- Initial Evaluation and Treatment
- Outpatient Care
- Intensive Medical Care
- Nonintensive Medical Care
- Noninvasive Testing
- Cardiac Catheterization and Myocardial Revascularization
- Hospital Discharge and Postdischarge Care
- Medical Record
- Rest angina within 1 week of presentation
- New onset angina of Canadian Cardiovascular Society Classification
(CCSC) class III or
IV within 2 months of presentation
- Angina increasing in CCSC class to at least CCSC III or IV
- Variant angina
- Non-Q-wave myocardial infarction
- Post-myocardial infarction angina (>24 hours)
Diagnosis of unstable angina depends on a careful clinical history, physical examination,
and examination of a resting 12-lead electrocardiogram (ECG). Therefore, the initial
evaluation of patients with symptoms consistent with ischemic pain usually should take place
in a medical facility and not by telephone.
- The ECG provides crucial information in the diagnosis of unstable angina, and
recordings taken both during periods of pain and after pain relief are useful.
- In patients with symptoms suggesting unstable angina, there are two complementary and
equally important components to the initial assessment: (1) assessment of the likelihood of
CAD (Table 1) and (2) assessment of the
risk of adverse outcomes (Table 2).
At the conclusion of this initial evaluation, the patient can be assigned to one of four
diagnostic categories: not coronary artery disease, stable angina, acute myocardial infarction
(MI), or unstable angina (Figure 1).
The certainty of diagnosis, severity of symptoms, hemodynamic state, and medication
history will determine the choice and timing of drugs used in individual patients. Drugs to be
considered for use at the time of initial evaluation and treatment of patients with unstable
angina include aspirin, heparin, nitrates, and beta blockers (Table 3).
- Begin treatment with an indicated drug in the emergency department; pharmacologic
treatment should not be delayed until hospital admission. The aggressiveness of drug dosage
will depend on the severity of symptoms and, for many drugs, will require modification
throughout the subsequent hospital course.
- Institute anti-ischemic therapy in the emergency department as soon as the working
diagnosis of unstable angina is made.
- Give supplemental oxygen to patients with cyanosis, respiratory distress, or high-risk
features. Monitor for adequate arterial oxygenation with finger pulse oximetry or blood gas
determinations.
- Place patients with intermediate- or high-risk unstable angina on continuous ECG
monitoring for ischemia and arrhythmia detection.
- Intravenous thrombolytic therapy is not indicated in patients who do not have evidence
of acute ST-segment elevation or left bundle branch block on their 12-lead ECG.
Patients with unstable angina who are judged in the initial evaluation and treatment
phase to be at low risk for adverse outcomes can, in many cases, be safely evaluated further
as outpatients. Typically, these are patients who have experienced new onset or worsening
symptoms that may be due to ischemia, but they have not had severe, prolonged, or rest
episodes in the preceding 2 weeks.
- Schedule a followup evaluation as soon as possible, generally within 72 hours after the
initial presentation.
- Conduct a systematic search for precipitating noncardiac causes that might explain the
new development of unstable angina symptoms or the conversion from a stable to an unstable
course. Thus, at the followup evaluation, each patient should have: a second ECG to look for
asymptomatic ischemia or arrhythmias, measurement of body temperature and blood pressure,
a hemoglobin or hematocrit determination, and a physical examination for evidence of other
cardiac diseases (particularly aortic valve disease and hypertrophic cardiomyopathy) or
hyperthyroidism.
- Review the patient's history to determine additional potential exacerbating factors, such
as a recent increase in physical activity level (especially in combination with environmental
temperature extremes), noncompliance with medical therapy, or a recent increase in
psychological stress levels.
- Advise patients diagnosed with unstable angina to take aspirin, 80 to 324 mg per day,
unless contraindications are present. For patients unable to take aspirin because of a history of
true hypersensitivity or recent significant gastrointestinal bleeding, ticlopidine, 250 mg twice a
day, may be used as a substitute.
- Begin therapy for newly diagnosed patients, generally with sublingual nitroglycerin as
needed, followed by oral beta blockers and/or long-acting topical or oral nitrates. Review the
medical regimen of patients with established coronary artery disease already on medical
therapy, and increase dosages as appropriate for symptom management and as tolerated.
