Coronary Artery Disease

Coronary Artery Disease
1. Definition
A. a narrowing of one or more coronary arteries from atherosclerotic disease which limits myocardial blood flow. Increasing degrees of stenosis first limit reserve flow, then reduce flow at rest, and finally may totally occlude the vessel.
2. Morphology
A. The normal coronary artery layers
1) Endothelium
2) Intima
3) Internal elastic lamina
4) Media
5) External elastic lamina
6) Adventitia
B. Lesions of atherosclerosis
1) Fatty streak begins in childhood
2) Lipid laden macrophages and T-lymphocytes with smooth muscle cells cause focal intimal thickening
3) More smooth muscle cells and connective tissue form in the intima
4) Eccentric fibrous plaque develops, which is white and elevated
5) Lipid deposition in cells and connective tissue
6) A luminal fibrous cap forms
7) Zone of necrotic tissue beneath the cellular area
3. Pathophysiology
A. Rupture and thrombosis of a plaque is the probable cause of most unstable angina and acute myocardial infarction
B. Acute ischemia commonly develops in vessels with less than 50% stenosis
C. More severe stenoses also occlude, but may not have acute ischemia due to protective collaterals
D. Hemorrhage may occur suddenly within a plaque
E. Platelet aggregation, vessel stenosis, and coronary spasm all play a role in acute narrowing/occlusion
F. Plaque regression occasionally occurs
G. Development of collaterals important in restoring regional perfusion
4. Vascular Anatomy
A. CAD usually involves proximal portions of the 3 major arteries, particularly at branch points
B. The LAD and RCA are more often involved than the CX
C. 40% of patients studied for symptoms will have significant stenoses in all 3 vessels
D. 95% of patients with 1 completely occluded artery will have a significant stenosis in at least one other artery
E. 10-20% of patients with significant disease will have L main involvement
F. Diffuse distal disease unsuitable for CAB is uncommon
5. Diagnosis
A. Coronary angiography
1) Severity of lesions and size of distal vessels may be underestimated
2) 75% reduction in cross-section = 50% diameter reduction (moderate)
3) 90% reduction in cross-section = 67% diameter reduction (severe)
4) Ejection fraction should be considered with heart size, as the heart size can be normal even in severe LV dysfunction
B. Tests of LV function
1) Resting LV function depends on the amount of myocardium devoid of scar
2) Exercise LV function reflects loss of coronary flow reserve, and is typically depressed when compared to resting function
3) Global LV function usually visually estimated on angiography as ejection fraction
4) Can also be evaluated by CASS score, which is the sum of five segmental scores
5) Segmental LV wall function assessed by local wall motion or thickening during cardiac cycle
6. Natural History
A. Progression of Stenoses
1) Rate of progression is highly variable
2) Young age, hyperlipidemia, and presence of PVD denote more rapid progression of coronary stenoses
3) 50% of patients will develop new significant lesions within 2 years
B. Progression of LV Dysfunction
1) As areas of ischemia become more extensive, global LV systolic function will fall during exercise testing
2) LVEDV will increase from the decreased systolic function
3) LV diastolic function also falls from impaired myocardial relaxation during early diastole
4) All factors ultimately result in increased LVEDP
5) LV dysfunction at rest is usually from myocardial scarring
6) Myocardial stunning or hibernation can cause resting LV dysfunction as well
7. Unfavorable Outcomes
A. Stable angina
1) Chest pain on exertion is a common event with progression of coronary stenoses
2) Graded exercise testing helps quantify the degree of reduction in flow reserve
3) Angina typically becomes more severe with time, although some patients do not progress
B. Unstable angina
1) Definitions:
a) Severe and persisting angina with EKG evidence of ischemia and minor CK-MB changes
b) Severe class IV angina within 2 months of onset
c) Severe angina lasting more than 15 minutes occuring within 10 days of presentation
d) Severe angina within 2 weeks of acute myocardial infarction
2) Plaque fissure and/or rupture is the probable cause of unstable angina
3) These patients have increased tendency to develop myocardial infarction
C. Acute myocardial infarction
1) Severe proximal LAD disease is prone to cause acute MI
2) 30% of patients studied will have an acute MI within 5 years
3) Probability of acute MI is increased by number of previous MIs and number of vessels involved
4) Thrombolytics have reduced current hospital mortality to less than 10%
5) Death usually the result of acute cardiac failure or sudden ventricular arrhythmia
D. Death
1) The majority of patients with CAD ultimately die from cardiac causes
2) Most common cause is acute or subacute cardiac failure
3) 20% of patients have sudden death
4) 10-year survival is about 60%
8. Risk Factors
A. Severity of reduction of regional coronary flow reserve
B. Number of myocardial regions with reduced flow reserve
C. Nature of plaque and internal thrombolytic/fibrinolytic state
D. Amount and distribution of scar
E. Hemodynamic instability
F. Ischemic instability
G. Ventricular electrical instability
H. Older age
I. Diabetes
J. Hypertension
K. Hyperlipidemia
L. COPD
M. Chronic renal disease
N. Smoking
O. Previous CVA
Number of vessels with stenoses 5-year survival
1 (any) 90-95%
1 (RCA) 96%
1 (LAD) 92%
1 (prox LAD) 90%
2 88%
3 70%
Left main 40-60%

















































































Myocardial Infarction
1. Acute Myocardial Infarction
A. Obstruction–> Thrombosis–> Occlusion
B. Ischemic injury prolonged–> Irreversible injury
2. Location and Size
A. Location and severity of obstruction
B. Size of vascular bed
C. O2 needs of myocardium
D. Collateral development
E. Coronary artery spasm
F. Tissue factors
G. Thrombotic and thrombolytic substances
3. Types of Infarction
A. Transmural
1) Acute coronary thrombosis
2) Localized zone of distribution
B. Subendothelial (non-transmural)
1) Coronaries narrowed but patent
2) Thrombotic occlusion–> thrombolysis
3) Increased oxygen demand and/or decreased oxygen delivery
4) Pulmonary embolism
5) Hypotension
6) Hypertension
7) Aortic stenosis
8) Anemia
9) Operative procedures
10) Cerebrovascular accident
4. Sites of Involvement
A. Most involve LV and interventricular septum
B. Up to 65% or IMI involve RV
C. Isolated RV in 3-5%
1) COPD
2) RVH
5. Pathology
Gross Changes
Time Changes
< 6 hours No change > 6 hours Pale, bluish, edematous
18-36 hours Tan, reddish purple
>48 hours Gray, yellow lines at periphery
8-10 days decreased wall thickness, coagulation necrosis
2-3 months Thin, form scar
6. Coronary Artery Thrombosis
A. Coronary atherosclerosis
B. Vasospasm
C. Plaque rupture
D. Platelet actuation
7. Coronary Atherosclerosis
A. Acute occlusion =Rapidity of development/Collateral circulation
1) Transmural
2) Subendocardial
3) None
B. Vasospasm
1) Increased Thromboxane A2
C. Plaque rupture
1) Ulceration
2) Fissure formation
D. Platelet activation
1) Adhesion–> aggregates–> increase Thromboxane A2
2) Decreased Fibrinolytic activity
3) Decreased tissue plasminogen activator
8. Collateral Circulation
A. Coronary occlusive disease
B. Chronic hypoxia
1) COPD
2) Anemia
3) Cyanotic CHF
C. LVH
9. Pathophysiology
A. Systolic Function
B. Infarcted area
1) Dyssynchrony
2) Hypokinesis
3) Akenisis
4) Dyskinesis
C. Non-infarcted areas
1) Hyperkinesis
D. Manifestations
1) Decreased diastolic compliance
2) Decreased ejection fraction (>15%)
3) CHF (>25)
4) Cardiogenic shock (>40%)
10. Infarct Size Limitation
A. O2 supply (coronary perfusion pressure)
B. O2 demand (ventricular wall tension)
C. Oxygen Supply and Demand
11. Complications
A. Hypotension
B. Arrhythmias
C. Congestive heart failure
D. Hypoxemia
E. Anemia
F. Infections
G. Hypertension
H. Cardiogenic shock
1) Pharmacologic
2) Mechanical
3) Surgical– VSD, MR, Ventricular rupture
12. Reperfusion of infarction
A. Increased systolic function
B. Increased diastolic function
C. Decreased mortality
13. Treatment
A. Coronary thrombolysis
B. Angioplasty
C. Coronary Atery Bypass
14. Coronary Thrombolysis
A. Agents
1) Streptokinase
2) Plasminogen streptokinase activation complex (APSAC)
3) Tissue-type plasminogen activator (tPA)
B. Indications
1) Impending or evolving MI
2) 3 hours of symptom onset
3) Heparin (bolus ==>infusion)
4) ASA
Duration of Coronary Occlusion
Time from Onset of Sypmtoms
15. Contraindications
A. Recent trauma
B. Major surgery (6 weeks)
C. GI bleeding (3 months)
D. Bleeding diathesis
E. Chronic liver disease
F. Allergy to thrombolytics
G. Stroke with residual
H. TIA (6 months)
I. Cerebral hemorrhage
J. Pregnancy
16. Angioplasty
A. Indications
1) Thrombolytic contraindicated
2) Thrombolytic unsuccessful
3) Extensive ischemia
17. Summary
A. Atherosclerotic coronary artery disease
1) Stenosis
2) Thrombosis
3) Vasoconstriction
4) Plaque disruption
B. Segmental disease
C. Endocardium–> epicardium
D. Irreversible injury >15-20 minutes occlusion
1) Maximal damage 4-6 hours
2) Best salvage 1-2
E. Size depends on collateral
1) Morbidity and mortality
2) O2 supply/O2demand
F. RV infarct with inferior MI














































































Coronary Artery Bypass
1. Indications
A. Stable angina
1) Survival depends on all patient-specific risk factors, not just angina
2) Class I/II if there is significant 3-vessel disease and some LV dysfunction
3) Class I/II if there is significant 3-vessel disease, good LV function, and one or more important proximal stenoses
4) Class III/IV if there is significant 3-vessel disease and sometimes 2-vessel disease, regardless of LV function
5) Left main stenosis at least 50%, even if asymptomatic
6) 2-vessel disease with severe proximal LAD stenosis or some LV dysfunction
7) Rarely indicated for single vessel disease
B. Unstable Angina
1) Stabilize initially with medical therapy
2) Same indications as for stable angina, but more urgent
3) Strongest indications are 3-vessel disease, LV dysfunction, and angina at rest
C. Other Situations
1) Angina after acute MI has same indications; delay CAB for at least 1 week
2) Emergent CAB for hemodynamic instability during acute MI can salvage over 50% of such patients
3) Emergent CAB indicated if PTCA results in hemodynamic instability
2. Operative Technique
A. General strategy
1) Goal is complete revascularization by bypassing all vessels with at least 50% stenosis
2) Patency enhanced by grafting to larger vessels with good runoff
B. Vein graft preparation
1) Avoid overdistension and spasm of the vein
2) Multiple large varices render the vein unsuitable for grafting
3) The vein should be untwisted, marked, and reversed for grafting
C. IMA preparation
1) Begin dissection at 6th intercostal space
2) Either a pedicle or skeletonized artery may be used
3) Distal end not divided until just prior to anastomosis
4) Avoid probing unless there is no bleeding from the cut end
D. Distal anastomosis
1) Incise anterior wall of coronary longitudinally 4 to 6 mm
2) Bevel vein end somewhat larger than coronary opening for most distal anastomosis
3) Incise vein longitudinally 10-20% longer than coronary opening for sequential anastomosis
4) Sutures run from inside to out on the coronary and outside to in on the vein graft
E. Proximal anastomosis
1) Lateral openings on the aorta are preferred to protect the grafts during reoperation
2) Bevel vein end somewhat larger than aortic opening
3. Reoperative CAB
A. Avoid manipulating intact grafts
B. Some recommend replacing all vein grafts older than 6 years
C. Others recommend only replacing vein grafts that are occluded or stenotic
D. Left thoracotomy with femoral CPB is useful in the setting of a functional IMA-LAD graft
4. Vascular Anatomy
A. CAD usually involves proximal portions of the 3 major arteries, particularly at branch points
B. The LAD and RCA are more often involved than the CX
C. 40% of patients studied for symptoms will have significant stenoses in all 3 vessels
D. 95% of patients with 1 completely occluded artery will have a significant stenosis in at least one other artery
E. 10-20% of patients with significant disease will have L main involvement
F. Diffuse distal disease unsuitable for CAB is uncommon
5. Results
A. Survival
1) Current hospital mortality is about 3%, most from acute cardiac failure
2) 5-year survival is 88% and 10-year survival 75%
3) IMA graft favorably affects the mid- and long-term survival (after 6 years)
4) About 25% of all deaths after CAB are unrelated to ischemic heart disease or CAB
B. Risk factors for death
1) Diminished LV function
2) Unstable angina
3) Acute hemodynamic instability after MI
4) Operation within 1 week of acute MI
5) Cardiogenic shock at time of operation
6) Older age
C. Procedural risk factors for death
1) Incomplete revascularization
2) Nonuse of IMA to LAD
3) Increased myocardial ischemic time
4) Increased CPB time
5) Earlier date of operation
D. Freedom from angina
1) About 60% of patients are free from symptoms at 10 years
2) Late recurrence is due to vein graft occlusion or progression of native coronary disease
3) Risk factors for return of angina are not as powerful as those for death
E. Freedom from MI
1) Perioperative incidence is 2-5%
2) 5-year freedom is greater than 95% after CAB
3) Survival is adversely affected by any post-CAB infarction
F. Freedom from sudden death
1) Uncommon after CAB; 97% freedom at 10 years
2) Poor preoperative LV function is the most significant risk factor for sudden death postop
3) Successful CAB does not affect the incidence of existing ventricular arrhythmias, as most of these are due to scar
G. Neurologic events
1) Up to 75% of patients may have subtle neurologic deficits in the perioperative period
2) Gross neurologic defects occur in less than 1% of younger patients but up to 5% of patients over age 70
H. Functional status
1) Maximal exercise capacity is improved, particularly when complete revascularization has been performed
2) Systolic function in hypokinetic, akinetic and even dyskinetic areas can be improved
3) A preop EF of 30% or less limits recovery of LV function after CAB
4) Exercise testing at 2 weeks postop in most patients shows a normal rise in EF, a normal increase in LVEDV, and the resolution of regional wall motion dysfunction.
6. Graft History
A. Vein grafts
1) Intimal hyperplasia is a universal finding after one month, but is not progressive
2) At 1 year, the graft diameter approximates the recipient coronary diameter
3) 10% close within the first few weeks if antiplatelet therapy is not used
4) 10-year patency is about 50-60%
5) Most grafts have evidence of atherosclerotic changes at 10 years
B. IMA grafts
1) Intimal hyperplasia also develops; the IMA is highly resistant to atherosclerosis
2) 10-year patency is about 90%
3) 5-10% develop late stenoses, but most of these do not progress to occlusion
4) Controversy exist over its use as a sequential graft and for bilateral IMA grafting
C. Other conduits
1) Long-term patency not yet conclusive on gastroepiploic, inferior mesenteric, and inferior epigastric arteries
2) The free radial artery graft is being re-evaluated for long-term patency
7. Reintervention after CAB
A. Most interventions are reoperative CAB, although PTCA used in about 25% of cases
B. 90% of patients are free from reoperative at 10 years
C. Vein graft stenosis is the most common cause for reoperation
D. IMA grafting reduces reoperations and extends time to reoperation
E. Overall risk for reoperative CAB is about twice that of first CAB
F. 10-year survival after reoperative CAB is about 65%


Randomized Studies of CAB
1. Comparisons of bypass surgery with medical therapy
Trial Cooperative Patients Randomized
VA cooperative trial (VA) 686 1972-74
European cooperative surgical study (ECSS) 768 1973-76
Coronary artery surgery study (CASS) 780 1974-79
Survival
2. Severity of angina
A. Objective evidence of ischemia
B. Instability of angina (crossover 20% 6 months, 50% 5 years)
C. Myocardial infarction
D. Severity of stenosis (L. main, 3 vessel, proximal LAD)
E. Left ventricular dysfunction
F. Age
3. Summary
A. Patients with single, double or triple vessel disease, good ventricular function (>50%) and no exercise induced ischemia have a good prognosis.
B. Improved survival is seen in patients with triple vessel disease, left main disease and reduced ejection fraction (>35%, <50%) following surgery. C. Improved surgical survival is seen in patients with any two of the following clinical risk factors: h/o hypertension, h/o myocardial infarction, resting ST- T abnormalities. 4. Comparison of bypass surgery with angioplasty A. The randomized interventional treatment of angina (RITA) - March 1993, Lancet (longest follow-up) B. The German Angioplasty Bypass Surgery Investigation (GABI) 1994 - New England Journal C. The Coronary Artery Bypass Revascularization Investigation (CABRI) August 1993 D. Argentine Randomized trial of Percutaneous Transluminal Coronary Angioplasty v/s coronary artery bypass surgery (ERACI) October 1993, JACC. 5. Rita Trial CABG PTCA Inclusion Criteria Symptomatic or asymptomatic SVD or MVD suitable for equivalent revascularization Baseline Characteristics Class 3-4 angina 59%; hx MI 43% 3VD 12% > 3Rx 38%
Patients (n) 501 510
Early outcome In-hospital In-hospital
Death 1.2% 0.8%
MI 2.4% 3.5%
Reintervention - 6.7%
Late outcome 2-2.5 years 2-2.5 years
Death 3.6% 3.1%
MI 5.2% 6.7%
CABG 0.8% 18.8%
PTCA 3.2% 18.2%
Event-free survival 89% 62%
Symptom-free 78% 69%
6. Gabi Trial
CABG PTCA
Inclusion Criteria Symptomatic MVD suitable for complete revascularization
Baseline Characteristics Class 4 angina, 19%; hx MI 50% mean LVEF 56%
Patients (n) 177 182
Early outcome In-hospital In-hospital
Death 2.2% 1.1%
MI 8.0 2.7
Reintervention NR NR
Late outcome 1 year 1 year
Death 2.8% 1.6%
MI 8.0% 3.8%
GABG 1.1% 23.0%
PTCA 4.5% 27.0%
Event-free survival 94% 58%
Symptom-free 80% 80%
7. Gabri Trial
CABG PTCA
Inclusion Criteria Symptomatic or asymptomatic MVD LVEF > 35%
Baseline Characteristics Class 3-4 angina 66%; hx MI 42% 3VD 40% > 3Rx 26%, mean LVEF 63%
Patients (n) 513 541
Early outcome 30 days 30 days
Death 0.9% 1.7%
MI 2.9% 3.1%
Reintervention 1.6% 10.1%
Late outcome 1 year 1 year
Death 2.1% 3.9%
MI 3.3% 2.9%
GABG 1.4 20.2%
PTCA 7.2% 20.1%
Event-free survival 85% 60%
Symptom-free 91% 85%
8. Eraci Trial
GABG PTCA
Inclusion Criteria Symptomatic MVD suitable for revascularization
Baseline Characteristics Class 3-4 angina LVEF > 35%
Patients (n) 64 63
Early outcome In-hospital In-hospital
Death 4.6% 1.5%
MI 6.2% 6.3%
Reintervention NR NR
Late outcome 1 year 1 year
Death 0% 3.2%
MI 0.8% 3.2%
GABG 0% 18.0%
PTCA 3.2% 14.0%
Event-free survival 83.5% 63.7%
Symptom-free 90% 65%
9. Survival (older 3v disease, + 2v disease, - 1v disease)
A. Symptom free survival
B. Incidence of myocardial infarction
C. Freedom from crossover to CABG after angioplasty (5 yrs - 25%)
D. Event free survival
10. For low risk patients with two vessel disease, angioplasty may provide modest survival benefits relative to medical therapy.
A. In single vessel disease, the primary treatment choice is between medicine and PTCA
B. Survival benefits of surgical revascularization are magnified on the absolute scale by factors that increase overall medical risk, especially left ventricular dysfunction and advanced age. These factors tend to increase procedural risks but offer proportionately greater long-term benefits than can be expected with medical treatment
11. Summary
A. The more extensive the coronary artery disease, the larger the benefit derived from surgical revascularization
B. In the most severe forms of coronary artery disease (Left main, triple vessel) bypass surgery provides the best long term survival results
C. In patients with two vessel disease, the higher the risk the more likely that patient will have improved survival with bypass surgery (eg. impaired left ventricular function, older age, co-existing vascular disease)
EXTENDED OUTLINE
Surgical Indications for Coronary Revascularization
1. Objectives of CABG
A. relieve ischemia
B. prolong survival
C. prevent MI..
D. preserve LV function
E. improve exercise tolerance
2. Assessing CABG Candidates
A. degree of symptoms
B. associated medical problems
C. evidence of reversible ischemia
D. Documentation of abnormal coronaries
E. LV function
3. Angina
A. Chronic Stable Angina defined as stable pain pattern for 4-6 weeks
B. Canadian Cardiovascular Society Classification
1) Class I. Angina: occurs with strenuous activity
2) Class II. Angina: pain with rapid walk or climbing multiple stairs
3) Class III Angina: pain with walking < 2 blocks on level ground @ a normal pace or climbing one flight of stairs 4) Class IV. : pain with minimal activity or @ rest if it last < 15 min. 5) Unstable Angina: pain @ rest that last more than 15 min. 4. Studies A. General 1) three major studies of medical vs. surgical treatment 2) use of early CABG techniques 3) no LIMA 4) no wide spread use of cardioplegia 5) no postop antiplatelet therapy B. VA Study (1970) 1) 686 patients 2) criteria a) > 50% lesion in one or more vessel
b) graftable vessels
c) acceptable LV function
3) results:
a) 36 month survival was 87% in the medical group and 88% in the surgical arm
(1) patients with a left main lesions were the only group to show a survival advantage with surgery
b) 7 year survival 70% with medical and 77% with surgical
c) beyond 7 years any survival advantage with surgery begins to disappear except in patients with three vessel disease and decreased LV function
C. European Cooperative Surgical Study (ECSS)
1) 768 men, < 65 yrs old, > 3 month hx of angina, @ least 2 vessel disease, and LV function > 50%
2) results:
a) survival @ 16 months was 93.5% in the surgical group and 84.1% in the medical group
b) survival advantage was greatest in patients with three vessel disease, left main disease , or two vessel disease with a proximal LAD lesion
3) Conclusion:
a) symptomatic stable angina with left main , three vessel, or two vessel disease including a proximal LAD lesion benefit from surgery
D. Coronary Artery Surgery Study (CASS)
1) 2099 patients, 780 truly randomized the other chose their therapy
2) set out to answer the question which was the best therapy for patients with minimal symptoms - most patients had class I and II angina
3) results:
a) survival @ 5 yrs was equal in medical and surgical groups
b) medical group had a 5%/ yr. conversion to surgery
c) increased survival @ 7 yrs for patients with decreased EF and three vessel disease
4) Conclusion:
a) mild angina with an EF between 35 - 50%, and three vessel disease had increased survival @ seven years
b) incidence of MI was the same in both groups
5. Indications for CABG
1) failure of medical therapy
2) unstable angina
3) Left main disease
4) symptomatic three vessel disease
5) post infarction angina
6) acute MI with shock
7) failed PTCA
8) reoperation for recurrent symptoms
9) congenital anomalies
10) Kawasaki's disease
A. Failure of medical therapy
1) CASS:
a) patients with three vessel disease and class III - IV angina had increased survival and decreased MI @ 5 years regardless of LV function
b) patients with one or two vessels with decreased LV function
B. Unstable Angina
1) surgery provides increased relief of symptoms, but no survival benefit compared to medical therapy
C. Left main
1) survival increased for 60% - 90% @ 4 yrs with surgery
D. 3 Vessel disease and decreased LV function
1) VA and CASS studies support
E. Post-infarction Angina
1) 5-10% incidence of MI with surgery
F. Acute MI with Shock
1) mortality > 80% in all comers
2) 30% mortality with surgery
G. Failed PTCA
1) incidence 3-4%
2) 5% mortality
3) 30-40% incidence of MI
H. Reop with recurrent symptoms
1) factors associated with decreased reop survival
a) failure to use the LIMA
b) decreased age
c) incomplete revascularization
d) smoking
2) Survival
Survival 5 Years 10 Years
first surgery 90% 75%
reop 80% 60%










































































































Non-surgical Revascularization
1. History
A. Developed by Andreas Gruentzig in 1977
B. Original series
1)169 patients
a) 133 successfully ballooned
(1)95% ten year survival with one lesion
(2)81% ten year survival with more than one lesion
b) 23% went to surgery in the ten year period
C. 1981 series
1) 427 patients
a) 88% had single vessel disease
b) 94% successfully ballooned
(1) 91% ten year survival
(2) 30% redo PTCA in ten year follow-up
(3) 23% required surgery
(4) 55% freedom from MI, death, and surgery @ ten years
2. PTCA after CABG
A. 94% success with PTCA of SVG
1) depends on location
a) distal anastamosis: good results secondary to intimal hyperplasia
(1) 24% restenosis rate
b) restenosis rate increases in mid and proximal lesions, and in vein grafts over two years old
3. Primary Angioplasty in Myocardial Infarction
A. most beneficial in older patients and in AWMI
1) AWMI mortality 1.4% with PTCA
vs. 11.9% with lytic therapy
2) Age > 65 yrs mortality 5.7% with PTCA
vs. 15% with lytic therapy
4. New Interventional Devices
A. Rotablator
B. Transluminal Extractor Atherectomy Catheter (TEC)
C. Excimer Laser
D. Stents
1) indications widening, but the text states for use
a) after a dissection secondary to PTCA,
b) acute closure after PTCA
c) reduce restenosis
2) Benestent Trial and STRESS
a) each trial had >1000 randomized patients
b) end point was luminal diameter @ 6 months
c) restenosis ( defined as 50% ) was 42% in PTCA vs. 32% with PTCA and stenting
d reintervention was 15% in PTCA vs. 10% with PTCA and stenting
3) cost:
a) increased bleeding
b) increased hospitalization
5. PTCA vs. CABG
A. Emory Angioplasty Surgery Trial (EAST)
1) single center trial
2) 392 patients randomized and 458 non randomized patients
3) 60% had double vessel disease and 40% had triple vessel disease
4) excluded left main lesion, occluded vessels, and severe LV dysfunction
5) results:
PTCA Surgery
Event mortality 1% 1%
3 year mortality 6.3% 7.1%
freedom from subsequent surgery 79% 99%
freedom from subsequent PTCA 60% 88%
Class I, II, III symptoms 20% 12%
6) Conclusion: PTCA can be safely done but will require repeat procedures
B. Bypass Angioplasty Revascularization Investigation (BARI)
1) largest trial ( 1829 patients ), followed for 5.4 years
2) multicenter
3) results:
CABG PTCA
Event mortality 1.3% 1.1%
Q-wave 4.6% 2.1%
Stroke 0.8% 0.2%
5 yr survival 89.3% 86.3
Revascularization @ 5 yrs. 8% 54%
Diabetic's survival 80.6% 65.5%
C. RITA (United Kingdom)
1) single and multivessel disease, although 50% were single
2) required complete revascularization and were more compulsive regarding randomization
D. CABRI (Europe)
1) need for surgery in one year in the PTCA group was 20%
E. GABI (Germany)
1) need for surgery in one year in the PTCA group was 21%
6. Indications for PTCA
A. Nomenclature
1) Class I. : general agreement that PTCA is indicated, but not the treatment
2) Class II. : Divergence of opinion
3) Class III. : agreement that PTCA not indicated
B. Symptomatic patients
1) Class I and II :
a) amenable lesions
b) ischemic on maximal therapy
c) angina on maximal therapy
d) side affects of medical therapy
C. Asymptomatic patients
1) severe ischemia on testing
2) rescue from angina
3) in need of high risk surgery
D. Myocardial Infarction
1) Class I and II. :
a) AWMI with duration less than 6 hrs.
b) persistent pain within 12 hrs.
c) cardiogenic shock or continued ischemia following lytic therapy
2) Class III. : following lytic therapy































































































































Post-Infarct Left Ventricular Aneursym
1. Definition
A. an area of thin scar devoid of muscle that occurs after myocardial infarction. This area is well-delineated and both walls bulge outward during systole.
