• Eagle KA, Guyton RA, Davidoff R, Edwards FH, Ewy GA, Gardner TJ, Hart JC, Herrmann HC, Hillis LD, Hutter AM Jr, Lytle BW, Marlow RA, Nugent WC, Orszulak TA. ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Bethesda (MD): American College of Cardiology; 2004. 99 p. [795 references]

This is the current release of the guideline.

This guideline updates a previous version: American College of Cardiology, American Heart Association, Eagle KA, Guyton RA, Davidoff R, Ewy GA, Fonger J, Gott JP, Herrmann HC, Marlow RA, Nugent WC, O'Connor GT, Orszulak TA, Rieselbach RE, Winters WL, Yusuf S, Gibbons RJ, Alpert JS, Eagle KA, Garson A Jr, Gregoratos G, Russell RO, Smith SC Jr. ACC/AHA Guidelines for coronary artery bypass graft surgery. J Am Coll Cardiol 1999 Oct;34(4):1262-347.

This document will be reviewed one year after the date of publication and yearly thereafter by the Task Force to determine whether a revision is needed. The guidelines will be considered current, unless the Task Force publishes revisions or a withdrawal.

Note from the National Guideline Clearinghouse (NGC): The recommendations listed below are from the Summary Article (see "Companion Documents" field). Readers are referred to the full-text original guideline document for context.

Levels of evidence (A-C) and classes of recommendations (I, IIa, IIb, and III) are defined at the end of the "Major Recommendations" field.

Outcomes

Hospital Outcomes

Predicting Hospital Mortality

Class IIa

1. It is reasonable to use statistical risk models to obtain objective estimates of coronary artery bypass graft (CABG) operative mortality. (Level of Evidence: C)

Morbidity Associated with CABG: Adverse Cerebral Outcomes

Class I

1. Significant atherosclerosis of the ascending aorta mandates a surgical approach that will minimize the possibility of arteriosclerotic emboli. (Level of Evidence: C)

Management Strategies

Reduction of Perioperative Mortality and Morbidity

Reducing the Risk of Brain Dysfunction After CABG

Atrial Fibrillation and Postoperative Stroke

Class IIa

1. In post-CABG atrial fibrillation that is recurrent or persists more than 24 hours, warfarin anticoagulation for 4 weeks is probably indicated. (Level of Evidence: C)

Recent Anterior Myocardial Infarction (MI), Left Ventricular (LV) Mural Thrombus, and Stroke Risk

Class IIa

1. Long-term (3 to 6 months) anticoagulation is probably indicated for the patient with recent anteroapical infarct and persistent wall-motion abnormality after CABG. (Level of Evidence: C)

Class IIb

1. In patients having a recent anterior MI, preoperative screening with echocardiography may be considered to detect left ventricular (LV) thrombus, because the technical approach and timing of surgery may be altered. (Level of Evidence: C)

Carotid Disease and Neurological Risk Reduction

Class IIa

1. Carotid endarterectomy is probably recommended before CABG or concomitant to CABG in patients with a symptomatic carotid stenosis or in asymptomatic patients with a unilateral or bilateral internal carotid stenosis of 80% or more. (Level of Evidence: C)
2. Carotid screening is probably indicated in the following subsets: age greater than 65 years, left main coronary stenosis, peripheral vascular disease, history of smoking, history of transient ischemic attack or stroke, or carotid bruit on examination. (Level of Evidence: C)

Reducing the Risk of Perioperative Myocardial Dysfunction

Myocardial Protection for Acutely Depressed Cardiac Function

Class I

1. Blood cardioplegia should be considered in patients undergoing cardiopulmonary bypass accompanying urgent/emergency CABG for acute MI or unstable angina. (Level of Evidence: B)

Protection for Chronically Dysfunctional Myocardium

Class IIa

1. Blood cardioplegia is probably indicated in patients undergoing cardiopulmonary bypass accompanying CABG in the presence of a chronically dysfunctional left ventricle. (Level of Evidence: B)

Cardiac Biomarker Elevation and Outcome

Class IIb

1. Assessment of cardiac biomarkers in the first 24 hours after CABG may be considered, and patients with the highest elevations of creatine kinase-muscle band (MB) (greater than 5 times upper limits of normal) are at increased risk of subsequent events. (Level of Evidence: B)

