I. Introduction
A. Background. Patients undergoing noncardiac surgeries can be at risk for major perioperative cardiac complications, particularly if they are elderly. Worldwide, it is estimated that approximately 500,000 to 900,000 patients per year undergoing noncardiac surgery suffer a perioperative cardiac death, nonfatal myocardial infarction (MI), or nonfatal cardiac arrest. Given the increasingly advanced age of patients undergoing surgeries, this risk is expected to remain substantial. The risk of death from a perioperative MI may be as high as 50%. The elevated risk of perioperative MI is multifactorial and may be primarily due to increased sympathetic tone, a proinflammatory state,
hypercoagulability, and occasional hypoxia during the first few days after surgery. In 1977, Goldman et al. (
1) developed a multifactorial index of risk for cardiac morbidity and mortality. Extensive work has subsequently been done on various aspects of perioperative cardiac evaluation, including clinical factors and noninvasive testing. The variety of strategies and practices used has led to high costs associated with preoperative risk assessment. Many studies have recently challenged common practices in the area of perioperative care that were found to have no clear benefit. The American College of Cardiology/American Heart Association (ACC/AHA) Task Force Committee developed practice guidelines aimed at providing a more efficient approach to preoperative evaluation. These guidelines were most recently updated in 2007.
B. Objective. The purpose of preoperative evaluation is not to “clear” patients for an operation. The purpose is to assess current medical status and cardiac risks posed by the planned operation and recommend strategies that may influence shortand long-term outcomes.
1. Although the preoperative assessment is a complex process, a few basic questions and observations by a physician with regard to the patient’s general health, functional capacity, cardiac risk factors, comorbid medical illnesses, and type of anticipated operation can assist in evaluating cardiac risk.
2. It is not prudent to order noninvasive tests for every patient. The physician tries to obtain as much information as possible by means of history and physical examination. Noninvasive tests are requested only if the results are likely to influence treatment and outcome.
3. As a general rule, preoperative intervention is rarely needed unless it is indicated irrespective of the preoperative context. Patients with clinically stable heart disease may not need extensive preoperative testing.
4. Communication is vital among primary physicians, consulting physicians, anesthesiologists, and surgeons for short- and long-term care of patients.
II. CLINICAL PRESENTATION
A. History
1. The clinician needs to identify cardiac conditions that place a patient at increased risk, such as recent MI, decompensated congestive heart failure (CHF), unstable angina, significant arrhythmias, and valvular heart disease.
2. Attention is directed at serious comorbid conditions such as diabetes mellitus, peripheral vascular disease, history of stroke, renal disease, and pulmonary disease.
3. Functional capacity is determined on the basis of the patient’s ability to perform certain daily tasks (
Table 34.1).
B. Physical findings. A thorough examination is crucial, and specific findings are addressed.
1. The physical examination includes checking blood pressure in both arms (supine and standing) and evaluation of carotid arterial pulse (character, volume, and upstroke), jugular venous pulsation, cardiac rhythm, heart sounds (murmurs, gallops, or rubs), and extremity pulses.
2. Lung fields are auscultated, and the abdomen is palpated for a possible aneurysm.
3. High-risk findings include severe aortic stenosis murmur, elevated jugular venous pressure, pulmonary edema, or S3 gallop.
C. Indices to predict cardiac risk. Cardiac risk is a function of patient characteristics and the proposed operation.
1. The Goldman index was developed in 1977. The index is a score derived from nine independent variables that predict perioperative cardiac events, and each is assigned a point value (
Table 34.2).
2. Detsky et al. (
2) developed a modified multifactorial index to address the severity of coronary artery disease (CAD) and heart failure (
Table 34.3).
3. In 1999,
Lee et al. (3) developed the Revised Cardiac Risk Index to simplify the process using only six risk factors (
Table 34.4). This is now the most widely used risk index and is the one incorporated in the ACC/AHA guidelines.
D. Clinical assessment of risk factors. Instead of dividing risk factors into major, intermediate, and minor groups, the new 2007 ACC/AHA guidelines adopted a more practical approach by recognizing the following conditions:
1. Active cardiac conditions. The presence of one or more of these conditions warrants intensive evaluation and management before proceeding with noncardiac surgery and may result in delay or cancellation of the scheduled surgery (
Table 34.5).
2. Clinical risk factors. With the exception of the type of surgery, these factors are the same risk factors identified by the Revised Cardiac Risk Index (
Table 34.4), and they include the following:
(a) History of ischemic heart disease
(b) History of compensated or prior heart failure
(c) History of cerebrovascular disease
(d) Diabetes mellitus
(e) Renal insufficiency
3. The original guidelines recognized a group of
minor predictors that included advanced age, abnormal electrocardiogram (ECG), rhythm other than sinus, and
uncontrolled hypertension.
Although the presence of many of these factors might lead to a higher suspicion of CAD, they have not been shown to increase perioperative risk independently, and therefore, they are no longer incorporated into the recommendations for treatment.
