Preoperative Dual Antiplatelet Therapy: Platelet Function and Influence of Cardiopulmonary Bypass

Study Overview
=================
Brief Summary
-----------------
Patients admitted for coronary artery bypass surgery taking antiplatelet medicine have an increased risk for bleeding. Present study aims to compare the platelet function in two patient groups using different types of heart-lung machine methods. It is assumed that one of the methods is superior verified by sensitive methods of testing platelet function.

Detailed Description
-----------------
Taking antiplatelet medication before cardiac surgery increases the risk for bleeding. The surgical procedure and the use of a heart-lung machine may disturb the function of platelets, why measures to protect the existing function of platelets are of prime concern. The present study aims to compare how two types of heart-lung machine methods influence platelet function in two groups of patients. The platelet function will be tested before, during and after surgery by the use of two independent methods.

Official Title
-----------------
Influence of Cardiopulmonary Bypass on Platelet Function in Patients With Preoperative Dual Antiplatelet Therapy:

Conditions
-----------------
Cardiopulmonary Bypass, Platelet Disorder, Bleeding Disorder, Platelet Dysfunction Due to Drugs

Intervention / Treatment
-----------------
* Procedure: CPB Low Dose
* Procedure: CPB High Dose


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients accepted for coronary bypass surgery with dual preoperative antiplatelet therapy suspended less than 4 days prior to surgery Exclusion Criteria: Abnormal coagulation verified from preoperative assessments, platelet count <100 000, Warfarin medication and renal insufficiency (GFR < 60 ml/min)

Ages Eligible for Study
-----------------
Minimum Age: 20 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CPB Low Dose<br>Conduct of cardiopulmonary bypass using a low heparin dose verified by the activated clotting time at 250 s | Procedure: CPB Low Dose<br>* Performing CPB with low dose heparin and coated equipment<br>|
| Experimental: CPB High Dose<br>Conduct of cardiopulmonary bypass using a high heparin dose verified by the activated clotting time at 480 s | Procedure: CPB High Dose<br>* Performing CPB with high dose heparin and uncoated equipment<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of platelet function following cardiopulmonary bypass using platelet aggregometry | Included aggregometry tests: Multiplate and Rotem Platelet | Test of platelet function will be analysed on arrival to the operating room, post cardiopulmonary bypass and on day 1 in the intensive care unit based on the area under the curve depited from the two employed aggremometers | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative bleeding | Blood loss 24 hrs post surgery | Postoperative bleeding 24 hrs |