American College of Cardiology

GIBBONS ET AL., MANAGEMENT OF PATIENTS WITH CHRONIC STABLE ANGINA UPDATE
http://www.acc.org/clinical/guidelines/stable/update_index.htm

ACC/AHA 2002 Guideline Update for the Management of Patients With Chronic Stable Angina

A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for the Management of Patients With Chronic Stable Angina)

This is a Guideline Update of the 1999 Chronic Stable Angina Guidelines. To highlight the changes, deleted text is indicated by strikeout, and revised text is presented in brown. A clean version of the document, with changes fully incorporated, is available for download and print.

I. Introduction

A. Organization of Committee and Evidence Review

The ACC/AHA Task Force on Practice Guidelines was formed to make recommendations regarding the diagnosis and treatment of patients with known or suspected cardiovascular disease. Ischemic heart disease is the single leading cause of death in the United States. The most common manifestation of this disease is chronic stable angina. Recognizing the importance of the management of this common entity and the absence of national clinical practice guidelines in this area, the task force formed the current committee to develop guidelines for the management of patients with stable angina. Because this problem is frequently encountered in the practice of internal medicine, the task force invited the American College of Physicians-American Society of Internal Medicine (ACP-ASIM) to serve as a partner in this effort by naming general internists to serve on the committee.

The committee reviewed and compiled published reports (excluding abstracts) through a series of computerized literature searches of the English language research literature since 1975 and a manual search of selected final articles. Details of the specific searches conducted for particular sections are provided as appropriate. Detailed evidence tables were developed whenever necessary on the basis of specific criteria outlined in the individual sections. The recommendations were based primarily on these published data. The weight of the evidence was ranked high (A) if the data were derived from multiple randomized clinical trials with large numbers of patients and intermediate (B) if the data were derived from a limited number of randomized trials with small numbers of patients, careful analyses of nonrandomized studies, or observational registries. A low rank (C) was given when expert consensus was the primary basis for the recommendation. A recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials. Even though randomized trials are not available, there may be a very clear clinical consensus that a particular test or therapy is useful and effective.

The customary ACC/AHA classifications I, II, and III are used in tables that summarize both the evidence and expert opinion and provide final recommendations for both patient evaluation and therapy:

Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective.

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

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/treatment is not useful/effective and in some cases may be harmful.

A complete list of many publications on various aspects of this subject is beyond the scope of these guidelines; only selected references are included. The committee consisted of acknowledged experts in general internal medicine from the ACP-ASIM, family medicine from the American Academy of Family Physicians (AAFP), and general cardiology, as well as persons with recognized expertise in more specialized areas, including noninvasive testing, preventive cardiology, coronary intervention, and cardiovascular surgery. Both the academic and private practice sectors were represented. Methodologic support was provided by the University of California, San Francisco-Stanford (UCSF-Stanford) Evidence Based Practice Center (EPC). This document was reviewed by three two outside reviewers nominated by the ACC, three two outside reviewers nominated by the AHA, and three two outside reviewers nominated by the ACPASIM, and two outside reviewers nominated by the AAFP. This document was approved for publication by the governing bodies of the ACC, AHA, and the Clinical Efficacy Assessment Subcommittee of the ACP-ASIM. The task force will review these guidelines 1 year after publication and yearly thereafter to determine whether revisions are needed. These guidelines will be considered current unless the task force revises or withdraws them from distribution.

B. Scope of the Guidelines

These guidelines are intended to apply to adult patients with stable chest pain syndromes and known or suspected ischemic heart disease. Patients who have “ischemic equivalents,” such as dyspnea or arm pain with exertion, are included in these guidelines. Some patients with ischemic heart disease may become asymptomatic with appropriate therapy. As a result, the follow-up sections of the guidelines may apply to patients who were previously symptomatic, including those with previous percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The diagnosis, risk stratification, and treatment sections of these guidelines are intended to apply to symptomatic patients. Where appropriate, separate subsections consider the approach to the special group of asymptomatic patients with known or suspected coronary artery disease (CAD) on the basis of a history and/or electrocardiographic (ECG) evidence of previous myocardial infarction (MI), coronary angiography, or an abnormal noninvasive test. The inclusion of asymptomatic patients with abnormal noninvasive tests does not constitute an endorsement of such tests for the purposes of screening but simply acknowledges the clinical reality that such patients often present for evaluation after such tests have been performed. Multiple ACC/AHA guidelines and scientific statements have discouraged the use of ambulatory monitoring, treadmill testing, stress echocardiography, stress myocardial perfusion imaging, and electron-beam computed tomography (EBCT), previously called ultrafast CT, as routine screening tests in asymptomatic individuals. The reader is referred to these documents (Table 1) for a detailed discussion of screening, which is beyond the scope of these guidelines. However, the diagnosis, risk stratification and treatment sections of the guidelines are intended to apply to symptomatic patients. Asymptomatic patients with “silent ischemia” or known coronary artery disease (CAD) that has been detected in the absence of symptoms are beyond the scope of these guidelines. Pediatric patients are also beyond the scope of these guidelines, because ischemic heart disease is very unusual in such patients and is primarily related to the presence of coronary artery anomalies. Patients with chest pain syndromes after cardiac transplantation are also not included in these guidelines.