Adjuncts to Myocardial Protection

Class IIa

1. The use of a prophylactic intra-aortic balloon pump (IABP) as an adjunct to myocardial protection is probably indicated in patients with evidence of ongoing myocardial ischemia and/or patients with a subnormal cardiac index. (Level of Evidence: B)

Inferior Infarct with Right Ventricular Involvement

Class IIa

1. After infarction that leads to clinically significant right ventricular dysfunction, it is reasonable to delay surgery for 4 weeks to allow recovery. (Level of Evidence: C)

Reducing the Risk of Perioperative Infection

Class I

1. Preoperative antibiotic administration should be used in all patients to reduce the risk of postoperative infection. (Level of Evidence: A)
2. In the absence of complicating circumstances, a deep sternal wound infection should be treated with aggressive surgical debridement and early revascularized muscle flap coverage. (Level of Evidence: B)

Class IIa

1. The risk for deep sternal wound infection is reduced by aggressive control of perioperative hyperglycemia by using a continuous, intravenous insulin infusion. (Furnary et al., 1999) (Level of Evidence: B)

Prevention of Postoperative Arrhythmias

Class I

1. Preoperative or early postoperative administration of beta-blockers in patients without contraindications should be used as the standard therapy to reduce the incidence and/or clinical sequelae of atrial fibrillation after CABG. (Level of Evidence: B)

Class IIa

1. Preoperative administration of amiodarone reduces the incidence of postcardiotomy atrial fibrillation and is an appropriate prophylactic therapy for patients at high risk for postoperative atrial fibrillation who have contraindications to therapy with beta-blockers. (Level of Evidence: B)
2. Digoxin and nondihydropyridine calcium-channel blockers are useful for control of ventricular rate but at present have no indication for prophylaxis. (Level of Evidence: B)

Class IIb

1. Low-dose sotalol can be considered to reduce the incidence of atrial fibrillation after CABG in patients who are not candidates for traditional beta-blockers. (Level of Evidence: B)

Maximizing Postoperative Benefit

Antiplatelet Therapy for Saphenous Vein Graft (SVG) Patency

Class I

1. Aspirin is the drug of choice for prophylaxis against early saphenous vein graft closure. It is the standard of care and should be continued indefinitely given its benefit in preventing subsequent clinical events. (Level of Evidence: A)

Pharmacological Management of Hyperlipidemia

Class I

1. All patients undergoing CABG should receive statin therapy unless otherwise contraindicated. (Level of Evidence: A)

Hormonal Manipulation

Class III

1. Initiation of hormone therapy is not recommended for women undergoing CABG surgery. (Level of Evidence: B)

Smoking Cessation

Class I

1. All smokers should receive educational counseling and be offered smoking cessation therapy after CABG. (Level of Evidence: B)
2. Pharmacological therapy including nicotine replacement and bupropion should be offered to select patients indicating a willingness to quit. (Level of Evidence: B)

Cardiac Rehabilitation

Class I

1. Cardiac rehabilitation should be offered to all eligible patients after CABG. (Level of Evidence: B)

Special Patient Subsets

Valve Disease

Class I

1. Patients undergoing CABG who have severe aortic stenosis (mean gradient greater than or equal to 50 mm Hg or Doppler velocity greater than or equal to 4 meters per second) who meet the criteria for valve replacement should have concomitant aortic valve replacement. (Level of Evidence: B)

Class IIa

1. For a preoperative diagnosis of clinically significant mitral regurgitation concomitant mitral correction at the time of CABG is probably indicated. (Level of Evidence: B)
2. In patients undergoing CABG who have moderate aortic stenosis and are at acceptable risk for aortic valve replacement (mean gradient 30 to 50 mm Hg or Doppler velocity 3 to 4 meters per second), concomitant aortic valve replacement is probably indicated. (Level of Evidence: B)

Class IIb

1. Patients undergoing CABG who have mild aortic stenosis (mean gradient less than 30 mm Hg or Doppler velocity less than 3 meters per second) may be considered candidates for aortic valve replacement if the risk of the combined procedure is acceptable. (Level of Evidence: C)

