frame: Within the first 15 minutes after CPB weaning.
To identify risk factors associated with a higher R-Ao gradient, based on patient biometric parameters and surgical variables
Time frame: From enrollment to 48 hours after surgery
To compare vasoactive drug requirements/dosages between patients with and without a significant arterial gradient
Time frame: within 30 minutes from the weaning of the CBP, up to 48 hours after surgery.
To compare the duration of invasive mechanical ventilation between patients with and without a significant arterial gradient.
Time frame: within the first 48 hours following weaning of the CBP
To compare the incidence of post-CPB blood transfusion between patients with and without a significant arterial gradient.
Time frame: within the first 48 hours following weaning of the CBP
To compare the incidence of renal dysfunction between patients with and without a significant arterial gradient.
Time frame: within 48 hours following weaning of the CBP
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Oct 2026.
- Background: PubMed 3994020Stern DH, Gerson JI, Allen FB, Parker FB. Can we trust the direct radial artery pressure immediately following cardiopulmonary bypass? Anesthesiology. 1985 May;62(5):557-61. doi: 10.1097/00000542-198505000-00002.
- Background: PubMed 36198991Jacquet-Lagreze M, Costescu A, Denault A. Can we trust radial artery pressure monitoring for cardiac surgery? Can J Anaesth. 2022 Nov;69(11):1319-1326. doi: 10.1007/s12630-022-02321-1. Epub 2022 Oct 5. No abstract available.
- Background: PubMed 36004190Bouchard-Dechene V, Kontar L, Couture P, Perusse P, Levesque S, Lamarche Y, Denault AY; Montreal Heart Institute Research Team. Radial-to-femoral pressure gradient quantification in cardiac surgery. JTCVS Open. 2021 Aug 5;8:446-460. doi: 10.1016/j.xjon.2021.07.031. eCollection 2021 Dec.
- Background: PubMed 38182129Dhanyee AS, Parida S, Thangaswamy CR, Jha AK, Rajappa M, Munuswamy H, Mishra SK. Relationship between difference of preoperative and cardiopulmonary bypass mean arterial pressure, and acute kidney injury in cardiac surgical patients undergoing valve surgery. Perfusion. 2025 Jan;40(1):164-173. doi: 10.1177/02676591231226161. Epub 2024 Jan 5.
- Background: PubMed 36203041Oh AR, Hong KY, Park J, Her S, Lee JH. Risk factors for femoral-to-radial artery pressure gradient after weaning from cardiopulmonary bypass: a historical cohort study. Can J Anaesth. 2022 Nov;69(11):1330-1339. doi: 10.1007/s12630-022-02320-2. Epub 2022 Oct 6.
- Background: PubMed 2729634Pauca AL, Hudspeth AS, Wallenhaupt SL, Tucker WY, Kon ND, Mills SA, Cordell AR. Radial artery-to-aorta pressure difference after discontinuation of cardiopulmonary bypass. Anesthesiology. 1989 Jun;70(6):935-41. doi: 10.1097/00000542-198906000-00009.
- Individual participant dataSharing planned: No
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.
Santiago Arze, MD principal investigator
División de Anestesiología, Pontificia Universidad Católica de Chile
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Gradient Between Radial and Central Aortic Pressure After Cardiopulmonary Bypass, run by Pontificia Universidad Catolica de Chile at 2 sites in Chile.
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 3 inclusion and 5 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: looking for participants now, as of the sponsor's last update on 5 Oct 2026. 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 Chile. 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.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Santiago Arze, MD (+56955049217, sarze@uc.cl), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To evaluate the occurrence of a significant radial-to-aortic (R-Ao) pressure gradient during the immediate post-cardiopulmonary bypass (CPB) period (time frame: within 15 minutes from the weaning of the CBP). 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 NCT07857811, which also lists 6 linked publications.
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 5 Oct 2026.