Am Fam Physician. 2004;70(10):2011-2021
The American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines recently issued a joint executive summary of guidelines for the management of ST-elevation myocardial infarction (STEMI). This “Practice Guideline” will focus on two sections of the guideline: hospital and long-term management. In the November 1, 2004, issue of American Family Physician, a Practice Guideline discussed management before STEMI and initial recognition and management in the emergency department sections of this guideline. The ACC/AHA guideline was published in the August 3, 2004, issue of Circulation and is available online athttp://www.acc.org/clinical/guidelines/stemi/index.htm.
This guideline focuses on advances in the diagnosis and management of STEMI since 1999. Recommendations for indications for a diagnostic procedure, a particular therapy, or an intervention in patients with STEMI are based on clinical evidence and expert opinion. Definitions of the evidence levels are as follows: Level A: Data derived from multiple randomized clinical trials or meta-analyses. Level B: Data derived from a single randomized trial, or nonrandomized studies. Level C: Only consensus opinion of experts, case studies, or standard-of-care. Class I: Procedure or treatment should be performed or administered. Class IIa: It is reasonable to perform procedure or administer treatment (additional studies with focused objectives needed). Class IIb: Procedure or treatment may be considered (additional studies with broad objectives needed; additional registry data would be helpful). Class III: Procedure or treatment should not be performed or administered because it is not helpful and may be harmful (no additional studies needed).
Hospital Management
EARLY, GENERAL MEASURES
Level of Activity
Class IIa
1. After 12 to 24 hours, it is reasonable to allow patients with hemodynamic instability or continued ischemia to have bedside commode privileges. (Level of Evidence: C)
Class III
1. Patients with STEMI who are free of recurrent ischemic discomfort, symptoms of heart failure, or serious disturbances of heart rhythm should not be on bed rest for more than 12 to 24 hours. (Level of Evidence: C)
Diet
Class I
Patients with STEMI should be prescribed the diet of the National Cholesterol Education Program Adult Treatment Panel III Therapeutic Lifestyle Changes, which focuses on reduced intake of fats and cholesterol, less than 7 percent of total calories as saturated fats, less than 200 mg of cholesterol per day, increased consumption of omega-3 fatty acids, and appropriate caloric intake for energy needs. (Level of Evidence: C)
Patients with diabetes who have STEMI should have an appropriate food group balance and caloric intake. (Level of Evidence: B)
Sodium intake should be restricted in STEMI patients with hypertension or heart failure. (Level of Evidence: B)
PATIENT EDUCATION IN THE HOSPITAL SETTING
Class I
Patient counseling to maximize adherence to evidence-based post-STEMI treatments (such as compliance with taking medication, exercise prescription, and smoking cessation) should begin during the early phase of hospitalization, occur intensively at discharge, and continue at follow-up visits with providers and through cardiac rehabilitation programs and community support groups, as appropriate. (Level of Evidence: C)
Critical pathways and protocols and other quality-improvement tools (such as the ACC “Guidelines Applied in Practice” and the AHA’s “Get with the Guidelines”) should be used to improve the application of evidence-based treatments by patients with STEMI, caregivers, and institutions. (Level of Evidence: C)
Analgesia/Anxiolytics
Class IIa
It is reasonable to use anxiolytic medications in patients with STEMI to alleviate short-term anxiety or altered behavior related to hospitalization for STEMI. (Level of Evidence: C)
It is reasonable to routinely assess the patient’s anxiety level and manage it with behavioral interventions and referral for counseling. (Level of Evidence: C)
RISK STRATIFICATION DURING EARLY HOSPITAL COURSE
Risk stratification requires the updating of initial assessments with data obtained during the course of the hospital stay. The recurrence of chest pain and persistence of electrocardiogram findings indicating infarction are indicators of failed reperfusion. These patients should undergo coronary angiography. Sudden onset of heart failure or presence of a new murmur herald increased risk and suggest the need for rapid intervention. For those who did not undergo primary reperfusion, changes in clinical status may herald a worsening clinical status and are an indication for coronary angiography. Patients with a low risk of complications may be considered for early discharge.
MEDICATION ASSESSMENT
BETA BLOCKERS
There is overwhelming evidence for the benefits of early use of beta blockers in patients with STEMI and no contraindications to their use. Studies have demonstrated benefits of their use in patients with and without concomitant fibrinolytic therapy, both early and late after STEMI.