Patients with nonanginal chest pain are generally at lower risk for ischemic heart disease. Often their chest pain syndromes have identifiable noncardiac causes. Such patients are included in these guidelines if there is sufficient suspicion of heart disease to warrant cardiac evaluation. If the evaluation demonstrates that ischemic heart disease is unlikely and noncardiac causes are the primary focus of evaluation, such patients are beyond the scope of these guidelines. If the initial cardiac evaluation demonstrates that ischemic heart disease is possible, subsequent management of such patients does fall within these guidelines.

Acute ischemic syndromes are not included in these guidelines. For patients with acute MI, the reader is referred to the “ACC/AHA Guidelines for the Management of Patients With Acute Myocardial Infarction: 1999 Update” (1,892). For patients with unstable angina, the reader is referred to the “ACC/AHA 2002 Guideline Update for the Management of Patients With Unstable Angina and Non–ST-Segment Elevation Myocardial Infarction” (893) Agency for Health Care Policy and Research (AHCPR) clinical practice guideline on unstable angina (2), which was endorsed by the ACC and the AHA. This guideline for unstable angina did describe some low-risk patients who should not be hospitalized but instead evaluated as outpatients. Such patients are indistinguishable from many patients with stable chest pain syndromes and are therefore within the scope of the present guidelines. Patients whose recent unstable angina was satisfactorily treated by medical therapy and who then present with a recurrence of symptoms with a stable pattern fall within the scope of the present guidelines. Similarly, patients with MI who subsequently present with stable chest pain symptoms more than 30 days after the initial event are within the scope of the present guidelines.

The present guidelines do not apply to patients with chest pain symptoms early after revascularization by either percutaneous techniques or CABG. Although the division between “early” and “late” symptoms is arbitrary, the committee believed that these guidelines should not be applied to patients who develop recurrent symptoms within six months of revascularization.

C. Overlap With Other Guidelines

These guidelines will overlap with a large number of recently published (or soon to be published) clinical practice guidelines developed by the ACC/AHA Task Force on Practice Guidelines; the National Heart, Lung, and Blood Institute (NHLBI); and the ACP-ASIM (Table 1).

This report includes text and recommendations from many of these guidelines, which are clearly indicated. Additions and revisions have been made where appropriate to reflect more recently available evidence. This report specifically indicates rare situations in which it deviates from previous guidelines and presents the rationale for such deviation. In some cases, this report attempts to combine previous sets of similar and dissimilar recommendations into one set of final recommendations. Although this report includes a significant amount of material from the previous guidelines, by necessity the material was often condensed into a succinct summary. These guidelines are not intended to provide a comprehensive understanding of the imaging modalities, therapeutic modalities, and clinical problems detailed in other guidelines. For such an understanding, the reader is referred to the original guidelines listed in the references.

D. Magnitude of the Problem

There is no question that ischemic heart disease remains a major public health problem. Chronic stable angina is the initial manifestation of ischemic heart disease in approximately one half of patients (3,4). It is difficult to estimate the number of patients with chronic chest pain syndromes in the United States who fall within these guidelines, but clearly it is measured in the millions. The reported annual incidence of angina is 213 per 100 000 population greater than 30 years old (3). When the Framingham Heart Study (4) is considered, an additional 350 000 Americans each year are covered by these guidelines. The AHA has estimated that 6 200 000 Americans have chest pain (5); however, this may be a conservative estimate.

