PFA-100 Platelet Function Analyzer In vitro method for platelet function testing
Clinical issue Insufficient bleeding tendency assessment before operation------- history taking, CBC,aPTT, PT, BT (Koscient J.MD, Ziemer S.MD, 2004) The effectiveness of anti-platelet drug is UNKNOW-------- 23% of 283 ACS patients Poulsen et al; ESC 2003 38% of 129 post-ami patients Andersen et al., 2003 10% of 325 patients with CVD Gum et al., 2001 27% of 89 patients with CVD, CAD Santos et al; ISTH 2001 42% of 31 pts. with stable angina Crowe et al; ISTH 2001 25% of 105 pts. with CAD von Pape et al; ASH 2000 58% of 43 pts. undergoing PTCA von Pape et al; ASH 2000 45% of 100 pts. with ACS Sambola et al; ISTH 2001 Average 25% No responder or non-complaint In Urology, Pediatric and Hemotology--------------------------- The NPV or PPV of BT is lower for clinical use Meyer, Fressinaud et al. 1998 2
Clinical issue The diagnostic approach to abnormalities of primary hemostasis is still a major challenge for clinical laboratories Investigation of unexplained bleeding, we need - Easy, reliable, inexpensive first-line screening tests and Second-line analysis 3
Hemostasis Vessel function vessel constriction Platelet function Formation of platelet plugs (primary hemostasis) Coagulation Formation of fibrin plugs (second hemostasis) Fibrinolysis Dissolution of blood clots (tertiary hemostasis) Carton video 4
Primary hemostasis First physiological response to vascular injury Platelet mediated process Mechanism - Adhesion - Recruitment (secretion) - Aggregation - Formation of the first hemostatic plug - initial arrest of bleeding Occurs in high shear flow environment (5000-6000s -1 ) Triggers the coagulation cascade leading to formation of a clot (secondary hemostasis) Affected by medications, blood composition, platelet function status, vessel wall status 5
Primary hemostasis 6
Clinical issue Platelet function is under diagnosis Platelet Sharp Change and Aggregation Weisel in PLATELETS (Michelson, 2 nd ed, Elseiver /Academic Press,2006) 7
Primary hemostasis Causes for Abnormal Platelet Hemostatic Capacity Platelet Defects - Congenital: Storage Pool Disease, Receptor Deficiencies - Acquired: - Drug-induced (ex. Aspirin), - Underlying Disease-related (Uremia), - Liver cirrhosis - Extra-Corporeal Circulation von Willebrand Disease Thrombocytopenia Low Hematocrit (High ESR rate) 8
Common anti-platelet drugs Plavix (clopidogrel) ADP Persantine (dipyridamole) Aggrenox (dipyrid. + ASA) Ticlid (ticlopidine) ADP phosphodiesterase ADP ReoPro Aggrastat Integrilin GP IIb/IIIa Fbg, vwf COX camp Activation collagen thrombin TXA 2 Aspirin, NSAID TXA 2 9
Primary hemostasis Laboratory Test on Platelet Platelet evaluation - Count - Morphology Traditional platelet function tests - Bleeding time (Duke, Template) - Platelet aggregation (PRP, WB) with an agonist panel of different concentrations von Willebrand factor - Antigenic level - Activity - Ristocetin-induced platelet aggregation (RIPA) - Multimer analysis 10
Traditional Platelet Function Tests In-vivo bleeding time in laboratory and clinical practice - Widely used because a lack of reliable alternatives - Insensitive and non-specific (non-diagnostic) - Invasive and time-consuming (template BT) - High inter-operator CV (poorly reproducible) - Affected by thrombocytopenia - Hard to perform on Irritable children - Not seem to correlate with bleeding tendency (poorly predictive) 11
Bleeding Time 12
Traditional Platelet Function Tests Platelet aggregation - Not ready to use (routine) - Labor intensive - Non-physiological (low shear stress & PRP) - Specialized equipment (expensive) - Time consuming (more 3.5 hrs) - Expertise to perform and interpret - Lag phase - Shape change - Primary and secondary aggregation - Clinical significance of mildly abnormal - aggregation to weak agonists? 13
