1. Inflammation, Thrombosis, and Bleeding
Jerrold H. Levy, MD
Professor of Anesthesiology
Deputy Chair for Research
Emory University School of Medicine
Director, Cardiothoracic Anesthesiology
Emory Healthcare
Atlanta, Georgia

2. Everybody talks about it, only a few people seem to understand it.
LOVE=COAGULATION
Everybody talks about it, only a few people seem to understand it.

3. Normal Hemostasis II TF-Bearing Cell II II Platelet IIa IIa VIIaX
VIII/vWF TF
VIIa Xa Va
IIa
TF-Bearing Cell
VIIIa TF
VIIa V Va IX
Platelet II
IXa X
Normal Hemostasis
This slide represents a schematic model of normal hemostasis that requires activation of both FX and FIX. FVIIa/tissue factor (TF)-activated FXa and FIXa play distinct roles in coagulation. FXa cannot move to the platelet surface because of the presence of normal plasma inhibitors, but instead remains on the TF-bearing cell and activates a small amount of thrombin. This thrombin is not sufficient for fibrinogen cleavage but is critical for hemostasis since it can activate platelets, activate and release FVIII from von Willebrand factor (vWF), activate platelet and plasma FV, and activate FXI. FIXa moves to the platelet surface, where it forms a complex with FVIIIa and activates FX on the platelet surface. This platelet surface FXa is relatively protected from normal plasma inhibitors and can complex with platelet surface FVa, where it activates thrombin in quantities sufficient to provide for fibrinogen cleavage.
Hoffman M et al. Blood Coagul Fibrinolysis 1998;9(suppl 1):S61–S65. Xa
IIa
IXa
VIIIa Va
Activated Platelet
VIIa
IXa Va
VIIIa Xa
IIa IX II X
Hoffman et al, Blood Coagul Fibrinolysis 1998;9(Suppl 1):S61

4. CAVEATS REGARDING INFLAMMATION
Inflammation has multiple humoral, cellular components, and undergoes amplification.
Defining clinical outcomes from inflammation is difficult.
Hemostatic activation/thrombin generation is an inflammatory response, and tissue injury is key.

5. MANIFESTATION OF INFLAMMATION
Bleeding
Ischemia/reperfusion injury
Infection
MOS dysfunction
CNS dysfunction

6. HEMOSTASIS
The stoppage of bleeding, hemorrhage, or blood flow through a blood vessel or body part.

7. COMPONENTS OF HEMOSTASIS
Vasculature
Coagulation proteins
Platelets

8. CAVEATS REGARDING COAGULATION/THROMBOSIS
Arterial clot is due to platelet-fibrinogen interactions. Heparin does not completely block this.
Venous clot and venous thromboembolic phenomenon are prevented by thrombin inhibitors

9. THROMBIN: Proinflammatory mediator
Chemotactic for PMNs, monocytes
Mast cell activator
Stimulates endothelium
Formed via endothelial injury by TF expression, induces cytokine expression

10. THROMBIN tPA THROMBIN GENERATION/EFFECTS TFPI EC * * * ATIII *
Contact (XIIa)
Tissue Factor (TF:VIIa)
BTG, PF4
Platelets
activation/consumption IX *
TFPI
FV, FVIII, FXI
FXIa, FVa/FVIIIa
IXa
FVi, FVIIIi X Xa
Protein C
VIIIa,
Ca++
, PL
Va, Ca++
, PL
APC
Thrombomodulin *
Prothrombin
THROMBIN
XIII
FPA
bradykinin
PT fragment 1.2 EC
ATIII
Fibrinogen
Fibrin (M)
XIIIa *
tPA
tPA:PAI1
FSP
Fibrin (Ps) *
TAT
PAI1
Plasminogen
PLASMIN
-2-antiplasmin
D-dimer
Fibrin (Pi)
PAP complexes
Platelet GP1b *
Endothelial-associated
Despotis GJ et al, Anesthesiology 1999;91:

11. VASCULAR ENDOTHELIUM
Huraux C et al: Circulation 1999;99:53-59

12. DIC Triggered by TF/endothelial injury
Produces fibrin deposition in microvasculature and MOS dysfunction
Path: Microangiopathic hemolytic anemia
Lab: platelets, fibrinogen, PT,
PTT, D-dimers, ATIII

13. ANTITHROMBIN ACTIVITY20
120
100 80 60 40
ANTITHROMBIN ACTIVITY
Normal Activity
Activity - %
Group 1
Group 2
X ± SEM
Heparin
Protamine 1 2 3 4 5 6 7 8 10 9 11 12 13
Measurement Period
Zaidan JR et al, Anesth Analg 1986;65:377-80

14. ACT (sec) PATIENTS ON HEPARIN THERAPY Baseline Heparin Heparin Heparin
900
800
700
678
612
ACT (sec)
600
567
500
496
478
400
453
AT III
300
No AT III
200
160
160
100
Baseline
Heparin
Heparin
Heparin
ACT
4.1 u/ml
5.4 u/ml
6.8 u/ml
Levy JH et al, Anesth Analg 2000;90:1076-9

