Weerachai Nawarawong M.D. Valve selection Weerachai Nawarawong M.D.

Akins CW: Ann Thorac Surg 1991,52:161-172 Mechanical valve advantage Children Patients <40 yrs High reoperation risk Small annular size Atrial fibrillation Pregnancy desired Patients > 70 yrs High thromboembolism risk High hemorrhage risk Tissue valve advantage Akins CW: Ann Thorac Surg 1991,52:161-172

Which valve ?

If one can choose the valve prosthesis one would choose: “One valve for life”

Myths about Mechanical Valves You’ll Never Need Another Operation You can Live without Restrictions Risks of TE/ACH are Minimal Coumadin is Not a Problem

“Nine Commandments for prosthetic valve” Embolism Prevention Durability Ease and Security of Attachment Preservation of Surrounding Tissue Function Reduction of Turbulance Reduction of Blood Trauma Reduction of Noise Use of Materials Compatible with Blood Development of Methods of Storage and Sterilization

Ideal valve Good hemodynamic Quiet Require no anticoagulation Last for life time Cheap Easy to implant

Valve Prosthesis Mechanical Bioprosthetic types: caged-ball, tilting-disk, bi-leaflet advantage: durability limitation: thrombogenicity Bioprosthetic types: heterografts, homografts advantage: short term anticoagulation limitation: structural failure leaflet calcification & tissue degeneration leading to valvular regurgitation rate of porcine valve degeneration 26% (aortic), 39% (mitral) in 10 yrs

Homografts 1956 - first aortic valve homograft was used in the descending thoracic aorta for aortic regurgitation 1962 - first sub-coronary use high incidence of post-op failure * (years) 5 10 15 20 survival rate (%) 85 66 53 38 re-operation (%) 22 62 85 95 * Circulation 1991; 84(suppl 3):III81-III88

Durability and hemodynamic Bleeding and thromboembolism

Thromboembolism and Bleeding

Wall Street Journal 8//16//07 Warfarin “is the second-most-likely drug, after insulin, to send Americans to the emergency room”. By one estimate, it accounts for 43,000 ER visits a year in the U.S.

Van der Meer : 42% more major bleeding complications for every one-point increase in INR. The incidence from major bleeding complications given in the literature varies between 1.6% and 5.2 % increasing with age

Incidence of major embolism after mechanical valve replacement Absence of antithrombotic therapy 4% per year plus 1.8% per year risk of valve thrombosis Antiplatelet therapy 2.2% per year plus 1.6% per year risk of valve thrombosis Wafarin therapy 1% per year 0.8% per year with an aortic valve 1.3% per year with a mitral valve plus 0.2% per year risk of valve thrombosis Incidence of major bleeding in patients treated with warfarin 1.4 per 100 patient-years. (Circulation. 1994;89:635-641.)

Anticoagulation Valve Thrombosis Major Embolism Total Embollsm* Incidence Rates of Valve Thrombosis and Major and Total Embolisms: Effect of Antithrombotic Treatment Incidence Rates per 100 Patient-Years (95% Confidence Intervals) Anticoagulation Valve Thrombosis Major Embolism Total Embollsm* None 1.8 (0.9-3.0) 4.0 (2.9-5.2) 8.6 (7.0-10.4) Antiplatelet 1.6 (1.0-2.5) 2.2 (1.4-3.1) 8.2 (6.6-10.0) Dipyridamole 4.1 (1.9-7.2) 5.4 (2.8-8.8) 11.2 (7.3-15.9) Aspirin 1.0 (0.4-1.7) 1.4 (0.8-2.3) 7.5 (5.9-9.4) Coumadin 0.2 (0.2-0.2) 1.0 (1.0-1.1) 1.8 (1.7-1.9) Coumadin and antiplatelet 0.1 (0.0-0.3) 1.7 (1.1-2.3) 3.2 (2.4-4.1) (Circulation. 1994;89:635-641.)