- Consider prescribing long-acting forms of antianginal drugs for enhanced patient
compliance.
Intensive medical treatment should begin immediately in the emergency department in
patients at high or intermediate risk of death or non-fatal MI. For high-risk patients, such as
those with ongoing angina at rest and/or those who appear unstable, simultaneous evaluation
and treatment assume an urgency greater than for intermediate-risk patients, such as those
with prior discomfort who are asymptomatic during the initial evaluation.
- Establish intravenous access while simultaneously obtaining a brief cardiovascular
history, physical examination, and ECG.
- Institute daily aspirin and intravenous heparin plus nitrates and beta blockers
(Table 3).
- Consider adding calcium channel blockers in the subset of patients who have significant
hypertension (systolic blood pressure >e;150 mmHg), in patients who have refractory ischemia
on beta blockers, and in those with variant angina.
Recurrent symptoms after the initial hemodynamic goals of therapy have been achieved
may be regarded as a failure of medical therapy and should prompt consideration of urgent
cardiac catheterization. Although it is theoretically desirable to have the maximal medical
regimen in place for >e;24 hours before declaring any patient a failure of medical therapy, to
do so in all cases may be inappropriate or even dangerous.
- Assign patients who have one or more recurrent severe, prolonged (>20 minutes)
ischemic episodes, particularly when accompanied by pulmonary edema, a new or worsening
mitral regurgitation murmur, hypotension, or new ST- or T-wave changes, to the high-risk
category regardless of the level of medical therapy and triage them to early cardiac
catheterization.
- Assign patients with shorter, less severe ischemic episodes without accompanying
hemodynamic or ECG changes to a substantially lower risk category and continue medical
therapy.
During the period of intensive medical therapy, appropriate monitoring includes:
- Obtain an aPTT (activated partial thromboplastin time) 6 hours after initial therapy is
started or any dosage change occurs and every 6 hours thereafter until a therapeutic level of
1.5 to 2.5 times control is obtained on two consecutive aPTTs.
- Obtain an aPTT every 24 hours, once a therapeutic range is achieved.
- Obtain an immediate aPTT if the patient's clinical condition changes significantly (e.g.
recurrent definite ischemia, bleeding, hypotension). Obtain an immediate
hemoglobin/hematocrit and platelet determination if any of the following occur: clinically
significant bleeding, recurrent symptoms, or hemodynamic instability. A drop in platelets
necessitates close monitoring for heparin-induced thrombocytopenia.
- Monitor hemoglobin/hematocrit and platelets daily for the first 3 days of heparin therapy.
- Monitor heart rate and blood pressure (target heart rate for beta blockade is 50 to 60
beats per minute).
- Monitor for congestive heart failure and bronchospasm.
- Utilize continuous ECG monitoring.
- Discontinue heparin after 3 to 5 days.
- Convert to an oral regimen of beta blockers after the initial intravenous load in patients
without limiting side effects. Selection of the oral agent should be based on the clinician's
familiarity with the agent as well as the risk of adverse effects.
- Change to oral or topical nitrate therapy when the patient has been symptom-free for 24
hours. Tolerance to nitrates is dose- and duration-dependent and typically becomes significant
after only 24 hours of continuous therapy. Responsiveness can be enhanced by increasing the
dose; switching the patient to a topical, oral, or buccal form of therapy; and using a
nitrate-free interval of 6 to 8 hours.
Most patients stabilize and have improvement in their chest pain after 30 minutes of
aggressive medical management and can be admitted to an intensive care unit or intermediate
care unit. Failure to respond to initial therapy should prompt reconsideration of other possible
catastrophic causes of chest pain including:
- Ongoing acute myocardial infarction.
- Aortic dissection.
- Pulmonary embolism.
- Pneumothorax.
- Esophageal rupture.
- Rupture or ischemia of intra-abdominal organs.
