American College of Cardiology

EAGLE ET AL., PERIOPERATIVE CARDIOVASCULAR EVALUATION FOR NONCARDIAC SURGERY UPDATE
http://www.acc.org/clinical/guidelines/perio/update/periupdate_index.htm

ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery

A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery)

I. Definition of the Problem

A. Purpose of These Guidelines

These guidelines are intended for physicians who are involved in the preoperative, operative, and postoperative care of patients undergoing noncardiac surgery. They provide a framework for considering cardiac risk of noncardiac surgery in a variety of patient and surgical situations. The task force that prepared these guidelines strove to incorporate what is currently known about perioperative risk and how this knowledge can be used in the individual patient.

The tables and algorithms provide quick references for decision making. The overriding theme of this document is that intervention is rarely necessary simply to lower the risk of surgery unless such intervention is indicated irrespective of the preoperative context. The purpose of preoperative evaluation is not to give medical clearance but rather to perform an evaluation of the patient's current medical status; make recommendations concerning the evaluation, management, and risk of cardiac problems over the entire perioperative period; and provide a clinical risk profile that the patient, primary physician, anesthesiologist, and surgeon can use in making treatment decisions that may influence short- and long-term cardiac outcomes. No test should be performed unless it is likely to influence patient treatment. Therefore, the goal of the consultation is the rational use of testing in an era of cost containment and the optimal care of the patient.

B. Methodology and Evidence

The ACC/AHA Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery conducted a comprehensive review of the literature relevant to perioperative cardiac evaluation since the last publication of these guidelines in 1996. Literature searches were conducted in the following databases: PubMed/MEDLINE, EMBASE, the Cochrane Library (including the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Register), and Best Evidence. Searches were limited to the English language, 1995 through 2000, and human subjects. In addition, related-article searches were conducted in MEDLINE to find further relevant articles. Finally, committee members recommended applicable articles outside the scope of the formal searches.

Major search topics included perioperative risk, cardiac risk, noncardiac surgery, noncardiac, intraoperative risk, postoperative risk, risk stratification, cardiac complication, cardiac evaluation, perioperative care, preoperative evaluation, preoperative assessment, and intraoperative complications. Additional searches cross-referenced these topics with the following subtopics: troponin, myocardial infarction, myocardial ischemia, Duke activity status index, functional capacity, dobutamine, adenosine, venous thrombosis, thromboembolism, warfarin, PTCA, adrenergic beta-agonists, echocardiography, anticoagulant, beta-blocker, diabetes mellitus, wound infection, blood sugar control, normothermia, body temperature changes, body temperature regulation, hypertension, pulmonary hypertension, anemia, aspirin, arrhythmia, implantable defibrillator, artificial pacemaker, pulmonary artery catheters, Swan Ganz catheter, and platelet aggregation inhibitors.

As a result of these searches, over 400 relevant, new articles were identified and reviewed by the committee for the update of these guideline. Using evidence-based methodologies developed by the ACC/AHA Task Force on Practice Guidelines, the committee updated the guidelines text and recommendations. New references are numbered 230-390 and are listed together at the end of the reference list. The ACC/AHA classifications of evidence are used in this report to summarize indications for a particular therapy or treatment as follows:

Class I: Conditions for which there is evidence for and/or general agreement that the procedure/therapy is useful and effective.

Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of performing the procedure/therapy.

Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy.

Class IIb: Usefulness/efficacy is less well established by evidence/opinion.

Class III: Conditions for which there is evidence and/or general agreement that the procedure/therapy is not useful/effective and in some cases may be harmful.

C. Epidemiology

The prevalence of cardiovascular disease increases with age, and it is estimated that the number of persons older than 65 years in the United States will increase 25% to 35% over the next 30 years ⁽¹⁾. Coincidentally, this is the same age group in which the largest number of surgical procedures is performed ⁽³⁹⁰⁾. Thus, it is conceivable that the number of noncardiac surgical procedures performed in older persons will increase from the current 6 million to nearly 12 million per year, and nearly a fourth of these-major intra-abdominal, thoracic, vascular, and orthopedic procedures-have been associated with significant perioperative cardiovascular morbidity and mortality.

D. Practice Patterns

There are few reliable data available regarding ⁽¹⁾ how often a family physician, general internist, subspecialty internist, or surgeon performs a preoperative evaluation on his or her own patient without a formal consultation and ⁽³⁹⁰⁾ how often a formal preoperative consultation is requested from either a generalist or a subspecialist such as a cardiologist for different types of surgical procedures and different categories of patients. The patterns of practice vary significantly in different locations in the country and vary between patients receiving care under different healthcare provider systems ⁽³⁾. There is an important need to determine the relative cost-effectiveness of different strategies of perioperative evaluation. In many institutions, patients are evaluated in an anesthesia preoperative evaluation setting. If sufficient information about the patient's cardiovascular status is available, the symptoms are stable, and further evaluation will not influence perioperative management, a formal consultation may not be required or obtained. This is facilitated by communication between anesthesia personnel and physicians responsible for the patient's cardiovascular care.

E. Financial Implications

The financial implications of risk stratification cannot be ignored. The need for better methods of objectively measuring cardiovascular risk has led to the development of multiple noninvasive techniques in addition to established invasive procedures. Although a variety of strategies to assess and lower cardiac risk have been developed, their aggregate cost has received relatively little attention. Given the striking practice variation and high costs associated with many evaluation strategies, the development of practice guidelines based on currently available knowledge can serve to foster more efficient approaches to perioperative evaluation.

F. Role of the Consultant

The consultant should review available patient data, obtain a history, and perform a physical examination pertinent to the patient's problem and the proposed surgery. A critical role of the consultant is to communicate the severity and stability of the patient's cardiovascular status and to determine whether the patient is in optimal medical condition, given the context of surgical illness. The consultant may recommend changes in medication and suggest preoperative tests or procedures. In some instances, an additional test is necessary based on the results of the initial preoperative test. In general, preoperative tests are recommended only if the information obtained will result in a change in the surgical procedure performed, a change in medical therapy or monitoring during or after surgery, or a postponement of surgery until the cardiac condition can be corrected or stabilized. Before suggesting an additional test, the consultant should feel confident that the information will provide a significant addition to the existing database and will have the potential to affect treatment. Redundancy should be avoided.