PREOP CARDIAC EVALUATION FOR NONCARDIAC SURGERY

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PREOP CARDIAC EVALUATION FOR NONCARDIAC SURGERY

• Yatish B. Merchant, MD, FACC
• Cardiology, New Jersey
• USA

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Ultimate Goal

• Quality of care and serving the patients best
  interests.

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Goals

• Understand how to estimate peri-operative CV risk
• Know when to perform stress testing
  preoperatively
• Learn how to reduce risk perioperatively in those
  at higher risk

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55 Years old man with history of hypertension
CAD but asymptomatic runs for 30 minutes daily,
needs inguinal hernia repair. You are consulted
to clear him for surgery.

• 1) Order Nuclear stress test to evaluate CAD.
• 2) Order Regular stress test
• 3) Order Cardiac catheterization
• 4) Clear for surgery

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Triggers

• Surgical Trauma
• Anesthesia/analgesia
• Intubation/extubation
• Pain
• Hypothermia
• Bleeding/anemia
• Fasting

• Anesthesia/analgesia
• Hypothermia
• Bleeding/anemia

• Surgical Trauma
• Anesthesia/analgesia

• Surgical Trauma
• Anesthesia/analgesia

Hypercoagulable State
?TNF-a ?IL-1 ?IL-6 ?CRP
? catecholamine and cortisol levels
? PAI-1 ? Factor VII ? Platelet reactivity ?
antithrombin III
?oxygen delivery
? BP ? HR ? FFAs ? relative insulin deficiency
Coronary artery shear stress
Plaque fissuring
Plaque fissuring
? Oxygen demand
Myocardial Ischemia
Acute Coronary Thrombus
Perioperative Myocardial Infarction
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Overview

• Risk Assessment
• Preoperative Testing
• Postoperative Management to Reduce Risk

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Approaches to Risk Assessment

• ASA/Dripps
• Goldman Multifactorial Index
• Detsky Modified Index
• Revised Risk Index
• ACC/AHA Task Force Recommendations

Quantitative
Strategic
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Dripps/ASA Classification
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Goldman Risk Index
Ref Goldman M, Caldera D, Southwick, et al
Multifactorial index of cardiac risk in
non-cardiac surgical procedures. N Engl J Med
1482120-2127, 1988.
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Goldman Risk Index
Ref Goldman M, Caldera D, Southwick, et al
Multifactorial index of cardiac risk in
non-cardiac surgical procedures. N Engl J Med
1482120-2127, 1988.
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ACC/AHA Guidelines
J Am Coll Cardiol, 2007 501707-1732
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Stepwise Approach to the Pre-operative Evaluation
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Stepwise Approach to Preoperative Cardiac
Assessment
Vigilant perioperative and postoperative
management
Need for emergencynoncardiacsurgery
Operating room
Yes
No
Evaluate and treatper ACC/AHA Guidelines
Active cardiac conditions
Consider Operating Room
Yes
No
Proceed withplanned surgery
Low RiskSurgery
Yes
No
Asymptomatic andgood functionalcapacity
Proceed withplanned surgery
Yes
Manage based onclinical risk factors
No
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Active Cardiac Conditions
High Risk

• Acute or recent MI (7-30 d)
• Unstable coronary syndrome
• Decompensated CHF
• Significant Arrhythmias
• Severe Valvular Disease

Surgery
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Stepwise Approach to Preoperative Cardiac
Assessment
Vigilant perioperative and postoperative
management
Need for emergencynoncardiacsurgery
Operating room
Yes
No
Evaluate and treatper ACC/AHA Guidelines
Active cardiac conditions
Consider Operating Room
Yes
No
Proceed withplanned surgery
Low RiskSurgery
Yes
No
Asymptomatic andgood functionalcapacity
Proceed withplanned surgery
Yes
Manage based onclinical risk factors
No
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Low Risk Surgery Risk lt 1

• Endoscopic procedures
• Superficial procedure
• Cataract surgery
• Breast surgery

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Low Risk Situations
Low Risk

• Low risk surgery
• Good functional capacity
• No cardiac symptoms
• No active cardiac conditions
• No clinical risk factors

Reasonable to proceed with surgery
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Functional Capacity
Metabolic Equivalents (METs)

• Correlates with maximum oxygen uptake on
  treadmill testing
• Demonstrated predictor of future cardiac events
• Poor functional capacity may hide low threshold
  cardiac symptoms

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What is basal O2 consumption (Vo2)?

