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Acquired Cardiac Disease Lucas Henn. Adult Cardiac Surgery: Ischemic Heart Disease (History). William Heberden- 1768- described angina pectoris. Claude Beck 1930’s - sought to increase myocardial blood flow indirectly with pericardial fat and omentum. Arthur Vineberg
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Adult Cardiac Surgery: Ischemic Heart Disease (History) • William Heberden- 1768- described angina pectoris. • Claude Beck • 1930’s- sought to increase myocardial blood flow indirectly with pericardial fat and omentum. • Arthur Vineberg • 1940’s- Mobilization of left internal mammary artery with implantation of bleeding end into the left ventricle. • 1964- follow-up study on 140 patients 33% mortality 85% relief from angina
Adult Cardiac Surgery: Ischemic Heart Disease (History) • F. Mason Sones, Jr., 1950’s- cine coronary arteriography. 1962- direct and reproducible catheterization of the coronary arteries. “Collectively, all of the cardiological advances in this century pale in comparison with this priceless achievement.” Floyd Loop, MD
New York Heart Association • Heart Failure Classes: 1: No functional limitation 2: Slight limitation of physical activity 3: Marked limitation 4: Inability to carry on any physical activity
Diagnostic Studies • EKG/Radiography: standard, rhythm disturbances/changes in heart size • Echo: valvular abnormalities, EF. Diastolic dysfunction • Radionuclide: Thalium- perfusion abnormalities • Cardiac Cath: gold standard- can be diagnostic and therapeutic
Adult Cardiac Surgery: Ischemic Heart Disease (CABG) • Early and widespread acceptance of coronary bypass was delayed. • Best known cooperative studies (1970-80’s) were the; VA CoronaryArterySurgeryStudy European Coronary Surgery Study
Adult Cardiac Surgery: VA Trial • Between 1970-74. Thirteen centers. • 686 patients. Stable angina • Randomized to surgical therapy (RSVG) vs. medical (nitrates, β-blockers). • Findings; • Left main disease (>50%)- CABG, survival (93% vs. 58% at 4 years). • Multi-vessel disease- no survival benefit up to 11 years. • 3V disease and LVF ( 50%)- 76% vs. 52% at 7 years, 50% vs. 37% at 11 years.
Adult Cardiac Surgery: CASS Trial • 1974-79. Multicenter, North America. • 780 patients randomized. • Exclusions; prior CABG, unstable angina, CHF. • Stratification into 3 groups; • angina and EF 50%. • angina and EF between 35-50%. • no angina after MI. • Specifically directed towards patients with less severe angina or if asymptomatic after MI. • Evaluated most appropriate initial therapy for minimally symptomatic patients.
Adult Cardiac Surgery: CASS Trial • No difference in survival at 5 years (95% vs. 92%). • Patients with ↓EF, survival better with surgery (84% vs. 70% at 7 years (and at 10 years). • Patients with 3V disease and ↓EF, survival better with surgery (88% vs. 65%) at 7 years (and at 10 years). • Patients excluded with 3V disease and Class III or IV angina, survival better with surgery (92% vs. 74%).
Adult Cardiac Surgery: ECSS Trial • 1973-6. Multicenter, randomized trial. • 767 patients under 65 years of age, with stable angina, at least 2V disease and EF 50%. • CABG improved overall survival, especially in patients with 3V disease (92% vs. 84%) at 5 years and at 12 years (71% vs. 67%) • No significant difference in patients with 2V disease unless involved proximal LAD. • Overall five and twelve year survival rates of 91% and 71% in the surgical group. • Angina significantly decreased in surgical group.
Adult Cardiac Surgery: Clinical Trials • Only VA had patients over 65. • No patients with unstable angina. • Only CASS included women (10%). • Internal mammary artery not used. • Patients with severe LV dysfunction were excluded. • Angiographic definition of CAD was 50% reduction in VA and ECSS and 70% in CASS.
