perioperative cardiovascular evaluation for noncardiac surgery

Perioperative Cardiovascular Evaluation for Noncardiac Surgery

By :Mahmoud M Othman MD,

Prof of Anesthesia & SICU,

Mansoura faculty of Medicine.

General Approach

Team Work– Patient – Primary care physician– Anesthesiologist– Surgeon– Medical consultant

Preoperative Clinical Evaluation Identification of serious cardiac disorder

– CAD, CHF, Arrhythmias(Initial history, Physical examination, ECG)

Define disease severity, stability, and prior treatment Functional capacity Age Comorbid conditions

(DM, peripheral vascular disease, renal dysfunction, chronic pulmonary disease)

Type of surgery– Consider higher risk

• vascular procedures• prolonged complicated thoracic, abdominal and head an

d neck procedures

Further Preoperative Testing to Assess Coronary Risk

CAD is the most frequent cause of perioperative cardiac mortality and morbidity after noncardiac surgery

Step-wise Bayesian strategyclinical markers

prior coronary evaluation and treatment

functional capacity

surgery-specific risk

Need for noncardiac surgery

O.R.emergencyPostoperative risk stratification and risk factor management

Urgent or elective

Coronary revascularization within 5 yrs

Recurrent symptoms or signs

Recent coronary evaluation

Recent coronary angiogram or stress test?

Intermediate

Clinical predictors

Major Minor or No

O.R.

yes

Unfavorable result and change in symptoms

favorable result and no change in symptoms

Stepwise Approach to Preoperative Cardiac Assessment

no

no

yes

yes

no

Major clinical predictors•Unstable coronary syndromes•Decompensated CHF•Significant arrhythmias•Severe valvular disease

Major clinical predictors

delay or cancel noncardiac surgery

Medical managementand risk factor modification

Coronaryangiography

Subsequent care dictated by findingsand treatment results


Intermediate clinical predictors•Mild angina pectoris•Prior MI•Compensated or prior CHF•DM

Intermediate clinical predictors

Poor(<4METs)

Moderate or excellent(>4METs)

High surgicalrisk precedure

Intermediate or lowsurgical precedure

Low surgicalrisk procedure

Noninvasivetesting

O.R. Postoperative risk stratificationand risk factor reduction

Consider coronaryangiography

Subsequent care dictated by findingsand treatment results

Low risk

High risk


Minor or no clinical predictors

Poor(<4METs) Moderate or excellent(>4METs)

High surgicalrisk procedure

Intermediatesurgical riskprocedure

Noninvasive testing O.R. Postoperative management

Subsequent care by findings and treatment results

Consider coronary angiographyMinor clinical predictors•Advanced age•Abnormal ECG•Rhythm other than sinus•Low functional capacity•History of stroke•Uncontrolled systemic hypertension

High risk

low risk


Clinical Predictors of Increased Perioperative Cardiovascular Risk(Myocardial Infarction, Congestive Heart Failure, Death)

MajorUnstable coronary syndromes– Recent myocardial infarction with evidence of important ischemic

risk by clinical symptoms or noninvasive study– Unstable or severe angina(Canadian Cardiovascular Society Class

III or IV)Decompensated CHFSignificant arrhythmias– High grade atrioventricular block– Symptomatic ventricular arrhythmias in the presence of underlying

heart disease– Supraventricular arrhythmias with uncontrolled ventricular rateSevere valvular disease

Clinical Predictors of Increased Perioperative Cardiovascular Risk(Myocardial Infarction, Congestive Heart Failure, Death)

IntermediateMild angina pectoris(Canadian Cardiovascular Society Class I or II)Prior myocardial infarction by history or pathological wavesCompensated or prior CHFDM

MinorAdvanced ageAbnormal EKG(LVH, LBBB, ST-T abnormalities)Rhythm other than sinus(eg, atrial fibrillation)Low functional capacity(eg, unstable to climb one flight or stairs with a bag of

groceries)History of strokeUncontrolled systemic hypertension

Estimated Energy Requirements for Various Activities

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 mphor 3.2-4.8 km/hrDo light work around the house dusting or washing dishes?

Climb a flight of stairs or walk up a hillWalk 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 moving heavy furniture?Participate in moderate recreational activities like golf, bowling, dancing, doubles tennis, or throwing a baseball or football?Participate in strenuous sports like swimming, singles tennis, football, basket ball, or skiing

1 MET

4 METs

4 METs

>10 METs

Cardiac Event Risk† Stratification for Noncardiac Surgical Procedures

High(reported cardiac risk often >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

Intermediate(Reported cardiac risk generally <5%)•Carotid endarterectomy•Head and neck•Intraperitoneal and intrathoracic•Orthopedic•Prostatic

Low‡

(reported cardiac risk generally <1%)•Endoscopic procedures•Superficial procedures•Cataract•Breast

† Combind incidence of cardiac death and nonfatal myocardial infarction

‡ Further preoperative cardiac testing is not generally required.

