What is it? Why do we need it POC? Coagulation Testing What is it? Why do we need it POC? Marcia L. Zucker, Ph.D. Director of Clinical Research ITC Educational Services, Edison, NJ
Coagulation Testing Monitoring hemostasis Bleeding Clotting
Coagulation Testing Monitoring therapy Heparin Coumadin Thrombolytics Intrinsic Pathway Extrinsic Pathway Common Pathway CLOT Heparin Coumadin Monitor with ACT / aPTT Monitor with PT Thrombolytics TT / Fibrinogen
Coagulation is Complex Platelet Adhesion shape change release 3 sec 10 sec 5 min ADP release Platelet Aggregation Coagulation Fibrin formation
Coagulation is Complex
Common(?) Coagulation Tests Laboratory PT.. aPTT TT.. Fib. Anti Xa Anti IIa Factor Assays Point of Care ACT Celite® Kaolin Glass beads Silica thromboplastin
Differences in test methods Standard Laboratory Platelet Poor Plasma Sodium Citrate Anticoagulant 1:9 Dilution Variable Preanalytical Delay Point of Care Whole Blood No Added Anticoagulant No Dilution No Preanalytical Delay
POC Coagulation Analyzers HEMOCHRON 401 / 801 / Response HEMOCHRON Jr. Signature ProTime Medtronic HMS / HemoTec ACT II CoaguChek / CoaguChek Pro DM Bayer RapidPoint i-STAT Others
POC Coag Analyzers Differ Test methodology Sample size and application Sample measurement Clot detection method Enzyme detection method Reagent composition Results
Clinical Applications Operating Room Cardiac Surgery Interventional Cardiology and Radiology Critical Care Satellite Sites Dialysis ECMO Emergency Room Anticoagulation Clinic
Activated Clotting Time Extrinsic Pathway Intrinsic Pathway ACT Common Pathway CLOT
What do we use an ACT for? Maintain Balance Heparin Bleeding Thrombosis Heparin Rapid Anticoagulant Effect Individual sensitivities vary significantly Potency differences Source: Bovine or Porcine Lot to Lot variability Rapidly Reversible with Protamine
Why are there so many different ACTs?
Monitoring - ACT Benefits Industry Standard Since 1970s Recommended as primary method in AmSECT guidelines (perfusion) Easy to run
Monitoring - ACT Disadvantages Each system yields different numbers High sensitivity to hypothermia and hemodilution (with exceptions) Little or no correlation to heparin level especially true for pediatric patients
Heparinized ACT - CPB Data from Huffman, et.al. 1998 AmSECT meeting 17
Monitoring in CPB - ACT Data from clinical evaluation, on file, ITC
Pharmaceutical Intervention Amicar or Tranexamic Acid No effect on standard celite ACT Continued debate on efficacy Multiple reports Reduction in post-operative blood loss Reduced transfusion requirements
Pharmaceutical Intervention Aprotinin Significant elevation of celite ACT Two dosing regimens Full Hammersmith 2 x 106 KIU loading dose; 2 x 106 KIU pump prime; 0.5 x 106 KIU/hr infusion Half Hammersmith 1 x 106 KIU loading dose; 1 x 106 KIU pump prime; 0.25 x 106 KIU/hr infusion
ACT Monitoring-Aprotinin Treatment Celite ACT Not recommended Still used with target times of >750 seconds Kaolin ACT Unaffected by moderate doses of aprotinin Used with target times of > 480 seconds ACT+ Unaffected by ALL doses of aprotinin Used with target times of > 400 seconds
ACT Monitoring -Aprotinin Treatment Data from clinical evaluation, on file, ITC
Alternative Monitoring - Aprotinin HiTT - High Dose Thrombin Time Adapted from Huyzen, et. al. J.CardioThorac. Vasc. Anesth. 8:153, 1994
Alternative Monitoring - Aprotinin Adapted from Huyzen, et. al. J.CardioThorac.Vasc.Anesth. 8:153, 1994
Thrombin Time TT Intrinsic Pathway Extrinsic Pathway Common Pathway CLOT
Other POC Coag in the OR aPTT / PT Fibrinogen Dosing Assays Pre- and post-procedural screening Fibrinogen Dosing Assays Customize heparin and protamine for each patient HEMOCHRON HRT / PRT Hepcon HMS RapidPoint
Other POC Coag in the OR Heparin neutralization verification Ensure complete removal of circulating heparin aPTT PDA-O - ACT based TT / HNTT - Thrombin Time based heparinase ACT
Outcome studies - POC in OR Reduced Blood Loss/Transfusion Use of HRT and PRT (RxDx System) Jobes, D. et. al., 1995. J.Thorac.Cardiovasc.Surg. Reduced Cost Resulting from POC Assays RxDx combined with TT / HNTT Jobes, D. et. al., 1996. Am Soc Anesth Mtg.