Traditional Platelet Function Tests Mainly to identify - The potential causes of abnormal bleeding - To monitor pro-hemostatic therapy in patients with a high risk of bleeding - To ensure normal platelet function either prior to or during surgery The diagnostic approach to abnormalities of primary hemostasis is still a major challenge for clinical laboratories History taking remains most important and helps in diagnosing bleeding disorders 14
PFA-100 Introduction & Test Principle In 1996, DB introduced PFA-100 analyzer to detect primary hemostasis based on the design of Krazter and Born (1984) 15
PFA-100 Introduction & Test Principle What is the PFA-100 test A global POC test system for platelet function. A high shear flow system to measure platelet adhesion and aggregation in buffered sodium citrated whole blood. Two tests : Col/EPI Col/ADP The time taken for blood to form aplatelet plug that occludes the aperture is an indication of global platelet function and is referred to as the Closure Time (CT). 16
PFA-100 Introduction & Test Principle The Instrument pump trigger dispenser vacuum line trigger solution membrane reagent coated sample reservoir pressure transducer feedback controller syringe capillary servo 17
PFA-100 Introduction & Test Principle In Vivo Haemostasis PFA-100 endothelial cell collagen fibrils - 40 mbar epinephrine or ADP aperture 150µm membrane collagen vwf vwf fibrinogen platelet erythrocyte lumen FLOW erythrocyte platelet capillary 200µm 18
PFA-100 Introduction & Test Principle Test Cartridge before and after a test before after cup 800 µl blood aperture 150 µm Filter + epinephrine or ADP Negative vacuum platelet aggregate collagen capillary 200 µm flash membrane 19
PFA-100 Introduction & Test Principle 20
PFA-100 Introduction & Test Principle Occlusion Process 21
PFA-100 Introduction & Test Principle Final Result and Print-out Closure Time (sec.) indicating Primary-Hemostasis Capacity PFA-100 PFA-100 REV. REV. 2.00 2.00 S/N: S/N: 00370 00370 14/07/97 14/07/97 14:01 14:01 ID#: ID#: 23456.17 23456.17 Test Test Type: Type: Collagen/EPI Collagen/EPI SAMPLE SAMPLE A: A: 110 110 SEC SEC 22
PFA-100 Introduction & Test Principle Two type tests: COL/EPI - 每 一 檢 測 盒 含 塗 覆 2 µg 馬 第 一 型 膠 原 蛋 白 (equine Type-I collagen) 和 10 µg 腎 上 腺 素 酸 性 酒 石 酸 鹽 (epinephrine bitartrate) - Primary screening cartridge - Sensitive to ASA, vwd, congenital platelet defects, thrombocytopenia, low hematocrit, GPIIbIIIa antagonists and other platelet inhibiting agents COL/ADP - 每 一 檢 測 盒 含 塗 覆 2 µg 馬 第 一 型 膠 原 蛋 白 (equine Type-I collagen) 和 50 µg 二 磷 酸 腺 苷 酸 (adenosine-5 -diphosphate) - Used to discriminate between ASA-induced dysfunction and congenital disorders - Sensitivity to ASA around 20% 23
PFA-100 Introduction & Test Principle 1. Sample Collection - System : either vacuum- or plonger-based - Collection medium : 3.2% (106 mm) or 3.8% (129mM) buffered sodium citrate - Technique : short cuff-time, needle-size 21G. - Thorough mixing of sample by inverting tube several times 2. Sample Processing - Transport and store the sample undisturbed at room temperature - Mix the sample carefully by inverting several times by hand - 800-1,000 µl blood inserted in cartridge, taking care that no air bubbles are introduced - Tubing has to be validated by the site that wants to use it 3. Sample Stability - Test the sample within 4 hours of collection (recap) 24
PFA-100 Introduction & Test Principle Reference Ranges 3.8% Sodium Citrate (n=176) - Collagen/Epinephrine - Mean 132 sec Range 94-193 sec - Collagen/ADP - Mean 92 sec Range 71-118 sec 3.2% Sodium Citrate (n=309) - Collagen/Epinephrine - Mean 110 sec Range 82-150 sec - Collagen/ADP - Mean 78 sec Range 62-100 sec * : data based on testing of 309 samples with confirmed normal platelet function in Germany 25
