Two Monitors for Measuring the Activated Clotting Time: A Comparison

Comparison of Two Point of Care Techniques Mechanical Versus Biochemical Activated Clotting Time

In this observational study a comparison is made between two different monitors for measurement of the activated clotting time (ACT): mechanical versus biochemical techniques

Study Overview

• Status: Completed
• Conditions: Cardiopulmonary Bypass; Blood Coagulation; Point-of-Care Testing
• Intervention / Treatment: Diagnostic test: Point-of-Care ACT

Detailed Description

The ACT is a functional test influenced by multiple factors, such as platelet function, coagulation factors, temperature and contact activation inhibitors. Results produced by different monitors are also prone to vary influenced by the specific method employed to perform the test.

The present clinical study aims to compare two types of ACT monitors: the Hemostatic Management System Plus (Medtronic) and i-STAT (Abbott) in 20 cardiac surgical patients by performing five intraoperative consecutive measurements using anti factor Xa as a reference for the actual heparin concentration.

Inclusion criteria comprised patients aged 20-80 years, scheduled for coronary bypass surgery.

Measurements: 1) before induction of anaesthesia 2 ) after heparin bolus 3) rewarming of the patient 4) weaning from cardiopulmonary bypass 5) after protamine administration.

The Hemostatic System Plus ACT monitor served as reference for dosing of heparin in all patients. The study protocol did not intervene with the standard protocol used for anticoagulation. No patient interventions were made.

It is hypothesised that the i-STAT ACT monitor has a better correlation with the actual heparin concentration than the Hemostatic Management System Plus

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

• Study Contact: Name: Micael Appelblad, PhD; Phone Number: +46 90 7853650; Email: micael.appelblad@kumu.se
• Study Contact Backup: Name: Samuel Nilsson, MS; Phone Number: +46907853650; Email: samuel.nilsson@vll.se

Study Locations

• Sweden
  • Umeå, Sweden, S-901 85
    • Heart Centre Umeå University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 78 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients admitted for routine coronary bypass surgery with the use of cardiopulmonary bypass

Description

Inclusion Criteria: Patients listed for coronary bypass surgery, -

Exclusion Criteria: Primary coagulation disorder, diabetes mellitus, ongoing anti-coagulation therapy, emergency, reduced kidney function, allergy for fish, sea food and protamine

-

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
CABG Surgical Patients; Patients undergoing coronary bypass grafting with cardiopulmonary bypass	Diagnostic test: Point-of-Care ACT; Comparison between two point-of-care devices for measurement of the activated clotting time

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Activated Clotting time	Coagulation Measure	Intraoperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anti-Factor Xa	Reference for heparin plasma concentration	Intraoperative

Collaborators and Investigators

• Sponsor: Umeå University
• Investigators: Study Director: Magnus Hedström, MD, Heart Centre, Umeå University Hospital, Sweden

Publications and helpful links

General Publications

• Teufelsbauer H, Proidl S, Havel M, Vukovich T. Early activation of hemostasis during cardiopulmonary bypass: evidence for thrombin mediated hyperfibrinolysis. Thromb Haemost. 1992 Sep 7;68(3):250-2.
• Hattersley PG. Progress report: the activated coagulation time of whole blood (ACT). Am J Clin Pathol. 1976 Nov;66(5):899-904. doi: 10.1093/ajcp/66.5.899.
• Guzzetta NA, Monitz HG, Fernandez JD, Fazlollah TM, Knezevic A, Miller BE. Correlations between activated clotting time values and heparin concentration measurements in young infants undergoing cardiopulmonary bypass. Anesth Analg. 2010 Jul;111(1):173-9. doi: 10.1213/ANE.0b013e3181e13470. Epub 2010 Jun 2.
• Svenmarker S, Appelblad M, Jansson E, Haggmark S. Measurement of the activated clotting time during cardiopulmonary bypass: differences between Hemotec ACT and Hemochron Jr apparatus. Perfusion. 2004;19(5):289-94. doi: 10.1191/0267659104pf755oa.
• Raymond PD, Ray MJ, Callen SN, Marsh NA. Heparin monitoring during cardiac surgery. Part 1: Validation of whole-blood heparin concentration and activated clotting time. Perfusion. 2003 Sep;18(5):269-76. doi: 10.1191/0267659103pf672oa.

Study record dates

Study Major Dates

• Study Start (Actual): April 18, 2017
• Primary Completion (Actual): October 1, 2017
• Study Completion (Actual): November 1, 2017

Study Registration Dates

• First Submitted: June 13, 2017
• First Submitted That Met QC Criteria: June 28, 2017
• First Posted (Actual): June 29, 2017

Study Record Updates

• Last Update Posted (Actual): May 12, 2023
• Last Update Submitted That Met QC Criteria: May 11, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: Point-of-Care Testing; Cardiopulmonary Bypass; Blood Coagulation Testing
• Other Study ID Numbers: 2017-HeartCentre-003

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No