Method of Assessing Cardiac Risk

Resting Left Ventricular Function

Exercise Stress Testing

Pharmacological Stress Testing

Ambulatory ECG monitoring

Coronary Angiography


Resting Left Ventricular Function– Increased risk:

• Ejection fraction < 35%• severe diastolic dysfunction

– CHF– prior CHF or dyspnea of unknown etiology


Exercise Stress Testing – treadmill or bicycle stress and ECG analysis,

echocardiography– degree of functional incapacity, symptoms of

ischemia, severity of ischemia(depth, time of onset, duration of ST depression), evidence of hemodynamic or electrical instability correlated with increasing ischemic risk


Pharmacological Stress Testing– for patients who are unable to exercise– Dipyridamole or adenosine with thallium

myocardial perfusion imaging– Dobutamine echocardiography

Ambulatory ECG Monitoring Coronary Angiography

Indications for Coronary Angiography in Perioperative Evaluation Before (or After) Noncardiac Surgery

Class I:Patients with suspected or proven CAD

–High-risk results during noninvasive testing

–Angina pectoris unresponsive to adequate medical therapy

–Most patient with unstable angina pectoris

–Nondiagnostic or equivocal noninvasive test in a high-risk noncardiac surgical procedure

Class I: conditions for which there is evidence for and/or general agreement that a procedure or a treatment is of benefit


Class II:

– Intermediate-risk results during noninvasive testing

–Nondiagnostic or equivocal noninvasive test in a lower-risk patients undergoing a high-risk noncardiac surgical procedure

–Urgent noncardiac surgery in a patient convalescing from acute MI

–Perioperative MIClass II: conditions for which there is a divergence of evidence and/or opinion about the treatment


Class III:– Low-risk noncardiac surgery in a patient with known CAD and

low-risk results on noninvasive testing– Screening for CAD without appropriate noninvasive testing– Asymptomatic after coronary revascularization, with excellent

exercise capacity(>7METs)– Mild stable angina in patients with good LV function, low-risk

noninvasive test results– Patient is not a candidate for coronary revascularization because

of concomitant medical illness– Prior technically adequate normal coronary angiogram within

previous 5years– Severe LV dysfunction(e.g., EF<20%) and patient not considered

candidate for revascularization procedure– Patient unwilling to consider coronary revascularization

procedure

Class III: conditions for which there is evidence and/or general agreement that the procedure is not necessary

Management of Preoperative Cardiovascular Conditions

Hypertension Valvular Heart Disease Myocardial Heart Disease Arrhythmias and Conduction Abnormalities


Hypertension– Severe HBP(DBP >110) should be controlled

before surgery when possible– Continuation of preoperative antihypertensive

treatment is critical to avoid severe postoperative hypertension.

– Consider the urgency of surgery and the potential benefit of more intensive medical therapy.


Valvular Heart Disease– Symptomatic stenotic lesions(MS or AS):

associated with risk of perioperative severe CHF or shock and often require percutaneous valvotomy or replacement to lower cardiac risk.

– Symptomatic regurgitant lesions(AR or MR): usually better tolerated perioperatively and may be stabilized before surgery with intensive medical therapy and monitoring


Myocardial Heart Disease– Dilated and hypertrophic cardiomyopathy are

associated with an increased incidence of perioperative CHF.

– Maximizing preoperative hemodynamic status and providing intensive postoperative medical therapy and surveillance.

Management of Preoperative Cardiovascular Conditions Arrhythmias and Conduction Abnormalities

– careful evaluation for underlying cardiopulmonary disease, drug toxicity, or metabolic abnormality.

– Therapy: reverse any underlying cause and treat the arrhythmia

Preoperative Coronary Revascularization

Coronary Artery Bypass Graft Surgery Coronary Angioplasty

Medical Therapy for Coronary Artery Disease

If patients require beta-blockers, calcium channel blockers, or nitrates before surgery, continue them into the operative and post-op period.

The same is true for therapies used to control CHF

Beta-blockers reduce postoperative ischemia,– Protection against ischemia may also reduce risk of MI

Anesthetic Considerations

Anesthetic agent– No one best myocardial protective anesthetic techniq

ue.– Opioid:cardiovascular stability, but need postoperativ

e ventilation– Inhalational agent: myocardial depression– Neuraxial block: sympathetic blockade

low level:minimal hemodynamic change

abdominal operation: profound effects(hypotension, reflex tachycardia)


Perioperative pain management– PCA(iv or epidural) leads to a reduction in post

operative catecholamine surges and hypercoagulability, both of which can theoretically impact myocardial ischemia.


Intraoperative nitroglycerine– Helpful or harmful

vasodilating properties of NTG with anesthetics can cause significant hypotension and even myocardial ischemia.

Transesophageal echocardiography– Guidelines for the use of TEE to diagnosis or

guide therapy are being developed by ASA

Perioperative Surveillance

Pulmonary artery catheters– recent MI complicated by CHF

– significant CAD with procedures assoc. with significant hemodynamic stress.

– Systolic or diastolic LV dysfunction

– cardiomyopathy

– valvular disease with high risk operation


Intraoperative and postoperative ST monitoring– Intraoperative and postoperative ST changes ar

e strong predictors of perioperative MI in patients at high risk who undergo noncardiac surgery

– proper use of computerized ST-segment analysis may improve sensitivity for detection of myocardial ischemia


Surveillance for perioperative MI– Clinical symptoms– Postoperative ECG changes– CK-MB, troponin-I, troponin-T, CK-MB isoforms– In patients with known or suspected CAD undergoing high

risk procedures, obtaining ECG at baseline, immediately after the procedure, and for the first 2 postoperative days appears to be cost effective

– Use of cardiac enzymes is best reserved for patients with clinical, ECG, or hemodynamic evidence of cardiovascular dysfunction.

Postoperative Therapy and Long-Term Management

Postoperative management should include assessment and management of modifiable risk factors for CAD, heart failure, HBP, stroke, and other cardiovascular diseases.

Assessment for hypercholesterolemia, smoking, hypertension, DM, physical inactivity, peripheral vascular disease, cardiac murmur(s), arrhythmias, perioperativeischemia, and MI may lead to evaluation and treatments that reduce future cardiovascular risk

perioperative cardiovascular evaluation for noncardiac surgery

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