The Influence of Preoperative Warfarin Medication on Thromboelastography and Blood Transfusion

Influence of Warfarin on Thromboelastography and Transfusion

Warfarin therapy is usually monitored using the international normalized ratio (INR), and prolonged INR means coagulation impairment that can leads elevating transfusion requirement after operation. This study was designed to assess the relationships with warfarin and TEG values related to transfusion amount, to set up blood transfusion strategy in patients on atrial fibrillation undergoing cardiac surgery.

Study Overview

• Status: Completed
• Conditions: Atrial Fibrillation

Detailed Description

This study was a retrospective evaluation of patients who have received cardiac surgery with Maze-operation from March 2008 to November 2013.

Patients who have atrial fibrillation undergoing cardiac surgery with Maze-operation were included.

The following exclusion criteria are applied:

1. Patients who have taken medicine related to coagulation (such as antiplatelets like aspirin and clopidogrel) except warfarin or bridged heparin
2. Patients whose laboratory values could not be confirmed by medical records review.

Patients were categorized by two groups.

1. W group: patients on atrial fibrillation who have taken warfarin for p.o medication.
2. C group: patients on atrial fibrillation who have not taken warfarin for p.o medication.

Using blood sample, authors examined as follows:

1. Preoperative (maximum 5days before operation) and postoperative (30min after ICU admission) coagulation values with haematologic values: PT/aPTT, INR, Hb, Hct, platelet levels.
2. ROTEM values at 30min after anaesthetic induction and 30min after ICU admission: Clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), maximum lysis (ML)
3. Intraoperative (during operation) and postoperative (during admission, an expected average of 5 weeks) total transfusion amount: RBC, FFP, PC, cryoprecipitate.
4. Post operative 24 hr bleeding amount in the chest tube drain bottle.
5. The duration (maximum 2 weeks) of warfarin discontinuation. (in W group)

Statistical analysis was performed using unpaired t-test and chi-square test to compare patients demographic data and other parameters. To determine the relationship of INR and ROTEM parameters with bleeding amount and transfusion amount, multiple linear regression model that accounted for all confounder variables was used. For each factor in the multiple regression model, variables with a p value of less than 0.10 were kept in the final model. The data was analyzed using the program Statistical Package for the Social Sciences ver. 18.0 (SPSS Inc, Chicago, USA). A value of p < 0.05 was considered statistically significant.

• Study Type: Observational
• Enrollment (Actual): 107

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 143-729
    • Konkuk University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients undergoing cardiac surgery with Maze-operation

Description

Inclusion Criteria:

1. Patients who have atrial fibrillation undergoing cardiac surgery with Maze-operation.

• W group : Patients who have had warfarin therapy before operation due to treat Atrial fibrillation
• C group : Patients who have not had warfarin therapy before operation

Exclusion Criteria:

• 1. Patients who have taken medicine related to coagulation (such as antiplatelets like aspirin and clopidogrel) except warfarin or bridged heparin.
• 2. Patients whose laboratory values could not be confirmed by medical records review.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Retrospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Rotational Thromboelastography : Clotting time (CT)	30min after anesthetic induction and 15 mins after CPB weaning status

Secondary Outcome Measures

Outcome Measure	Time Frame
Rotational Thromboelastography : clot formation time (CFT)	30min after anesthetic induction and 15 mins after CPB weaning status

Other Outcome Measures

Outcome Measure	Time Frame
Rotational Thromboelastography : maximum clot firmness (MCF)	30min after anesthetic induction and 15 mins after CPB weaning status
Rotational Thromboelastography : maximum lysis (ML) level Rotational Thromboelastography : maximum lysis (ML) level	30min after anesthetic induction and 15 mins after CPB weaning status
amount of Blood transfusion	intraoperative (during operation) and postoperative (during admission, an expected average of 5 weeks)
Coagulation values : preprothrombin time (PT)	preoperative (maximum 5days before operation) and postoperative (30min after ICU admission)
Coagulation values : activated partial thromboplastin time (aPTT)	preoperative (maximum 5days before operation) and postoperative (30min after ICU admission)

Collaborators and Investigators

• Sponsor: Konkuk University Medical Center

Study record dates

Study Major Dates

• Study Start: June 1, 2014
• Primary Completion (Actual): February 1, 2015
• Study Completion (Actual): February 1, 2015

Study Registration Dates

• First Submitted: June 29, 2014
• First Submitted That Met QC Criteria: July 14, 2014
• First Posted (Estimate): July 16, 2014

Study Record Updates

• Last Update Posted (Estimate): February 25, 2015
• Last Update Submitted That Met QC Criteria: February 23, 2015
• Last Verified: February 1, 2015

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Arrhythmias, Cardiac; Atrial Fibrillation
• Other Study ID Numbers: KUH1160068