Patients considered to have unstable angina after further evaluation and who fail to
respond within 30 minutes to initial treatment are at increased risk for myocardial infarction
or cardiac death. The major ischemic complications seen in unstable angina are recurrent
unstable angina, acute ischemic pulmonary edema, new or worsening mitral regurgitation,
cardiogenic shock, malignant ventricular arrhythmias, and advanced atrioventricular block. For
these patients, in addition to maximizing the medical regimen described in the previous
section and instituting appropriate adjunctive therapy (e.g., pulmonary artery pressure
monitoring and inotropic therapy for shock, antiarrhythmic therapy for malignant ventricular
arrhythmias, pacemaker for symptomatic high grade atrioventricular block), the clinician
should consider insertion of an intra-aortic balloon pump and cardiac catheterization.
If emergency cardiac catheterization is not possible, an intra-aortic balloon pump should
be placed in unstable angina patients who have symptoms refractory to medical management
and those who have symptoms in conjunction with hemodynamic instability. An intra-aortic
balloon pump can also serve as a bridge to stabilize the patient on the way to the
catheterization laboratory or operating room. Exceptions to this recommendation include
patients with severe peripheral vascular disease, significant aortic insufficiency, or known
severe aorto-iliac disease, including aortic aneurysm.
- Refer for urgent diagnostic catheterization patients who have received an intra-aortic
balloon pump for stabilization.
- Transfer patients who have received an intra-aortic balloon pump for stabilization to a
facility capable of providing diagnostic catheterization and revascularization.
- Reevaluate patients who have not stabilized after placement of the pump to reaffirm the
diagnosis of acute ischemic heart disease and then consider for emergency catheterization.
For patients who stabilize after initial treatment, this guideline proposes two alternative
strategies for definitive treatment of unstable angina termed, "early invasive" and "early
conservative."
Patients who prefer continued intensive medical management and patients who are not
candidates for revascularization will continue to receive care at a level and duration dictated
by the level of their disease activity.
Figure 3 describes the cardiac catheterization and myocardial
revascularization phase.
Most patients with unstable angina stabilize and become pain-free with appropriate
intensive medical management. Transfer from intensive to nonintensive medical management
occurs when:
- The patient is hemodynamically stable (including no uncompensated congestive heart
failure) for >e;24 hours.
- Ischemia has been successfully suppressed for >e;24 hours.
Once these criteria are reached:
- Convert parenteral to nonparenteral medications.
- Reassess heparin use. Discontinue in selected patients (for example, those found to have
a secondary cause for ischemia such as anemia). Continue for 2 to 5 days in others.
- Continue aspirin at 80 to 324 mg/day.
- Assure that appropriate enzyme levels are obtained: Total CK (creatinine kinase) and
CK-MB (cardiac muscle) every 6 to 8 hours for the first 24 hours after admission. Lactate
dehydrogenase levels may be useful in detecting cardiac damage in patients presenting
between 24 and 72 hours after symptom onset.
- Obtain a followup 12-lead ECG 24 hours after admission or whenever the patient has
recurrent symptoms or a change in clinical status.
- Obtain a chest x-ray within 48 hours of admission in all stable patients. In
hemodynamically unstable patients, obtain a chest x-ray initially and repeat as necessary.
- Measure resting left ventricular function in patients who do not have early cardiac
catheterization but who have had previous infarct or who have cardiomegaly by physical
examination or chest radiograph. Either a radionuclide ventriculogram or a two-dimensional
echocardiogram may be used.
All hospitalized patients with unstable angina and without contraindications receive cardiac
catheterization within 48 hours of presentation.
Unless contraindicated, hospitalized patients with unstable angina receive a cardiac
catheterization if they have one or more of the following high-risk indicators: prior
revascularization; associated congestive heart failure or depressed left ventricular function
(ejection fraction <0.50) by noninvasive study; malignant ventricular arrhythmia; persistent or
recurrent pain/ischemia; and/or a functional study indicating high risk. All other patients
receive medical management and undergo cardiac catheterization only when medical
management fails.
Patients with unstable angina judged to be at moderate risk may be admitted initially to a
monitored intermediate care unit until the diagnosis of myocardial infarction can be excluded
and it is clear that the patient's symptoms are adequately controlled on medical therapy. These
patients then enter the nonintensive phase of management.
Other moderate-risk and some low-risk patients may be admitted directly to a regular
hospital bed with telemetry capabilities, thereby proceeding directly to the nonintensive phase.
