TAVI and Valve Replacement Thromboprophylaxis. Warren Prokopiw Pharmacy Resident

Transcription

1 TAVI and Valve Replacement Thromboprophylaxis Warren Prokopiw Pharmacy Resident

2 Case Mr MW 76 yo Admitted 14 May for worsening CHF PMH: Aortic Stenosis, CVD (CABG x4 1980, PCI x3 stent 2008) AFib, CHF, Sinus bradycardia with pacemaker, COPD, DM, restless leg syndrome Echo: - jet velocity 3.45 m/s, EF 45% mean gradient 26.4 mmhg aortic valve area 0.98 cm 2

3 Aortic Stenosis Abnormal narrowing of aortic valve Caused by calcification Bases to leaflets Similar process to atherosclerosis Lipid accumulation Inflammation Calcification

4 Pathophysiology Obstruction develops over decades Pressure causes LV hypertrophy Decreased ejection fraction Insufficient coronary blood flow Resulting ischemia - further dysfunction Increased sensitivity to injury - RR = 50% Larger infarct Increased mortality

5 Natural history Affects 25% or adults over 65 Risk factors age, sex, hypertension, smoking, hypercholesterolemia and diabetes mellitus Prolonged latent period Wide variability in progression Symptoms - angina, syncope, or heart failure Average survival 2-3 years Sudden cardiac death

6 Diagnosis Systolic murmur Echocardiogram Valve anatomy LV response size and function Doppler Echo Jet velocity

7 Staging Indicator Mild Moderate Severe Jet velocity (m per second) Mean gradient (mm Hg)* Less than Greater than 4.0 Less than Greater than 40 Valve area (cm2) Greater than Less than 1.0 a disease continuum no single value that defines severity

8 Management Medical Anti-hypertensives Lipid lowering - no impact Prophylactic antibiotics for infective endocarditis no longer recommended Surgical Valve replacement required once symptomatic

9 Management

10 Mechanical Valve Replacement Ball and cage noisy and inefficient Single tilting disk severe compromise if thrombosis Bileaflet quiet, stable, efficient Most common today Require warfarin

11 Bioprostheic Valves Tissue types porcine aortic or bovine pericardial Bovine better hemodynamic performance Stented or not Attempts for better efficiency - not observed stented more common No warfarin

12 Comparison Mechanical valve more durable Tissue valves deteriorate by years Higher in younger patients Mechanical valve higher bleeding risk Recommendations Mechanical if have other mechanical valve or < 65 yo and can take warfarin Tissue if warfarin is contraindicated or >65 without other risk factors for thrombolembolism

13 Aortic Balloon Valvotomy Palliative option for inoperable patients Percutaneous approach to decrease severity Fractures calcific deposits in leaflets early improvement Restenosis and deterioration in 6-12 months

14 Transcatheter Aortic Valve Insertion (TAVI)

15 TAVI percutaneously delivered aortic heart valve trileaflet bovine pericardial tissue tubular slotted stent SAPIEN

16 Valve Placement

17 Partner Study prospective, un-blinded, multicentre RCT Two distinct arms High risk operable n=699 Inoperable n=358 Inoperable 50% predicted probability of mortality or serious irreversible complication by 30 days by 1 cardiologist and 2 cardiothoracic surgeons

18 Trial Flow

19 High Risk outcomes

20 Inoperable Outcomes Overall, the benefit from TAVR in inoperable patients with symptomatic severe AS greatly exceeds the risk

21 Two year Results N Engl J Med 2012;366:

22 Rate of death from any cause

23 Rate of death cardiac causes

24 Rate of rehospitalization

25 Rate of death or stroke

26 Stroke Disturbing complication Higher in TAVI group Causes 1 year (11.2% vs. 5.5%, P = 0.06) 2 years (13.8 vs. 5.5%, P = 0.01) 66% occurring in first 30 days Thromboembolism at valve site Artherothromobic emboli from plaques in aortic arch dislodged during catheter manipulation

27 Antithrombotic Therapy Valve Replacement

28 POD 1-5 Bridging Bioprothetic valves No studies no recommendations Mechanical valves Evidence summary at 30 d bridge to warfarin Tromboembolism % Bleed % Prophylactic UFH Therapeutic LMWH Therapeutic UFH Use prophylactic UFH or LMWH (therapeutic or prophylactic) until INR stable

29 Bioprosthetic Valves High clot risk first 3 months Varies by location Aortic - ASA over warfarin if in NSR increased risk of bleed with warfarin over ASA, no difference in events Mitral warfarin INR risk of stroke up to 40 events per 100 patient years Warfarin lowered risk, higher INRs increased bleed

30 Bioprosthetic Valves Thromboembolism risk beyond three months Mitral position 0.2 to 2.6% per year Aortic position 0.2% per year If in NSR ASA indefinitely

31 Mechanical Valves Warfarin to no anti-coagulation 0.21 (CI, ) RR of thromboembolism 0.11 (95% CI, ) RR of valve thrombosis Aortic INR Mitral INR More thrombogenic due to different hemocynamic and flow over the valve Dual valves Treat as per mitral

32 Mechanical Valves New meta analysis for addition of ASA to warfarin reduction in mortality (RR, 0.58;95% CI, ) thromboembolic outcome (RR, 0.42; 95% CI, ) increase in risk of major hemorrhage (RR 1.44; 95% CI, ) Add ASA mg to warfarin for patients with no risk of bleeding

33 Trascahterter Aortic Valves Bioprosthetic valve Non-drug eluting stent Clopidogel plus ASA x 3 months No studies for anti-thrombotic Extension of practice in coronary stenting

34 Questions?

35 References 1. Holmes DR, Mack MJ, Kaul S, Agnihotri A, Alexander KP, Bailey SR, et al ACCF/AATS/SCAI/STS Expert Consensus Document on Transcatheter Aortic Valve Replacement. Journal of the American College of Cardiology [Internet] Jan 30 [cited 2012 Mar 14];59(13): Available from: 2. Bonow RO, Carabello B a, Chatterjee K, de Leon AC, Faxon DP, Freed MD, et al. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Journal of the American College of Cardiology [Internet] Aug 1 [cited 2012 Mar 10];48(3):e Available from: 3. Makkar RR, Fontana GP, Jilaihawi H, Kapadia S, Pichard AD, Douglas PS, et al. Transcatheter aortic-valve replacement for inoperable severe aortic stenosis. The New England journal of medicine [Internet] May 3;366(18): Available from: 4. Whitlock RP, Sun JC, Fremes SE, Rubens FD, Teoh KH. Antithrombotic and Thrombolytic Therapy for Valvular Disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest [Internet] Feb [cited 2012 Mar 3];141(2 Suppl):e576S 600S. Available from: 5. Wilson W, Taubert K a, Gewitz M, Lockhart PB, Baddour LM, Levison M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation [Internet] Oct 9 [cited 2012 Mar 10];116(15): Available from: