Surgical Management of Valvular Heart Disease

1. Surgical Management of Valvular Heart Disease Current Treatment and Future Trends Anthony J. Palazzo, M.D.F.A.C.S.

2. Objectives • Brief discussion of most common pathologic valvular disease involving aortic and mitral valves • Focus on aortic stenosis and mitral regurgitation • Indications for surgical intervention • Best choice of prosthetic device • Current and future trends

3. Aortic Stenosis • Etiology • Degenerative (Calcification) • Bicuspid • Rheumatic

4. Aortic Stenosis - Classification Normal Aortic Valve Area 2-4 cm²

5. Aortic Stenosis-Pathophysiology • Increased transvalvular gradient • Increased left ventricular afterload • Leads to development of LVH

6. Aortic Stenosis-Natural History • Multiple echocardiographic studies have demonstrated that the average rate of decrease in aortic valve area is approximately 0.12 cm² per year • Ross and Braunwald study (1968)- landmark paper revealing natural history as it relates to symptoms • average survival with angina/syncope 3 yrs • average survival with dyspnea 2 yrs • average survival with CHF 1.5 yrs

7. Aortic Stenosis-Natural History • Loma Lima study • Retrospective review of 453 patients with documented severe aortic stenosis on ECHO • Treated non-surgically • Survival at 1, 5, and 10 years was 62%, 32% and 18% • Demonstrated grave prognosis of patients with severe aortic stenosis • AnnThorSurg, 2006

8. Aortic Stenosis-Indications for Surgery • Patients with symptoms • Asymptomatic patients with evidence of diminished left ventricular function (EF < 50%) • Asymptomatic patients with normal ventricular function should be followed closely with serial echocardiography every 6 months due to known history of progression of 0.1-0.12 cm² and risk of death of 1-3% per year

9. Aortic Stenosis-Salient Points • Once diagnosis is suspected echocardiogram is single best non-invasive diagnostic test to determine aortic valve morphology, gradient and jet velocity • Symptomatic patients should be referred for surgical evaluation • Asymptomatic patients need to be followed closely for natural progression of disease • Asymptomatic patients with diminished left ventricular function should be referred for surgery

10. Aortic Regurgitation-Etiology • Calcific degeneration (mixed lesion with stenosis) • Bicuspid aortic valve • Connective tissue disease (Marfan’s) • Aortic aneursym • Aortic dissection • Endocarditis

11. Aortic Regurgitation-Pathophysiology • Increased left ventricular overload • Left ventricular dilatation • Diminishing left ventricular function

12. Aortic Regurgitation-Indications for Surgery • Symptomatic patients with severe aortic regurgitation patients with angina have >10% mortality/year >20% mortality/year with CHF • Endocarditis with hemodynamic decompensation • Asymptomatic patients •surgery for patients with EF <50% •surgery for patients with evidence of left ventricular distension (end-diastolic dimension > 75 mm and end-systolic dimension > 55 m)

13. Mitral Stenosis • Normal mitral valve area 4-6 cm² • Rheumatic heart disease most common cause • prevalence decreased significantly • Thickening and calcification of leaflets • Thickening of subvalvular structures (chords) • May have mixed lesions-MS/MR • Stenosis tends to progress slowly

14. Mitral Stenosis-Classification Normal mitral valve area = 4-6 cm²

15. Mitral Stenosis-Indications for Surgery • Patients with severe mitral stenosis with class NYHA class III and IV symptoms who are not candidates for percutaneous balloon mitral valvulotomy (patients with mixed lesions or heavy calcification) • Asymptomatic patients with severe MS and severe pulmonary hypertension (PAP > 60 mm Hg) • No therapy recommended in asymptomatic patients without evidence of severe pulmonary hypertension

16. Mitral Regurgitation-Etiology • Degenerative “myxomatous” isolated leaflet prolapse Barlow’s disease • Ischemic acute- ruptured papillary muscle/chord 2° AMI chronic- chronic myocardial ischemia • Endocarditis

17. Mitral Regurgitation-Etiology • Isolated “P-2” segmental prolapse

18. Mitral Regurgitation-Etiology Barlow’s disease

19. Ischemic Mitral Regurgitation Chronic ischemic mitral regurgitation annular dilatation papillary muscle retraction

20. Mitral Regurgitation-Diagnosis • ECHO most informative non-invasive diagnostic test • Assess leaflet morphology • Chordal rupture • Leaflet prolapse • Regurgitant jets • Ejection fraction

21. Mitral Regurgitation-Indications for Surgery (Class I indications) • Symptomatic acute mitral regurgitation ruptured chord ruptured papillary muscle • Symptomatic patients with chronic severe MR as long as EF > 30% • Acute endocarditis with hemodynamic compromise, persistent sepsis, annular abscess, recurrent emboli • Asymptomatic patients with severe MR and EF 30-60%

22. Mitral Regurgitation-Class IIa and IIb Indications • Patients with severe MR with class III-IV symptoms and EF < 30% and/or end-systolic dimension > 55 mm and if a repair is highly likely • There are 2 class IIb indications with asymptomatic patients with severe MR with EF > 60% who develop new onset atrial fibrillation and/or pulmonary hypertension (PAP > 50 mm Hg)

23. Mitral Regurgitation-Asymptomatic • Asymptomatic patients with severe MR should be followed closely with ECHO every 6 months • If there is evidence of left ventricular dysfunction with a decreased EF < 60 %, patients should be referred for surgery • Preoperative EF important predictor of long term survival after mitral valve surgery

24. Effect of preoperative EF • Long term postoperative prognosis is related to preoperative EF Circulation, 1995

25. Mitral Regurgitation-Salient Points • In asymptomatic patients with severe mitral regurgitation ventricular function should be followed closely • If EF decreases to < 60% or left ventricular end systolic diameter dimension exceeds 40 mm patient should be referred for surgery • Mitral valve repair is the ideal procedure

26. Prosthetic Valves • No “perfect” prosthetic valve • Bioprosthetic valves versus mechanical

27. Prosthetic Valves porcine bovine pericardial mechanical

28. Prosthetic Valves-Selection • Generally, if patient is > 65 a tissue valve is recommended • Due improvements in the manufacturing process tissue valves have increased durability demineralization to prevent calcification “zero pressure” tissue fixation • General trend to place tissue valves in younger patients • Ultimate decision is patient’s

29. Prosthetic Valve Selection • Some tissue valves have demonstrated 85% 15 year structural free deterioration • Some evidence to suggest antiplatelet therapy may be sufficient anticoagulation in select patients with mechanical AVR (not a guideline) select cohort normal LV function normal sinus rhythym bileaflet mechanical valve ongoing clinical trails to determine efficiacy

30. Early Anticoagulation in bioprosthetic valves • Historically “early” anticoagulation recommended in immediate postoperative period for tissue valves is warfarin for 3 months (AHA/ACC guidelines) • Expanding clinical evidence to support use of antiplatelet therapy alone after aortic tissue valve placement in early postoperative period unless there is some other indication for warfarin¹΄² JTCS,2005 JTCS,2010

31. Percutaneous Therapy • TAVI (transcatheter aortic valve implantation) • Reserved for patients with severe aortic stenosis who are not surgical candidates for open procedure • Recently FDA approved • Likely will be regulated • Should involve societal (STS) oversights and database • Should be collaborative, multidisciplinary approach

32. Percutaneous Aortic Valve • ? Long term durability • Aortic insufficiency • equivalent 1 year survival¹ • compared to open surgery • in some studies 1. NEJM, 2010