Preoperative Evaluation of Cardiac Patients Undergoing Non-cardiac

Surgery

Moderator: Prof. Dr Baburaja Shrestha

22 Dec,2014

• 1-5 % of unselected pts have perioperative cardiac morbiditya

• Pre-op Approachclinical risk indicespre-op cardiac testing

Cardiac disease

• Structural heart disease• Coronary artery disease• Valvular heart disease• Cardiomyopathies• Heart failure / Cor pulmonale

Perioperative cardiac morbidity

• 1-5% of unselected pts• Myocardial infarction

• Heart failure

• Arrhythmias

• Sudden Cardiac death

Goals

• Define risks• Determine if further testing beneficial• Appropriate anesthetic plan• Peri-op ?beta blockade, interventional

therapy,

History • Symptoms, h/o cardiac disease

• Associated co-morbidities: peripheral vascular disease, cerebrovascular disease, diabetes mellitus, renal impairment, and chronic pulmonary disease

• History of surgery, anesthetic course

• Use of mechanical devices: ICD/pacemaker/stents/prosthetic valves

• Exercise tolerance

• Indicators of disease severity: PND, orthopnea, dyspnea, angina

• recent change in symptoms?

• Drug therapy & compliance : disease specific; over-the-counter and illicit drugs, herbal and other nutritional supplements; dosages/compliance/side-effects

• Alcohol, tobacco use

• Bleeding tendencies

Physical examination

• General appearance provides invaluable evidence of patient’s overall status

• Assessment of vital signs (including measurement of blood pressure in both arms)

• Carotid pulse contour and bruits, jugular venous pressure and pulsations, auscultation of the lungs, precordial palpation and auscultation, abdominal palpation, and examination of the extremities for edema and vascular integrity.

• The presence of an implanted pacemaker or ICD

Risk Stratification

• Risk indices range from ASA-PS grading to Goldman to revised cardiac risk index

Goldman’s cardiac risk index

Risk factors Points

Third heart sound, raised JVP 11

Recent myocardial infarction (within 6 months) 10

Rhythm other than sinus or >5 premature atrial contractions

7

>5 premature ventricular contractions/min 7

Age >70 yrs 5

Emergency operations 4

Poor general health condition 3

Intrathoracic, intraperitoneal or aortic surgery 3

Severe aortic stenosis 3

Total score 53

Interpretation of scores of Goldman’s cardiac risk index

Points Risk of cardiovascular complications

0-5 1%

6-12 7%

13-25 14%

26-53 78%

Detsky cardiac risk indexRisk Points

Age older than 70 years 5

Myocardial infarction within six months 10

Myocardial infarction before six months 5

Canadian Cardiovascular Society Angina

Classification

Class III 10

Class IV 20

Unstable angina within six months 10

Alveolar pulmonary edema

Within one week 10

Ever 5

Suspected critical aortic stenosis 20

Arrhythmia

Rhythm other than sinus or sinus plus atrial premature beats 5

More than five premature ventricular beats 5

Emergency operation 10

Poor general medical status 5

Class Points Cardiac riskI 0 to 15 Low

II 20 to 30 Moderate

III 31 + High

Interpretation of scores of Detsky cardiac index

Revised Cardiac Risk IndexSIX independent predictors,1999

Clinical variable PointsHigh-risk surgery 1

H/o Ischemic heart disease 1H/o Congestive heart failure 1H/o cerebrovascular disease 1Insulin treatment for diabetes mellitus 1Pre-operative serum creatinine level >2.0 mg/dl (180 mcgmol/L) 1

Risk class Points Risks of complications (%)

I. Very low 0 0.4 %II. Low 1 0.9 %III. Moderate 2 7.0 %IV. High 3+ 11.0 %

Interpretation of risk score

Clinical Predictors of Increased Perioperative Cardiovascular Risk

• Major - Unstable coronary syndromes Acute or recent MI with evidence of important ischemic risk by clinical

symptoms or noninvasive study Unstable or severe angina (Canadian class III and IV)

- Decompensated heart failure - Significant arrhythmias High-grade atrioventricular block Symptomatic ventricular arrhythmias in the presence of underlying heart disease Supraventricular arrhythmias with uncontrolled ventricular rate - Severe valvular disease

• Intermediate - Mild angina pectoris (Canadian class I or II) - Previous MI by history or pathological Q waves - Compensated or prior heart failure - Diabetes mellitus (particularly insulin dependent) - Renal insufficiency

• Minor - Advanced age - Abnormal ECG (left ventricular hypertrophy, left bundle-branch block, ST-T

abnormalities) - Rhythm other than sinus (eg, atrial fibrillation) - Low functional capacity (eg, inability to climb one flight of stairs with a bag of groceries) - History of stroke - Uncontrolled systemic hypertension

(ACC/AHA Guideline Update on Perioperative Cardiovascular Evaluation for Noncardiac Surgery)

ACC/AHA cardiac evaluationguidelines

• Step 1- determine urgency/emergencyif emergency- risk reduction, ↑peri-op monitoring

• Step 2any active cardiac condition?Acute MI,Unstable angina, CHF, severe valvular disease, significant arrhythmiasSTILL ? Benefits > risks (lifesaving procedure)

• Postpone surgery in ACUTE, RECENT MI (with symptoms,+ve stress test)

• Step 3- determination of surgical risk/severitylow risk surgery without active cardiac condition can proceed

• STEP 4- Pts functional capacityasymptomatic/excellent functional capacity>> proceed to surgery

• Step 5 – poor functional status– Further invasive test only “if it will change the management

ACC/AHAguidelines

Disease specific

Hypertension

• Two or more readings > 140/90

• PAC an opportunity to identify pts with HTN & initiate therapy

• Degree of end-organ damage, morbidity & mortality correlate with disease duration and severity

