Kevin Saunders MD CCFP Rivergrove Medical Clinic Wellness SOGH April

Transcription

1 Kevin Saunders MD CCFP Rivergrove Medical Clinic Wellness SOGH April

2 Family physician with Rivergrove Medical Clinic Practice in the north end since 1985 Medical Director of the Wellness Seven Oaks General Hospital Past-president College of P & S of Manitoba Special interests in medical research, health promotion, and medical education

3 Speaker for: Most major pharmaceutical companies including Pfizer, AstraZeneca, Merck, Novartis, Boehringer, Lilly, BMS. Received grant/research support for Phase II, III, and IV studies from most major pharmaceutical companies including all of the above Received honoraria from: Wellness Institute, AstraZeneca, Lilly, Pfizer, BMS, Leo, B.I., Novartis

4 Learning Objectives At the end of this educational program, the participants should have an enhanced understanding of the following: 1. Understand the 2012 CCS recommendations for anticoagulation of atrial fibrillation patients 2. Understand the role of the newer (novel) anticoagulants for stroke prevention in patients with atrial fibrillation

5 Atrial Fibrillation Remains a major risk factor for stroke 1. Afib Investigation Group. Arch Intern Med. 1994;154: Wolf PA, et al. Stroke 1991;22: Most common heart rhythm disturbance - 25% of individuals aged 40 yr or greater develop AF Independent risk factor - increases the risk of stroke by 5-fold 1,2,3 Accounts for 15-20% of all strokes nationally 1,4 Risk of stroke - 1.5% in year olds 23.5% in year olds Stroke risk similar in paroxysmal or permanent AF 3. Savelieva I, et al. Ann Med 2007;39: Singer DE, et al. Chest 2008;133:546S-592S

6 Stroke Results in Significant Disability Approximately 30% of men and 35% of women die within a year of an initial stroke - Over 50% of people die within 5 years of a first stroke 20% of men and 25% of women aged 65 yr with a first stroke, have a recurrent stroke within 5 years At 6 months survival, 26% of patients ( 65 yr) remain dependent on others for help with daily activities Majority of survivors need community services such as physiotherapy, occupational and speech/language therapy 1. Roger VL, et al. Circulation 2011;123: e18-e209

7 CCS 2012 Update to A.F. Guidelines Evaluation of patients with atrial fibrillation should include both stroke and bleeding risk Stroke risk assessment tools include both CHADS2 and CHA2DS2-VASc Bleeding risk assessment tool includes HASBLED

8 CCS 2012 Update to AF Guidelines When oral anticoagulant therapy is indicated, most patients should receive dabigatran, rivaroxaban, or apixaban*, in preference to warfarin Dabigatran and apixaban have greater efficacy and rivaroxaban has similar efficacy for stroke prevention Dabigatran and rivaroxaban have no more major bleeding and apixaban has less All three new oral anticoagulants have less intracranial hemorrhage and are much simpler to use *Not yet approved in Canada 1. Skanes AC, et al. Can J Cardiol 2012;28:

9 CCS 2012 Update to A.F. Guidelines Lack of a specific antidote should not preclude use of a new oral anticoagulant in appropriate patients VERY important to note : these treatment recommendations are for NONVALVULAR atrial fibrillation

10 CCS 2012 Update to AF Guidelines Assess Thromboembolic Risk (CHADS 2 ) CHADS 2 = 0 CHADS 2 = 1 CHADS 2 2 Increasing stroke risk No antithromboti c No additional risk factors for stroke *OAC = Oral anticoagulant ASA = Aspirin ASA OAC* OAC* OAC* Either female sex or vascular disease 1. Skanes AC, et al. Can J Cardiol 2012;28: Age 65 yrs or combination of female sex and vascular disease *Aspirin is a reasonable alternative in some as indicated by risk/benefit Consider stroke risk vs. bleeding risk Only when the stroke risk is low and bleeding risk is high does the risk/benefit ratio favour no antithrombotic therapy

11 CHADS 2 Score (Simple Prediction Tool for Assessing Stroke Risk) 1 point for Congestive Heart Failure 1 point for Hypertension 1 point for Age 75 years 1 point for Diabetes Mellitus 2 points for Prior Stroke or TIA CHADS 2 Score* Stroke Rate, %/yr (95 %CI) ( ) ( ) ( ) ( ) ( ) ( ) ( ) *Score 0: Patients can be administered aspirin *Score 1: Patients can be administered aspirin or anticoagulant therapy *Score 2: Patients should be administered anticoagulant therapy 1. Gage BF, et al. JAMA. 2001;285:

12 Bleeding risk assessment A bleeding risk assessment should be performed in all patients prior to prescribing antithrombotic therapy Bleeding risk assessment tools, such as the HAS- BLED* are available A high score indicates a higher risk of bleeding, but should not preclude the use of an anticoagulant in patients at risk for stroke *In HAS-BLED, major bleeding was defined as fatal or clinically overt bleeding associated with either transfusion of 2 U of blood or 20 g/l decrease in hemoglobin or bleeding involving a critical anatomic site other than the brain parenchyma 1. Pisters R, et al. Chest 2010; 138(5):