Incidence Rates of Valve Thrombosis and Major and Total Embolisms With Coumadin Therapy: Effect of Valve Position Incidence Rates per 100 Patient-Years (95% Confidence Intervals) Valve Position Valve Thrombosis Major Embolism Total Embolism* Aortic 0.1 (0.1-0.2) 0.8 (0.7-0.9) 1.1 (1.0-1.3) Mitral 0.5 (0.3-0.7) 1.3 (1.1-1.5) 2.7 (2.3-3.0) Both 0.4 (0.2-0.7) 1.4 (1.0-1.9) 2.1 (1.6-2.7) (Circulation. 1994;89:635-641.)

Types of prosthetic valves and thrombogenicity Type of valve Model Thrombogenicity Mechanical Caged ball Starr­Edwards + + + + Single tilting disc Bjork­Shiley, Medtronic Hall + + + Bileaflet St Jude Medical, Sorin Bicarbon, Carbomedics + + Bioprosthetic Heterografts Carpentier­Edwards, Tissue Med (Aspire), Hancock II + to + + Homografts +

Mitral heart valve prostheses carry a risk of embolism that is almost twice as high as aortic valve prostheses Cannegieter SC, Rosendaal FR, Briet E (1994) Thromboembolic and bleeding complications in patients with mechanical heart valve prostheses. Circulation 89 :635–641

Zellner et al “Long term experience With the St Zellner et al “Long term experience With the St.Jude Medical Valve Prosthesis” South Carolina,USA AVR 418 pts, mean age 54.8yrs Re-operation inc. 1.0%/pt/y

Hemodynamic advantages

Gradient Comparison of mean pressure gradients for     commonly implanted prosthetic valves.

EOA Comparison of EOAs for commonly implanted     prosthetic valves.

Patient prosthesis mismatch

There are trends in the United States and Europe toward the increasing use of tissue rather than mechanical valves and toward the use of bioprostheses in progressively younger patients Dagenais F, Cartier P, Voisine P, Desaulniers D, Perron J, Maillot R, Raymond G, Métras J, Doyle D, Mathieu P. Which biologic valve should we select for the 45- to 65-year-old age group requiring aortic valve replacement? J Thorac Cardiovasc Surg. 2005;129:1041–1049.

Reasons for increasing use of Bioprosthesis Newer generation bioprosthesis are more durable and better. Reoperation rates for patients over 65 years of age are particularly low with modern stented bioprostheses The risks of reoperation have continued to decrease Patients undergoing AVR today are older population than those studied in the randomized trials. Young patients undergoing aortic valve surgery are often reluctant to accept warfarin therapy and the activity constraints associated with anticoagulants. There are some nonrandomized but relatively large comparative trials that have shown apparent survival benefit for patients receiving bioprostheses, particularly for those over the age of 65 years .

Why bioprosthesis Better fixation technique Better anticalcification technique Better long term result in newer generation valve Better surgical technique , redo less dangerous

Durability

Two historic randomized clinical trials compared outcomes after valve replacement with a first-generation porcine heterograft and the original Bjork-Shiley tilting-disc mechanical valve: The Edinburgh Heart Valve Trial, conducted between 1975 and 1979 with an average follow-up of 12 years, The Veteran Affairs (VA) Cooperative Study on Valvular Heart Disease, conducted between 1979 and 1982 with an average follow-up of 15 years.

The Edinburgh trial both trials showed a small survival advantage associated with a mechanical valve in the aortic but not in the mitral position; both trials showed increased bleeding associated with mechanical valves increased reoperation with tissue valves; structural failure of tissue valves and overall thromboembolic complications were greater after mitral than after aortic valve replacement.

A meta-analysis of 32 articles evaluated mortality from 15 mechanical and 23 biological valve series including 17,439 patients and 101, 819 patient-years of follow-up. no difference in riskcorrected mortality between mechanical and bioprosthetic aortic valves regardless of patient age choice between a tissue and mechanical valve should not be based on age alone. Lund O, Bland M. Risk-corrected impact of mechanical versus bioprosthetic valves on long-term mortality after aortic valve replacement. J Thorac Cardiovasc Surg. 2006;132:20 –26.