15. FACTORS AFFECTING ACT Factor deficiency: fibrinogen, XII, VIII
Contact activation inhibitors: aprotinin
Warfarin therapy
Heparin therapy
Hypothermia
Thrombocytopenia/cytosis
Platelet inhibitors

16. Aprotinin Use in CABG Reoperations
Donor-Blood-Product Requirements
P < .001
P < .001
Lemmer et al
J Thorac Cardiovasc Surg 1994;107:543-53
Levy et al
Circulation 1995;92:

17. Neurologic Deficit (Stroke)
Number of Patients %
Placebo 5 /
Aprotinin Pump Prime 1 /
Low Dose 0 /
High Dose 0 /
P = 0.01
Incidence of Stroke in Repeat CABG Surgery
Levy et al, Circulation 1995;92:

18. International Multicenter Aprotinin Graft Patency Experience
796 (91%) Patients assessable for blood loss, usage
703 (81%) Patients assessable by angiography for saphenous vein-graft patency (at mean of 10.8 days postop)
831 (95%) Patients assessable for MI by ECG and cardiac enzyme evaluation
FDA rules for investigational study reporting requires that any protocol deviation must have the data excluded from analysis of drug efficacy. However, all data, including protocol violations are included in assessment for drug safety.
870 patients were randomized in this study (aprotinin = 436; placebo = 434). 74 patients were excluded from analysis of blood loss and replacement, for reasons that included protocol violation (n = 21), and exclusion for a confounding postop event (n = 53), the most common of which were re-exploration for surgical bleeding (n = 30) and an additional postop surgical procedure (n = 14).
However, the data from patients in whom there had been a protocol violation were included in the angiographic analysis of graft patency. Assessment was not available in 167 patients, the majority of whom (n = 117) did not consent to the investigation.

19. IMAGE Study Blood Loss and Blood Product Replacement
Drainage and Transfusion
Patients Requiring Any Blood Product
P <.001
P <.001
Alderman, Levy, Rich et al, JTCS 1998;116:716-30

20. IMAGE Study
P = .01
P = .03
P = .72
Alderman et al, J Thorac Cardiovasc Surg 1998;116:716-30

21. IMAGE Study Death 1.6% 1.4% (6/434) (5/436)
Adverse Outcome Placebo Aprotinin
Death % % (6/434) (5/436)
Myocardial Infarction
Definite % %
(16/421) (12/410)
Def+probable % 8.6%
(38/418) (35/407)
Def+prob+possible 12.0% 12.3%
(50/418) (50/408)
Alderman et al, J Thorac Cardiovasc Surg 1998;116:716-30

22. Role of the Tissue Factor – Thrombin Pathway in Myocardial Ischemia-Reperfusion Injury

23. Inhibition of Thrombin PAR-1 Activation by Aprotinin
Protease (Thrombin)
APROTININ X
(Irreversible)
Cell Membrane
G protein
Coughlin SR, Proc Natl Acad Sci USA 1999;96:

24. APROTININ: Use in Orthopedic Surgery (1)
Janssens M: High-dose aprotinin reduces blood loss in pts undergoing THR surgery. Anesthesiology 1994; 80: 23–9.
Murkin JM: Aprotinin decreases blood loss in patients undergoing revision or bilateral total hip arthroplasty. Anesth Analg 1995; 80: 343–8.
Murkin JM: Aprotinin decreases exposure to allog blood during primary unilateral THR. J Bone Joint Surg Am 2000; 82: 675–84.
Capdevila X Aprotinin decreases blood loss and transfusions in pts undergoing major orthopedic surgery. Anesthesiology 1998; 88: 50–7.

25. APROTININ: Use in Orthopedic Surgery (2)
Hayes A The efficacy of single-dose aprotinin 2 million KIU in reducing blood loss and DVTs in THR surgery. J Clin Anesth 1996; 8: 357–60.
Kasper SM A retrospective study of the effects of small-dose aprotinin on blood loss and transfusion needs during total hip arthroplasty. Eur J Anaesthesiol 1998; 15: 669–75.
Amar D: Antifibrinolytic therapy and periop blood loss in cancer pts undergoing major orthopedic surgery. Anesthesiology 2003;98:
Samama CM: Aprotinin vs placebo in major ortho surgery: a randomized/DB/, dose-ranging study. Anesth Analg 95:287-93,

26. APROTININ FOR HIGH RISK PATIENTS
Repeat sternotomy
Jehovah’s witnesses
Valve surgery/combined procedures
Aortic root surgery/DHCA
Dialysis patient
Endocarditis
Minimally invasive valve surgery
Transplants/VADs
Recent Plavix

27. SUMMARY
Thrombin generation modulates the thrombotic effects of vascular injury and pharmacologic intervention
Thrombin activation of PAR-1 receptors activates pathologic mechanism of injury
Aprotinin inhibits pathologic hemostatic activation by blocking PAR-1 receptors
Safety data from clinical studies including orthopedic surgery have not demonstrated a prothrombotic effect of aprotinin