High-risk unstable angina patients will be moved to the nonintensive phase after 1 or more
days of intensive management and stabilization.
Once patients reach the nonintensive phase of management, reasons for continued
hospitalization include optimization of medical therapy, evaluation of the propensity for
recurrent ischemia or ischemic complications, and risk stratification to determine the need for
catheterization and revascularization.
- Discontinue continuous monitoring of the ECG in this phase for most patients.
- Instruct all patients to notify nursing personnel immediately if chest discomfort recurs.
- Recurrent ischemic episodes should prompt a brief nursing assessment and an emergent
ECG and should be brought to the attention of a physician.
- Reevaluate the patient's medical regimen and adjust doses of anti-ischemic agents as
tolerated.
- Encourage the patient to progress gradually to a level of activity, under the observation
of the health care team, commensurate with that required to perform activities of daily living.
- Advise the patient and his or her family regarding risk-factor modification and have
them work with the health care team to set appropriate goals.
Many patients reaching this phase will be referred within 1 to 2 days for either
noninvasive functional testing or cardiac catheterization.
- Transfer patients who have pain or ECG evidence of ischemia increasing in severity >20
minutes and unresponsive to nitroglycerin back to the intensive medical management phase
protocol.
- Patients who respond to sublingual nitroglycerin generally do not need to return to
intensive medical management. However, a second recurrence of chest pain of at least 20
minutes duration in the setting of appropriate medical therapy should prompt return of the
patient to a monitored environment and the management steps outlined in the intensive
management phase.
The goals of noninvasive testing in a recently stabilized patient with unstable angina are
to estimate the subsequent prognosis, especially for the next 3 to 6 months, decide which
additional tests and adjustments in therapy are required based on this prognosis, and provide
the patient with the information and reassurances necessary to return to a lifestyle as full and
productive as possible (Figure 2).
- Conduct exercise or pharmacologic stress testing of low-risk patients with unstable
angina who are to be managed as outpatients, unless contraindicated.
- Perform noninvasive testing within 72 hours of presentation (in most cases) in low-risk
patients who are to be managed as outpatients.
- Perform noninvasive exercise or pharmacologic stress testing in low- or intermediate-risk
patients hospitalized with unstable angina who have been stabilized and free of angina and
congestive heart failure for a minimum of 48 hours, unless cardiac catheterization is indicated.
- Base the choice of the stress testing modality on an evaluation of the patient's resting
ECG, ability to perform exercise, and the local expertise and technologies available.
- Employ the exercise treadmill test as the standard mode of stress testing in patients with
a normal ECG who are not taking digoxin.
- Test patients with widespread resting ST depression (>e;1mm), ST changes secondary to
digoxin, left ventricular hypertrophy, left bundle branch block/significant intraventricular
conduction deficit, or pre-excitation using an imaging modality.
- Use pharmacologic stress testing in combination with an imaging modality for patients
unable to exercise due to physical limitations (e.g., arthritis, amputation, severe peripheral
vascular disease, general debility).
An exercise treadmill is the most commonly used stress test and has the largest
reported experience for use in patients with unstable angina. A nomogram useful to convert
results from this test into an assessment of risk has been derived on a large sample of patients
with coronary artery disease exclusively (not in patients presenting with unstable angina) (See
the Clinical Practice Guideline, Unstable Angina: Diagnosis and Management). Use
of this nomogram to quantitate risk from results of treadmill examinations provides more
clinically useful information than a simple normal/abnormal reading.
Implications and appropriate followup for the exercise treadmill tests are outlined in
Table 4.
The goal of cardiac catheterization in patients with unstable angina is to provide detailed
structural information necessary to assess prognosis and select an appropriate long-term
management strategy. The procedure is usually helpful in choosing between medical therapy,
percutaneous transluminal coronary angioplasty, and coronary artery bypass graft surgery in
patients at significant risk for future cardiac events (Figure 3).
Patients undergoing cardiac catheterization include those managed under either the "early
invasive" or "early conservative" strategies mentioned in the section on intensive medical
management, patients undergoing emergency catheterization directly from the emergency
room, and those who experienced recurrent ischemic episodes while being managed as
outpatients.
- Patients with contraindications to revascularization because of extensive comorbidity and
patients who do not wish to consider interventional therapy should not undergo diagnostic
catheterization.