The prevalence of angina can also be estimated by extrapolating from the number of MIs in the United States (1,892). About one half of patients presenting at the hospital with MI have preceding angina (6). The best current estimate is that there are 1 100 000 patients with MI each year in the United States (5); about one half of these (550,000) survive until hospitalization. Two population-based studies (from Olmsted County, Minnesota, and Framingham, Massachusetts) examined the annual rates of MI in patients with symptoms of angina and reported similar rates of 3% to 3.5% per year (4,7). On this basis, it can be estimated that there are 30 patients with stable angina for every patient with infarction who is hospitalized. As a result, the number of patients with stable angina can be estimated as 30 × 550,000, or 16,500 000. This estimate does not include patients who do not seek medical attention for their chest pain or whose chest pain has a noncardiac cause. Thus, it is likely that the present guidelines cover at least six million Americans and conceivably more than twice that number.

Ischemic heart disease is important not only because of its prevalence but also because of its associated morbidity and mortality. Despite the well-documented recent decline in cardiovascular mortality (8), ischemic heart disease remains the leading single cause of death in the United States (Table 2) and is responsible for 1 of every 4.8 deaths (9). The morbidity associated with this disease is also considerable: each year, more than 1 000 000 patients have an MI. Many more are hospitalized for unstable angina and evaluation and treatment of stable chest pain syndromes. Beyond the need for hospitalization, many patients with chronic chest pain syndromes are temporarily unable to perform normal activities for hours or days, thereby experiencing a reduced quality of life. According to the recently published data from the Bypass Angioplasty Revascularization Investigation (10), about 30% of patients never return to work after coronary revascularization, and 15% to 20% of patients rated their own health fair or poor despite revascularization. These data confirm the widespread clinical impression that ischemic heart disease continues to be associated with considerable patient morbidity despite the decline in cardiovascular mortality.

The economic costs of chronic ischemic heart disease are enormous. Some insight into the potential cost can be obtained by examining Medicare data for inpatient diagnosis-related groups (DRGs) and diagnostic tests. Table 3 shows the number of patients hospitalized under various DRGs during 1995 and associated direct payments by Medicare. These DRGs represent only hospitalization of patients covered by Medicare. The table includes estimates for the proportion of inpatient admissions for unstable angina, MI, and revascularization for patients with a history of stable angina. Direct costs associated with non-Medicare patients hospitalized for the same diagnoses are probably about the same as the covered charges under Medicare. Thus, the direct costs of hospitalization are more than $15 billion.

Table 4 shows the Medicare fees and volumes of commonly used diagnostic procedures in ischemic heart disease. Although some of these procedures may have been performed for other diagnoses and some of the cost of the technical procedure relative value units may have been for inpatients listed in Table 3, the magnitude of the direct costs is considerable. When the 1998 Medicare reimbursement of $26.6873 per relative value unit is used, the direct costs to Medicare of these 61.2 million relative value unit can be estimated at $2.25 billion. Again, assuming that the non-Medicare patients costs are at least as great, the estimated cost of these diagnostic procedures alone would be about $4.5 billion.

These estimates of the direct costs associated with chronic stable angina obviously do not take ino account the indirect costs of workdays lost, reduced productivity, long-term medication, and associated effects. The indirect costs have been estimated to be almost as great as direct costs (4). The magnitude of the problem can be succinctly summarized: chronic stable angina affects many millions of Americans, with associated annual costs that are measured in tens of billions of dollars.

Given the magnitude of this problem, the need for practice guidelines is self-evident. This need is further reinforced by the available information, which suggests considerable regional differences in the management of ischemic heart disease. Figure 1 shows published information from the Medicare database for rates of coronary angiography in different counties of the country (11). Three- and four-fold differences in adjusted rates for this procedure in different counties within the same state are not uncommon, which suggests that the clinical management of such patients is highly variable. The reasons for such variation in management are unknown.

E. Organization of the Guidelines

These guidelines are arbitrarily divided into four sections: diagnosis, risk stratification, treatment, and patient followup. Experienced clinicians will quickly recognize that the distinctions between these sections may be arbitrary and unrealistic in individual patients. However, for most clinical decision making, these divisions are helpful and facilitate presentation and analysis of the available evidence.

The three flow diagrams that follow summarize the management of stable angina in three algorithms: clinical assessment (Fig. 2), stress testing/angiography (Fig. 3), and treatment (Fig. 4). The treatment mnemonic (Fig. 5) is intended to highlight the 10 treatment elements that the committee considered most important.

Although the evaluation of many patients will require all three algorithms, this is not always true. Some patients may require only clinical assessment to determine that they do not belong within these guidelines. Others may require only clinical assessment and treatment if the probability of CAD is high and patient preferences and comorbidities preclude revascularization (and therefore the need for risk stratification). The stress testing/angiography algorithm may be required either for diagnosis (and risk stratification) in patients with a moderate probability of CAD or for risk stratification only in patients with a high probability of CAD.