Noncardiac Surgery in the Cardiac Patient

1
Noncardiac Surgeryin the Cardiac Patient

• David Putnam, MD
• Albany Medical College

2

• Coronary heart disease is the most frequent cause
  of perioperative cardiac mortality and morbidity
  after noncardiac surgery

3
Noncardiac SurgeryMagnitude of the Problem

• 25 million patients undergo noncardiac surgery
  each year in the United States
• 3 million patients have clinical evidence or
  multiple risk factors for CAD
• 4 million patients are gt 65 years old
• Nearly 1/3 of surgical patients are at risk for
  cardiovascular complications

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Noncardiac SurgeryMagnitude of the Problem

• Aging of the population
• Lower threshold for performing major procedures
  on elderly patients
• Patients with multiple comorbid illnesses

5
Noncardiac SurgeryMagnitude of the Problem

• Advances in anesthesia, post-op analgesia, and
  surgical technique have contributed to a reduced
  rate of major cardiac complications
• Overall risk of cardiac complications with
  noncardiac surgery remains low
• Risk of perioperative MI 0.1
• Risk of cardiac death 0.4

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Non-Cardiac SurgeryRisk of Perioperative MI/Death

• No history of ischemic heart disease 0.1
• History of prior MI 6

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Reinfarction in Post-MI Patients
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Non-Cardiac Surgery

• Although consultants are frequently asked to
  clear a patient for surgery, their role is
  considerably more complex

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Noncardiac Surgery General

• Successful perioperative evaluation and treatment
  of cardiac patients
• Teamwork and communication between
• Patient
• Primary Care Physician
• Anesthesiologist
• Surgeon
• Medical Consultant

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Preop Role of Consultant

• Assess individual patients risk of cardiac
  complications
• Determine if specialized testing is appropriate
• Recommend risk reduction strategies
• Participate in postoperative medical management

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Pre-Operative Cardiac Evaluation

• What is the question?

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Pre-Operative Cardiac Evaluation

• Can this patient reasonably have noncardiac
  surgery?

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Pre-Operative Cardiac Evaluation

• Would coronary revascularization improve the
  long-term prognosis from a cardiac standpoint and
  protect the patient from adverse events during
  the necessary noncardiac surgery?

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Preoperative Risk Assessment

• Dripps-ASA classification
• Goldman classification
• ACC recommendations

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ASA Physical Status Assessment

• Class I Healthy patient/elective operation
• Class II Patient with mild systemic disease
• Class III Severe systemic disease that limits
  activity but is not incapacitating
• Class IV Incapacitating systemic disease that
  is a constant threat to life
• Class V Moribund patient not expected to
  survive 24 hours with or without operation

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Dripps-ASA ClassificationShortcomings

• Subjective
• Poorly reproducible in certain subsets
• Elderly
• Obese
• Prior MI
• Mild systemic diseases

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Preoperative Cardiac AssessmentGoldman
Classification

• Predicts life-threatening cardiac complications
  or perioperative cardiac death based on presence
  of preoperative risk factors

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Goldman Multifactorial Index
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Goldman Multifactorial Index
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Preoperative Cardiac Assessment

• American College of Cardiology Recommendations
  JACC 199627910-948

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Noncardiac Surgery General

• Indications for further cardiac
  testing/treatments are the same as those in the
  nonoperative setting
• Urgency of noncardiac surgery
• Patients risk factors
• Specific surgical considerations

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Noncardiac Surgery General

• Preoperative testing should be limited to
  circumstances in which the results affect patient
  treatment and outcomes

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Noncardiac Surgery General

• A conservative approach to the use of expensive
  tests and treatments is recommended

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Preop Cardiac EvaluationConsiderations

• Type of surgery
• Functional capacity
• Clinical history and physical examination

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Noncardiac Surgery Higher Risk Procedures

• Vascular
• Prolonged, complicated
• Thoracic
• Abdominal
• Head and neck
• Total hip replacement

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Preop Cardiac Evaluation

• Patients with a low functional capacity (less
  than 4 Mets) have a worse prognosis than patients
  with a good functional capacity

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Preop Cardiac Evaluation

• Clinical data from a careful history and physical
  examination are the critical initial steps

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Noncardiac Surgery Preoperative Clinical
Evaluation

• Identification of potentially serious cardiac
  disorders
• Prior MI
• Angina pectoris
• Congestive heart failure
• Symptomatic arrhythmias
• Significant valvular heart disease

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Noncardiac SurgeryPreoperative Clinical
Evaluation

• Preexisting manifested heart disease
• Presence
• Severity
• Stability
• Prior treatment