2. Morphology
A. The fibrous scar is transmural and delineated from surrounding myocardium
B. Underlying endocardium is smooth and non-trabeculated
C. The aneurysm is thin, devoid of muscle, and often large
D. The walls are akinetic or dyskinetic during systole
E. LVEF is usually depressed to 35% or worse
3. Pathophysiology
A. Fibrous scar tissue develops in about one month after infarct
B. Early aneurysms (7-10 days after infarct) are mostly necrotic muscle and therefore not true aneurysms
C. Overlying pericardium is usually adherent
D. Mural thrombus is present in about 50%, but rarely produces thromboembolism
E. Calcification of thrombus and/or pericardium is common
F. The non-aneurysmal portion of the LV gradually increases in both volume and thickness, resulting in depressed LVEF
Location
Anterolatera 85%
Posterior 5-10%
Lateral less than 5%
G. 50% of posterior aneurysms are false aneurysms
H. True posterior aneurysms are associated with post-infarct mitral insufficiency
4. Clinical Features
A. Small and moderate sized aneurysms often have no specific associated symptoms
B. Classic presentation is history of previous MI and CHF
C. Ventricular arrhythmias are present in 15-30%, more often when the septum is involved
D. Thromboembolism is infrequent
5. Diagnosis
A. ECG: ST elevation, loss of R wave anteriorly, or evidence of previous infarction
B. CXR: enlarged heart, may show convexity if aneurysm is large and profiled
C. ECHO: demonstrates aneurysm, evaluates LV function and mitral insufficiency
D. Catheterization: look for following features -
1) systolic akinesia or dyskinesia
2) permanent outward bulging
3) thinning of wall
4) loss of trabeculations
5) clear demarcation of aneurysm area
6) concomitant CAD
7) segmental and global LVEF
8) presence of LV thrombus
9) presence and degree of mitral insufficiency
6. Natural History
A. Incidence
1) 10-30% after significant myocardial infarction if untreated
2) The incidence has been reduced by thrombolytic therapy, HTN control, and avoidance of corticosteroids
3) The aneurysm evolves over 6 months and is unlikely to enlarge after 1 year
B. LV function
1) There is global cardiac remodeling and dilitation
2) Systolic efficiency is reduced due to paradoxical movement of the aneurysm
C. Survival (non-operative)
1) Larger size of the aneurysm is a risk factor for premature death
2) With small aneurysms, survival is related to concomitant CAD risk factors rather than the aneurysm
3) The prognosis is poorer with dyskinesia and poor function of the LV
Function 5-year survival
Akinesia 69%
Dyskinesia 54%
Dyskinesia + poor LVEF 36%
7. Operative Indications
A. Large aneurysm, with or without symptoms (angina, CHF)
B. Recurrent ventricular tachycardia
C. Risk of late rupture
D. Evidence of thromboembolism
E. A small aneurysm may be a possible indication when undergoing concomitant cardiac procedure
F. Avoid operation with diffuse hypokinesis and no discrete aneurysm
G. Patients with severe LV dysfunction may be candidates for transplant
8. Operative Technique
A. Basic Considerations
1) Avoid clot dislodgement and thoroughly remove all thrombus
2) Remove all LV free wall that has smooth endocardium
3) Excise entire aneurysm, leaving thin rim of scar for closure
B. Methods
1) Incise anterior aneurysm longitudinally and preserve LAD if possible
2) Incise posterior aneurysm along long axis, avoiding papillary muscle
3) Objective is to preserve geometry and maintain LVEF
4) Classic linear closure does cause some distortion and is best used for small or apical aneurysms
5) Remodeling ventriculoplasty (Dor repair) uses patch to recreate wall architecture and is probably the optimum repair
6) Additional procedures as indicated (CAB, arrhythmia surgery)
9. Results
A. Symptoms
1) Symptomatic improvement occurs in most patients
2) Paradoxical wall movement is usually eliminated in the border zones
3) Symptomatic improvement is not always associated with improved LV function
4) Most evident in patients with preoperative CHF
B. Operative Mortality
1) About 5%, most from acute cardiac failure
2) Preoperative risk factors:
a) residual untreated CAD
b) resting LV dysfunction
c) chronic CHF
d) ventricular tachycardia
e) reduced cardiac output
f) elevated LVEDP
g) decreased septal systolic function
h) poor NYHA class
i) poor segmental wall motion
C. Late Mortality
1) 65% 5-year survival; particularly evident in patients with 3-vessel disease
2) One-third die from progressive CHF
3) One-third die from another myocardial infarction
4) Ventricular arrhythmias and sudden death in 15%
10. Special Situations
A. Pseudoaneurysm