CABG in Acute Coronary Syndromes

Class I

1. If clinical circumstances permit, clopidogrel should be withheld for 5 days before the performance of CABG surgery. (Level of Evidence: B)

Impact of Evolving Technology

Arterial and Alternate Conduits

Class I

1. In every patient undergoing CABG, the left internal mammary artery (IMA) should be given primary consideration for revascularization of the left anterior descending (LAD) artery. (Level of Evidence: B)

Transmyocardial Laser Revascularization (TMLR) (refer to the TMR section of the Stable Angina Update)

Class IIa

1. Transmyocardial surgical laser revascularization, either alone or in combination with CABG, is reasonable in patients with angina refractory to medical therapy who are not candidates for percutaneous coronary intervention (PCI) or surgical revascularization. (Level of Evidence: A)

Indications

Clinical Subsets

Asymptomatic or Mild Angina

Class I

1. CABG should be performed in patients with no angina or mild angina who have significant left main coronary artery stenosis. (Level of Evidence: A)
2. CABG should be performed in patients with no angina or mild angina who have left main equivalent: significant (greater than or equal to 70%) stenosis of the proximal LAD and proximal left circumflex artery. (Level of Evidence: A)
3. CABG is useful in patients with no angina or mild angina who have 3-vessel disease. (Survival benefit is greater in patients with abnormal LV function; e.g., ejection fraction [EF] less than 0.50 and/or large areas of demonstrable myocardial ischemia.) (Level of Evidence: C)

Class IIa

1. CABG can be beneficial for patients with no angina or mild angina who have proximal LAD stenosis with 1- or 2-vessel disease. (This recommendation becomes Class I if extensive ischemia is documented by a noninvasive study and/or left ventricular ejection fraction (LVEF) is less than 0.50.) (Level of Evidence: A)

Class IIb

1. CABG may be considered for patients with no angina or mild angina who have 1- or 2-vessel disease not involving the proximal LAD. (If a large area of viable myocardium and high-risk criteria are met on noninvasive testing, this recommendation becomes Class I). (Level of Evidence: B)

Stable Angina

Class I

1. CABG is recommended for patients with stable angina who have significant left main coronary artery stenosis. (Level of Evidence: A)
2. CABG is recommended for patients with stable angina who have left main equivalent: significant (greater than or equal to 70%) stenosis of the proximal LAD and proximal left circumflex artery. (Level of Evidence: A)
3. CABG is recommended for patients with stable angina who have 3-vessel disease. (Survival benefit is greater when LVEF is less than 0.50.) (Level of Evidence: A)
4. CABG is recommended in patients with stable angina who have 2-vessel disease with significant proximal LAD stenosis and either EF less than 0.50 or demonstrable ischemia on noninvasive testing. (Level of Evidence: A)
5. CABG is beneficial for patients with stable angina who have 1- or 2-vessel coronary artery disease (CAD) without significant proximal LAD stenosis but with a large area of viable myocardium and high-risk criteria on noninvasive testing. (Level of Evidence: B)
6. CABG is beneficial for patients with stable angina who have developed disabling angina despite maximal noninvasive therapy, when surgery can be performed with acceptable risk. If the angina is not typical, objective evidence of ischemia should be obtained. (Level of Evidence: B)

Class IIa

1. CABG is reasonable in patients with stable angina who have proximal LAD stenosis with 1-vessel disease. (This recommendation becomes Class I if extensive ischemia is documented by noninvasive study and/or LVEF is less than 0.50.) (Level of Evidence: A)
2. CABG may be useful for patients with stable angina who have 1- or 2-vessel CAD without significant proximal LAD stenosis but who have a moderate area of viable myocardium and demonstrable ischemia on noninvasive testing. (Level of Evidence: B)