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Noncardiac Surgery Preoperative Clinical
Evaluation

• Always
• History
• Physical exam
• ECG
• Commonly
• Echocardiogram/EST
• Sometimes
• Cardiac cath/MUGA scan

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Preoperative ECGsRecommended

• Intrathoracic surgery
• Intraperitoneal surgery
• Aortic surgery
• Neurosurgical procedure
• Emergency operations

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Preoperative ECGsRecommended

• History/physical suggesting heart disease
• Men gt 40-45 years old
• Women gt 55 years old
• Systemic conditions that may be associated with
  unrecognized cardiac abnormality
• Medications that can cause cardiac toxicity or
  ECG changes
• Patients at risk for major electrolyte
  abnormalities

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Methods of Assessing Cardiac RiskExercise
Stress Testing

• Provides substantial information about risk of
  perioperative MI/cardiac death
• Poor functional capacity, particularly associated
  with myocardial ischemia predicts high risk
• Gradient of increasing ischemic risk seen in
  association with degree of functional capacity,
  symptoms of ischemia, severity of ischemia, and
  hemodynamic instability

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Methods of Assessing Cardiac RiskPharmacological
Stress Testing

• Dipyridamole or adenosine with thallium/sestamibi
• High sensitivity/specificity for perioperative
  events, especially in intermediate risk group
• Perioperative ischemic events appear to correlate
  with the magnitude of ischemia
• Pharmacological stress testing involving
  echocardiogram is a viable option

35
Methods of Assessing Cardiac RiskResting LV
Function

• LVEF lt 35 increases risk of surgery
• Severe diastolic dysfunction increases risk of
  surgery
• Evaluate LV function in presence of CHF
• Probable evaluation of LV function with history
  of CHF or dyspnea of unknown etiology

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Management Options after Noninvasive Testing

• Intensified medical therapy
• Cardiac catheterization
• Cancel or delay surgery
• Proceed with surgery
• Coronary revascularization prior to surgery

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Noninvasive Pre-Op Testing

• The good news is that noninvasive tests are
  sensitive to the presence of CAD
• The bad news is that the positive predictive
  value is poor because the likelihood of
  perioperative events is less than 10

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Methods of Assessing Cardiac RiskCoronary
Angiography

• Appropriate in certain patients at high risk,
  including those with evidence of significant
  ischemia or suspicion of left main/three-vessel
  CAD
• Indications are similar to those in the
  nonoperative setting
• Essential that management with PTCA/CABG is a
  viable option

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Coronary AngiographyClass I Indications

• High-risk results during noninvasive testing
• Angina pectoris unresponsive to adequate medical
  therapy
• Most patients with unstable angina
• Nondiagnostic or equivocal noninvasive test in a
  high-risk patient undergoing a high-risk
  noncardiac surgical procedure

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Coronary AngiographyClass II Indications

• Intermediate-risk results during noninvasive
  testing
• Nondiagnostic or equivocal noninvasive test in a
  lower-risk patient undergoing a high-risk
  noncardiac surgical procedure
• Urgent noncardiac surgery in a patient
  convalescing from acute MI
• Perioperative MI

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Noncardiac SurgeryPreoperative CABG

• Indications are same as those in the nonoperative
  setting
• Cardiac risk of CABG often exceeds that of
  noncardiac surgery
• Rarely indicated simply to get a patient through
  the perioperative period

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Noncardiac SurgeryPreoperative PTCA

• No controlled trials
• Several small observational studies suggest that
  cardiac death is infrequent in patients who have
  PTCA prior to noncardiac surgery
• Indications are similar to those in nonoperative
  setting

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Noncardiac Surgery Emergency/Immediate Surgery

• Consultant may function best by making
  recommendations for perioperative medical
  management and surveillance
• Postoperative risk stratification may be
  appropriate for some patients who have not had
  such an assessment

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Major Clinical Predictors of Increased
Perioperative Cardiovascular Risk

• Unstable coronary syndromes
• Recent MI with evidence of ischemic risk
• Unstable or severe angina
• Decompensated CHF
• Significant arrhythmias
• High-grade AV block
• Symptomatic ventricular arrhythmias
• SVTs with uncontrolled ventricular rate
• Severe valvular disease

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Noncardiac Surgery Major Clinical Predictors

• Cancel or delay surgery if surgery is elective
• Many of these patients are referred for coronary
  angiography

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Major Clinical Predictors
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Intermediate Predictors on Increased
Perioperative Cardiovascular Risk

• Mild angina pectoris
• Prior MI by history or pathological Q-waves
• Compensated or prior CHF
• Diabetes mellitus