- Consider the possibility of noncoronary symptom etiologies in patients found at
catheterization to have normal coronary arteries or insignificant lesions.
- Refer patients found at catheterization to have significant left main disease (>e;50%) or
significant (>e;70%) three-vessel disease with depressed left ventricular function (ejection
fraction <0.50) for coronary artery bypass graft surgery.
- Refer patients with two-vessel disease with proximal severe subtotal stenosis (>e;95%) of
the left anterior descending artery and depressed left ventricular function for revascularization.
- Consider for prompt revascularization (angioplasty or coronary artery bypass grafting)
patients with significant coronary artery disease if they have any of the following: failure to
stabilize with medical treatment; recurrent angina/ischemia at rest or with low-level activities;
and/or ischemia accompanied by congestive heart failure symptoms, an S3 gallop, new or
worsening mitral regurgitation, or definite ECG changes.
For some patients without these high-risk features, revascularization may still be an
option depending on recurrent symptoms, test results, and patient preferences.
The health care team should educate the patient, his or her family, and advocate about
the expected risks and benefits of revascularization and determine individual patient
preferences and fears that may affect the selection of therapy.
The need for continued hospitalization of the patient with unstable angina is determined
by whether the inpatient objectives of that hospital admission have been achieved. Patients
who have undergone successful revascularization will usually have the remainder of their
hospitalization defined by the standard protocol for the given procedure (e.g., 1 to 2 days for
angioplasty, 5 to 7 days for coronary artery bypass graft surgery).
Patients opting medical treatment after a cardiac catheterization or functional study
include both a low-risk group that can be rapidly discharged (e.g., 1 to 2 days after testing)
and high-risk group unsuitable for or unwilling to have coronary revascularization. These
patients may require a prolonged hospitalization to ensure adequate (or as adequate as
possible) symptom control.
The goal during the hospital discharge phase is to prepare the patient for normal
activities to the extent possible.
- Give specific instructions on smoking cessation, daily exercise, and diet.
- Consider referral, where possible and appropriate, to a smoking-cessation program or
clinic and/or an outpatient cardiac rehabilitation program.
- Discuss resumption of sexual relations (e.g., 2 weeks for low-risk patients to 4 weeks
for postsurgery coronary artery bypass graft patients).
- Give specific instructions, beyond "daily exercise," on activities that are permissible and
those that should be avoided (e.g., heavy lifting, climbing stairs, yard work, household
activities).
- Discuss resumption of driving and return to work.
- Continue all patients on aspirin, 80 mg to 324 mg per day, indefinitely after discharge
unless contraindications are present.
- Continue medications necessary to achieve adequate symptom control.
- Consider discontinuation of antianginal therapy in patients with successful
revascularization without recurrent ischemia.
- If patients have unsuccessful revascularization or recurrent symptoms following
revascularization, continue the antianginal regimen required in hospital to control their
symptoms.
- Instruct patients who are continuing on antianginal therapy on the use of sublingual
nitroglycerin.
- Continue antihypertensive and antihyperlipidemic workups and therapies started prior to
admission or initiated in the hospital.
- Plan for followup medical care at the time of discharge whenever possible.
- Schedule followup of low-risk patients and patients with successful coronary artery
bypass grafting or angioplasty at 2 to 6 weeks and higher risk patients at 1 to 2 weeks.
- Instruct the patient (and relevant family members or advocate) in the purpose, dose, and
major side effects of each medicine prescribed, using language the patient can understand.
- Give specific instructions for the proper use of sublingual nitroglycerin, especially since
response of chest pain to this medication is useful in assessing the nature of recurrent
symptoms.
- Instruct the patient that recurrent symptoms lasting more than 1 to 2 minutes should
prompt him or her to stop all activities, sit down, and place a nitroglycerin tablet under the
tongue. This may be repeated twice at 5 minute intervals for two additional tablets. If
symptoms persist after three nitroglycerin tablets, the patient should promptly seek medical
attention.
- Instruct the patient that if symptoms change in pattern (e.g., asymptomatic to
symptomatic, more frequent, or more severe symptoms), he or she should contact their
primary care physician and discuss whether changes in the management plan are warranted.