PFA-100 Introduction & Test Principle Data Interpretation The Closure Time is dependent on platelet function, vwf level, platelet count (> 100,000-150,000) and hematocrit > 30~35%. Expected Patterns Col/Epi normal and Col/ADP normal ---Platelet function is normal, If the patient s history/physical check are confirmed normal. Col/Epi Porlong and Col/ADP normal ---Drug induced platelet dysfunction, review the patient s chart and medication. Col/Epi Prolong and Col/ADP Prolong --- Platelet function is abnormal, commonly seen in VWD or congenital platelet defect, most patient with prolonged Col/ADP CT manifest abnormalities in primary hemostasis in primary hemostasis---increased risk of bleeding in surgical procedure. 26
PFA-100 Introduction & Test Principle PFA-100 PFA-100 REV. REV. 2.00 2.00 S/N: S/N: 00370 00370 PFA-100 PFA-100 REV. REV. 2.00 2.00 S/N: S/N: 00370 00370 14/07/2008 14/07/2008 14:01 14:01 ID#: ID#: 23456.17 23456.17 Test Test Type: Type: Collagen/EPI Collagen/EPI SAMPLE SAMPLE A: A: 146 146 SEC SEC ID#: ID#: 23456.17 23456.17 Test Test Type: Type: Collagen/ADP Collagen/ADP SAMPLE SAMPLE A: A: 87 87 SEC SEC 14/07/2008 14/07/2008 14:01 14:01 ID#: ID#: 23456.17 23456.17 Test Test Type: Type: Collagen/EPI Collagen/EPI SAMPLE SAMPLE A: A: 289 289 SEC SEC ID#: ID#: 23456.17 23456.17 Test Test Type: Type: Collagen/ADP Collagen/ADP SAMPLE SAMPLE A: A: 87 87 SEC SEC Normal pattern Aspirin pattern or Milder platelet dysfunction 27
PFA-100 Introduction & Test Principle PFA-100 PFA-100 REV. REV. 2.00 2.00 S/N: S/N: 00370 00370 14/07/2008 14/07/2008 14:01 14:01 ID#: ID#: 23456.17 23456.17 Test Test Type: Type: Collagen/EPI Collagen/EPI SAMPLE SAMPLE A: A: 246 246 SEC SEC ID#: ID#: 23456.17 23456.17 Test Test Type: Type: Collagen/ADP Collagen/ADP SAMPLE SAMPLE A: A: 187 187 SEC SEC Abnormal pattern 28
Causes of a Prolonged Closure Time 29
Limitation-platelet count PFA-100 should be run only on normal Plt count samples! If a CT is normal in spite of abnormal plt count, the clinician still has an indication that platelet function per se is present Sourav K., Eric J., Clin Appl Thrombosis/Hemostasis, 2(4):124-249,1996 30
Limitation-Hct PFA-100 should be run only on normal Hct samples! If a CT is normal in spite of abnormal Hct, the clinician still has an indication that platelet function per se is present Sourav K., Eric J., Clin Appl Thrombosis/Hemostasis, 2(4):124-249,1996 31
Article review Analytical variable-1 Haematocrit : low Hct can lead to prolong CT 25%~50% (Rohit cariappa, Timothy R. J pediatric Hematology/Oncology 2003) 20%~50% (Platelet Function Testing; Proposed Guideline by Aggregometry, CLSI(NCCLS) 2007) Hemoglobin < 8 g/dl (Paul Harrison, Helen Segal, Stroke 2007) > 30% (Luc Christiaens, Blood Coagulation and Fibrinolysis, 2007) Platelet Count : low PC can also lead to prolong CT 100,000/μl (Rohit cariappa, Timothy R. J pediatric Hematology/Oncology 2003) > 50,000/μl (Platelet Function Testing; Proposed Guideline by Aggregometry, CLSI(NCCLS) 2007) 90,000~450,000/μl (Paul Harrison, Helen Segal, Stroke 2007) 100,000/μl (Luc Christiaens, Blood Coagulation and Fibrinolysis, 2007) 32
Test Advantages and Benefits Objective, Accurate, Cost Efficiency Convenience No special sample collection and preparation Permanent availability in combination with STAT Objective and quantitative results Accurate and reproducible results High sample stability Less stress on personnel though a minimal hands-on time Less stress on patient because a routine venous blood sample can be used 33
