Thrombosis Canada Clinical Tools Perioperative Management

Thrombosis Canada Clinical Tools

Perioperative Management of AnticoagulantsAntithrombotic Use in Atrial Fibrillation

Dr. Benjamin Bell, MD FRCPCStaff General Internist

North York General HospitalLecturer, University of TorontoExecutive Member, Thrombosis Canada

Dr. Pascal Bastien, MD FRCPCHead, Division of General Internal Medicine

North York General HospitalLecturer, University of TorontoMember, Thrombosis Canada

Faculty/Presenter Disclosure

• Faculty: Dr. Benjamin Bell• Relationships with commercial interests:*

– Grants/Research Support: N/A– Speakers Bureau/Honoraria: Bayer– Advisory Boards: Bristol Meyers Squibb/Pfizer and Sanofi Aventis – Consulting Fees: N/A– Other: N/A

Faculty/Presenter Disclosure

• Faculty: Dr. Pascal Bastien• Relationships with commercial interests:*

– Grants/Research Support: N/A– Speakers Bureau/Honoraria: Bayer– Advisory Boards: Sanofi Aventis – Consulting Fees: N/A– Other: N/A

Disclosure of Commercial Support• This program has received financial support from Alexion Canada, Leo

Pharma, Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Covidien, Novartis, Octapharma, BMS/Pfizer Alliance, Pfizer Canada Injectables, Aspen Pharmacare and Sanofi in the form of an Unrestricted Educational Grant

• This program has not received in-kind support from any commercial organization

• Potential for conflict(s) of interest:– Thrombosis Canada developed a free clinical app that will be discussed

in this program

Mitigating Potential Bias

• No commercial or other non-commercial organization have had any input to the content of this program

• No commercial or other non-commercial organization have been present at or privy to any discussions, meetings, or other activities related to the content of this program

Stroke Prevention in Atrial Fibrillation

Dr. Pascal Bastien, MD FRCPCHead, Division of General

Internal MedicineNorth York General Hospital

Lecturer, University of TorontoMember, Thrombosis Canada

Objectives

• Review updated CCS algorithm from 2014 Atrial Fibrillation guidelines

• Describe the complementary roles of NOACs and warfarin in stroke prevention in atrial fibrillation

• Showcase a safe, effective and prompt strategy to assist in the choice and dosing of antithrombotics for atrial fibrillation

Atrial Fibrillation Scope of Problem

• AF is responsible for a 5‐ to 7‐fold increase in stroke risk

• 350,000 Canadians have AF• Prevalence of AF increases with age

– 0.5% in patients 55‐59 yo– 10% in patients ≥ 80 yo

• Almost all patients with AF should be anticoagulated

Projected Number of Adults with AF in USA between 1995 and 2050

Go AS, et al. JAMA. 2001;285(18):2370–2375.

CCS Guidelines for AF Stroke Prevention

CHADS2 CHA2DS2‐VASc CCS algorithm

Case 1

• 36 yo woman, otherwise healthy, complaining of palpitations

• She undergoes a 48h Holter and is found to have symptomatic paroxysms of AF

• Rate vs. rhythm control• Stroke prophylaxis

Rate vs. Rhythm Control

Audience Poll: What antithrombotic agent would you recommend for this woman?A. WarfarinB. DabigatranC. AspirinD. None

A. B. C. D.

0% 0%0%0%

10

Stroke Prophylaxis

Is there an app for that?

Take Home Point 1

• Not all patients with AF need to receive antithrombotic therapy

• Female sex alone is not sufficient to justify antithrombotic therapy in AF

Case 2

• 54 yo man, current smoker, with history CAD but no CHADS risk factors

• A routine ECG incidentally shows AF at 94 bpm

• Rate vs. rhythm control• Stroke prophylaxis


Take Home Point 2

• Aspirin is an appropriate antithrombotic agent in a select group of patients.

• Vascular disease alone is not sufficient to justify OAC in AF (in contrast to ESC guidelines)

Case 3

• 75 year old man with diabetic nephropathy and ESRD on dialysis (guidelines suggest that warfarin is favored if GFR<30).


