Transcript Pre-operative Cardiac Risk Assessment for Non

ACC/AHA 2007 Guidelines on
Perioperative Cardiovascular
Evaluation and Care for
noncardiac surgery
Dr. Sonia Anand
McMaster University
Overview
• Guidelines- reflect evidence
synthesis and consensus
• Evidence as of October 2007
• Important Decision points:
– Urgent vs Elective Surgery
– High risk surgery vs intermediate vs low
– Active Cardiac Condition vs non-active
The Search For High Risk
Methods for Assessing
Risk Pre-Operatively
Patient Based
– High risk conditions
– Functional Capacity
Surgery Based
– Vascular Surgery
– Emergency surgery
Intervention Based
–Medications
–Revascularization
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
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
•
•
•
•
•
Minor Risk*
Age > 70
Abnormal ECG
Nonsinus rhythm
Uncontrolled
systolic BP
Functional Capacity
• Functional status has shown to be a
reliable periop and long-term predictor
of cardiac events
• Functional status determined based on
ability to do ADL’s
• 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
• CARP – if none of these – no advantage of
revasc
Functional Test
• Exercise test with ECG
• If abnormal ECG, Rx perfusion
imaging
– Adenosine
– Dipyridamole
– Dobutamine
– Dobutamine stress echo
Effect of Prior CABG on Cardiac Risk of
Vascular Surgery: The CASS Registry
10 (n=314)
***
8.5
Periop MI
Death
8
6
4
*
2.8
3.0
*
2
***
0.6 1.1
0
0 No CAD
CAD:
Medical Rx
CAD:
CABG
Eagle et al. Circulation, 1997
Coronary Revascularization Does Not
Improve Immediate or Long-Term Outcomes
510 VA pts, aged 66 years, with stable CAD, scheduled for elective
AAA repair (33%) or infrainguinal bypass (67%), randomized to
Revasc (PCI 59%, CABG 41%) or conservative management.
25
20
15
10
5
0
Post-Op MI
30 Day
2.7 Year
Mortality
Mortality
Revascularization Conservative Mgmt
McFalls, E. CARP Trial;AHA 2004
High Risk Patients &
Revascularization Pre-Op
101 pts with extensive ischemia randomly assigned to pre-op revascularization
or not. Endpoints: all-cause death or MI at 30 days and 1-year follow-up.
50
40
%
30
20
2VD in 12 (24%),
3VD in 33 (67%),
Left main in 4 (8%).
10
0
7
14
21
28
Days since surgery
0
3
6
9
12
Months since surgery
Poldermans, D. JACC 2007; 49(17): 1763
The Effect of Percutaneous Revascularization
Above Optimal Medical Therapy:
COURAGE
Survival Free of Death/MI
2287 Pts w/myocardial ischemia and CAD randomized to PCI with
optimal medical therapy (PCI group) and 1138 to medical therapy alone.
1.0
0.9
0.8
0.7
Medical therapy
0.6
PCI + Medical therapy
0.5
0
1
2
3
4
Years
5
6
7
Boden, W. NEJM 2007; 356:1503
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
Statins Improve Survival After
Vascular Surgery
100 pts randomized 20 mg atorvastatin or placebo for 45 days.
Vascular surgery ~ 30 days after randomization. F/U 6 months
Primary Endpoint
CV death +
NFMI+
Ischemic stroke+
Unstable Angina
Durazzo, AES. JVS 2004:39(5):975
Statins Improve Long-Term
Survival After Vascular Surgery
.75
.50
Statin (+)
p < 0.004
.25
Statin (-)
0
Survival
1.00
Retrospective review of 446 consecutive infrainguinal bypass surgeries
0
20
60
40
Time (months)
80
100
Ward, RP. Int J Card 2005; 104(3):264
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
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
• 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.