PFA-100 : Technical Advantage Collected by vacutainer or syringe technique Same anticoagulant as coagulation screening tests Simple to perform Rapid (maximal CT of 300 sec.) Reported within and day-to-day imprecision (CV) <12% Relative small volume of citrate blood (0.8 ml per cartridge) up to 4 hour at RT from sampling Daily instrument QC check Available proficiency test from CAP-2006 Useful in children (cooperation is not needed) 34
Test Advantages and Benefits High Diagnostic Value High sensitivity to platelet-related dysfunctions of primary hemostasis Col/EPI : PPV-81.8%, NPV-93.4% Col/ADP: PPV-77.3%, NPV-79.4% High sensitivity to vwd High sensitivity to Aspirin-related platelet deficiency Medication efficacy monitoring possible (DDAVP, Aspirin, ReoPro ) Highly suitable tool for pre-surgical screening Aid to demonstrate platelet transfusion efficacy Pre-screening of platelet-donors 35
Indication 類 血 友 病 及 血 小 板 功 能 障 礙 篩 檢 DDAVP 在 第 一 型 類 血 友 病 患 者 之 治 療 評 估 阿 斯 匹 靈 之 治 療 評 估 術 前 之 出 血 危 險 評 估 Col/EPI & Col/ADP 二 項 得 同 時 申 請 * 中 央 健 保 局 於 2008 年 新 核 准 之 適 應 症 及 使 用 規 模 編 號 診 療 項 目 基 層 院 所 地 區 醫 院 區 域 醫 院 醫 學 中 心 支 付 點 數 備 註 08131C 血 小 板 功 能 閉 鎖 時 間 - 膠 原 蛋 白 / 腎 上 腺 素 Platelet function closure time-col/epi 註 : 不 得 與 08018C 08019C 08069C 同 時 申 報 v v v v 367 增 列 08132C 血 小 板 功 能 閉 鎖 時 間 - 膠 原 蛋 白 / 二 磷 酸 腺 苷 酸 Platelet function closure time-col/adp 註 : 不 得 與 08018C 08019C 08069C 同 時 申 報 v v v v 367 增 列 36
Clinical experience and Applications More 200 articles published for clinical studies and uses in global in Hematology in Tertiary Care in Cardiology in Pediatrics in Neurology in Urology 37
Hemostasis Propositus Define reasons for investigation (recent ASA intake?, drug monitoring, vwd? Haemophilia,?platelet disorder,? DDAVP trial) E.J. Favaloro, Haemophilia (2001.7.170-179) Bleeding disorder? Clinical History (If available) Bleeding history, family history, age, gender (if female: oestrogen therapy?, pregnant?, excessive menstrual bleeding?) blood group Clinical index of Suspicion regarding likely present of vwd. Haemophilia, and/or platelet disorder Select test panel as appropriate ( ie. Considering specific history and testing urgency) PT & aptt vwf Ag FVIII:C vwf:cba Platelet count +/- vwf: RCof PFA-100 Abnormal Normal 38
Hemostasis E.J. Favaloro, Haemophilia (2001.7.170-179) Abnormal Investigate further as required and depending on initial test resulets: eg more extensive vwf studies. RIPA, PFS, factor studies.? Drug effect.? Platelet disorder.etc Normal 1. If initial suspicion low: no further investigation 2. If initial suspicion strong. Repeat testing for confirmation 39
Clinical experience and Applications Comparison of the PFA-100 with in vivo Bleeding Time Test Receiver/Operator characteristics (ROC) of PFA (Col/Epi) and Bleeding Time test 1 Sensitivity PFA-100 Bleeding Time test PFA-100 Bleeding Time test Area Under Curve 0.977 0.70 Error 0.008 0.04 Population of 206 normal and 176 abnormal subjects 0 0 1 - Specificity 1 To : Mammen, Alshameeri e Comp. 40
Clinical experience and Applications Study Design Bleeding Time Sensitivity PFA-100 Sensitivity Reference 12 volunteers on 250 mg ASA daily, for 5 days. 30% (estimated) 70% (estimated) Marshall etal. Br J Clin Pharmacol 1997; 44: 151-155 60 von Willebrand Disease patients (vwd) 66% 97% Fressinaud et al. Blood 1998; 91: 1325-1331 120 donors after 1 bolus of 325 mg ASA 44 vwd, 5 Glanzmann Thrombasthenia 59% 96% Mammen etal. Semin Thromb Hemost 1998; 24: 195-202 52 vwd 65% 87% Cattaneo etal. Thromb Haemost 1999; 82: 35-39 23 type 1 vwd pre- & post-desmopressin (DDAVP) Correction recorded in 90% of cases Correction recorded in 100% of cases Fressinaud et al. Br J Haematol 1999; 106: 777-783 32 vwd; 5 Hermansky-Pudlak, 1 Glanzmann 55% 84% Kerenyi et al. Thromb Res 1999; 96: 487-492 BT and PFA agreed 113 hospital inpatients on 74% of the Francis et al. cases. In 86% of Platelets 1999; the discordant cases, PFA-100 10: 132-136 was in concordance with aggregometry 41