13 HAS-BLED Bleeding Score (Simple Tool for Assessing Bleeding Risk) Letter Clinical Characteristic* Points Awarded: Score H Hypertension 1 A Abnormal renal or liver function (1 point each) 1 or 2 S Stroke 1 B Bleeding 1 L Labile INRs 1 E Elderly 1 D Drugs or alcohol (1 point each) 1 or 2 *Hypertension - uncontrolled, >160 mm Hg systolic; Abnormal renal/liver function (one point for presence of renal or liver impairment, maximum two points); Stroke (previous history, particularly lacunar); Bleeding history or predisposition (anemia); Labile international normalized ratio (INR) (i.e. therapeutic time in range < 60%); Elderly ( >65 years); Drugs/alcohol concomitantly (antiplatelet agents, nonsteroidal anti-inflammatory drugs; one point for drugs plus one point for alcohol excess, maximum two points). 1. Pisters R, et al. Chest 2010; 138(5):

14 HAS-BLED Bleeding Score (Simple Tool for Assessing Bleeding Risk) Risk Factor Score Major Bleeds (%/yr) Pisters R, et al. Chest 2010; 138(5):

15 So what are these new anticoagulants? apixaban (BMS / Pfizer : Eliquis) Factor Xa inhibitor 2.5 & 5 mg tablets for prevention of thromboembolic events (VTE) in adult patients who have undergone elective hip or knee surgery for prevention of stroke and systemic embolism in patients with atrial fibrillation

16 So what are these new anticoagulants? rivaroxaban (Bayer : Xarelto) Factor Xa inhibitor 10, 15, & 20 mg tablets prevention of VTE in patients who have undergone elective THA or TKA prevention of stroke or systemic embolism in patients with atrial fibrillation in whom anticoagulation is appropriate treatment of DVT without symptomatic pulmonary embolism

17 So what are these new anticoagulants? dabigatran (Boehringer Ingelheim : Pradaxa) direct thrombin inhibitor 75, 110, & 150 mg capsules prevention of VTE in patients who have undergone elective THA or TKA prevention of stroke or systemic embolism in patients with atrial fibrillation, in whom anticoagulation is appropriate

18 Recent Oral Anticoagulation Trials: Ischemic Stroke Not intended as cross-trial comparison Data obtained from intention-to-treat analysis Apixaban not yet approved in Canada for stroke prevention in patients with atrial fibrilliation 1. Connoly SJ, et al. N Engl J Med 2009;361: Patel MR, et al. N Engl J Med 2011;365: Granger C, et al. N Engl J Med 2011;365:

19 Recent Oral Anticoagulation Trials: Stroke or Systemic Embolism The new oral anticoagulant agents are consistently associated with a numerically lower risk for stroke or systemic embolism compared to warfarin Not intended as cross-trial comparison Data obtained from intention-to-treat analysis Apixaban not yet approved in Canada for stroke prevention in patients with atrial fibrilliation 1. Connoly SJ, et al. N Engl J Med 2009;361: Patel MR, et al. N Engl J Med 2011;365: Granger C, et al. N Engl J Med 2011;365:

20 Recent Oral Anticoagulation Trials: Hemorrhagic Stroke The new oral anticoagulants are consistently associated with a numerically lower risk of hemorrhagic stroke compared with warfarin Not intended as cross-trial comparison Data obtained from intention-to-treat analysis Apixaban not yet approved in Canada for stroke prevention in patients with atrial fibrilliation 1. Connoly SJ, et al. N Engl J Med 2009;361: Patel MR, et al. N Engl J Med 2011;365: Granger C, et al. N Engl J Med 2011;365:

21 Recent Oral Anticoagulation Trials: Major Bleeding HR (95% CI) New Agent Better Warfarin Better Not intended as cross-trial comparison Data obtained from intention-to-treat analysis Apixaban not yet approved in Canada for stroke prevention in patients with atrial fibrilliation 1. Connoly SJ, et al. N Engl J Med 2009;361: Patel MR, et al. N Engl J Med 2011;365: Granger C, et al. N Engl J Med 2011;365:

22 CCS 2012 Update to AF Guidelines GFR Warfarin Dabigatran Rivoraxaban Apixaban* GFR 60 ml/min Dose adjusted for INR mg BID or 110 mg BID 20 mg daily 5 mg BID GFR ml/min Dose adjusted for INR mg BID or 110 mg BID 20 mg daily 5 mg BID GFR ml/min Dose adjusted for INR mg BID or 110 mg BID 15 mg daily 5 mg BID (for GFR >25 ml/min only Consider 2.5 mg BID GFR ml/min (not on dialysis) GFR < 15 ml/min (on dialysis) No RCT data No RCT data No RCT data ml/min only 5 mg BID (for GFR >25 Consider 2.5 mg BID No RCT data No RCT data No RCT data No RCT data *Not yet approved by Health Canada Consider Apixaban 2.5 mg po bid if GFR 25 ml/min, especially if age > 80 or body weight < 60 kg Dose adjusted warfarin has been used, but observational data regarding safety and efficacy is conflicting Modelling studies suggest that dabigatran 75 mg bid might be safe for patients with GFR ml/min; not been validated in a prospective cohort No published studies support a dose for this level of renal function; product monographs suggest the drug is contraindicated for this level of renal function 1. Skanes AC, et al. Can J Cardiol 2012;28: