Transcript Pre-operative Cardiac Risk Assessment for Non

Epidemiology of
Noncardiac Surgery
Dr. Mohammed Naser
Overview
• Important Decision points:
– Urgent vs Elective Surgery
– High risk surgery vs intermediate vs low
-Active Cardiac Condition vs non-active
Functional capacity on basis of pt ablility
To perform certain activities
The Search For High Risk
Methods for Assessing
Risk Pre-Operatively
Is the surgery emergency
PROCEED
and manage post operatively
according to AHA& ACC
guidelines
If the surgery emergency..??
Active/Major Cardiac
Conditions
• Unstable Coronary Conditions
• Decompensated CHF
• Significant arrhythmias (i.e. 3⁰HB, new
Vtach)
• Severe Valvular Disease (aortic
stenosis >40 mm hg gradient or valve
area <1.0cm₂)???????
Non-Active Cardiac Factors
• Intermediate Risk
• Hx of CHD
• History of prior
CHF
• Hx of stroke
• Diabetes
• Renal insufficiency
* Not associated with cardiac risk
•
•
•
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•
Minor Risk*
Age > 70
Abnormal ECG
Nonsinus rhythm
Uncontrolled
systolic BP
Six Independent predictors of
cardiac risk
1) ischemic heart disease
2) congestive heart failure
3) cerebrovascular disease
4) high risk surgery (AAA, orthopedic sx)
5) pre-operative insulin tx for diabetes
6) preoperative creatinine for creat > 2
mg/dL
Lee et al
Functional capacity
Functional Capacity
• Functional status has shown to be a
reliable periop and long-term predictor
of cardiac events
• MET: metabolic equivalent resting
oxygen consumption of 70 kg, 40 yr old
man at rest
• Periop risk is increased if person
cannot > 4 METS
1 MET 4 MET
10 MET
The Trump Card:
Functional Capacity
• Perioperative cardiac risk is increased in
patients unable to exercise 4 METs
• Functional capacity can be estimated in
the office
– Energy expenditure for eating, dressing, walking around
house, dishwashing ranges from 1-4 METs
– Climbing a flight of stairs, running a short distance,
scrubbing floors, and golf ranges from 4-10 METs
– Swimming and singles tennis exceeds 10 METs
Surgery Risk Type
Type
Cardiac risk
examples
High
> 5%
Aortic, peripheral vasc sx
Intermediate risk
1-5%
Intraperitoneal
Intrathoracic
Carotid End
Head and neck
Orthopedic Sx
Prostate Sx
Low
<1%
Endoscopic procedures
Superficial
Cataract Sx
Breast Sx
Ambulatory Sx
Surgery-Specific Risk:
High Risk*
• Major emergency surgery
• Vascular surgery including:
aortic surgery, infra-inguinal
bypass
• Prolonged surgery with large
fluid shifts or blood loss
* Reported risk of cardiac death or nonfatal MI >5%
Stepwise Approach
• Step 1: Determine urgency of surgery
• Step 2: Active cardiac condition?-→test
• Step 3: Undergoing low-risk surgery? < 1%*
• Step 4: Good functional capacity?
* Combined morbidity and mortality < 1% even in high risk patients
The Catheterization Questions
to Ask Yourself
• Does this patient have symptomatic
coronary disease that will have a mortality
benefit from revascularization now?
• Am I willing to send the patient to CABG?
• Am I doing this just to know the anatomy?
Is pre-op coronary revasc
advantageous?
• If high risk surgery and patient has active
cardiac issue
• Functional test and perfusion Imaging
and if
• L main 50% or 3 VD, 2VD + LAD Prox,
LVEF < 20%, aortic stenosis – consider
revasc pre-op
STENTS
If upcoming Sx is known then PTCA
alone or BMS with 4-6 wks dual
antiplatelet tx after
If received DES....
– 1) postpone sx until > 12 months,
– 2) do sx on both asa+clop
– 3) do sx on single ap tx
Use of a DES for coronary
revascularization before imminent
or planned non cardiac sx that will
necessitate d/c of antiplatelet
agents is not recommended
Medical tx
1) beta blockers-if on keep them if
not....
2) Statins continue, ? Start -need
randomized trials
Other Issues
• DVT/PE prophylaxis
• Anesthetic technique-volatile agent with
general anesthetic - ↓ troponin ↑ LV
function >> propofol, midazolam, balanced
anesthesia (Grade B)
• No evidence that epidural anesthesia
>>general anesthesia for cardiac
outcomes
• Routine troponin monitoring not
recommended
Surveillance for Perioperative
Myocardial Infarction
• ECGs
–All intermediate and high-risk patients
should get a post-op ECG.
–As need for signs or symptoms of
ischemia
• Troponin / CK
–In patients with signs or symptoms of
ischemia
–Do not do screening biomarkers
High Risk Features
• Severe obstructive or restrictive
pulmonary disease
• Diabetes
• Renal impairment
• Anemia, polycythemia, thrombocytosis
PCI pre-op
• ST-elevation MI
• Unstable angina
• Non ST elevation MI
2007 ACC/AHA Perioperative Guidelines
Take Home Messages
Take Home Messages
• Unstable syndromes require management prior to surgery. Look
for
– Unstable angina
– Signs of heart failure
– Stenotic valve lesions
– Ventricular arrhythmias
• Functional tolerance is the best single predictor of outcome
• Be very specific in your history (one step at at time, regular or slow
pace, etc)
• If patient on beta blockers & statins continue them, more trials to
mandate them
• PCI/CABG only if patient needs it independent of surgery. Think
twice because of stent data and delays.