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Antiplatelets and Anticoagulants in Valvular Heart Disease. David J. Moliterno, MD Professor and Chairman Division of Cardiovascular Medicine. Background. Valvular abnormalities can lead to increased occurrence of thromboembolic events
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Antiplatelets and Anticoagulantsin Valvular Heart Disease David J. Moliterno, MD Professor and Chairman Division of Cardiovascular Medicine
Background • Valvular abnormalities can lead to increased occurrence of thromboembolic events • Antiplatelet and anticoagulant therapies reduce the occurrence of thrombotic and embolic events • Normal human valve < homograft < bioprosthesis < mechanical < single-disc or ball-in-cage < mitral position < high-risk features (afib, low EF, hypercoaguable) • Prosthetic valve thrombosis
Valvular Heart Disease Guidelines ACCP Guidelines, 8th ed. Chest, June 2008. Bonow et al, JACC 2008;52:e1-e142.
ACCP Antithrombotic Guidelines If we are confident that benefits do or do not outweigh harms, burden, and costs, we make a strong recommendation in our formulation, Grade 1. If we are less certain of the magnitude of the benefits and risks, burden, and costs, and thus their relative impact, we make a weaker Grade 2 recommendation. For grading methodologic quality, randomized controlled trials (RCTs) begin as high-quality evidence (designated by "A"), but quality can decrease to moderate ("B"), or low ("C") as a result of poor design and conduct of RCTs, imprecision, inconsistency of results, indirectness, or a high likelihood for reporting bias. Observational studies begin as low quality of evidence (C) but can increase in quality on the basis of very large treatment effects. Strong (Grade 1) recommendations can be applied uniformly to most patients. Weak (Grade 2) suggestions require more judicious application, particularly considering patient values and preferences and, when resource limitations play an important role, issues of cost. Guyatt et al. Chest 2008;134:473
Valvular Heart Disease Anticoagulation • Native Valve Disease
Mitral Valve Rheumatic Disease RHD LAD >55 AFIB THROMBUS INR ASA GRADE + - - - - - 2C + + - - 2.5 - 2C + + 2.5 - 1A + + + 2.5 + 2C + + + 3.0 - 2C Prolapse/structural MVP CNS AFIB INR ASA GRADE + - - - - 1C + + - - + 1B + + + 2.5 + 2C ACCP Guidelines, 8th ed. Chest, June 2008.
Valvular Heart Disease Anticoagulation • Native Valve Disease • Prosthetic Valve Thromboprophylaxis
Replacement Valves Orifice Area for Various Valves
Mechanical Prosthetic Valves Starr-Edwards Ball-in-Cage Valve Bjork-Shiley Single Tilting Disk Valve
Replacement Valves Medtronic-Hall Valve Tilting Disk St. Jude Valve Bi-leaflet Tilting Disk
IIa IIb III I B * Risk factors include atrial fibrillation, previous thromboembolism, LV dysfunction, hypercoagulable condition Antithrombotic Therapies for VHD AVR, mechanical bileaflet (or Medtronic Hall) and no risk factors INR target 2.0-3.0 AVR, mechanical bileaflet (or Medtronic Hall) with risk factors INR target 2.5-3.5 AVR, Starr-Edwards or other disc valve and no risk factors INR target 2.5-3.5 Bonow et al, JACC 2008;52:e1-e142.
IIa IIb III I C Antithrombotic Therapies for VHD MV, mechanical valve INR target 2.5-3.5 AVR, biological valve with risk factors INR 2.0-3.0 MV, biological valve with risk factors INR 2.0-3.0 Bonow et al, JACC 2008;52:e1-e142.
IIa IIb III I C IIa IIb III I B Antithrombotic Therapies for VHD AVR or MV, unable to take warfarin ASA 75-325 mg daily Any mechanical heart valve ASA 75-100 mg daily Biological valve with risk factors ASA 75-100 mg daily AVR or MV, biological valve and no risk factors ASA 75-100 mg daily Bonow et al, JACC 2008;52:e1-e142.
IIa IIb III I C IIa IIb III I C Antithrombotic Therapies for VHD AVR, mechanical valve During first 3 months INR 2.5-3.5 AVR or MV, biological valve During first 3 months and no risk factors INR 2.0-3.0 Any prosthetic heart valve At high risk and unable to take ASA Administer clopidogrel or warfarin INR 3.5-4.5 Bonow et al, JACC 2008;52:e1-e142.
Antithrombotic Therapy Recommendations for Prosthetic Heart Valves Aspirin Warfarin Warfarin No (75-100 mg) (INR 2.0-3.0) (INR 2.5-3.5) Warfarin Mechanical Valves AVR-low risk <3 months Class I Class I Class IIa >3 months Class I Class I AVR-high risk Class I Class I MVR Class I Class I Biological Valves AVR-low risk <3 months Class I Class IIa Class IIb >3 months Class I Class IIa AVR-high risk Class I Class I MVR-low risk <3 months Class I Class IIa >3 months Class I Class IIa MVR-high risk Class I Class I Bonow et al, JACC 2008;52:e1-e142.
Mitral Valve Prosthetic Valve Disease AFIB LAE AAMI INR ASA Grade Mechanical Valves Bileaflet - - - 3.0 1B Tilting-Disc - - - 3.0 1B Starr-Edwards - - - 3.0 1B Any Mechanical + + + 3.0 + 1B ▪Avoid ASA if increased bleeding risk or age >80 2C ▪If systemic embolism occurs, add ASA if not already receiving, and increase INR by 0.5 2C Biological Valves Any Biological First 3 months 2.5 1B After 3 months + 1B ACCP Guidelines, 8th ed. Chest, June 2008.
