Pre-operative Cardiac Assessment



Pre-operative Cardiac Assessment


Debabrata Mukherjee

Kim A. Eagle



Patients with peripheral vascular disease necessitating vascular surgery often have co-existent coronary artery disease (CAD) and are at an increased risk for cardiac complications because the risk factors contributing to peripheral vascular disease (e.g., diabetes mellitus, tobacco use, hyperlipidemia, hypertension) are also risk factors for coronary atherosclerosis. The usual symptoms of CAD in these patients may be absent due to limiting intermittent claudication or advanced age. CAD symptoms may be atypical in female patients. Likewise, major arterial operations are time-consuming and may be associated with substantial fluctuations in extravascular fluid volumes, cardiac filling pressures, systemic blood pressure, heart rate, and thrombogenicity. Pre-operative risk assessment is an important step in helping to reduce perioperative morbidity and mortality in this high-risk group. Answers to a few basic questions regarding general health, functional capacity, cardiac risk factors, comorbid conditions, and the type of operation allow an initial overall estimate of cardiac risk.

Overall, cardiac complications account for >50% of the morbidity and mortality seen after vascular surgery. Fatal events are almost five times more likely to occur in the presence of standard pre-operative indicators of CAD, and appropriate pre-operative measures may significantly reduce risk.


Clinical Evaluation

The purpose of pre-operative evaluation is not to clear patients for surgery but to assess medical status, cardiac risks posed by the planned surgery, and recommend strategies to reduce risk. The history and physical examination should be focused on identification of cardiac risk factors and current cardiac status. The goal is to identify cardiac conditions such as recent myocardial infarction (MI), heart failure (HF), unstable angina, significant arrhythmias, and significant valvular heart disease. One should also identify serious comorbid conditions such as diabetes, stroke, renal insufficiency, and pulmonary disease, as these illnesses are important predictors of adverse periprocedural outcomes. The history should elicit functional capacity and ability to perform activities of daily living. An individual’s functional capacity (Table 7-1) has significant prognostic implications. However, claudication in patients with peripheral vascular disease may make it difficult to precisely assess the individual’s functional capacity using only clinical criteria.








Table 7-1 Assessment of Functional Capacity and Estimated Energy Requirements for Various Activities


















































• 1 MET

• Eat, dress, use the toilet

• Walk indoors around the house

• Walk on level ground at 2 mph

• Complete light housework, such as washing dishes


• 4 METs

• Climb a flight of stairs

• Walk on level ground at 4 mph

• Run short distance

• Lift heavy furniture or vacuum

• Play golf or doubles tennis


• >10 METs

• Swimming

• Singles tennis

• Basketball

• Skiing


(Modified from Eagle KA, Berger PB, Calkins H, et al. ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery—Executive Summary. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2002;39:542-553. Eagle KA, Brundage BH, Chaitman BR, et al. Guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery. Circulation 1996; 93:1278-1317.)


The physical examination should include examination of the general appearance (cyanosis, pallor, dyspnea during conversation and/or minimal activity, Cheyne-Stokes respiration, poor nutritional status, obesity, skeletal deformities, tremor, and anxiety), blood pressure in both arms, carotid pulses, extremity pulses, and ankle-brachial indices. Jugular venous pressure and positive hepatojugular reflex are reliable signs of hypervolemia in chronic HF, and pulmonary rales and chest x-ray are more indicative of pulmonary congestion in acute HF. Auscultation for cardiac rhythm, heart sounds (murmurs, gallops) and abdominal examination for aneurysm should also be performed. The physical exam can point to the presence of a pacemaker or implantable defibrillator (ICD),
which might need to be reprogrammed in the peri-operative period. Patients with a significant aortic stenosis murmur, elevated jugular venous pressure, pulmonary edema, and/or a third heart sound are at high surgical risk. Clinical predictors of increased peri-operative cardiovascular risk based on the American Heart Association/American College of Cardiology (AHA/ACC) guidelines are summarized in Table 7-2.