Take Home Point 3

• Warfarin remains the agent of choice for AF in a number of circumstances– CrCl < 30cc/min *– AF with rheumatic mitral stenosis– Poor medication adherence (although failure to undergo blood testing favors NOAC)

– In association with another indication for warfarin• eg. mechanical valve, LV thrombus

Case 4

• 85 yo man with hypertension, diabetes, CKD (CrCl 55) and atrial fibrillation. His weight is 60kg.

Audience Poll: Most appropriate agent for stroke prevention*A. Dabigatran 150 mg BIDB. Dabigatran 110 mg BIDC. Rivaroxaban 20 mg ODD. Rivaroxaban 15 mg ODE. Apixaban 5 mg BIDF. Apixaban 2.5 mg BIDG. Warfarin

A. B. C. D. E. F. G.

0% 0% 0% 0%0%0%0%

10

*there’s more than 1 right choice!

Patient has risk factor for stroke

Estimate CrCl

<30 mL/min

30‐49 mL/min

>50 mL/min

Elderly and/or risk

factors forbleeding

Age <75 years

Age 75‐80 years

Age >80 years

110mg BID 150mg BID 150mg BID 110mg BID 110mg BID150mg BID

Contra‐indicated

One other risk factor

for bleeding

Dabigatran

Recommended dose

Dose can be considered

Canadian Dosing Recommendations for Stroke Prevention in AF


Patient has risk factor for

stroke

Estimate CrCl

30‐49 mL/min

>50 mL/min

20 mg OD15 mg OD

<30 mL/min

Not recommended

Rivaroxaban

Recommended dose*Rivaroxaban 15mg and 20mg should be taken with food


Recommended dose

Apixaban

Patient has risk factor for stroke

Estimate CrCl

≥25 mL/min

5 mg BID2.5 mg BID

<15 mL/min

Not recommended

Check Age Check Weight

Check Serum Creatinine

≥ 80 years ≤ 60 kg≥ 133

micromol/L

If ≥ 2 features

If ≤ 1 features

≥15 ‐24

mL/min

No dosing recommendation can be made*

* In patients with eCrCL 15 ‐ 24 mL/min, no dosing recommendation can be made as clinical data are very limited


Take Home Point 4

• NOACs are considered first line over warfarin, in most patients, but require appropriate dosing.

Perioperative Management of Anticoagulants

November 2014Benjamin Bell, MD FRCPC

Staff General Internist, North York General HospitalExecutive Member, Thrombosis Canada

Objectives

• Develop an evidence‐based approach to the perioperative management of anticoagulants

• Accurately risk stratify patients• Bleeding risk associated with procedure• Thrombotic risk associated with indication

• Introduce online, point of care tools and apps

Case• Dentist calls• 81 year old male patient needs a few teeth pulled

• On rivaroxaban 15 mg daily• AF, hypertension, diabetes, CKD (eGFR 35mL/min)

• Dentist wants to know how to manage anticoagulant

Audience Poll: Your Advice?A. Discontinue

rivaroxaban 5 days before procedure

B. Discontinue rivaroxaban 2 days before procedure

C. Continue rivaroxaban

A. B. C.

0% 0%0%

10

Recommended risk assessment algorithm1. What is the

procedural risk of bleeding?

2. What is the patient’s risk of thrombosis?

3. Which antithrombotic agent is/are being used and what is its half‐life?

Surgicalbleeding risk

Patientthrombosis risk

Guidelines








Procedural risk of bleeding

• Low

• Moderate (2 day risk of major bleed 0‐2%)

• High (2 day risk of major bleed 2‐4%)

Continue antithrombotic

Hold antithrombotic

Hold antithrombotic

Procedural risk of bleedingModerate risk procedures(2‐day risk of major bleed 0%‐2%)• Cholecystectomy• Abdominal hysterectomy

• Carpal tunnel repair

• Knee/hip replacement and shoulder/foot/hand surgery and arthroscopy

• Dilatation and curettage

• Skin cancer excision

• Abdominal hernia repair

• Axillary node dissection

• Hydrocele repair• Noncataract eye surgery

• Noncoronary angiography

• Bronchoscopy ±biopsy

• Cutaneous and bladder/prostate/ thyroid/breast/lymph node biopsies

High risk procedures(2‐day risk of major bleed 2%‐4%)• Any major operation (duration > 45 minutes)