Class I
Patient receiving beta blockers within the first 24 hours of STEMI without adverse effects should continue to receive them during the early convalescent phase of STEMI. (Level of Evidence: A)
Patients without contraindications to beta blockers who did not receive them within the first 24 hours after STEMI should have them started in the early convalescent phase. (Level of Evidence: A)
Patients with early contraindications within the first 24 hours of STEMI should be reevaluated for candidacy for beta-blocker therapy. (Level of Evidence: C)
Nitroglycerin
Class I
Intravenous nitroglycerin is indicated in the first 48 hours after STEMI for treatment of persistent ischemia, congestive heart failure, or hypertension. The decision to administer intravenous nitroglycerin and the dosage used should not preclude therapy with other proven mortality-reducing interventions, such as beta blockers or angiotensin-converting enzyme (ACE) inhibitors. (Level of Evidence: B)
Intravenous, oral, or topical nitrates are useful beyond the first 48 hours after STEMI for treatment of recurrent angina or persistent congestive heart failure (CHF) if their use does not preclude therapy with beta blockers or ACE inhibitors. (Level of Evidence: B)
Class IIb
The continued use of nitrate therapy beyond the first 24 to 48 hours in the absence of continued or recurrent angina or CHF may be helpful, although the benefit is likely to be small and is not well established in contemporary practice. (Level of Evidence: B)
Class III
Nitrates should not be administered to patients with systolic pressure less than 90 mm Hg or greater than or equal to 30 mm Hg below baseline, severe bradycardia (less than 50 bpm), tachycardia (more than 100 bpm), or right ventricular infarction. (Level of Evidence: C)
INHIBITION OF THE RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM
Class I
An ACE inhibitor should be administered orally during convalescence from STEMI in patients who tolerate this class of medication, and it should be continued over the long term. (Level of Evidence: A)
An angiotensin-receptor blocker (ARB) should be administered to STEMI patients who are intolerant of ACE inhibitors and have clinical or radiologic signs of heart failure or left ventricular ejection fraction (LVEF) less than 0.40. Valsartan and candesartan have demonstrated efficacy for this recommendation. (Level of Evidence: B)
Long-term aldosterone blockade should be prescribed for post-STEMI patients without significant renal dysfunction (creatinine should be less than or equal to 2.5 mg per dL [221.0 μmol per L] in men and less than or equal to 2.0 mg per dL [176.8 μmol per L] in women) or hyperkalemia (potassium should be less than or equal to 5.0 mEq per L [5.0 mmol per L]) who are already receiving therapeutic doses of an ACE inhibitor, have an LVEF less than or equal to 0.40, and have symptomatic heart failure or diabetes. (Level of Evidence: A)
Class IIa
In patients with STEMI who tolerate ACE inhibitors, an ARB can be useful as an alternative to ACE inhibitors provided there are either clinical or radiologic signs of heart failure or LVEF is less than 0.40. Valsartan and candesartan have established efficacy for this recommendation. (Level of Evidence: B)
Antiplatelets
Class I
Aspirin (162 to 325 mg) should be given on day 1 of STEMI and in the absence of contraindications should be continued indefinitely on a daily basis thereafter at a dosage of 75 to 162 mg. (Level of Evidence: A)
A thienopyridine (preferably clopidogrel) should be administered to patients who are unable to take aspirin because of hypersensitivity or major gastrointestinal intolerance. (Level of Evidence: C)
For patients taking clopidogrel for whom coronary artery bypass graft surgery is planned, if possible, the drug should be withheld for at least five days, and preferably seven, unless the urgency for revascularization outweighs the risk of bleeding. (Level of Evidence: B)
For patients who have undergone diagnostic cardiac catheterization and for whom percutaneous coronary intervention (PCI) is planned, clopidogrel should be started and continued for at least one month after bare metal stent implantation (three months for sirolimus, six months for paclitaxel) and up to 12 months in patients who are not at high risk for bleeding. (Level of Evidence: B)
Antithrombotics
Class I
Intravenous unfractionated heparin (bolus of 60 U per kg, maximum 4,000 U IV; initial infusion 12 U per kg per hour, maximum of 1,000 U per hour) or low-molecular-weight heparin (LMWH) should be used in patients after STEMI who are at high risk for systemic emboli (large or anterior myocardial infarction, atrial fibrillation, previous embolus, known left ventricular thrombus, or cardiogenic shock). (Level of Evidence: C)
Class IIa
It is reasonable that patients with STEMI who are not undergoing reperfusion therapy and do not have a contraindication to anticoagulation be treated with intravenous or subcutaneous unfractionated heparin or with subcutaneous LMWH for at least 48 hours. In patients whose clinical condition necessitates prolonged bed rest and/or minimized activities, it is reasonable that treatment be continued until the patient is ambulatory. (Level of Evidence: C)
Class IIb
Prophylaxis for deep venous thrombosis (DVT) with subcutaneous LMWH (dosed appropriately for specific agent) or with subcutaneous unfractionated heparin, 7,500 U to 12,500 U twice per day until completely ambulatory, may be useful, but the effectiveness of such a strategy is not well established in the contemporary era of routine aspirin use and early mobilization. (Level of Evidence: C)
Oxygen
Class I
Supplemental oxygen therapy should be continued beyond the first six hours in STEMI patients with arterial oxygen desaturation(SaO2 less than 90 percent) or overt pulmonary congestion. (Level of Evidence: C)
ESTIMATION OF INFARCT SIZE
Measurement of infarct size is a vital element in the overall care of patients with STEMI. The guidelines discuss the five major modalities that apply to measuring myocardial infarction, including electrocardiographic techniques, cardiac biomarker methods, radionuclide imaging, echocardiography, and magnetic resonance imaging.