• 1.5 ml/kg/min
• 2.5 ml/kg/min
• 3.5 ml/kg/min
• 4.5 ml/kg/min

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Duke Activity Status Index

• 1 MET Can you take care of yourself?
• Eat, dress, or use the toilet?
• Walk indoors around the house?
• Walk a block or two on level ground at 2-3 mph
  or 3.2-4.8 km/h?
• 4 METs Do light work around the house like
  dusting or washing clothes?
• MET metabolic equivalent

• 4 METs Climb a flight of stairs or walk up a
  hill?
• Walk on level ground at 4 mph or 6.4 km/h?
• Run a short distance?
• Do heavy work around the house like scrubbing
  floors or lifting or moving heavy objects?
• Participate in moderate recreational activities
  like golf, bowling, dancing, doubles tennis, or
  throwing a baseball or football?
• 10 METs Participate in strenuous sports like
  swimming, singles tennis, football, baseball, or
  skiing?

Resting or basal O2 consumption(Vo2) of a 70 kg,
40 yrs old man is 3.5 mL per kg per min, or 1 MET.
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Clinical Risk Factors

• Known Ischemic Heart Disease
• Compensated or Prior Heart Failure
• Diabetes
• Renal Insufficiency
• Cerebrovascular disease

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Stepwise Approach to Preoperative Cardiac
Assessment
Vigilant perioperative and postoperative
management
Need for emergencynoncardiacsurgery
Operating room
Yes
No
Evaluate and treatper ACC/AHA Guidelines
Active cardiac conditions
Consider Operating Room
Yes
No
Proceed withplanned surgery
Low RiskSurgery
Yes
No
Asymptomatic andgood functionalcapacity
Proceed withplanned surgery
Yes
Manage based onclinical risk factors
No
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Clinical Risk Factors

• History of heart disease
• Compensated or prior CHF
• Cerebrovascular disease
• Diabetes Mellitus
• Renal Insufficiency

Proceed Cautiously
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Asymptomatic butpoor/unknown functionalcapacity
Manage based onclinical risk factors
3 or more clinical risk factors
1 or 2 clinical risk factors
No clinical risk factors
Vascular Surgery
Intermediate risk surgery
Vascular Surgery
Intermediate risk surgery
Proceed withplanned surgery
Proceed with planned surgery with HR controlor
consider non-invasive testing
Consider Testing
Clinical risk factors known ischemic heart
disease, compensated or prior HF, diabetes, renal
insufficiency, cerebrovascular disease
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Intermediate Risk Surgery Risk lt 5
Carotid endarterectomy Endovascular AAA
repair Head and neck Intraperitoneal and
intrathoracic Orthopedic Prostate
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High Risk Surgery Risk gt 5

• Emergent major operations (3-5 times more risk)
• Aortic and other major vascular
• Peripheral vascular
• Anticipated prolonged or associated with large
  fluid shifts and/or blood loss

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Overview

• Risk Assessment
• Preoperative Testing
• Postoperative Management to Reduce Risk

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Most preoperative testing assesses for presence
of obstructive CAD and NOT plaque vulnerability
which truly predicts the risk.
Unfortunately we have no way of predicting this.
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ACC/AHA Recommendations

• Echocardiography
• Dyspnea of unknown origin (Class IIa)
• Current or hx of HF and no echo in 12 months
  (Class IIa)
• 12 Lead ECG
• Vascular surgery and 1 CRF (class I)
• CRFs and intermediate risk surgery (class I)
• All vascular surgery (class IIa)

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ACC/AHA Recommendations

• Treadmill stress testing
• High cardiac risk conditions
• 3 CRFs, poor functional capacity vascular
  surgery (class IIa)
• Nuclear stress testing

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Which test to choose?
Most ambulatory patients
Treadmill Stress Test
Abnormal resting ECG (dig, LVH)
Exercise echo or sestamibi
LBBB
DSEAdenosine sestamibi dipyridamole sestamibi
Unable to exercise
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Preoperative TestingNegative Predictive Value
Freedom from MI or Death
Eagle et al. JACC 199627910.
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Preoperative Testing
Caveats

• Whenever feasible, an exercise stress test is
  best choice
• Dipyridamole or adenosine perfusion scan and DSE
  are reasonable choices if
• unable to exercise
• BBB or other resting ECG abnormality
• Avoid dipyridamole and adenosine scan if
  bronchspasm
• Avoid DSE if serious arrhythmias or severe
  hypertension

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Overview

• Risk Assessment
• Preoperative Testing
• Perioperative Management to Reduce Risk

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60 yrs old man with history of CAD, HTN, DM
Creatinine of 2.5 showed small I W ischemia on
nuclear stress test at 10 METS asymptomatic,
needs to have prostatectomy for Ca. How
would you treat?

• Cardiac cath PCI as indicated.
• Cancel surgery request other Rx option.
• BB with heart rate control perioperative.
• Give nitrates CCB proceed with surgery.