Outcome studies - POC in OR Reduced Complication Rates TT /HNTT Re-Exploration for Bleeding Reduced from 2.5% to 1.1% Re-Exploration for Coagulopathy Reduced from 1.0% to 0.0% Jobes, et.al. 1997, NACB Presentation, Phila.
Clinical Applications Operating Room Cardiac Surgery Interventional Cardiology and Radiology Critical Care Satellite Sites Dialysis ECMO Emergency Room Anticoagulation Clinic
Procedures Diagnostic Interventional Catheterization Electrophysiology locate and map vessel blockage(s) determine need for interventional procedures Electrophysiology Interventional Balloon angioplasty Arthrectomy (roto-rooter)
Diagnostic – Low dose heparin Catheterization and Electrophysiology 2500 - 5000 unit bolus dose frequently not monitored if monitored – ACT aPTT
Interventional – Moderate dose Angioplasty and Arthrectomy 10,000 unit bolus dose or 2 - 2.5 mg/kg target ACT 300 - 350 seconds unless platelet inhibitors used 200 – 300 in presence of ReoPro
Why use platelet inhibitors?
Angioplasty promotes aggregation
Platelet Inhibitors ReoPro Integrelin Aggrastat elevates ACTs target time = 250 sec with ReoPro determined using FTCA510 tube Integrelin No reported effects on ACT Aggrastat
Clinical Applications Operating Room Cardiac Surgery Interventional Cardiology and Radiology Critical Care Satellite Sites Dialysis ECMO Emergency Room Anticoagulation Clinic
ACT or aPTT Determine when to pull the femoral sheath Premature sheath pull can lead to bleeding. Delayed removal can increase time in CCU. Target set at each site. ACT targets range from 150 – 220 seconds aPTT targets range from 40 – 70 seconds
ACT or aPTT Monitor heparin therapy Target times determined by each facility APTT outcome study Reduce time to result (112 vs <5 minute) Reduce time to stabilization Reduce dose adjustments Reduce length of stay By using POC aPTT instead of lab Poster at AACC 2000 – Staikos, et.al.
What did it say? Mean time to lab result = 112 min Mean time to POC result <5 min Fewer dose adjustments needed in POC group to reach therapeutic level Shorter time required to reach therapeutic level in POC group Fewer dose changes in POC group
Activated Partial Thromboplastin Time Extrinsic Pathway Intrinsic Pathway APTT Common Pathway CLOT
Activated Partial Thromboplastin Time NOT a PTT PTT is the predecessor of the aPTT Not used anymore Laboratory or Point of Care High APTT values the presence of heparin underlying coagulopathy Monitor heparin / coumadin® cross-over
Heparin versus Warfarin
Prothrombin Time PT Intrinsic Pathway Extrinsic Pathway Common Pathway CLOT
Prothrombin Time Monitor warfarin therapy Monitor heparin/warfarin crossover Target times are set by International Normalized Ratio (INR) ISI = international Sensitivity Index INR target ranges are specified by patient populations prophylactic therapy for DVT: INR= 2.0 - 3.0 artificial heart valve: INR=3.0 - 4.0
Will POC Results Match the Lab? NO! (Probably Not) but it WILL Correlate
Correlate Does Not Mean Match
Coag is NOT Chemistry
Compare for your site. Same System / Multiple Sites
Are differences important? Sometimes no - aPTT C
Sometimes VERY - aPTT SP
Lot to Lot Reproducibility
Clinical Applications Operating Room Cardiac Surgery Interventional Cardiology and Radiology Critical Care Satellite Sites Dialysis ECMO Emergency Room Anticoagulation Clinic
Dialysis / ECMO ACT (or nothing in dialysis) Majority use P214 glass activated ACT Some use ACT-LR; HemoTec Better Control of Anticoagulation Leads to Increased Dialyzer Reuse Potential for Long Term Cost Savings No Compromise in Dialysis Efficacy (Kt/V) Ouseph, R. et.al. Am J Kidney Dis 35:89-94; 2000
Emergency Room ACT; aPTT; PT; Fibrinogen Immediate Identification of Coagulopathies Optimization of Critical Decision Pathways ACT Allows Early Detection of Traumatic Coagulopathy Allows Early Treatment Decisions Aids Damage Control Decisions Aucar, J. et.al. 1998 SW Surgeons Congress Optimize Staffing During Off Hours
Anticoagulation Clinics Results Available While Patient is Present Improved Anticoagulation Management Improved Standard of Care Staff Efficiency Immediate Retesting (if needed) Fingerstick Sampling Same System for Clinic and Home Bound Patients Standardized ISI / PT normal Test System Specific
Anticoagulation Clinics Potential for Self-Testing High Risk Patients Patients Who Travel Frequently Home-Bound Patients in Rural Areas Far from Clinic Improved Outcomes Through More Frequent Testing
How to compare INR differences Has the Hemostatic Balance been Upset? Is the Clinical Response Different?