Retrospective study comparing mechanical and tissue aortic valve replacement in 3062 patients with combined follow-up of 22 182 patientyears age but not valve type was predictive of valve-related mortality. reoperation was higher after tissue aortic valve replacement only for patients ≤60 years of age, combined valverelated morbidity was higher after mechanical valve replacement for all patients 40 years of age. Chan V, Jamieson WRE, Germann E, Chan F, Miyagishima RT, Burr LH, Janusz MT, Ling H, Fradet GJ. Performance of bioprostheses and mechanical prostheses assessed by composite of valve-related complications to 15 years after aortic valve replacement. J Thorac Cardiovasc Surg. 2006;131:1267–1273.

Advances in tissue fixation and anticalcification treatment have resulted in current-generation bioprostheses that have superior durability

Freedom from structural valve deterioration Carpentier-Edwards pericardial aortic valve (age 65) 94% at 10 years 77% at 15 years 10% chance that a 65-year-old patient would require reoperation before 80 years of age. Third-generation bioprostheses may be even more durable, with 92.8% at 12 years (mean age of 54 years) In addition, advances in myocardial protection and cardiac surgical techniques have led to lower risks at reoperation, making the prospect of redo valve surgery less dangerous. Banbury MK, Cosgrove DM III, White JA, Blackstone EH, Frater RWM, Okies JE. Age and valve size effect on the long-term durability of the Carpentier-Edwards aortic pericardial bioprosthesis. Ann Thorac Surg. 2001;72:753–757. Bach DS, Metras J, Doty JR, Yun KL, Dumesnil JG, Kon ND. Freedom from structural valve deterioration among patients 60 years of age and younger undergoing Freestyle aortic valve replacement. J Heart Valve Dis. In press.

Freedom from structural valve deterioration after 15 years 2nd generation Hancock II aortic valve 81.5% ( age 65 years) 1st generation Hancock bioprosthesis. 57.4% (age 69 years ) David TE, Ivanov J, Armstrong S, Feindel CM, Cohen G. Late results of heart valve replacement with the Hancock II bioprosthesis. J Thorac Cardiovasc Surg. 2001;121: 268–278. Cohn LH, Collins JJ Jr, Rizzo RJ, Adams DH, Couper GS, Aranki SF. Twenty-year follow-up of the Hancock modified orifice porcine aortic valve. Ann Thorac Surg. 1998; 66(suppl):S30 –S34.

Hancock Valve Durability Data

ACC/AHA VHD Guidelines: 2008

ACC/AHA VHD Guidelines: 2008

M. O’Brien et al “The Homograft Aortic Valve:29 yrs” J. Heart V M.O’Brien et al “The Homograft Aortic Valve:29 yrs” J. Heart V. Dis 2001;10:334-345 1,022 patients mean age 47yrs: Actuarial Survival

Aortic Homograft Durability vs Age: Freedom from Re-op O’Brien et al,2001 Aortic Homograft Durability vs Age: Freedom from Re-op

Reasons for tissue valve Expected life expectancy < 10-12 yrs Anticoagulation contraindicated. Patient cannot or will not take anticoagulant. Patient at increased risk for bleeding with anticoagulation. INR difficult to control Poor compliance Difficult follow up

The main indication for re-operation of mitral valve prostheses Structural deterioration of (tissue) valves, Endocarditis, Para- valvular defects, Valve thrombosis, Pannus formation Residual or recurrent tricuspid incompetence. Progressive coronary artery disease

Risk factors for early mortality after reoperation Emergency operation for thrombosis of a prosthesis, Acute endocarditis, Acute valvular dehiscence with clinical deterioration, and surgical problems. Older age and NYHA class also play a major role

Reoperation Single mitral valve re-replacement elective normal left and right ventricular function risk 1.5 % . The peri-operative mortality with emergency operation up to 40%, double valve replacement to 22%, with poorer NYHA class, (from 2.2% to 15.5%), concomitant procedures to 16 %