Adult Cardiac Surgery: Clinical Trials • VA- 75% stenosis of LM do better with surgery. • ECSS- severity of symptoms correlated with more favorable prognosis if surgery performed. • CASS- less symptomatic patients showed benefit from surgery if LVF was depressed. • CABG has not been shown to improve survival in patients with 1V disease. • CABG does not protect against future MI.
Adult Cardiac Surgery: CABG Techniques • Median sternotomy • Cardiopulmonary bypass • Cardioplegic arrest • Mammary artery, reversed saphenous vein, radial artery • Minimally access incisions (Port Access) • “Off-pump”
Conduit Patency • SVG: 5 year = 80%, 15 year = 30-40% • LIMA: 10 year = 90-95% Other potential conduits -Radials -RIMA
Ventricular Aneurysm • Occurs in 10-15% of patients following MI (4-8 weeks later) • Patients present with dyspnea or angina- also can have arrhythmias • Surgical Goal is restore normal ventricular architecture with excision and patching
Adult Cardiac Surgery: Valvular Heart Disease • Aortic stenosis- • Age-related degenerative • Mild AS: AVA > 1.5cm2 ; Moderate 1-1.5cm2 ; Severe <1cm2 • Indications for surgery largely based on symptoms • Syncope, angina, dyspnea and CHF • Aortic regurgitation- • Calcific aortic disease, idiopathic degenerative disease, endocarditis, rheumatic disease, bicuspid valve, aortic dissection, Marfan, etc. • Indications for surgery • Acute AR- inadequate time for ventricular compensation • Chronic AR- symptoms, decreasing EF, LVEDD >75mm, LVESD >55mm
Adult Cardiac Surgery: Valve Prostheses • Mechanical Valves • Caged-ball valves • Tilting disc valves • single leaflet • bileaflet • Tissue Valves • Animal tissue (porcine aortic valves, bovine pericardium) • Human tissue (Homografts, Autografts)
Adult Cardiac Surgery: Aortic Valve Replacement • Median sternotomy, hemi-sternotomy • Cardiopulmonary bypass • Cardioplegic arrest • Excision of the valve • Debridement • Implantation
Adult Cardiac Surgery : Valvular Heart Disease • Mitral Regurgitation- • Myxomatous degeneration, ischemic, rheumatic valve disease, endocarditis, chordal rupture, dilated cardiomyopathy, etc. • Surgical indications • Symptomatic with 3+ to 4+ MR, asymptomatic with 3+ to 4+ MR and a decrease in EF, LV dilatation, new onset of atrial fibrillation • Mitral Stenosis- • Rheumatic heart disease, annular/leaflet calcification, congenital deformities, endocarditis, etc. • Surgical indications • MVA ≤ 1.0cm2
Adult Cardiac Surgery : Mitral Valve Surgery • Repair more commonly performed than replacement. • Replacement necessary in some cases • Rheumatic heart disease, endocarditis, complications of MI, etc. • Median sternotomy • Minimal access incisions • Cardiopulmonary bypass • Cardioplegic arrest
Adult Cardiac Surgery: ACC/AHA Task Force: 1998 • All patients with mechanical valves require warfarin therapy. Even with warfarin, risk of thromboembolism (TE) is 1-2%/yr. • Risk of TE in patients with biological valves in NSR is 0.7%/yr. • Risk of TE is greater with a valve in the mitral (mechanical or biological) than aortic position.
Adult Cardiac Surgery: ACC/AHA Task Force: 1998 • Aortic position • Bileaflet- INR of 2-3 • Other disk valves and Starr-Edwards- INR 2.5-3.5 • In patients with higher risk of TE, INR 2.5-3.5 with addition of aspirin 80-100mg/d. (AF, ↓EF, prior TE, hypercoagulable state) • Mitral position • All- INR 2.5-3.5
Adult Cardiac Surgery: ACC/AHA Task Force: 1998 • Tissue prosthesis- • Anticoagulation recommended in first 3 months, although aspirin alone in aortic position in some centers. INR 2.5-3.5 • After 3 months, discontinue unless other circumstances