Class III

1. CABG is not recommended for patients with stable angina who have 1- or 2-vessel disease not involving significant proximal LAD stenosis, patients who have mild symptoms that are unlikely due to myocardial ischemia, or patients who have not received an adequate trial of medical therapy and:
   1. Have only a small area of viable myocardium (Level of Evidence: B) or
   2. Have no demonstrable ischemia on noninvasive testing. (Level of Evidence: B)
2. CABG is not recommended for patients with stable angina who have borderline coronary stenoses (50 to 60% diameter in locations other than the left main coronary artery) and no demonstrable ischemia on noninvasive testing. (Level of Evidence: B)
3. CABG is not recommended for patients with stable angina who have insignificant coronary stenosis (less than 50% diameter reduction). (Level of Evidence: B)

Unstable Angina/Non-ST-Segment Elevation Myocardial infarction (MI)

Class I

1. CABG should be performed for patients with unstable angina/non–ST-segment elevation MI with significant left main coronary artery stenosis. (Level of Evidence: A)
2. CABG should be performed for patients with unstable angina/non–ST-segment elevation MI who have left main equivalent: significant (greater than or equal to 70%) stenosis of the proximal LAD and proximal left circumflex artery. (Level of Evidence: A)
3. CABG is recommended for unstable angina/non–ST-segment elevation MI in patients in whom percutaneous revascularization is not optimal or possible, and who have ongoing ischemia not responsive to maximal nonsurgical therapy. (Level of Evidence: B)

Class IIa

1. CABG is probably indicated in patients with unstable angina/non–ST-segment elevation MI who have proximal LAD stenosis with 1- or 2-vessel disease. (Level of Evidence: A)

Class IIb

1. CABG may be considered in patients with unstable angina/non–ST-segment elevation MI who have 1- or 2-vessel disease not involving the proximal LAD when percutaneous revascularization is not optimal or possible. (If there is a large area of viable myocardium and high-risk criteria are met on noninvasive testing, this recommendation becomes Class I.) (Level of Evidence: B)

ST-Segment Elevation MI (STEMI)

Class I

1. Emergency or urgent CABG in patients with STEMI should be undertaken in the following circumstances:
   1. Failed angioplasty with persistent pain or hemodynamic instability in patients with coronary anatomy suitable for surgery. (Level of Evidence: B)
   2. Persistent or recurrent ischemia refractory to medical therapy in patients who have coronary anatomy suitable for surgery, who have a significant area of myocardium at risk, and who are not candidates for percutaneous coronary intervention (Level of Evidence: B)
   3. At the time of surgical repair of postinfarction ventricular septal rupture or mitral valve insufficiency. (Level of Evidence: B)
   4. Cardiogenic shock in patients less than 75 years old with ST-segment elevation or left bundle-branch block or posterior MI who develop shock within 36 hours of MI and are suitable for revascularization that can be performed within 18 hours of shock, unless further support is futile because of the patient's wishes or contraindications/unsuitability for further invasive care. (Level of Evidence: A)
   5. Life-threatening ventricular arrhythmias in the presence of greater than or equal to 50% left main stenosis and/or triple-vessel disease. (Level of Evidence: B)

Class IIa

1. CABG may be performed as primary reperfusion in patients who have suitable anatomy and who are not candidates for or who have had failed fibrinolysis/PCI and who are in the early hours (6 to 12 hours) of evolving STEMI (Level of Evidence: B)
2. In patients who have had an ST-segment elevation MI or non–ST-segment elevation MI, CABG mortality is elevated for the first 3 to 7 days after infarction, and the benefit of revascularization must be balanced against this increased risk. Beyond 7 days after infarction, the criteria for revascularization described in previous sections are applicable. (Level of Evidence: B)

Class III

1. Emergency CABG should not be performed in patients with persistent angina and a small area of myocardium at risk who are hemodynamically stable. (Level of Evidence: C)
2. Emergency CABG should not be performed in patients with successful epicardial reperfusion but unsuccessful microvascular reperfusion. (Level of Evidence: C)

Poor LV Function

Class I

1. CABG should be performed in patients with poor LV function who have significant left main coronary artery stenosis. (Level of Evidence: B)
2. CABG should be performed in patients with poor LV function who have left main equivalent: significant (greater than or equal to 70%) stenosis of the proximal LAD and proximal left circumflex artery. (Level of Evidence: B)
3. CABG should be performed in patients with poor LV function who have proximal LAD stenosis with 2- or 3-vessel disease. (Level of Evidence: B)