Aortic Valve Prosthetic Valve Disease AFIB LAE AAMI INR ASA GRADE Mechanical Valves Bileaflet - - - 2.5 1B Medtronic-Hall - - - 2.5 1B Starr-Edwards - - - 3.0 1B Any Mechanical + + + 3.0 + 1B Biological Valves Any Biological - - - + 1B ACCP Guidelines, 8th ed. Chest, June 2008.
Valvular Heart Disease Anticoagulation • Native Valve Disease • Prosthetic Valve Thromboprophylaxis • Bridging Therapy • Embolic Events While on Therapy
Antithrombotic Therapy: Embolic Events Definite Embolic Episode While on Therapy Warfarin, INR 2.0-3.0 Increase warfarin, INR 2.5-3.5 Warfarin, INR 2.5-3.5 Increase warfarin, INR 3.5-4.5 Not taking ASA Add ASA 75-100 mg daily Warfarin + ASA Increase ASA to 325 mg daily ASA alone Increase ASA to 325 mg daily, add clopidogrel 75 mg daily, and/or add warfarin Bonow et al, JACC 2008;52:e1-e142.
Valvular Heart Disease Anticoagulation • Native Valve Disease • Prosthetic Valve Thromboprophylaxis • Bridging Therapy
IIa IIb III I B Antithrombotic Therapy: Bridging Low risk of thrombosis (bileaflet mechanical AVR with no risk factors), warfarin should be stopped 48-72 h before procedure (so INR falls <1.5) and restarted within 24 h after procedure. Heparin is usually unnecessary. High risk of thromobosis (any mechanical MV or a mechanical AVR with any risk factors), therapeutic intravenous UFH should be started when the INR falls <2.0 (typically 48 h before surgery), stopped 4-6 h before the procedure, restarted as early after surgery as bleeding stability allows, and continued until the INR is again therapeutic with warfarin therapy. Bonow et al, JACC 2008;52:e1-e142.
IIa IIb III I B IIa IIb III I B Antithrombotic Therapy: Bridging In patients at high risk of thrombosis, therapeutic doses of subcutaneous UFH (15000 U every 12 h) or LMWH (100 U per kg every 12 h) may be considered during the period of a subtherapeutic INR. In patients with mechanical valves who require interruption of warfarin therapy for noncardiac surgery, invasive procedures, or dental care, high-dose vitamin K should not be given routinely, because this may create a hypercoagulable condition. Bonow et al, JACC 2008;52:e1-e142.
IIa IIb III I B Antithrombotic Therapy: Bridging It is reasonable to give fresh frozen plasma to patients with mechanical valves who require interruption of warfarin therapy for emergency noncardiac surgery, invasive procedures, or dental care. Fresh frozen plasma is preferable to high-dose vitamin K. Bonow et al, JACC 2008;52:e1-e142.
Valvular Heart Disease Anticoagulation • Native Valve Disease • Prosthetic Valve Thromboprophylaxis • Bridging Therapy • Embolic Events While on Therapy • Prosthetic Valve Thrombosis
Prosthetic Valve Thrombosis Thrombus NYHA Valve Size Class Treatment Grade TV, PV Large III-IV Fibrinolytic 1C MV, AV Very small I-II UFH + Doppler 2C MV, AV Small I-II Fibrinolytic 2C MV, AV Large III-IV Surgery 2C ACCP Guidelines, 8th ed. Chest, June 2008.
B B B B C Yes / No C C C Which Valve is Replaced ? Unable to take warfarin? ASA 75-325 mg daily (Ib) Unable to take ASA? Clopidogrel or warfarin, INR 3.5-4.5 (IIb) MVR AVR Replacement Valve Type Replacement Valve Type Mechanical Biological Mechanical ? ? ASA 75-100 (Ib) 1st 3 mos INR 2.5-3.5 (IC) ASA 75-100 (Ib) 1st 3 mos INR 2.5-3.5 (IC) ? Bileaflet [Medtronic-Hall] Starr-Edwards Risk Factors Risk Factors ? Yes No Risk Factors ? During first 3 mos No Yes No ASA 75-100 mg INR 2.0-3.0 INR 2.5-3.5
Valvular Heart Disease Anticoagulation • Native Valve Disease • Prosthetic Valve Thromboprophylaxis • Bridging Therapy • Embolic Events While on Therapy • Prosthetic Valve Thrombosis • Future Agents
RE-LY • Dabigatranetexilate • Oral, prodrug, serum esterase • Competitive thrombin inhibitor • 80% renal excretion • 12-17 hour half-life • Monitoring not required Atrial Fibrillation N = 18,113 Dabigatran 150-mg BID Dabigatran 110-mg BID Warfarin INR 2.0-3.0 • 2-Year median follow-up for stroke or systemic embolization • Connolly et al. N Engl J Med 2009;361
RE-LY Connolly et al. N Engl J Med 2009;361
Valvular Heart Disease Anticoagulation • Native Valve Disease • Prosthetic Valve Thromboprophylaxis • Bridging Therapy • Embolic Events While on Therapy • Prosthetic Valve Thrombosis • Future Agents