Clinical experience and Applications Bleeding time better PFA-100 better Von Willebrand s Disease Aspirin Ingestion Platelet secretion defect (c/adp) Congenital platelet receptor disorders Platelet secretion defect (col/epi) 1. PFA and BT agree in 70~80% cases 2. PFA correlation more closely with aggregation 3. PFA is more useful in clinical practice Francise et al. Platelets 1999..132-136 42
Clinical experience and Applications Study on 60 von Willebrand Disease Patients 36 Type 1 10 Type 2A 3 Type 2B 4 Type 3 2 Type 2N 5 Acquired Meyer, Fressinaud et al. Blood, Vol 91, No 4, 1325-1331, 1998 43
Clinical experience and Applications Comparing the PFA-100 with Aggregometry Platelet Function normal abnormal PFA-100 normal abnormal 183 9 23 167 Overall agreement between PFA-100 and Platelet Aggregometry is 87.5% Aggregometry specificity sensitivity normal abnormal specificity sensitivity 88.8% 94.9% Platelet Function normal abnormal 182 10 24 166 88.3% 94.3% To : Comp, Larkin, Greenberg et al. 44
Article review Newborns and neonates have relatively short CTs compared to shool-age childern and adults. (probably by high vwf conc.) No correlation with age and gender. * Bock M, De Haan J, Br J haematol 1999 * Carcao MD, Blanchette VS, Br J haematol 1998. * Knofler R, Weissbach G, Semin Thromb Hemost 1998. * Rand ML, Carcao MD, Semin Thromb Hemost 1998. 45
Article review Conclusion: Given the difficulties of offering and interpreting BT in pediatric patients and compares the performance of PFA with BT, PFA could replace BT for detection platelet dysfunction and vwd. Combined platelet deficiencies vwd Specificity Sensitivity Efficiency Sensitivity Efficiency C/EPI 97% (32/33) 100%(19/19) 98% (51/52) 100%(12/12) 98%(44/45) C/ADP 80%(12/15) 87%(13/15) 83%(25/30) 80%(8/10) 80%(20/25) BT 88%(29/33) 37%(7/19) 69%(36/52) 17%(2/12) 69%(31/45) Rohit Cariappa. Ph D., Timothy R. B.A., Curtis A. Parvin, Ph.D., & Lori Luchtman-Jones, M.D. Comparison of PFA- 100 and Bleeding Time Testing in Pediatric Patient with Suspected Hemorrhagic Problems. Journal of Padiatric Hematology/Oncology, 2003;25(6):474. 46
Preoperative management of patients with impaired primary hemostasis-1 Transient Platelet dysfunction : occurrence with 3%~5% in acquired (drug-induced) and congenital platelet dysfunction or vwd. Both of severe thrombocytopenia or hemophilia are easily identified via history taking, physical examination or Palelet count, aptt, PT and BT. But PC and BT are poor reliably and reproducible. There is no validated concept of when use drugs or how to assess their effects before or during a surgical intervention. PFA-100 enable to identify all patients with impaired primary hemostasis. Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 47
Preoperative management of patients with impaired primary hemostasis-2 Setting: Berlin German Sample: A total of 5649 unselected adult patients were enrolled to identify impaired hemostasis before surgical intervention. 254 having acquired and inherited impaired primary hemostasis. Method: A standardized questionnaire concerning bleeding history. aptt, PT, platelet count, PFA (CPI and ADP) were routine processed. And BT, vwf Ag were performed in additional with positive bleeding history and /or evidence of impaired hemostasis, drug ingestion. Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 48