Class IIa

1. CABG may be performed in patients with poor LV function with significant viable noncontracting, revascularizable myocardium and without any of the above anatomic patterns. (Level of Evidence: B)

Class III

1. CABG should not be performed in patients with poor LV function without evidence of intermittent ischemia and without evidence of significant revascularizable viable myocardium. (Level of Evidence: B)

Life-Threatening Ventricular Arrhythmias

Class I

1. CABG should be performed in patients with life-threatening ventricular arrhythmias caused by left main coronary artery stenosis. (Level of Evidence: B)
2. CABG should be performed in patients with life-threatening ventricular arrhythmias caused by 3-vessel coronary disease. (Level of Evidence: B)

Class IIa

1. CABG is reasonable in bypassable 1- or 2-vessel disease causing life-threatening ventricular arrhythmias. (This becomes a Class I recommendation if the arrhythmia is resuscitated sudden cardiac death or sustained ventricular tachycardia.) (Level of Evidence: B)
2. CABG is reasonable in life-threatening ventricular arrhythmias caused by proximal LAD disease with 1- or 2-vessel disease. (This becomes a Class I recommendation if the arrhythmia is resuscitated sudden cardiac death or sustained ventricular tachycardia.) (Level of Evidence: B)

Class III

1. CABG is not recommended in ventricular tachycardia with scar and no evidence of ischemia. (Level of Evidence: B)

CABG After Failed Percutaneous Transluminal Coronary Angioplasty (PTCA)

Class I

1. CABG should be performed after failed PTCA in the presence of ongoing ischemia or threatened occlusion with significant myocardium at risk. (Level of Evidence: B)
2. CABG should be performed after failed PTCA for hemodynamic compromise. (Level of Evidence: B)

Class IIa

1. It is reasonable to perform CABG after failed PTCA for a foreign body in crucial anatomic position. (Level of Evidence: C)
2. CABG can be beneficial after failed PTCA for hemodynamic compromise in patients with impairment of the coagulation system and without previous sternotomy. (Level of Evidence: C)

Class IIb

1. CABG can be considered after failed PTCA for hemodynamic compromise in patients with impairment of the coagulation system and with previous sternotomy. (Level of Evidence: C)

Class III

1. CABG is not recommended after failed PTCA in the absence of ischemia. (Level of Evidence: C)
2. CABG is not recommended after failed PTCA with inability to revascularize due to target anatomy or no-reflow state. (Level of Evidence: C)

Patients With Previous CABG

Class I

1. Coronary bypass should be performed in patients with prior CABG for disabling angina despite optimal nonsurgical therapy. (If angina is not typical, then objective evidence of ischemia should be obtained.) (Level of Evidence: B)
2. Coronary bypass should be performed in patients with prior CABG without patent bypass grafts but with Class I indications for surgery for native-vessel coronary artery disease (significant left main coronary stenosis, left main equivalent, 3-vessel disease). (Level of Evidence: B)

Class IIa

1. Coronary bypass is reasonable in patients with prior CABG and bypassable distal vessel(s) with a large area of threatened myocardium by noninvasive studies. (Level of Evidence: B)
2. Coronary bypass is reasonable in patients with prior CABG if atherosclerotic vein grafts with stenoses greater than 50% supplying the LAD coronary artery or large areas of myocardium are present. (Level of Evidence: B)

Definitions:

Levels of Evidence

Level of Evidence A: Data derived from multiple randomized clinical trials or meta-analyses
Level of Evidence B: Data derived from a single randomized trial, or nonrandomized studies
Level of Evidence C: Only consensus opinion of experts, case studies, or standard-of-care

Classes of Recommendations

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

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

None provided

The type of supporting evidence is identified and graded for each recommendation.

Recommendations provided in this document are based primarily on published data. Because randomized trials are unavailable in many facets of coronary artery disease (CAD) treatment, observational studies and, in some areas, expert opinion form the basis for recommendations that are offered. In each section of the Indications (see Section 9 of the original guideline document), the relative levels of evidence favoring the Class I, II, and III indications were noted.

• Eagle KA, Guyton RA, Davidoff R, Edwards FH, Ewy GA, Gardner TJ, Hart JC, Herrmann HC, Hillis LD, Hutter AM Jr, Lytle BW, Marlow RA, Nugent WC, Orszulak TA. ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Bethesda (MD): American College of Cardiology; 2004. 99 p. [795 references]

Not applicable: The guideline was not adapted from another source.

1999 Oct (revised 2004)

American College of Cardiology Foundation - Medical Specialty Society
American Heart Association - Professional Association

The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA). No outside funding accepted.

American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for Coronary Artery Bypass Graft Surgery)

The Committee consists of acknowledged experts in cardiac surgery, interventional cardiology, general cardiology, internal medicine, and family practice. The Committee included representatives from the American Academy of Family Physicians (AAFP) and the American College of Physicians (ACP), as well as the Society for Thoracic Surgery (STS). Both academic and private practice sectors were represented.

Writing Committee Members: Kim A. Eagle, MD, FACC, FAHA (Co-chair); Robert A. Guyton, MD, FACC, FAHA (Co-chair); Ravin Davidoff, MB, BCh, FACC, FAHA; Fred H. Edwards, MD, FACC, FAHA; Gordon A. Ewy, MD, FACC, FAHA; Timothy J. Gardner, MD, FACC, FAHA; James C. Hart, MD, FACC; Howard C. Herrmann, MD, FACC, FAHA; L. David Hillis, MD, FACC; Adolph M. Hutter, Jr., MD, MACC, FAHA; Bruce Whitney Lytle, MD, FACC; Robert A. Marlow, MD, MA, FAAFP; William C. Nugent, MD; Thomas A. Orszulak, MD, FACC

Task Force Members: Elliott M. Antman, MD, FACC, FAHA (Chair); Sidney C. Smith, Jr., MD, FACC, FAHA (Vice Chair); Joseph S. Alpert, MD, FACC, FAHA*; Jeffrey L. Anderson, MD, FACC, FAHA; David P. Faxon, MD, FACC, FAHA; Valentin Fuster, MD, PhD FACC, FAHA; Raymond J. Gibbons, MD, FACC, FAHA*#; Gabriel Gregoratos, MD, FACC, FAHA*; Jonathan L. Halperin, MD, FACC, FAHA; Loren F. Hiratzka, MD, FACC, FAHA; Sharon Ann Hunt, MD, FACC, FAHA; Alice K. Jacobs, MD, FACC, FAHA; Joseph P. Ornato, MD, FACC, FAHA

*Former Task Force Member

#Immediate Past Chair

American Association of Thoracic Surgery - Medical Specialty Society
Society of Thoracic Surgeons - Medical Specialty Society

This is the current release of the guideline.

This guideline updates a previous version: American College of Cardiology, American Heart Association, Eagle KA, Guyton RA, Davidoff R, Ewy GA, Fonger J, Gott JP, Herrmann HC, Marlow RA, Nugent WC, O'Connor GT, Orszulak TA, Rieselbach RE, Winters WL, Yusuf S, Gibbons RJ, Alpert JS, Eagle KA, Garson A Jr, Gregoratos G, Russell RO, Smith SC Jr. ACC/AHA Guidelines for coronary artery bypass graft surgery. J Am Coll Cardiol 1999 Oct;34(4):1262-347.

This document will be reviewed one year after the date of publication and yearly thereafter by the Task Force to determine whether a revision is needed. The guidelines will be considered current, unless the Task Force publishes revisions or a withdrawal.

None available

This summary was completed by ECRI on December 29, 1999. The information was verified by the guideline developer on April 17, 2000. This summary was updated by ECRI on October 13, 2004. The updated information was verified by the guideline developer on November 3, 2005. This summary was updated by ECRI on March 6, 2007 following the U.S. Food and Drug Administration (FDA) advisory on Coumadin (warfarin sodium). This summary was updated by ECRI Institute on September 7, 2007 following the revised U.S. Food and Drug Administration (FDA) advisory on Coumadin (warfarin). This summary was updated by ECRI Institute on November 6, 2007, following the U.S. Food and Drug Administration advisory on Antidepressant drugs.