SECONDARY PREVENTION
Unless contraindicated, secondary prevention strategies are essential components of managing STEMI. The accompanying table provides recommended interventions for secondary prevention for patients with STEMI.
The hospital management section of the guidelines also includes guidelines for hemodynamic disturbances, arrhythmias after STEMI, recurrent chest pain after STEMI, other complications (including ischemic stroke, DVT, and pulmonary embolism), coronary artery bypass graft surgery after STEMI, and convalescence, discharge, and post-myocardial infarction care. It also includes an algorithm for the emergency management of complicated STEMI, cardiogenic shock, or acute pulmonary edema.
Long-Term Management
PSYCHOSOCIAL IMPACT OF STEMI
Class I
The psychosocial status of the patient should be evaluated, including inquiries regarding symptoms of depression, anxiety, or sleep disorders and the social support environment. (Level of Evidence: C)
| Goals | Intervention Recommendations |
| Smoking: Goal is complete cessation. | Assess tobacco use. Strongly encourage patient and family to stop smoking and to avoid secondhand smoke. Provide counseling, pharmacologic therapy (including nicotine replacement and bupropion), and formal smoking-cessation programs as appropriate. |
| Blood pressure control: Goal is less than 140/90 mm Hg or less than 130/80 mm Hg if chronic kidney disease or diabetes. | If blood pressure is 120/80 mm Hg or greater: |
| • Initiate lifestyle modification (weight control, physical activity, alcohol moderation, moderate sodium restriction, and emphasis on fruits, vegetables, and low-fat dairy products) in all patients. If blood pressure is 140/90 mm Hg or greater or 130/80 mm Hg or greater for individuals with chronic kidney disease or diabetes: | |
| • Add blood pressure medications, emphasizing the use of beta blockers and inhibition of the renin-angiotensin-aldosterone system. | |
| Lipid management: (TG level less than 200 mg per dL [2.26 mmol per L]) Primary goal is LDL-C level substantially less than 100 mg per dL (2.60 mmol per L). | Start dietary therapy in all patients (less than 7 percent of total calories as saturated fat and less than 200 mg per day cholesterol). Promote physical activity and weight management. Encourage increased consumption of omega-3 fatty acids. |
| Assess fasting lipid profile in all patients, preferably within 24 hours of STEMI. | |
| Add drug therapy according to the following guide: | |
| LDL-C level substantially less than 100 mg per dL (baseline or on-treatment): | |
| • Statins should be used to lower LDL-C. | |
| LDL-C level substantially greater than 100 mg per dL (baseline or on-treatment): | |
| • Intensify LDL-C-lowering therapy with drug treatment, giving preference to statins. | |
| Lipid management: (TG 200 mg per dL or greater) Primary goal is non-HDL-C* substantially lower than 130 mg per dL (3.36 mmol per L). | If TG is greater than or equal to 150 mg per dL (1.67 mmol per L) or HDL-C is less than 40 mg per dL (1.03 mmol per L): |
| • Emphasize weight management and physical activity. Advise smoking cessation. | |
| If TG is 200 to 499 mg per dL (2.26 to 5.64 mmol per L): | |
| • After LDL-C-lowering therapy,† consider adding fibrate or niacin.‡ | |
| If TG is greater than or equal to 500 mg per dL (5.65 mmol per L): | |
| • Consider fibrate or niacin‡ before LDL-C-lowering therapy.† | |
| • Consider omega-3 fatty acids as adjunct for high TG. | |
| Physical activity: minimum goal is 30 minutes, three to four days per week; optimal is daily. | Assess risk, preferably with exercise test, to guide prescription. |
| Encourage minimum of 30 to 60 minutes of activity, preferably daily, or at least three to four times weekly (walking, jogging, cycling, or other aerobic activity) supplemented by an increase in daily lifestyle activities (such as walking breaks at work, gardening, household work). Cardiac rehabilitation/secondary prevention programs, when available, are recommended for patients with STEMI, particularly those with multiple modifiable risk factors and/or those moderate- to high-risk patients in whom supervised exercise training is warranted. | |
| Weight management: Goal is BMI 18.5 to 24.9 kg per m2; waist circumference less than 40 inches for men and less than 35 inches for women. | Calculate BMI and measure waist circumference as part of evaluation. Monitor response of BMI and waist circumference to therapy. |
| Start weight management and physical activity as appropriate. Desirable BMI range is 18.5 to 24.9 kg per m2. | |