- Instruct the patient to seek transportation to the nearest hospital emergency department,
either by ambulance or the fastest available alternative, if he or she cannot reach a physician
and chest pain persists for more than 20 minutes or despite three nitroglycerin tablets.
The natural history of unstable angina is typically characterized by either progression to
nonfatal myocardial infarction or death, on the one hand, or resumption of the more quiescent
clinical course of chronic stable angina/coronary artery disease, on the other. The acute phase
of unstable angina is usually over within 4 to 6 weeks. The goal of postdischarge outpatient
care is to make adjustments in the discharge regimen that appear most appropriate after an
initial period away from direct patient care.
The long-term management of unstable angina ends as the patient reenters the stable
phase of coronary artery disease.
- Age and sex.
- Duration and nature of symptoms prior to presentation.
- Previous history of coronary artery disease; if yes, prior noninvasive test result, prior
cardiac catheterization result, prior revascularization procedure (bypass or angioplasty).
- Medication and drug use.
- Risk factors (diabetes, smoking, hypercholesterolemia, hypertension).
- Systemic causes for precipitating or exacerbating ischemia.
- Electrocardiogram interpretation.
- Initial and final assignment of likelihood of coronary artery disease (high, intermediate,
low) and basis.
- Initial and final risk assignment (high, intermediate, low) and basis.
- Summary of other pertinent positive and negative findings.
- Major or minor complications of diagnosis or treatment.
- Patient counseling, including assessment of patient response.
- Disposition for further care.
- Death classified as noncardiac or cardiac.
- Cardiac deaths classified as precipitated by arrhythmia, progressive ischemia, or
progressive cardiac failure.
- Results of ancillary clinical studies.
- Final diagnosis.
- Final disposition.
- Effectiveness of antianginal medication used.
- Intensity of pain (1-10) and duration (<20 minutes, <1 hour, >1 hour) of each episode of
angina or equivalent ischemic symptoms.
- Duration of longest anginal episode during the phase.
- Summary of pharmacologic therapy used.
- Documentation of the status of patient teaching including evidence of what the patient
appears to understand.
- Documentation of alternate treatment options discussed with the patient.
- Documented plan for further care as patient with stable CAD.
- Medications at the beginning and conclusion of this phase.
- Number, severity, and duration of ischemic episodes.
- Complications during this phase.
- Evaluation of patient's understanding of recommended lifestyle changes and assessment
of the patient's willingness to adhere to recommendations.
- Indications for test.
- Type of test performed.
- Summary of test results including electrocardiographic changes, symptoms,
hemodynamic changes, reason for termination (exercise tests).
- Test complications.
- Summary of post-test prognosis (low, intermediate, high risk, or probability of adverse
event calculation).
- Reasons for cardiac catheterization.
- Cardiac catheterization findings summarized by number of major coronary arteries with
70 percent or greater stenosis, presence or absence of a 50 percent or greater left main
stenosis, left ventricular ejection fraction, presence and severity of valvular disease.
- For patients undergoing interventional therapy, the primary reason for the procedure,
indicated as enhanced survival, pain relief, both, or other.
- Complications occurring during one procedure that led to another, different procedure
(angioplasty failure leading to coronary artery bypass graft surgery), including assessment of
severity at the beginning of the second procedure.
- Indicate discharge medical regimen.
- Major instructions about postdischarge activities and rehabilitation, and the patient's
understanding and plan for adherence to the recommendations.
- Summarize cardiac events.
- Document current symptoms.
- Medication changes since hospital discharge or last outpatient visit.
- Cairns JA, Gent M, Singer J et al.
- Aspirin,
sulfinpyrazone, or both in unstable angina.
Results of a Canadian multicenter trial.
N Engl J Med 1985 Nov; 313(22): 1369-75.
- Held PH, Yusuf S, Furberg C.
- Calcium channel
blockers in acute myocardial infarction and unstable angina: an overview. Br Med J
1989 Nov; 299: 1187-92.
- Hirsh J.
- Heparin. N Engl J Med
1991; 324: 565-74.
- ISIS-2 (Second International Study of Infarct Survival) Collaborative
Group.