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Noncardiac SurgeryIntermediate Clinical
Predictors

• Consideration of functional capacity ( risk
  increased in patients unable to meet 4-METs of
  activity )
• Consideration of level of surgery-specific risk
• Type of surgery
• Degree of hemodynamic stress

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Cardiac Event Risk Stratification

• High Risk ( gt 5 )
• Emergent major operations, particularly in the
  elderly
• Aortic and other major vascular
• Peripheral vascular
• Anticipated prolonged surgical procedures
  associated with large fluid shifts and/or blood
  loss

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Cardiac Event Risk Stratification

• Intermediate Risk ( lt 5 )
• Carotid endarterectomy
• Head and neck
• Intraperitoneal and intrathoracic
• Orthopedic
• Prostate

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Cardiac Event Risk StratificationPatients w/
Intermediate Predictors

• Patients with moderate/excellent functional
  capacity can generally undergo intermediate-risk
  surgery
• Consider further noninvasive testing
• Poor functional capacity/intermediate-risk
  surgery
• Moderate functional capacity/high-risk surgery

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Intermediate Predictors
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Minor Predictors of Increased Perioperative
Cardiovascular Risk

• Advanced age
• Abnormal ECG
• Rhythm other than sinus
• Low functional capacity
• Uncontrolled systemic hypertension

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Noncardiac SurgeryCABG within Five Years

• Stable clinical status without recurrent
  symptoms/signs of ischemia
• Further cardiac testing generally not necessary

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Noncardiac SurgeryStable Angina/CABG gt 5 Years

• Coronary evaluation within past two years?
• Favorable findings
• Usually not necessary to repeat testing unless
  there has been a change in symptoms

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Cardiac Event Risk StratificationPatients w/
Minor Predictors

• Noncardiac surgery generally safe
• Further testing on an individual basis ( patients
  with several minor clinical predictors facing
  higher-risk operations, ie vascular surgery )

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Minor Predictors
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• Management of Specific Preoperative
  Cardiovascular Conditions

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Noncardiac Surgery Hypertension

• Severe hypertension should be controlled before
  surgery when possible
• Continuation of preoperative antihypertensive
  treatment through the perioperative period is
  critical

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Hypertension

• Perioperative swings of pressure often occur in
  hypertensive patients
• Patients who are adequately treated
  preoperatively have less marked deviations of
  blood pressure
• Surges of BP most common during
• Induction
• Intubation
• Skin incicision
• 12 to 24 hours post-op

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Noncardiac SurgeryValvular Heart Disease

• Indications for evaluation/treatment identical to
  those in nonoperative setting
• Symptomatic stenotic lesions associated with risk
  of perioperative CHF/shock
• Symptomatic regurgitant lesions usually better
  tolerated perioperatively

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Patients on Anticoagulants Preop

• Risk of surgical hemorrhage vs. danger of serious
  embolization

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Patients on Anticoagulants PreopLow Risk for
Thromboembolism

• Discontinue coumadin 3 days preop
• Restart coumadin postop

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Patients on Anticoagulants PreopHigh Risk for
Thromboembolism

• Discontinue coumadin 3 days preop
• Begin heparin by constant infusion, maintaining
  PTT 1.5 - 2.5 X control
• Discontinue heparin 6 - 8 hrs preop
• Shortly after surgery, restart IV heparin and po
  coumadin
• Discontinue heparin infusion when PT is
  therapeutic
• Low molecular weight heparin may be used as an
  alternative agent to IV fractionated heparin

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Patients on Coumadin PreopRisk for
Thromboembolism

• Higher Risk
• Atrial fibrillation with structural heart disease
• Prosthetic mitral valve with or without a fib
• Prosthetic aortic valve with a fib

• Lower Risk
• Atrial fibrillation without structural heart
  disease
• Prosthetic aortic valve with sinus rhythm and
  normal ejection fraction

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• The optimal management of patients with known
  coronary artery disease remains complex.

