Clinical trial NCT01675817: Evaluation of Heparin Rebound in Cardiac Surgery
Official title: Evaluation of Heparin Rebound in Cardiac Surgery
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Coagulation Delay
Keywords: heparin rebound
protamine
cardiopulmonary bypass
cardiac surgery
anti-Xa
anti-IIa
Lead sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
Sponsor class: OTHER
Collaborators: name: Academic Medical Organization of Southwestern Ontario
First posted: 2012-08-30
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: OTHER
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Patients undergoing elective cardiac surgery

Brief summary: Recent work has shown that heparin rebound is common after cardiac surgery.

The exact doze of protamine required to neutralize heparin at the end of CPB is unknown. Besides, the precise doze of protamine to treat heparin rebound is also unknown. It is also unknown if precise titration of protamine perioperatively in cardiac surgery can influence transfusion requirements after cardiac surgery.

Detailed description: This study will assess how much protamine is required to neutralize residual heparin perioperatively in cardiac surgery through measurement of functional assays of heparin (anti-Xa and anti-IIa levels). In the first phase of this study, protamine titration assays will be carried out on normal pooled plasma incubated with heparin in the laboratory.

Once the correct dose of protamine required to neutralize the heparin is established in the laboratory, the second phase will begin. Herein, plasma samples from patients undergoing cardiac surgery (with anticoagulation with two different commercial preparations of heparin) will be evaluated for residual heparin (Anti-Xa and anti-IIa levels). Protamine titration assays wil then be carried out in vitro to assess neutralization of heparin.

Eligibility criteria: Inclusion Criteria:

* Age \>18 years
* Written consent
* Scheduled for cardiac surgery under CPB (cardiopulmonary bypass)--(elective or emergency)
* 10 patients undergoing cardiac surgery where CPB time is anticipated to be short (isolated primary CABG (coronary artery bypass graft);isolated mitral-valve repair or aortic-valve replacement)
* 10 patients undergoing cardiac surgery where CPB time is anticipated to be longer (CABG + valve surgery combined; reoperations)

Exclusion Criteria:

* Known coagulopathies
* Liver dysfunction
* Patients receiving unfractionated or low molecular weight heparin thrombin inhibitors, warfarin, antiplatelets within the past 7 days
* Patients expected to undergo hypothermic CPB or circulatory arrest

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: London
country: Canada
facility: Dr. Ravi Taneja
state: Ontario
Study officials:
affiliation: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
name: Ravi Taneja, MD, FRCPC
role: PRINCIPAL_INVESTIGATOR
References:
citation: Taneja R, Berry L, Pappu U, Stitt L, Sayal P, Allen P, Hoogendoorn H, Chan A. Protamine requirements in cardiac surgery: effect of changes in the heparin reference standard. J Cardiothorac Vasc Anesth. 2014 Oct;28(5):1227-32. doi: 10.1053/j.jvca.2014.04.024.