Preoperative management of patients with impaired primary hemostasis-3 Intervention (treatment): All patient (254) with impaired primary hemostasis were preoperatively treat with 30-minute infusion of 0.3 μg/kg DDAVP (Minirin ) desmopressin acetate, and retest by PFA- 100. All responders underwent with same drug as below table. vwd patient were treated with factor VIII containing vwf after non-responding DDAVP. All other non-responders were treated with aprotinin (Trasyol ) or tranexamic acid (Ugurol ) Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 49
Preoperative management of patients with impaired primary hemostasis-4 Drug Preoperative Doses Perioperative Total Cost ( ) DDAVP 0.3 μg/kg i.v. 3 x 0.3 μg/kg i.v. (interval: 12h) 220 ( ) Factor VIII with vwf 50-80IE/kg i.v. 50-80IE/kg i.v. (interval: 12h) 5-7 d postoperatice 26,000 ( ) Aprotinin 1,000,000 KIE i.v. 500,000 KIE i.v. intraoperative 450 ( ) Tranexamic acid 500 mg/kg i.v. 250 mg/kg i.v. intraoperative Until 4h of OP-end 3x250 mg p.o. 3 d postoperative 40 ( ) Conjugated estrogens 25 mg i.v. 25 mg intraoperative i.v. and 25 mg postoperative i.v. 90 ( ) Platelets 1 SAPC i.v. 1 SAPC i.v. 1,100 ( ) 50
Preoperative management of patients with impaired primary hemostasis-5 Result: Patients N=5,649 Negative bleeding history N=5,021 (88.8%) Positive bleeding history N=628 (11.2%) Abnormal screening test N=9 (0.2%) Abnormal screening test N=256 (40.8%) 51 aptt n=9 (0.2%) PC n=0 PFA C/EPI n=250 (97.7%) PFA C/ADP n= 199(77.7%) BT n=188(73.4%) aptt n=24(9.4%) PT n=10(3.9%) PC n=2(0.8%) vwf Ag n=39(15.2%)
Preoperative management of patients with impaired primary hemostasis-6 Result1: Hemostasis Tests (Abnormal) PFA-100: C/EPI Normal Hemostasis (n=5393) 0 of 5393 Impaired Hemostasis (n=256) 250* of 256 (97.7%) PFA-100: C/ADP 0 of 5393 199 of 256 (77.7%) aptt (sec) 9 of 5393 24 of 256 (9.4%) PT (%) 0 of 5393 10 of 256 (3.9%) Platelet count 0 of 5393 * A total of 23 of 250 received blood transfusion 2 of 256 (0.8%) Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 52
Preoperative management of patients with impaired primary hemostasis-7 Result2: DDAVP administration resulted in correction of platelet dysfunction in 229 of 254 (90.2%), as tested by C/EPI, 66.9% by C/ADP, 60% by BT. Tranexamic acid was effective in 12 of 16. Aprptinin was effective in 3 0f 5. Factor VIII with vwf was effective in 4. Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 53
Preoperative management of patients with impaired primary hemostasis-8 Result3: Impaired hemostasis N=256 Second hemostasis disorders N=2 (0.8%) Primary hemostasis disorders N=187 (73.0%) Combined hemostasis disorders N=67 (26.2%) 54 Congenital Dysfibrinogenaemia N=1 age:26 Hereditary Factor VII-deficiency N=1 age: 34 Acquired thrombopathies N=169 age=37~78 Uremia associate n=7 Drug induced n=162 ASA n=87, dicofenac, ibuprofen, clopidogrel Hereditary thrombopathies N=18 Failure to release n=16 vwd N=34 age:17~47 vwd-1 N=40 vwd-possible 1 N=12 vwd-2a N=2 Liver cirrhosis N=13 age: 35~62
Preoperative management of patients with impaired primary hemostasis-9 Retrospective study similar group at same hospital in 1999 (n=5102) Impaired hemostasis N=317 Second hemostasis disorders N=0 (0%) Primary hemostasis disorders N=299 (94.3%) Combined hemostasis disorders N=19 (5.7%) Acquired thrombopathies N=291 age=33~80 Drug induced n=291 ASA, dicofenac, ibuprofen, clopidogrel Hereditary thrombopathies N=8 Failure to release n=8 vwd N=10 age:19~41 Liver cirrhosis N=8 age: 29~65 55
Preoperative management of patients with impaired primary hemostasis-10 Retrospective study Elective operations Prospective study Patients N=5102 Patients N=5649 Normal hemostasis N=4785 Nontreated abnormal hemostasis N=317 Normal haemostasis N=5393 Corrected abnormal hemostasis N=256 Blood transfusions Blood transfusions Blood transfusions Blood transfusions N=541 (11.3%) N=283 (89.3%) N=660 (12.2%) N=24 (9.4%) P< 0.001 P=0.202 Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 56 2004;10(3):195.