50-year-old man with no comorbidities undergoing aortic valve replacement

Mechanical aortic valve replacement Anticipated, operative mortality is 1.5% EuroSCORE regardless of the prosthesis implanted. After mechanical valve replacement, 0.3%/y chance of reoperation,yielding a 9% risk of reoperation if the man lives to be 80 years of age. chance of death at reoperation is 24%,assuming that reoperation is done on an emergency basis at 65 years of age, yielding a 2.1% chance of death at reoperation. Valve-related mortality is 0.5%/y for a patient 51 to 60 years of age 1.1%/y in patients 61 years of age, yielding a cumulative risk of valverelated mortality of 27% over 30 years: (10 0.5%)(20 1.1%). Valve-related morbidity 2.2%/y for a patient 51 to 60 years of age, 2.7%/y for a patient 61 to 70 years of age, 2.9%/y for a patient 71 years of age, yielding a cumulative risk of valve-related morbidity of 78% over 30 years, (10 2.2%)(10 2.7%) (10 2.9%), Cumulative 108.6% risk of valve-related morbidity or mortality (30.6% mortality78% morbidity) over 30 years. Chan V, Jamieson WRE, Germann E, Chan F, Miyagishima RT, Burr LH, Janusz MT, Ling H, Fradet GJ. Performance of bioprostheses and mechanical prostheses assessed by composite of valve-related complications to 15 years after aortic valve replacement. J Thorac Cardiovasc Surg. 2006;131: 1267–1273. Roques F, Michel P, Gladstone AR, Nashef SAM. The logistic EuroSCORE. Eur Heart J. 2003;24:1–2.

Bioprosthesis valve replacement At least 1 anticipated reoperation before 80 years of age. If reoperation occurs at 65 years of age (15 years after initial surgery), operative risk is 5.8%,assuming that surgery is done electively. The anticipated risk of valve-related mortality after bioprosthetic valve replacement is 0.6%/y for a patient 51 to 60 years of age, 1.0%/y for a patient 61 to 70 years of age, 1.3%/y for a patient 71 years of age, yielding a cumulative risk of valve-related mortality of 29% over 30 years: (10 0.6%)(10 1.0%)(10 1.3%), similar to that after mechanical valve replacement. Valve-related morbidity 0.3%/y for a patient 51 to 60 years of age, 0.4%/y for a patient 61 to 70 years of age, 0.5%/y for a patient age 71 years of age, yielding a cumulative risk of valve-related morbidity of 12% over 30 years—(10 0.3%)(10 0.4%) (10 0.5%) Cumulative 48.3% risk of valve-related morbidity or mortality— 36.3% mortality12% morbidity— over 30 years. Even if the patient required a second reoperation, the cumulative risk increases by only 10.8% (calculated at 75 years of age). Chan V, Jamieson WRE, Germann E, Chan F, Miyagishima RT, Burr LH, Janusz MT, Ling H, Fradet GJ. Performance of bioprostheses and mechanical prostheses assessed by composite of valve-related complications to 15 years after aortic valve replacement. J Thorac Cardiovasc Surg. 2006;131: 1267–1273.

Projected Future Risks After Aortic Valve Replacement in a 50-Year-Old Man, Assuming 30-Year Survival Mechanical Valve Bioprosthetic Valve Replacement, % Replacement, % Operative mortality 1.5 1.5 Death at reoperation (risk of reoperationrisk of 2.1 5.8 death at reoperation) (10.8 for second reoperation) Valve-related mortality (cumulative for 30 y) 27 29 Valve-related morbidity (cumulative for 30 y) 78 12 Total risk of morbidity and 108.6 48.3 mortality over 30 y (59.1 if 2 reoperations)

Life expectancy >30 yr Durable valve repair possible Yes No Physician assessment Life expectancy <15 yr co morbidity Life expectancy >30 yr No co morbidity Life expectancy 15-30 yr No co morbidity Accept risk of reoperation No coagulation Minimal life style change No reoperation Will take anticoagulation Accept life style change Patient preference Valve repair Mechanical valve Tissue valve

If the patient’s characteristics do not sway the balance in favor of any particular valve substitute, The surgeon should use the valve most familiar to him. “No one should test the depth of a river with both feet.” Lawrence Bonchek, M.D