Table 7-2 Clinical Predictors of Increased Peri-operative Cardiovascular Risk


























































































•

Major predictors

•

Acute or recent MI* with evidence of ischemia based on symptoms or noninvasive testing

•

Unstable or severe† angina (Canadian class III or IV)‡

•

Decompensated HF

•

High-grade atrioventricular block

•

Symptomatic ventricular arrhythmias with underlying heart disease

•

Supraventricular arrhythmias with uncontrolled ventricular rate

•

Severe valvular heart disease


•

Intermediate predictors

•

Mild angina pectoris (Class 1 or 2)

•

Prior MI by history or Q waves

•

Compensated or prior HF

•

Diabetes mellitus (particularly insulin-dependent)

•

Renal insufficiency (creatinine ≥2.0 mg/dL)


•

Minor predictors

•

Advanced age

•

Abnormal ECG (left ventricular hypertrophy, left bundle branch block, ST-T abnormalities)

•

Rhythm other than sinus (e.g., atrial fibrillation)

•

Low functional capacity (inability to climb one flight of stairs with a bag of groceries)

•

History of stroke

•

Uncontrolled systemic hypertension


ECG, electrocardiogram


* Recent MI is defined as greater than 7 days but less than or equal to one month; acute MI is within 7 days

† May include stable angina in patients who are usually sedentary

‡ Campeau L. Letter: Grading of angina pectoris. Circulation 1976;54:522-523.


(Adapted from Eagle KA, Berger PB, Calkins H, et al. ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery—Executive Summary. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2002;39:542-553.)


While clinical factors and risk indices are an important part of the evaluation of most patients, clinical evidence of CAD may be obscured in patients with peripheral vascular disease. Thus, risk classifications based exclusively on clinical criteria may not be as helpful when applied to patients with peripheral vascular disease as compared to a general population. Figure 7-1 demonstrates a stepwise approach to cardiac risk assessment prior to noncardiac surgery.


Type of Surgery

The type of surgery has significant implications for peri-operative risk. Table 7-3 categorizes surgery into high, intermediate, and low risk. Patients undergoing major vascular surgery constitute a particular challenge (i.e., high-risk operations in a patient population with a high prevalence of significant CAD). Several studies have attempted to stratify the incidence of perioperative and intermediate-term outcomes according to the type of vascular surgery performed. In a prospective series of 53 aortic procedures and 87 infra-inguinal bypass grafts, Krupski et al. demonstrated that the risk for fatal/nonfatal MI within a 2-year follow-up period was 3.5 fold higher (21% vs. 6%) among patients who received infra-inguinal bypass grafts. This difference is potentially attributable to the fact that diabetes mellitus, history of previous MI, angina, or HF were all significantly more prevalent in the infra-inguinal bypass group. Fleisher et al. analyzed a sample of Medicare claims of patients undergoing major vascular surgery. In this analysis, 2,865 individuals underwent aortic surgery with a 7.3% 30-day mortality rate and an 11.3% 1-year mortality rate; 4,030 individuals underwent infra-inguinal surgery with a 5.8% 30-day mortality rate and 16.3% 1-year mortality rate. This study further showed that aortic and infra-inguinal surgery continues to be associated with high 30-day and 1-year mortality, with aortic surgery being associated with the highest short-term and infra-inguinal surgery being associated with the highest long-term mortality rates. L’Italien et al. presented comparable data regarding the peri-operative incidence of fatal/nonfatal MI and the 4-year event-free survival rate after 321 aortic procedures, 177 infra-inguinal bypass grafts, and 49 carotid endarterectomies. Slight differences in the overall incidence of MI among the three surgical groups, which may have been related to the prevalence of diabetes mellitus, were exceeded almost entirely in significance by the influence of cardiac risk factors (previous MI, angina, HF, fixed or reversible thallium defects, and ST-T depression during stress testing). These and other
studies suggest that presence and severity of CAD in a patient who has peripheral vascular disease appear to be better predictors of subsequent cardiac events than the type of peripheral vascular surgery performed.








Table 7-3 Cardiac Risk Stratification for Different Types of Surgical Procedures














































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Jun 16, 2016 | Posted by in CARDIAC SURGERY | Comments Off on Pre-operative Cardiac Assessment

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• High risk (reported cardiac risk* >5%)

• Emergency major operations, particularly in the elderly

• Aortic, major vascular, and peripheral vascular surgery

• Extensive operations with large volume shifts/and or blood loss


• Intermediate risk (reported cardiac risk <5%)

• Intraperitoneal and intrathoracic

• Carotid endarterectomy

• Head and neck surgery

• Orthopedic

• Prostate


• Low risk† (reported cardiac risk <1%)

• Endoscopic procedures

• Superficial biopsy

• Cataract

• Breast surgery


* Combined incidence of cardiac death and nonfatal MI

† Do not generally require further pre-operative cardiac testing