1) Develops after acute rupture of contained area
2) Usually fatal, but hemopericardium can be small and contained
3) Small neck distinguishes this from large, wide neck of true aneurysm
4) The wall consists of pericardium and adhesions and gradually expands
5) More often located posteriorly or laterally
6) More likely to rupture than true aneurysm
7) Resection is indicated when the diagnosis is made
B. Post Infarct Free Wall Rupture
1) Occasionally massive with sudden death from exsanguination
2) Usually a more gradual process of dissection through the myocardium
3) Sudden death then occurs from pericardial tamponade
4) Surgical salvage is possible if LV has good function
C. Congenital Left Ventricular Aneurysm
1) Very rare
2) Long, finger-shaped projection projects into epigastrium
3) Rupture is not uncommon; can be excised without CPB
D. Traumatic Left Ventricular Aneurysm · Severe localized contusion causes probable pseudoaneurysm · Should be resected due to thin wall and propensity to rupture






























































Post-infarct VSD
1. Morphological Features
A. Location: 60% anterior, 40% posterior
B. Associated with total occlusion coronary artery, few collaterals
1) Large loss of myocardium
C. My be multiple; staged appearance
D. Posterior VSD- can have MR
E. Late complication- aneurysm
2. Clinical Features & Diagnosis
A. Murmur, pansystolic, LLSB
1) (Also consider acute MR murmur)
B. Chest X-Ray- pulmonary venous hypertension, large pulmonary blood flow
C. ECHO- site, size, ?MR
D. Swan-Ganz- Qp:Qs >/= 2, hemodynamics
E. Cardiac catheterization (optional??)
1) Coronary angiography
2) Left ventriculography (only if condition permits)
3. Natural History
A. Occurence- 1-2% of MI
1) (Decreased since thrombolytics)
B. Timing- 2-3 days post MI up to 2 weeks
C. Early death is common
4. Indications for Operation
A. Indication = presence of VSD
B. Timing
1) Urgent- for hemodynamic or end-organ decline
2) Delayed (2-3 weeks) - if stable
5. Operative Considerations
A. Urgency, IABP
B. Approached through LV
C. Patch technique
1) 2 patches unless apical
D. Concomittant procedures
1) CABG
2) MV replacement
3) Aneurysm resection
4) Free wall perforation (especially posterior)
6. Results or Repair
A. Survival: 35% early mortality
B. Functional status: good
C. Modes of death
1) 50% CHF, acute
2) 10% sudden death
3) 5% CHF, chronic, intractable
4) CVA
D. Risk factors
1) Hemodynamic status & RV function preoperatively
2) Extent of myocardial necrosis
3) Posterior VSD >> anterior VSD







































































Combined Carotid & Coronary Disease
1. Coronary Surgery
Carotid Stenosis > 50%
CABG 5-8%
CABG > 65 17%
CABG + Left main 50%
2. Risk Factors for Stroke Following CABG
A. Overall stroke risk 1-3.5%
B. Mural thrombi in the left ventricle
C. Atheromatous lesions in the ascending aorta
D. Air embolism
E. History of previous stroke
3. Carotid Artery Stenosis and CABG
A. Carotid stenoses are less of a risk factor for stroke with CABG because with CPB:
1) Cerebral vascular resistance lowered
2) Hypothermia reduces brain metabolism and oxygen requirement
3) Hemodilution
4) Auto-regulation of cerebral blood flow is related more to flow than MAP
B. Indications for combined coronary and carotid procedures are limited
C. Indications for combined coronary and carotid artery procedures
1) Severe CAD: unstable angina, left main stenosis or 3 vessel CAD with poor LV function and
2) An actively symptomatic carotid artery stenosis
4. Indications for Staged Operations for Coronary and Carotid Artery Disease
A. Significant 1, 2 or 3 vessel CAD requiring CABG in a patient with asymptomatic high grade CAS with medically controlled symptoms
B. Patient with actively symptomatic carotid artery stenosis with stable angina and adequate LV function
5. Combined Coronary and Carotid Artery Disease
A. Controversial Areas
1) Stable angina requiring CABG and coexistent asymptomatic high grade (> 80%) bilateral carotid stenosis
2) Redo CEA or CABG with coexistent lesions in the other vascular system
6. Operative Strategies for Combined Procedures
A. Ensure adequate exposure of neck in addition to chest and legs
B. Pre - bypass vs. on bypass CEA
C. After CEA, wound left open until systemic heparinization reversed
7. Results of Combined Procedures
A. Morbidity and mortality for patients requiring combined procedures is higher than for either procedure alone
1) Mortality 4%
2) Post-operative stroke 9%
3) Peri-operative MI 6%
B. Therefore: Only 1-3% of patients requiring CABG or CEA will be candidates for combined procedures
Duplex
Angiography