| If waist circumference is greater than or equal to 35 inches in women or greater than or equal to 40 inches in men, initiate lifestyle changes and treatment strategies for metabolic syndrome. | |
| Diabetes management: Goal is A1C less than 7 percent. | Appropriate hypoglycemic therapy to achieve near-normal fasting plasma glucose, as indicated by A1C. Treatment of other risks (such as physical activity, weight management, blood pressure, and cholesterol management). |
| Antiplatelet agents/anticoagulants: | Start and continue indefinitely aspirin 75 to 162 mg per day if not contraindicated. Consider clopidogrel 75 mg per day or warfarin if aspirin is contraindicated. Manage warfarin to INR of 2.5 to 3.5 in post-STEMI patients when clinically indicated or for those not able to take aspirin or clopidogrel. |
| Renin-angiotensin-aldosterone system blockers: | ACE inhibitors in all patients indefinitely; start early in stable high-risk patients (anterior MI, previous MI, Killip class greater than or equal to II [S3 gallop, rales, radiographic CHF], LVEF less than 0.40). |
| ARBs in patients who are intolerant of ACE inhibitors and who have either clinical or radiologic signs of heart failure or LVEF less than 0.40. | |
| Aldosterone blockade in patients without significant renal dysfunction§ or hyperkalemia∥ who are already receiving therapeutic doses of an ACE inhibitor, have an LVEF less than or equal to 0.40, and have either diabetes or heart failure. | |
| Beta-blockers: | Start in all patients. Continue indefinitely. Observe usual contraindications. |
Class IIa
Treatment with cognitive-behavioral therapy and selective serotonin reuptake inhibitors can be useful for STEMI patients with depression that occurs in the year after hospital discharge. (Level of Evidence: A)
CARDIAC REHABILITATION
Class IIa
Cardiac rehabilitation/secondary prevention programs, when available, are recommended for patients with STEMI, particularly those with multiple modifiable risk factors and/or those moderate- to high-risk patients in whom supervised exercise training is warranted. (Level of Evidence: C)
FOLLOW-UP VISIT WITH MEDICAL PROVIDER
Class I
A follow-up visit should delineate the presence or absence of cardiovascular symptoms and functional class. (Level of Evidence: C)
The patient’s list of current medications should be reevaluated in a follow-up visit, and appropriate titration of ACE inhibitors, beta blockers, and statins should be undertaken. (Level of Evidence: C)
The predischarge risk assessment and planned work-up should be reviewed and continued. This should include a check of left ventricular function and possibly Holter monitoring for those patients whose early post-STEMI ejection fraction was 0.31 to 0.40 or lower, in consideration of possible implantable cardioverter-defibrillator use. (Level of Evidence: C)
The health care provider should review and emphasize the principles of secondary prevention with the patient and family members. (Level of Evidence: C)
The psychosocial status of the patient should be evaluated in follow-up, including inquiries regarding symptoms of depression, anxiety, or sleep disorders and the social support environment. (Level of Evidence: C)
In a follow-up visit, the health care provider should discuss in detail issues of physical activity, return to work, resumption of sexual activity, and travel, including driving and flying. (Level of Evidence: C)
Patients and their families should be asked if they are interested in cardiopulmonary resuscitation training after the patient is discharged from the hospital. (Level of Evidence: C)
Clinicians should actively review the following issues with patients and their families:
The patient’s heart attack risk. (Level of Evidence: C)
How to recognize symptoms of STEMI. (Level of Evidence: C)
The advisability of calling 9-1-1 if symptoms are unimproved or worsening after five minutes, despite feelings of uncertainty about the symptoms and fear of potential embarrassment. (Level of Evidence: C)
A plan for appropriate recognition and response to a potential acute cardiac event, including the phone number to access emergency medical services, generally 9-1-1. (Level of Evidence: C)
Cardiac rehabilitation/secondary prevention programs, when available, are recommended for patients with STEMI, particularly those with multiple modifiable risk factors and/or those moderate- to high-risk patients in whom supervised exercising training is warranted. (Level of Evidence: C)
This guideline also discusses management before STEMI, out-of-hospital cardiac arrest, prehospital issues, and initial recognition and management in the emergency department.