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Perioperative Nitrates?
Dodds, et al. Anesth. Analg. 199376705-13
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Perioperative Management

• Revascularization
• Beta blockers
• Statins
• Alpha-2 agonists
• Calcium channel blockers

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Revascularization

• 5859 vets screened prior to vascular surgery4669
  excluded
• 510 randomized to
• Revascularization (258)
• 99 CABG
• 141 PCI
• 18 not revascularized
• 252 no revascularization
• 9 revascularized
• 143 medical rx

McFalls, et al. NEJM 20043512795-2804
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Intervention is rarely necessary to simply lower
the risk of surgery. Revascularization (surgery
or PCI) should be considered only if standard
indications are present.
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PCI before anticipated surgery
Acute MIHigh Risk ACSHigh risk anatomy
Bleeding risk of anticipated surgery
Stent and continued Dual-antiplatelet rx
Low
Not low
14 to 29 Days
30 365 Days
gt 365 Days
Balloon angioplasty
Bare-metalstent
Drug-elutingstent
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Timing of Surgery After PCI
Balloon angioplasty
Bare-metalstent
Drug-elutingstent
lt 14 days
gt 14 days
lt 30-45 days
gt 30-45 days
lt 365 days
gt 365 days
Delay
Surgery with ASA
Delay
Delay
Surgery with ASA
Surgery with ASA
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Perioperative Management

• Revascularization
• Beta blockers
• Statins
• Alpha-2 agonists
• Calcium channel blockers

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Postoperative Mortality ReductionBeta-Blockers

• 200 pts undergoing non-cardiac surgery
• Random assignment to
• IV followed by oral atenolol or
• Placebo
• Double-blind follow-up over 2 years

Mortality
Mangano, et al. NEMJ 19963351713.
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Postoperative Cardiac Events In High Risk
Patients

• 173 patients undergoing vascular surgery with
  positive DSE
• Randomized to BB 1 week pre-op or placebo
• Followed for 30 days

Bisoprolol n59
Placebo n53
Poldermans et al. NEJM 19993411789.
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Perioperative Beta Blockers
AHA/ACC Recommendations 2006 Update

• Beta blockers required in recent past to control
  symptoms of angina or patients with symptomatic
  arrhythmias or hypertension
• Patients at high cardiac risk owing to the
  finding of ischemia on preoperative testing who
  are undergoing vascular surgery
• Patients undergoing vascular surgery and with
  identified CAD
• Vascular surgery and multiple cardiac risk
  factors
• Moderate or high risk surgery and multiple
  cardiac risk factors

Key Point if known or suspected CAD and
undergoing moderate or high risk surgery, use a
beta blocker!
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Perioperative Management

• Revascularization
• Beta blockers
• Statins
• Alpha-2 agonists
• Calcium channel blockers

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Perioperative Statins?

• 100 patients pre-op before vascular surgery
• Random assignment
• Atorvastatin 20 mg
• Placebo
• Started 30 days preoperatively
• Follow-up 6 month
• Endpoint
• Cardiac death
• Non-fatal MI
• USA
• Stroke

J Vasc. Surgery 200439967
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Perioperative Statins
Hindler, et al. Anesthesiology 20061051260-72
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Perioperative Statins

• 44 reduction in mortality after all types of
  surgery.
• 59 after vascular surgery alone

Hindler, et al. Anesthesiology 20061051260-72
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Perioperative Management

• Revascularization
• Beta blockers
• Statins
• Alpha-2 agonists
• Calcium channel blockers

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Perioperative Alpha-2 Agonists

• Clonidine prophylaxis in patients with or at risk
  of CAD undergoing noncardiac surgery reduced
  perioperative ischemia significantly. (P0.01)
  mortality up to 2 yrs was also reduced (P0.035)
• 
  Wallace et al (PDBT)

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Perioperative Management

• Revascularization
• Beta blockers
• Statins
• Alpha-2 agonists
• Calcium channel blockers

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Preoperative Hgb and Mortality
Study of Untreated Anemia
Carson, et al. Lancet. 19963481055-60
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Perioperative Hypothermia

• 300 pts undergoing general surgery
• Randomized, double blinded assignment to routine
  care or supplemental warming

Frank SM JAMA 1997227(14)
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Triggers

• Surgical Trauma
• Anesthesia/analgesia
• Intubation/extubation
• Pain
• Hypothermia
• Bleeding/anemia
• Fasting

• Anesthesia/analgesia
• Hypothermia
• Bleeding/anemia

• Surgical Trauma
• Anesthesia/analgesia

• Surgical Trauma
• Anesthesia/analgesia

Hypercoagulable State
?TNF-a ?IL-1 ?IL-6 ?CRP
? catecholamine and cortisol levels
? PAI-1 ? Factor VII ? Platelet reactivity ?
antithrombin III
?oxygen delivery
? BP ? HR ? FFAs ? relative insulin deficiency
Coronary artery shear stress
Plaque fissuring
Plaque fissuring
? Oxygen demand
Myocardial Ischemia
Acute Coronary Thrombus
Perioperative Myocardial Infarction
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Key Point
Avoid Sympathetic Stimulation in those at Risk!

• Beta blocker if able
• Limit hypothermia
• Aggressive post-operative pain control
• Avoid significant anemia

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THANK YOU