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Clinical Clips: Damage Control - Myocardial Infarction Treatment Guidelines
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The American Heart Association (AHA) and American College of Cardiology (ACC) have revised some of their joint guidelines for the management of myocardial infarction (MI).
Released in late 2007, the revisions outline evidence-based data on ways to optimize patient outcomes for the most critical type of heart attack — ST-elevation myocardial infarction (STEMI) — and for unstable angina/non-STEMI (UA/NSTEMI). The guidelines, which can be found online at pt.wkhealth.com/pt/re/aha/ua_nstemi.htm, reinforce that faster times to treatment and better systems of care are associated with reduced morbidity and mortality.
“Because of the high incidence of heart disease in the United States, all nurses need to be aware of early recognition and treatment of heart attack,” said Mary Beth Mancini, RN, MSN, PhD, professor and associate dean at the University of Texas at Arlington School of Nursing.
In addition, the revised guidelines put greater emphasis on secondary prevention and education about risk factors for all patients at risk for recurrent MI.
New data from clinical trials spurred the changes to the 2004 STEMI guidelines and 2002 UA/NSTEMI guidelines, according to the AHA. “We now know which treatment is best for the right patient at the right time,” Mancini said.
Risk assessment and treatment
Past guidelines for UA/NSTEMI recommended initial invasive therapy. In a major change, the current guidelines advise to differentiate between high-risk and low-risk patients using evidence-based risk scores. Unstable or high-risk patients with UA/NSTEMI should receive early invasive intervention, such as diagnostic angiography and revascularization. Initial conservative, noninvasive treatment (e.g., stress test, echocardiogram) is recommended for stabilized patients and low-risk patients.
For STEMI guidelines, an important change was to recommend that first responders perform a prehospital, 12-lead electrocardiogram (ECG), to shorten the time to diagnosis and treatment. This recommendation will not change clinical practice for the emergency department nurse or the need to obtain a 12-lead ECG in the ED, said Deborah Klein, RN, MSN, CS, CCRN, a clinical nurse specialist for Cleveland Clinic’s cardiac intensive care unit. However, ED staff will receive early information from emergency medical systems that can assist in planning and initiating appropriate interventions, she said.
For any patient with heart attack symptoms, Klein stressed it is important that nurses ask about the use of nonsteroidal anti-inflammatory drugs (NSAIDs). Because of accumulating evidence that these medications, except for aspirin, appear to increase cardiac risk, the AHA/ACC guidelines say NSAIDs (except aspirin) should be discontinued during hospitalization.
Secondary prevention
Guidelines for both types of heart attack stress the need for secondary prevention. The new guidelines stress a more proactive approach in helping patients make lifestyle modifications, Klein said. “[Clinicians] need to do more than say, ‘Quit smoking,’ ” she said. “We need to come up with a plan to help them quit smoking, and talk about it at each visit.”
The modified recommendation for smoking cessation says to assess patients’ willingness to quit and to advise all patients to avoid second-hand smoke at work and home. According to the reworded guidelines, the recommended 30 to 60 minutes of aerobic activity on most days of the week should be moderate in intensity. A new recommendation is to add resistance training two days a week.
The guidelines also emphasize better control of cholesterol and blood pressure. Low-density lipoprotein (LDL) or “bad” cholesterol should be lowered below 70 mg/dL. The previous recommendation was under 100 mg/dL. The blood pressure goal remains at lower than 140/90 mm Hg (less than 130/80 for patients with diabetes or chronic kidney disease).
REVISED HEART ATTACK TREATMENT GUIDELINES
UA/NSTEMI
• Upon the patient’s arrival, the risk of unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI) must be quickly assessed using evidence-based risk scores.
• Early invasive intervention (e.g., diagnostic angiography, angioplasty, stent placement) will be reserved for high-risk patients. Low-risk patients initially should be evaluated using noninvasive cardiac tests.
• Be prepared to start antiplatelet and anticoagulation therapy as soon as possible if a diagnosis of UA/NSTEMI is likely or definite.
• Long-term medical therapy should include angiotensin-converting enzyme (ACE) inhibitors, which protect the heart muscle.
• Antiplatelet therapy with clopidogrel (Plavix) should continue (unless contraindicated) for up to one year after placement of a drug-eluting stent and for one to 12 months for patients receiving bare-metal stents and those receiving medical therapy only.
STEMI
• In the pre-hospital setting, 12-lead electrocardiograms (ECGs) should be used to decrease the time to diagnosis.
• Do NOT give intravenous beta-blockers to patients with STEMI who have signs of any of the following: heart failure or a low cardiac output state (in cardiogenic shock); increased risk for cardiogenic shock or other relative contraindications, such as active asthma, reactive airway disease, or second-degree (partial) or third-degree (complete) heart block.
• To aspirin therapy, add clopidogrel for at least two weeks in all patients.
Both (UA/NSTEMI and STEMI)
• If the patient is taking nonsteroidal anti-inflammatory drugs (NSAIDs), these medications, except aspirin, should be discontinued during hospitalization.
• As part of discharge planning and post-discharge teaching, patient education should include:
- Reduce risk factors, especially by quitting smoking and tightly controlling blood pressure and cholesterol.
- Consider LDL-lowering therapy if the baseline LDL cholesterol is between 70 and 100 mg/dL.
- Obtain a yearly flu shot.
• Postmenopausal women who have suffered a heart attack should discontinue hormone replacement therapy.
• High-dose antioxidant vitamin supplements, such as beta carotene, should not be used in patients recovering from a heart attack.
Sources: American Heart Association; Mary Beth Mancini, RN, MSN, PhD