Patient Management 6.0 5.0 4.0 3.0 2.0 1.0 Target INR 3.0 Must change dose Target INR 3.0 Range 2.5 -3.5 Call Clinic May change dose Patient Management
What’s the catch? Regulatory compliance Connectivity
Regulatory compliance Who sets the rules? JCAHO Joint Commission on Accreditation of Health Care Organizations CAP College of American Pathologists FDA Food and Drug Administration
CLIAC CLIA Committee CLIA - Clinical Laboratory Improvement Act Define and interpret CLIA regulations CLIA - Clinical Laboratory Improvement Act Designed to ensure accuracy of results from clinical laboratories Compliance required to pass JCAHO and / or CAP inspections CLIA defines regulations for each test CDC / FDA complexity categories
CLIA Applies to ALL Testing Areas Central Laboratory Satellite Labs Critical Care Surgical Suite Clinics Bedside testing Doctor’s office
CLIA Regulations for Coagulation Central Laboratory can hold the CLIA license Satellites can have independent licensure Moderately Complex tests Except - ProTime and Coaguchek are waived Requires Certified Laboratory Director Record Keeping Training Quality Policy
Implementing POC coag requires: RECORD KEEPING Method Validation - accuracy comparison to current standard Linearity Assessment Also used for ACT “calibration/ verification” Is assay performance appropriate to clinical needs? Does linear range span clinical range? Training competency evaluations at predetermined intervals
Routine Quality Control Instrument Performance Verification Electronic Quality Control with Numeric Output Two levels per 8 hour shift Assay Performance Verification Wet QC as per Manufacturer’s Recommendation Two levels for each box of reagent when opened
Connectivity Everyone wants it Multiple definitions Almost no one is ready to implement Multiple definitions Download to computer To LIS or to HIS or to both or to data management software Real time or batch QC data, patient data, or both
Short term solutions Interim programs for data capture, QC compliance tracking transfer to file format easily adaptable Requires independent transfer protocol e.g., ITC ReportMaker Dedicated interface specific to one manufacturer’s instrumentation e.g., Abbott; Lifescan Manufacturer ensures system compatibility
Instrument manufacturer neutral interface RALS-plus Telcor Manufacturer works with interface supplier to ensure compatibility Interface supplier works with LIS / HIS supplier to ensure compatibility
Quick Script or Quick EDI Telcor concept Quick Serv (DM) LIS/HIS Quick Script or Quick EDI Quick Linc ITC Dawning box Data translation Via hospital Ethernet OR Cath lab CCU
RALS plus concept RALS-Core System (RCS) RALS-IMS LIS HIS Glucose ICU Results that meet user-defined criteria are transferred to the LIS for placement on the patient’s permanent medical record HIS RALS-ADT gathers demographic data to enable patient verification Test results are transferred from a RALS-Plus Test Station to the RALS-Plus Core System (RCS) Glucose ICU RALS Dataport Coagulation ER RALS Plus Test Station Urinalysis 9 West RALS Remote Connect Hospital Client PC POCC’s can view, analyze, or edit results using the RALS-Plus IMS (Information Management System) RALS-IMS RALS-Core System (RCS) Located in the Hospital Data Center Blood Gas
Long term Solutions POC Connectivity Industry Consortium Accepted as NCCLS document POCT1-A sections of the CIC specification approved by: IEEE HL7 Standardization of POC connectivity: Messages Protocols Technologies
Why Bother with POC Coag? Improved TAT - Turn Around Time Defined from the Clinician, not Lab view When is Turn Around Important Emergency Room ICU/CCU Dose Adjustments Operating Room / Cath Lab STAT Testing Turn Around
STAT Testing TAT Fitch, et.al, J. Clin Monit & Comput. 1999. 15:197-204
Standardized Clinical Interpretation Defined Assay Sensitivity Requires Lot to Lot Reproducibility Defined Reagent Variability Identical Instrumentation and Reagents at All Testing Sites Defined Critical Clinical Decision Points No Change of Normal Ranges or Target Times Between Lots of Test Reagents or Testing Locations NEED TWO COPIES OF THIS SLIDE
Why Bother with POC Coag? Improved Clinical Outcome Reduced LOS – Length of Stay Improved, timely patient care