• IHD most common end organ damage associated

• HTN with LVH have higher peri-op risk than non HTN (Barash,7th edn)

• Evaluate to identify causes of HTN, end organ damage, therapy and compliance

• Order ECG, BUN,Creatinineelectrolytes if on diuretics

• LVH and strain pattern>> futher evaluation• Dyspnea/heart failure >> ECHO• Little association between SBP <180 mm Hg or DBP

<110 mm Hg and peri-op outcomes • In the absence of end-organ changes (eg renal

insufficiency/ LV strain) the benefits of optimizing BP must be weighed against the risks of delaying surgery

Coronary Artery Disease

• History, Physical exam & ECG• RISK FACTORS as imp. as symptoms since CAD

can be insidious• Classic risk factors (age,

gender,smoking,↑cholesterol) NOT direct/independent risk to peri-op cardiac event

• Enquiry abt type, duration, precipitating/relieving factors of chest discomfort

• Dyspnea with CAD risk factors >> further IHD investigations

PERIOPERATIVE RISK OF EVENTS• Patients With No Prior History Of MI Have A Low Risk Of Perioperative

MI (0.1%-0.6%)

• Patients With A History Of Prior MI Are At A Significantly Higher Risk (2.8%-7%).

• MI Within 3 Mnths.-37% Increase In Events

• MI Within 3-6 mnths.-16% Increase In Events

• MI Greater Than 6 Mnths.-4% Increase In Events

• Taken together,data suggest that <60 days (recent MI) should elapse after a MI before noncardiac surgery in the absence of a coronary intervention

• Recent MI also independent risk factor for peri-op stroke (8 fold mortality)

Greatest risk

• Extensive 3-vessel disease• Left main disease• Ventricular dysfunction• Residual ischemia remaining from previous MI• Mortality rates exceed 50%

Heart failure

• Symptoms- SOB, fatigue,orthopnea,PND, cough,periph. edema,recent wt gain

• Signs- S3/S4, tachycardia, rales, ↑JVP,ascites,hepatomegaly

• Identification and grading

NYHA Heart Failure Classification

Class Description

1 No limitation of physical activity - ordinary physical activity doesn't cause tiredness, heart palpitations, or shortness of breath

2 Slight limitation of physical activity - comfortable at rest, but ordinary physical activity results in tiredness, heart palpitations, or shortness of breath

3 Marked or noticeable limitations of physical activity - comfortable at rest, but less than ordinary physical activity causes tiredness, heart palpitations, or shortness of breath

4 Severe limitation of physical activity - unable to carry out any physical activity without discomfort. Symptoms also present at rest. If any physical activity is undertaken, discomfort increases.

• Decompensated HF >> postpone surgery• Correlation betwn HF and BNP levels

BNP > 100pg/ml >> heart failureN-terminal pro-BNP < 300 pg/ml virtually excludes acute HF!

• ECG,CXR,electrolytes,urea/creat & possible BNP indicated

• ECHO for LVEF, Ventricular performance & diastolic function

MURMURS &VALVULAR ANOMALIES

Recommendations • CLASS I• 1. clinically suspected moderate or greater degrees of valvular

stenosis or regurgitation• undergo preop echo if

1) no prior echocardiography within 1 year or2) significant change in clinical status or physical examination since last evaluation

• 2. for indications of valvular intervention (replacement and repair) on the basis of symptoms and severity of stenosis or regurgitation, valvular intervention before elective noncardiac surgery is effective in reducing perioperative risk (15). (LOE: C)

Importance of type of surgery

Cardiac riska stratification for non-cardiac surgery

• High (reported cardiac risk often greater than 5%) - Emergent major operations, particularly in the elderly - Aortic and other major vascular surgery - Peripheral vascular surgery - Anticipated prolonged surgical procedures associated with large fluid shifts and/or blood loss

• Intermediate (reported cardiac risk generally less than 5%) - Carotid endarterectomy - Head and neck surgery - Intraperitoneal and intrathoracic surgery - Orthopedic surgery - Prostate surgery

• bLow (reported cardiac risk generally less than 1%) - Endoscopic procedures - Superficial procedure - Cataract surgery - Breast surgery

Functional capacity

METs

• functional capacity is classified asExcellent (>10 METs),Good (7 METs to 10 METs)moderate (4 METs to 6 METs),poor (<4 METs)or unknown.

• Periop cardiac and long-term risks are increased in pts unable to perform 4 METs of work during daily activities

METs

Fliesher et al. “2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery.” http://content/onlinejacc.org/

Dukes Activity status index

The 12-Lead Electrocardiogram: Recommendations

CLASS IIa• ECG reasonable for patients with known coronary heart disease,• significant arrhythmia, peripheral arterial disease, cerebrovascular• disease, or other significant structural heart disease,• except for those undergoing low-risk surgery (137–139).• (Level of Evidence: B)• CLASS IIb• ECG may be considered for asymptomatic patients without known coronary heart

disease,except for those undergoing low-risk surgery• (Level of Evidence: B)• CLASS III: NO BENEFIT• Routine 12-lead ECG is not useful for asymptomatic patients undergoing low-risk

surgical procedures• (Level of Evidence: B)

Stepwise Approach to Preoperative Cardiac Assessment

Poor(<4 METs)

6. Intermediateclinical

predictor

Moderate orexcellent(>4 METs)

Intermediateor low surgicalrisk procedure

High surgicalrisk procedure

Low surgicalrisk procedure

8. Noninvasivetesting

Considercoronary

angiography

Subsequentcare dictated

by findings andtreatment results

Operating room

Postoperativerisk stratification

and risk factorreduction

Low risk

High risk

Functionalcapacity

Surgicalrisk

Noninvasivetesting

Invasivetesting