- Randomized trial of intravenous streptokinase, oral aspirin, both, or
neither among 17,187 cases of suspected acute myocardial infarction: ISIS-2. Lancet
1988 Aug; 2(8607): 349-60.
- Lee TH, Cook EF, Weisberg M et al.
- Acute chest
pain in the emergency room. Identification and examination of low-risk patients. Arch
Intern Med 1985 Jan; 145(1): 65-9.
- Lewis HDJ, Davis JW, Archibald DG et al.
-
Protective effects of aspirin against acute myocardial infarction and death in men with
unstable angina. Results of a Veterans Administration Cooperative Study. N Engl J
Med 1983 Aug; 309(7): 396-403.
- Lubsen J, Tijssen JG.
- Efficacy of nifedipine and
metoprolol in the early treatment of unstable angina in the coronary care unit: findings from
the Holland Interuniversity Nifedipine/metoprolol Trial (HINT). Am J Cardiol
1987 Jul; 60(2): 18A-25A.
- Luchi RJ, Scott SM, Deupree RH.
- Comparison of
medical and surgical treatment for unstable angina pectoris. Results of a Veterans
Administration Cooperative Study. N Engl J Med 1987
Apr; 316(16): 977-84.
- Mark DB, Nelson CL, Califf RM et al.
- The
continuing evolution of therapy for coronary artery disease: initial results from the era of
coronary angioplasty. Circulation, in press.
Mark DB, Shaw L, Harrell FE et al.
- Prognostic
value of a treadmill exercise score in outpatients with suspected coronary artery
disease. N Engl J Med 1991 Sep; 325: 849-53.
- McCormick JR, Schick ECJ, McCabe CH et al.
-
Determinants of operative mortality and long-term survival in patients with unstable angina.
The CASS experience. J Thorac Cardiovasc Surg 1985
May; 89(5): 683-8.
- Muller JE, Turi ZG, Pearle DL et al.
- Nifedipine
and conventional therapy for unstable angina pectoris: a randomized double-blind
comparison. Circulation 1984 Apr; 69: 728-39.
- Parisi AF, Folland ED, Hartigan P et al.
- A
comparison of angioplasty with medical therapy in the treatment of single-vessel coronary
artery disease. N Engl J Med 1992 Jan; 326(1): 10-6.
- Parisi AF, Khuri S, Deupree RH et al.
- Medical
compared with surgical management of unstable angina. 5-year mortality and morbidity in the
Veterans Administration Study. Circulation 1989
Nov; 80(5): 1176-89.
- Pryor DB, Shaw L, McCants CB et al.
- Value of the
history and physical in identifying patients at increased risk for coronary artery disease.
Ann Intern Med 1993 Jan; 118: 81-90.
- RISC Group.
- Risk of myocardial infarction and
death during treatment with low dose aspirin and intravenous heparin in men with unstable
coronary artery disease. Lancet 1990
Oct; 336(8719): 827-30.
- RITA Trial Participants.
- Coronary angioplasty
versus coronary artery bypass surgery: the Randomized Intervention Treatment of Angina
(RITA) trial. Lancet 1993 Mar; 341(8845): 573-80.
- Rouan GW, Lee TH, Cook EF et al.
- Clinical
characteristics and outcome of acute myocardial infarction in patients with initially normal or
nonspecific electrocardiograms (A report from the multicenter chest pain study). Am J
Cardiol 1989; 64: 1087-92.
- Russell RO, Moraski RE, Kouchoukos N et al.
-
Unstable angina pectoris: national cooperative study group to compare surgical and medical
therapy. Am J Cardiol 1978 Nov; 42: 839-48.
- Scott SM, Luchi RJ, Deupree RH.
- Veterans
Administration Cooperative Study for treatment of patients with unstable angina. Results in
patients with abnormal left ventricular function. Circulation 1988
Sep; 78(3 Pt 2): I113-21.
- Selker HP, Griffith JL, D'Agostino RB.
- A tool for
judging coronary care unit admission appropriateness, valid for both real-time and
retrospective use. A time-sensitive predictive instrument (TIPI) for acute cardiac ischemia: a
multicenter study. Med Care 1991; 29: 610-27.
- Sharma GV, Deupree RH, Khuri SF et al.