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Noncardiac SurgeryMedical Rx of CAD

• Continuation of preoperative medications into the
  operative and postoperative period recommended
  for ischemic protection
• Beta blockers reduce the incidence of
  postoperative ischemia

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Beta Blockade in Patients Undergoing Major
Vascular Surgery

• Randomized trial of 112 patients
• Started on bisoprolol one week prior to surgery
• Followed for 30 days
• Cardiac complication rate/placebo 33.9
• Cardiac complication rate/bisoprolol 3.4
• Poldermans D. NEJM 19993411789-1794

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Noncardiac SurgeryIntraoperative Nitroglycerin

• Insufficient data on use of prophylactic
  intraoperative nitroglycerin
• Vasodilatory properties when combined with
  anesthetic agent may lead to hypotension and
  ischemia
• Hemodynamic effects of other agents needs to be
  considered

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Noncardiac SurgeryCongestive Heart Failure

• Patients with preop CHF are at increased risk for
  postoperative exacerbation
• Treatment of manifestations of heart failue
  before surgery may reduce complication rates
• Overdiuresis may lead to hypotension
• New onset of CHF in patients without prior
  history suggests postop MI

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Noncardiac SurgeryArrhythmias Conduction
Abnormalities

• Careful evaluation for underlying cardiopulmonary
  disease, drug toxicity, or metabolic abnormality
• Indications for antiarrhythmic therapy and
  cardiac pacing identical to those in the
  nonoperative setting

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Noncardiac SurgeryEvaluation of Pulmonary
Function

• Patients scheduled for thoracic surgery
• Patients scheduled for upper abdominal surgery
• Patients w/ history of heavy smoking/cough
• Obese patients
• Patients gt 70 years of age
• Patients with pulmonary disease
• Value of routine PFTs remains controversial NEJM
  1999340937

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PFTs Indicators of High Risk
Morbidity/Mortality

• Spirometric
• Maximal breathing capacity lt 50 predicted
• FEV1 lt 2.0 liters
• Arterial Blood Gases
• Arterial PCO2 gt 45 mm/hg
• Hypoxemia not reliable

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Noncardiac SurgeryAnesthetic Agent

• Choice should be left to the discretion of the
  anesthesia care team
• Opiod-based anesthetics popular because of
  cardiovascular stability, but high doses result
  in postoperative ventilation
• All inhalational agents have cardiovascular
  effects

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• Any anesthetic technique that does not
  effectively eliminate pain will be associated
  with markedly increased cardiac demands

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Noncardiac SurgeryAnesthetic Agent

• Neuraxial Techniques
• Spinal and epidural anesthesia
• Cause sympathetic blockade
• Infrainguinal procedures associated with mininal
  hemodynamic changes
• Abdominal procedures may result in more profound
  effects hypotension/reflex tachycardia

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Noncardiac SurgeryAnesthetic Agent

• Monitored Anesthesia
• Local anesthesia supplemented by intravenous
  sedation/analgesia
• Failure to produce complete anesthesia may lead
  to increased stress response producing myocardial
  ischemia

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Noncardiac SurgeryPerioperative Pain Management

• Patient-controlled intravenous and/or epidural
  analgesia
• Reduces severity and duration of postoperative
  pain
• Reduction in postoperative catecholamine surges
  and hypercoagulability
• Theoretically may decrease myocardial ischemia

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Noncardiac SurgeryPulmonary Artery Catheters

• Patients most likely to benefit
• Recent MI complicated by CHF
• Patients with significant CAD undergoing
  procedures associated with significant
  hemodynamic stress
• Patients with systolic/diastolic dysfunction,
  cardiomyopathy, and valvular disease undergoing
  high-risk operations

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Noncardiac Surgery Postop Ischemia

• Myocardial ischemia more common, more severe in
  early postoperative phase
• Infarction is frequently silent
• Non-Q MI often occurs on the first or second
  postoperative days
• Q-wave MI often occurs on the second to fourth
  postoperative days
• CHF/pulmonary edema commonly occurs on postop day
  2 or later

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Noncardiac SurgerySurveillance for
Perioperative MI

• Few studies have examined the optimal method
• Indicators of ischemia
• Clinical symptoms
• ECG changes
• Elevation of cardiac enzymes

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Noncardiac SurgerySurveillance for
Perioperative MI

• Patients without known CAD surveillance should
  probably be restricted to patients with signs of
  cardiovascular dysfunction
• Patients with known or suspected CAD undergoing
  high-risk procedures baseline, then serial
  ECGs recommended
• Cardiac enzymes reserved for patients with
  evidence of cardiovascular dysfunction

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Noncardiac SurgeryST-Segment Monitoring

• ST changes indicating myocardial ischemia are
  strong predictors of perioperative MI in patients
  at high clinical risk
• Postoperative ischemia is a significant predictor
  of long-term MI/cardiac death
• ST depression in low-risk patients may be a
  nonspecific finding

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Noncardiac SurgeryPostop Rx and Long-Term
Management

• Assessment and management of modifiable risk
  factors for cardiovascular disease
• May be first opportunity for a systematic
  cardiovascular evaluation in many patients
• Patients who experience repetitive postop
  myocardial ischemia and/or myocardial infarction
  are at substantially increased risk