Transcript Internal Medicine Lecture Series: Cardaic Cleance.

Internal Medicine
Lecture Series:
Cardiac Clearance
James Lin, DO
July 20, 2005
Millcreek Community Hospital
General Background
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Each year 28 million American
Adults undergo noncardiac surgery.
1 million have know CAD
2-3 million have cardiac risk factors
4 million are 65 yrs of age or older.
Perioperative Risks:

3 Categories
Patient Specific
 Procedure Specific
 Anesthesia Specific

Patient Specific:

Many interdependent variables that
define the patient and the patient’s
surgical indications and co morbid
diseases.
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Age
Race
Gender
Nutritional Status
Level of fitness
Coexisting conditions
ASA
ASA Class
I.
No organic or psychiatric disease 0.07%
II.
III.
IV.
V.
Mild to moderate systemic
disturbances 0.20%
Severe system disturbance, but not
necessarily life threatening 1.15%
Severe systemic disturbance; life
threatening 7.66%
Moribund with little chance of survival
33.58%
In the event of an emergency operation, the number is preceded by “E”
Procedure Specific
Risk of a specific surgical procedure
is proportional to the physiologic
stress associated with the
procedure
High Risk Procedures:
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Thoracic Surgery
Major Joint replacement
Craniotomy
Cardiac Procedure
Large Bowl Surgery
Major Head and Neck procedures
Low Level Risk:
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Most plastic surgery procedures
Tubal Ligation
D&C
Hysterectomy
Eye and Oral surgery
Hernia Repairs
Anesthesia Specific

This involves the Direct VS Indirect
anesthetic agents and the
physiologic responses to:
Surgically induced hypotension
 Blood loss
 Anemia
 Post operative pain

Most anesthetic deaths are due to failure to ventilate adequately,
unsuspected hypoxia, or anesthetic agent overdose.
MANAGING
CARDIOVASCULAR
RISK

The most common cardiovascular
complications are the following:
Perioperative acute ischemia and
myocardial infarction
 Congestive hear failure
 Arrhythmias
 Hypotension
 Hypertension

ACC-AHA Preoperative
Cardiac Risk
Assessment
A.Step 1: Evaluate urgency of
noncardiac surgery
1.Emergency requires surgery
regardless of risk
A.Step 2: Noninvasive cardiac testing
not required
1.Coronary revascularization in
past 5 years
a.Must be stable and no
recurrent symptoms or signs
2.Coronary evaluation in last 2
years
a.Evaluation must have been
favorable and adequate
b.No new symptoms or signs
since evaluation
A.Step 3: Indications for noninvasive cardiac testing
1.See Eagle's Cardiac Risk Assessment
2.Major patient risk factors
a.Cardiac evaluation needed in all cases
3.Intermediate Risk: Indications for cardiac
evaluation
a.Decreased functional capacity (<4 METS)
b.Surgery with higher cardiovascular risk
See High Risk Surgery
4. Minor risk: Indications for cardiac
evaluation
a.Evaluate on individual basis
b.Consider in decreased functional capacity (<4
METS)
Eagles Cardiac Risk
Assessment
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Major Cardiovascular Risks: Unstable
Coronary Syndromes
A.
B.
C.
D.
E.
Recent MI (within 30 days)
Unstable Angina or severe Angina
(class 3-4)
Decompensated CHF
Severe valvular disease
Significant arrhythmia
A.
B.
C.
High grade AV Block
Symptomatic ventricular arrhythmia
Uncontrolled rate in supraventricular
arrhythmia
Eagle’s Cardiac Risk
Assessment
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Intermediate Cardiovascular
Risks
A.
B.
C.
D.
E.
Mild Angina Pectoris (Angina
Class 1-2)
Prior MI by history or EKG
Compensated or prior CHF
Renal Insufficiency (serum
Creatinine >2 mg/dl)
Diabetes Mellitus
Eagle’s Cardiac Risk
Assessment
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Minor Cardiovascular Risks
A.
B.
C.
D.
E.
F.
Advanced age
Abnormal EKG (LVH, LBB, ST segment
abnormalities, T Wave abnormalities)
Hear rhythm other than sinus rhythm
(e.g. A-Fib)
Low functional Capacity (<4 METS)
History of CVA
Uncontrolled HTN
NONINVASIVE TESTING
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ACC/AHA guidelines, pt with minor
clinical predictors do not require
noninvasive testing unless they
have poor functional capacity and
are undergoing a high-risk
procedure.
Functional Status
Assessment
Excellent >7
METS
Moderate 4-7 Poor <4
METS
METS
Squash
Jogging (10
min/ mile)
Scrubbing
floors
Single Tennis
Cycling
Climbing a flight
of stairs
Golf without Carts
Walking 4 MPH
Yard work (e.g,
raking leaves,
weeding, pushing
a power mower)
Vacuuming
ADL’s (eating,
dressing,
bathing)
Walking 2 MPH
Writing
ACP Preoperative
Cardiac Risk
Assessment

A. Indications for surgery without
further evaluation.
Young healthy pt undergoing minor
surgery
 Noncardiac emergency surgery
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CASE #2:
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You are asked to evaluate a 73 y/o male with
stable class II angina treated with nitrates and no
previous MI or CHF. He has mild hypertension
controlled on lisinopril and has no hx of diabetes.
He had moderate exercise capacity (5 METS)
until he injured his ankle 2 weeks ago. At that
time , he was found to have 5.2 cm abdominal,
aortic aneurysm. His exam is unremarkable, and
his BP is 154/86. His ECG is normal. He is
scheduled to undergo AAA repair. You would:
CASE#2: Con’t
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A) Exercise Stress Test
B)DSE Or DTI
C) No further cardiac testing and
proceed with surgery
D) Cardiac Catheterization
CASE #2: Con’t
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B.

His history of chronic stable class II angina puts him at
intermediate risk before a high risk vascular procedure. Exercise
ECG is impractical because of his recent ankle injury.
Pharmacological stress testing is the best approach to assess
ischemic risk. Even with a negative test result, perioperative
atenolol is recommended.
ACP Preoperative
Cardiac Risk
Assessment
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B. Detsky’s Modified Cardiac Risk Index

Class I Risk Index
Eagle and Vanzetto criteria: 0 to 1
Considered low risk of cardiac event 3%.
Proceed to surgery without further evaluation
 Eagle and Vanzetto criteria: 2 or more (see
above)
Intermediate risk of cardiac event (3-15%)
Proceed to surgery without further evaluation.
Nonvascular surgery proceeds without
evaluation. Vascular surgery evaluation with
Stress imaging:
Neg. test: Surgery may proceed
Pos. Test: Manage as high risk.

ACP Preoperative
Cardiac Risk
Assessment

Class II or Class III Risk Index:
Considered high risk of cardiac
event (>15%)
 Consider revascularization for CAD
 Manage CHF, arrhythmia, valve
disease.
 Minimize cardiac risk.

Eagle and vanzetto
criteria
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Age over 70 yrs
Diabetes Mellitus
Q waves on ECG
Hx of Angina Pectoris
Hx of MI
Hx of ventricular ectopy
Hx of CHF
ST segment abnormalities on EKG
HTN with LVH
Detsky’s Modified Cardiac Risk Assessment
Age older than 70 years
5
MI within 6 months
10
MI after 6 months
5
Canadian Cardiovascular society angina
Class III
Class IV
Unstable Angina within 6Months
10
20
10
Pulmonary Edema
within 1 week
Ever
10
5
Critical Aortic Stenosis
20
Rhythm other than sinus or sinus plus atrial
premature beats
5
More than five premature ventricular beats
5
Emergency operation
10
Poor General medical status
5
Detsky’s Modified Cardiac Risk Assessment
Class
I
Points
0 to 15
II
20 to 30
III
30 +
Cardiac Risk
Low
High
ACC/AHA VS. ACP
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Similarities:
Emergent surgery proceeds
directly to the operating room
without further risk stratification
 Both algorithms incorporate the
Detsky predictors
 Pts are eventually stratified into
low, intermediate, or high risk
categories.

ACC/AHA VS. ACP
Differences:
ACC/AHA
ACP
The presence or absence of
CAD is the first risk
assessment.
- Clinical predictors derived
from Goldman and Detsky
criteria.
-Functional status incorporated
into the algorithm
-Pts with poor functional status
require stress testing
-The Detsky criteria are the
-
first determinants of risk
stratification.
-Minor clinical predictors
derived from Eagle and
Vanzetto criteria
-ACP felt functional status not
proved to be useful risk
predictor
-Pts undergoing vascular
surgery require stress testing.
Case #1:
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You are asked to see a 54 year old man with a 15 year history of noninsulin-dependent diabetes mellitus and hypertension, currently treated
with diet, glyburide, metformin, and lisinopril. He has mild retinopathy
and 300 mg/d of proteinuria. His last laboratory studies 2 weeks ago
showed a creatinine of 1.4 mg%, total cholesterol of 216 mg%, high
density lipoprotein cholesterol 39 mg%, LDL 122 mg%, triglycerides of
210 mg%, and glycosylated hemoglobin of 7.2%. He has no past
history of cardiovascular disease and denies current chest pain,
palpitations, or dyspnea of exertion. For the past year, he has had
limited physical activity due to progressive osteoarthritis of the hip and
is scheduled for a total hip replacement in 3 weeks. The surgeon has
asked you for advice regarding his perioperative management. On
examination, his weight is 220 lb, with a body mass index of 32, his BP
is 132/84, and his pulse is 84. His funduscopic examination shows
mild background retinopathy. His cardiac and pulmonary examinations
are normal, while the remainder of his examination is otherwise
unremarkable except for mildly diminished dorsalis pedis pulses, and
decreased position sense in his toes. His ECG shows nonspecific STT changes. As part of your recommendations you would
Case #1 con’t
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A) U/S vascular evaluation of the
lower extremities
B)Dipyridamole thallium imaging or
dobutamine stress
echocardiography
C) No further cardiac testing and
proceed with surgery
D)Cardiac catheterization.
Case #1: Con’t Answer
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B.
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There is room for debate on how to
proceed. The patient is clearly at
high risk for CAD with longstanding
diabetes mellitus, HTN, and a LDL
that was high. His planned
procedure is of intermediate risk.
Given that level of overall risk,
many would risk stratify with
noninvasive testing.
Case #1: Con’t
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Your evaluation yields no new
findings. As part of his
perioperative management, you
recommend:
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A) Holding his oral diabetes medications on the day of surgery
B)Maintaining his intraoperative glucose between 150 and 200
mg with regular insulin if necessary
C) Atenolol preoperatively and in the immediate postoperative
period.
D) All of the above.
Case #1: Con’t Answer
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D.
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Stopping oral agents on the day of surgery usually
is sufficient to protect against hypoglycemia. The
anesthesiologist much monitor glucoses
intraoperatively and supplement with short-acting
subcutaneous insulin to maintain glucoses in the
stated therapeutic range. Given the patient’s
multiple risk factors, atenolol would suppress
vascular instability associated with anesthesia
induction and withdrawal.