Preoperative antithrombotic

management: before cardiac surgery

S. Demertzis

Facts

> CABG-related bleeding complications & perioperative acute coronary

events are strongly influenced by the management of pre- & postop

antithrombotic therapy

> Significant postop bleeding with transfusions of blood & blood products

increase the risk of death & compromise the long-term benefit of CABG

> Lack of randomized trials on different strategies

It’s all a matter of perspective…

Activated platelets

Hemostasis in surgery (the good)

Suture in arterial lumen

(x1000 magnification - REM)

Stent thrombosis - acute MI (the bad)

… and mastery of navigation and troubleshooting!

The Odyssey

Odysseus is hindered by the efforts of Poseidon and the

sea monsters throughout the ocean. Odysseus faced

both Charybdis and Scylla while rowing through a narrow

channel. He ordered his men to avoid Charybdis thus

forcing them to pass near Scylla, which resulted in the

death of six of his men.

Later, stranded on a raft, Odysseus was swept back

through the strait to face Scylla and Charybdis once

more. This time, Odysseus passed near Charybdis. His

raft was sucked into Charybdis' maw, but he survived by

clinging to a fig tree growing on a rock over her lair. On

the next outflow of water, his raft was expelled.

Odysseus recovered it and paddled away safely.

Cardiac Surgery under Double Antiplatelet Therapy (DAPT)

Hongo et al. JACC 2002; 40(2): 231-7.

Reoperation for bleeding after CABG

0,00%

1,75%

3,50%

5,25%

7,00%

8,75%

no cplopidogrel n=165 clopidogrel n=59

10 x

0

6

12

18

24

30

clopidogrel n=189 prasugrel n=179

CABG-related TIMI major bleeding

TRITON–TIMI 38 study, N Engl J Med 2007;357:2001-15.

4 x

An important issue

Current recommendations

Prospective observational study n= 405 consecutive CABG patients with ACS

aspirin and ticagrelor (n = 173) or aspirin and clopidogrel (n = 232).

EJCTS 46 (2014) 699-705

Coronary artery bypass grafting-related bleeding

complications in real-life acute coronary syndrome

patients treated with clopidogrel or ticagrelor

Know your enemy and know yourself and you

can fight a hundred battles without disaster.

(Sun Tzu - The Art of War (chinese: trad.孫子兵法, simp. 孙子兵法, lit. "Master Sun's Rules for Army")

Casso G. et al.(2015). Point-of-care platelet function tests. In C. E. Marcucci & P Schoettker (Ed.),

Perioperative Hemostasis (pp. 45-63). Berlin Heidelberg, Springer.

Primary hemostasis - Platelet physiology

Antiplatelet agents

mod. from Chassot et al. in Marcucci, Schoettker (eds.)

Perioperative Hemostasis, Springer 2015

Substance Commercial product Route Half-life

Clopidogrel Plavix p.o. 7.5 h

Prasugrel Effient, Iscover p.o. 3.7 h

Ticagrelor Brilique, Brilinta, Possia p.o. 7-10 h

Cangrelor Kengrexal i.v. 3 min

Abciximab ReoPro i.v. 23 h

Eptifibatid Integrillin i.v. 2.5 h

Tirofiban Aggrastat i.v. 2 h

A game changer:

Point-of-Care platelet & coagulation testing

ROTEM® Multiplate®

Multiplate® - concept

Casso G. et al.(2015). Point-of-care platelet function tests. In C. E. Marcucci & P Schoettker (Ed.),

Perioperative Hemostasis (pp. 45-63). Berlin Heidelberg, Springer.

Multiplate® - concept II

Multiplate® - working mechanism

Multiplate® - working mechanism

Multiplate® - Summary

Assessment of drug effect

+ −

• Aspirin

• P2Y12 inhibitors

• GP IIb/IIIa inhibitors

• Rapid (<10 min) and easy test

• Whole blood, no requirements for

sample preparation

• Low sample volume (0.3ml/test)

• Multiple agonists available allowing

a wide range of different acquired

and inherited platelet dysfunction

detection

• Requires pipetting

(consider Verify Now®)

• Dependent to levels of

calcium (Hirudin is

preferred to citrate)

• Sensitive to

thrombocytopenia

(PC > 150 G/l ASPI test,

>100 G/l ADP and COL

test, > 50 G/l TRAP test)

Casso G. et al.(2015). Point-of-care platelet function tests. In C. E. Marcucci & P Schoettker (Ed.),

Perioperative Hemostasis (pp. 45-63). Berlin Heidelberg, Springer.

Ann Thorac Surg 2011;91:123–30

ADP Test AUC < 31 U

Retrospective study n=87

Preoperative evaluation of M-ADP

ROTEM® - the new thrombelastogram

EXTEM

Tissue thromboplastin -tissue factor

INTEM

Contact phase - intrinsic system

FIBTEM

As in EXTEM but with blocked platelets

- fibrin formation & polymersation

APTEM

Aprotinin inhibits fibrinolysis in vitro

HEPTEM

As in INTEM but with blocked heparin

Clinical scenarios

Acute STEMI - PCI not successful / too risky: emergent surgery

> high probability of active DAPT (prehospital protocols) and periprocedural GP IIb/IIa antagonists

> platelet function test + alert the blood bank!

> hemorrhagic complications highly probable

Acute / subacute NSTEMI - subacute STEMI: stable hospitalized patient for urgent surgery

> withdrawal of DAPT

> bridge-to-surgery with i.v. heparine, GP IIb/IIa antagonists (soon with cangrelor)

> timing of surgery according to platelet- and coagulation testing (POC)

Acute NSTEMI - instable patient: urgent / emergent surgery

> pre-hospital protocols should be conservative regarding DAPT

> bridge-to-surgery with i.v. heparine, GP IIb/IIa antagonists (soon with cangrelor) possible

Conclusions

> Major “diffuse” bleeding after CABG is a serious complication with a

significant impact on the final outcome - it has to be considered

seriously

> DAPT introduction in the pre-hospital setting has to be conscious

and wise!

> Discontinuation of DAPT ± possible bridging (heparine, GP IIb/IIa

antagonists, cangrelor) is advised - clinical judgement!

> Platelet function monitoring (POC) can guide the Extended Heart

Team in the timing / scheduling of surgery

Thanks to the Extended Heart Team!

Special thanks to Dr. Casso and Dr. Cassina (Cardio-anaesthesiology & ICU) for the precious

help in this difficult navigation (POC) and for their support for this presentation.

Invasive

CardiologyNon invasive

Cardiology

Cardiac Surgery

Cardio-anaesthesiology & Intensive Care Unit