Edward Evans MD FACC Desoto Heart Clinic Disclosures Medtronic:speaker St. Jude Medical:speaker

Valvular Surgery YearSurgeonDescription 1960Dwight Harken1 st successful aortic valve replacement (AVR). A caged ball valve was used 1960Starr and Edwards 1 st successful mitral valve replacement (MVR) using caged-ball valve of their own design Approx Starr-Edwards valves implanted 1962HeimbeckerToronto. 1 st clinical implant of an aortic hemograft valve. 1962Daniel Ross1 st successful aortic valve homograft implant 1964Duran and Gunning Aortic valve replacement with xenograft porcine aorti valve (formaldehyde-fixed xenografts->tissue degradation and calcification). 1971CarpentierXenograft valves fixed with glutaraldehyde and mounted on a stent to produce a bioprosthesis

Improved bottle stopper conceptual impetus for the first successful ball and cage design

5 1960s - Commercially Available Valves Caged-ball valves were improved and became commercially available 1960: Harken implanted a double-cage ball valve into aortic annulus 1960: first implant of the Starr-Edwards valve - mitral position (first sold in 1965)

Prosthetic Heart Valve Management

Post-operative surveillance Prevention of infection Prevention of thrombosis Management of complications

Surveillance Initial post-op visit: – H&P, CXR, EKG –class 1 – 2D echo – class 1 if unsatisfactory…other studies – Labs: CBC, INR

Surveillance Later visits: (patients without complications) – Routine follow-up yearly. Earlier if clinical changeClass I – Routine serial echoClass IIb Echo if change in exam New regurgitationecho every 3-6 months.

Prevention of Infection Class I – 2% risk of infection at 14 days with no prophylaxis. Dental procedures Invasive Respiratory procedures with incision or biopsy Surgery involving infected skin or musculoskeletal tissue

Prevention of Infection min before procedure Amoxicillin 2g PO/Ampicillin 2g IV/IM Cephalexin 2g PO Azithromycin 500mg PO Clindamycin 600mg PO or IV Cefaxolin or Ceftriaxone 1g IV/IM

Anticoagulation Mechanical valves: – Risk of thromboembolic event Untreated: up to 8% per year Treated: less than 2% per year – Mitral greater risk than aortic – Higher risk early post-operatively Bioprosthetic valves: – 0.7% per year risk

Anticoagulation All valves require anticoagulation – Duration – Agent(s) Valve type and position Patient risk factors – Atrial fibrillation – Previous thromboembolic event – Hypercoagulable state – Low EF < 30% Contraindications

Anticoagulatioin Aspirin mg daily – All patients – class 1 – Use alone with bioprosthetic AVR and MVR with no risk factors Coumadin (INR ) – Mechanical AVR bileaflet, no risk factors – Bioprosthetic First 3 months – class 2a Long term with risk factors.

Anticoagulation Coumadin (INR ) – All others Starr-Edwards run higher >3.0

Anticoagulation Events while at target: – INR 2-3: increase to 2.5 to 3.5 – INR : increase to 3.5 to 4.5 Short term interruption: – Bileaflet AVR no risk factors: No bridge – Bridge all others with UFH – LMWH is class 2b – FFP in emergencies – No vitamin K

Complications Structural valve deterioration Non-structural Valve Dysfunction Thrombosis and Embolism Valvular endocarditis Hemolysis

Structural Valve Dysfunction

Structural Valve Dysfunction Mechanical Primary failures rare now. Led to discontinuation of certain valves Now mainly valve ring-tissue interface Mechanisms: – Valve dehiscence – Perivalvular regurgitation – Tissue in growth (pannus) and thrombosis

Structural Valve Dysfunction Bioprosthetic Incidence 20-30% at 10 years, 50% at 15 years Tissue degeneration Secondary calcification – Stenosis increasing after 6 years – More likely with MVR, youth, pregnancy, and chronic renal failure Perforation Perivalvular regurgitation

Nonstructural Valve Dysfunction Clinically significant obstruction in the setting of normal prosthetic function Patient prosthetic mismatch Occurs mostly in older women Thrombus and Pannus

SEVERE MODERATE MILD/NONE (non significant) Indexed EOA (cm 2 /m 2 )

LVEF 40% 3% 5% P= % P< %P= % 67%P<0.001 Short-Term Mortality Short-Term Mortality (%) (%) LVEF < 40% Combined Impact of PPM and LV Dysfunction on Short-term Mortality

Thrombosis and Embolism Incidence 0.6% to 2.3% per patient year – Anticoagulated mechanical rate same as unanticoagulated bioprosthetic – Mitral position greater risk than aortic – Tricuspid greatest risk Intrinsic thrombogenicity of valve materials, flow turbulence and stagnation, shear stresses, risk factors

Valve thrombosis Echo, TEE, Fluoroscopy, MRI/CT Thrombolysis – 70-90% effective – Mortality 4-12% acutely – Better for right sided valves – Duration < 24hours Surgery – Class 2a for large clot, NYHA 3-4 – Class 1 small clot, failure or contraindications to lysis

Embolism Mechanical valves – No anticoagulation: 4% per year – Aspirin: 2% per year – Coumadin (therapeutic) 1% per year – Mitral valves twice the risk of aortic valves

Prosthetic valve endocarditis Yearly risk 0.5% despite prophylaxis Highest risk MVR No difference mechanical and bioprosthetic Risk greatest in first 6 months Usually involves the valve ring Substantial mortality

Prosthetic Valve Endocarditis Medical – Hospitalize at CV surgery center – Delay antibiotics until organism identified – TEE – Prolonged antibiotics with ID guidance Surgery – Heart failure, abscess, dehiscence, relapsing infection, failed antibiotic

Macroangiopathic hemolytic anemia Anemia post operatively – Microcytic – Increased LDH – Decreased haptoglobin – NO suspicion of ITP/TTP – Schistocytes May lead to heart failure Transfusion dependent anemia Potential need for re-do valve surgery

Summary Prosthetic valves are not a cure for valvular disease Associated with large number of potential medical management issues Careful post-operative valvular surveillance is important

Questions?