• Any procedure involving neuraxial anesthesia

• Heart valve replacement

• Coronary artery bypass

• Abdominal aortic aneurysm repair

• Neurosurgical/urologic/head and neck/abdominal/breast cancer surgery

• Laminectomy• TURP• Kidney biopsy• Polypectomy, variceal treatment, biliary sphincterectomy, pneumatic dilatation

• PEG placement• Endoscopically guided fine‐needle aspiration

• Vascular surgery• Bilateral knee replacement

Blood. 2012;120(15):2954‐2962

Very low risk procedures• Minor dental procedures

• Conservation work• Prosthodontics• Scaling/polishing• Extractions (single and multiple)

• Endodontics• Minor dermatologic procedures

• Skin biopsy• Excisions

• Cataract extraction• Endoscopy withoutadvanced therapeutic procedures (eg. polypectomy)

Managing bleeding

• Local hemostatic measures• Ensure INR in therapeutic range• Avoidance of NSAID for postoperative pain control• Dental procedures

• Use of tranexamic mouthwash (5cc before procedure and QID x 2 days following procedure)

What about warfarin?

• Same approach!

Take home points

• There is no need to hold anticoagulation (including NOACs) for procedures associated low bleeding risk

• Avoid NSAIDs for analgesia

• Local hemostatic measures will manage bleeding

Case• 78 F severe OA• Scheduled for L TKA next week

• Seen in the preoperative clinic by an internist last week

• Mechanical mitral valve for severe MS

• AF, HTN, CKD (CrCl~45mL/min)

• On warfarin 3.5 mg OD, amlodipine 5 mg OD

• Doesn’t trust whatever the “hospital doctor” said and wants your advice for warfarin








Risk of thrombosis

• Must be considered when anticoagulants are to be held

• Low

• Moderate

• High

No bridging therapy

Consider bridging therapy

Bridging therapy indicated

Risk of thrombosis

Bridging

Time in subtherapeutic range

Time

Degree ofanticoagulation

Warfarin held Intervention

x

x

x

Bridging

Time


Intervention


Warfarin held

x

x

x

Intervention

Time


Bridging

Warfarin held

Sample Bridging ProtocolDay Warfarin LMWH

‐6 ✔ X

‐5 X X

‐4 X X

‐3 X ✔

‐2 X ✔

‐1 X ✔*

Surgery X X

+1 ✔ ✔**

+2 ✔ ✔**

+3 ✔ ✔***

* Use half daily dose** If high bleeding risk, hold, or use prophylactic dose LMWH

*** Continue LMWH until INR in therapeutic range

Take home points

• Anticoagulants must be held for patients undergoing moderate/high bleeding risk procedures

• Bridging with LMWH should be considered for patients at moderate/high risk for thrombosis

Case: but what about the NOACs?• 76 M new BRBPR, Fe deficiency anemia

• Scheduled for colonoscopy with polypectomy expected

• AF, HTN, previous stroke, diabetic CHF, CKD (CrCl~38mL/min)

• On rivaroxaban 15 mg daily, amlodipine 5 mg, Lasix 60 mg, ramipril 10 mg, metformin 1 g BID, sitagliptin 100 mg

• GI on vacation until day before procedure, lost instructions








Drug pharmacology

Drug Renal clearance

c‐max t ½ CrCl >50 t ½ CrCl 30‐50

Dabigatran 80% 2h 14h 18h

Rivaroxaban 33% 4h 8h 9h

Apixaban 25% 4h 7h 17h

Dalteparin 70% 4h 2‐5h 4‐8h

Blood. 2012;120(15):2954‐2962

Bridging

Time


NOAC held

Intervention


How long to hold the drug?

Blood. 2012;120(15):2954‐2962

Take home points

• Bridging anticoagulation is virtually never indicated for patients treated with a NOAC

• Duration off the drug depends on patient renal function and surgical bleeding risk

Take home points• Do not withhold anticoagulants for low bleeding risk procedures

• Bridging recommended for patients at high thromboembolic risk undergoing moderate/high bleed risk procedures who are anticoagulated with warfarin

• Bridging is not necessary for patients anticoagulated with NOACs

• Duration of cessation of NOAC depends on agent, renal function and surgical bleeding risk … so use an app to make appropriate recommendations

Documents

Thrombosis Canada Clinical Tools Perioperative Management