Preoperative management of patients with impaired primary hemostasis-11 Discussion-1: There are two reasons for DDAVP use, low cost and low side effect compared with other two drugs. DDAVP may lead to improvement of hemostasis by increasing the level of factor VIII, vwf and plasminogen activator. Others,may increase the expression GP-Ib receptor, conjugated estrogens seem to increase aggregation. The improvement was confirmed by platelet function assay, C/EPI. Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 57
Preoperative management of patients with impaired primary hemostasis-12 Discussion-2: Preoperative correction of platelet dysfunction was found to reduce the need for blood transfusion in almost all cases. Recommend initial treatment with DDAVP and secondline with others drugs. Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 58
Preoperative management of patients with impaired primary hemostasis-13 Discussion-3: Based on the data (retrospective group), the positive and negative predictive values for blood transfusion are 91.7% and 89.6% for PFA C/EPI, 86.5% and 86.6% for PFA C/ADP. Area under ROC curve=0.9237. Findings of groups, the PFA is clearly superior to BT.aPTT, PT,vWF:Ag. Sensitivity : 90.8%. All patients with positive bleeding history to primary or combined hemostasis disorder could be identified using PFA-100, and they are also detected abnormalities who 14 patient failed to report anti-platelet drug use. Koscient J.MD, Ziemer S.MD, Radtke H.MD, Schmutzler M.MD, Kiesemutzler M.MD, A Practical Concept for Preoperative Identification of Patients with Impaired Primary Hemostasis. Clin Appl Thrombosis/Hemostasis, 2004;10(3):195. 59
Clinical experience and Applications Assessing the Response to ASA Aspirin is the most widely consumed drug in the world and a cost-effective medication for the prevention and treatment of heart disease and stroke. Aspirin inhibits platelet function and may dampen the role of platelets as inflammatory mediators, two factors strongly implicated in promoting acute coronary syndromes (ACS). 60
Clinical experience and Applications Assessing the Response to ASA However, studies suggest that significant insensitivity (5% - 60%) to aspirin occurs among patients with defined coronary disease, cardiovascular disease and stroke. Despite the demonstrated benefit of aspirin in secondary prevention and its possible beneficial effects in selected individuals for primary prevention, there remains a large segment of the population at risk that does not benefit from aspirin Halushka et al. 2002 61
Clinical experience and Applications Assessing the Response to ASA Cardiac Population Review of the literature on 1,105 patients... 23% of 283 ACS patients Poulsen et al; ESC 2003 38% of 129 post-ami patients Andersen et al., 2003 10% of 325 patients with CVD Gum et al., 2001 27% of 89 patients with CVD, CAD Santos et al; ISTH 2001 42% of 31 pts. with stable angina Crowe et al; ISTH 2001 25% of 105 pts. with CAD von Pape et al; ASH 2000 58% of 43 pts. undergoing PTCA von Pape et al; ASH 2000 45% of 100 pts. with ACS Sambola et al; ISTH 2001 Σ= 25% of low-responders or non-compliants! 62
Clinical experience and Applications 63 (Marilena, Augusto, et al 2008)
Article review A systemic review of 53 studies (64 population, 6,450 subjects) for ASA no-responding detected by PFA-100. Pooling these studies, the risk of vascular clinical events appeared to be significantly higher in non- responders to aspirin. (RR: 1.63, 95% CI: 1.16-2.28) Cutoff of Col/EPI: 174 ~193 sec. Non-responding : 27% Marilena Crescente, Augusto Di, Theomb Haemost. 2008 64
Article review Recommendation: Prolonged CT can reflect other abnormalities (vwd), and as such, abnormal results require further diagnostic evaluations. Normal CT can help exclude some severe platelet defect. C.P.M. Hayward, P. Harrison, M. Cattaneo, T.L. Ortel & A.K. Rao, Platelet function analyzer(pfa)-100 closure time in the evaluation of platelet disorders and platelet function. Journal of Thrombosis and Haemostasis, 2006;4:312-319. 65
THE END Thank You 66