- Coronary
bypass surgery improves survival in high-risk unstable angina. Results of a Veterans
Administration Cooperative Study with an 8-year follow-up. Veterans Administration
Unstable Angina Cooperative Study Group. Circulation 1991 Nov; 84 (5
Suppl): III260-7.
- Telford AM, Wilson C.
- Trial of heparin versus
atenolol in prevention of myocardial infarction in intermediate coronary syndrome.
Lancet 1981 Jun; 1(8232): 1225-8.
- Theroux P, Ouimet H, McCans J et al.
- Aspirin,
heparin, or both to treat acute unstable angina. N Engl J Med 1988
Oct; 319(17): 1105-11.
- Theroux P, Taeymans Y, Morissette D et al.
- A
randomized study comparing propranolol and diltiazem in the treatment of unstable
angina. J Am Coll Cardiol 1985 Mar; 5(3): 717-22.
- Theroux P, Waters D, Qiu S et al.
- Aspirin versus
heparin to prevent myocardial infarction during the acute phase of unstable angina.
Circulation 1993 Nov; 88(part 1): 2045-48.
- TIMI IIIA Investigators.
- Early effects of tissue-type
plasmogen activator added to conventional therapy on the culprit coronary lesion in patients
presenting with ischemic cardiac pain at rest. Circulation 1993
Jan; 87: 38-52.
- TIMI IIIB Investigators.
- Effects of tissue plasmogen
activator and a comparison of early invasive and conservative strategies in unstable angina
and non-Q-wave infarction: Results of the TIMI IIIB trial. Circulation, in press.
Wallentin LC.
- Aspirin (75 mg/day) after an
episode of unstable coronary artery disease: long-term effects on the risk for myocardial
infarction, occurrence of severe angina and the need for revascularization. Research Group on
Instability in Coronary Artery Disease in Southeast Sweden. J Am Coll Cardiol
1991 Dec; 18(7): 1587-93.
- Williams DO, Kirby MG, McPherson K et al.
-
Anticoagulant treatment of unstable angina. Br J Clin Prac 1986
Mar; 40(3): 114-6.
- Yusuf S, Wittes J, Friedman L.
- Overview of results
of randomized clinical trials in heart disease. II. Unstable angina, heart failure, primary
prevention with aspirin, and risk factor modification. JAMA 1988
Oct; 260(15): 2259-63.
This Quick Reference Guide for Clinicians contains recommendations on the care of
patients with unstable angina based on a combination of evidence obtained through extensive
literature reviews and consensus among members of a private-sector, expert panel. Principal
conclusions include:
- Many patients suspected of having unstable angina can be discharged home after
adequate initial evaluation.
- Further outpatient evaluation may be scheduled for up to 72 hours after initial
presentation for patients with clinical symptoms of unstable angina judged at initial evaluation
to be at low risk for complications.
- Patients with acute ischemic heart disease judged to be at intermediate or high risk of
complications should be hospitalized for careful monitoring of their clinical course.
-
Intravenous thrombolytic therapy should not be administered to patients without evidence of
acute myocardial infarction.
- Assessment of prognosis by noninvasive testing often aids selection of appropriate
therapy.
-
Coronary angiography is appropriate for patients judged to be at high risk for cardiac
complications or death based on their clinical course or results of noninvasive testing.
- Coronary artery bypass surgery should be recommended for almost all patients with left
main disease and many patients with three-vessel disease, especially those with left
ventricular dysfunction.
- The discharge care plan should include continued monitoring of symptoms; appropriate
drug therapy, including aspirin; risk-factor modification; and counseling.
This document is in the public domain and may be used and reprinted without special
permission, except for those copyrighted materials noted for which further reproduction is
prohibited without the specific permission of copyright holders.
AHCPR and NHLBI appreciate citation as to source, and the suggested format is as
follows:
Braunwald E, Mark DB, Jones RH et al. Diagnosing and Managing Unstable Angina.
Quick Reference Guide for Clinicians, Number 10. AHCPR Publication No. 94-0603.
Rockville, MD. U.S. Department of Health and Human Services, Public Health Service,
Agency for Health Care Policy and Research and National Heart, Lung, and Blood Institute.
May 1994 (amended).
