AHA, ACC Update Management Guidelines for ST-Elevation MI

Steve Stiles
December 13, 2007 — The two major US cardiology societies have jointly issued an update to their 2004 guidelines on the management of acute ST-elevation myocardial infarction (STEMI) that not only brings recommendations on antithrombotic therapy, percutaneous coronary intervention (PCI), thrombolytics, and other clinical issues up to date with the literature, it puts new emphasis on integration of the various stages of management that STEMI patients pass through[1].
One prominent message of the document, according to Dr Elliott M Antman (Brigham and Women's Hospital, Boston, MA), is "that we need to move beyond the drugs and devices that have been the subject of our investigations over the past one to two decades and move into systems of care." The team system of care, Antman observed for heartwire, follows the management of STEMI patients "from the very first [emergency medical service] EMS and [emergency department] ED contacts, all the way through community hospital and interhospital transport, to the PCI-capable hospital and the catheterization team itself."
Other new guidelines in the document strengthen the indications for clopidogrel (whether or not reperfusion is achieved with PCI), restrict the use of nonsteroidal anti-inflammatory agents (NSAIDs), and provide a roadmap for using the array of antithrombotic agents that are now available.
Antman is chair of the American Heart Association (AHA)/American College of Cardiology (ACC) guidelines writing group. The update was published this week on the organizations' websites and is scheduled for the January 15, 2008 issues of their flagship journals, Circulation and Journal of the American College of Cardiology, the AHA announced.
Reperfusion therapy: Strive for PCI, otherwise lytics
Compared with the 2004 guidelines, Antman said, the update strengthens the emphasis on cutting the time to reperfusion, achieved preferably with PCI if it can be initiated within 90 minutes after the patient presents. If PCI can't take place on-site or off-site within 90 minutes of initial presentation, thrombolysis, unless there are contraindications, should be initiated within 30 minutes of presentation.
Also important, according to Antman, is shrinking the time from symptom onset to reperfusion, "and that means we have to do a better job with patient education and in the EMS and ED arenas." Also, the prehospital ambulance phase should be streamlined to stay within the 90-minute window. "That means we need to have prehospital ECGs [electrocardiograms] more widely available. We need the ambulance [crew] to triage patients directly and to consider the benefits of recognizing STEMI in the field, calling PCI-capable hospitals so the cath team can be arriving as the patient's being transported," he said. "Pretty soon, you've saved a substantial amount of time."
Rescue PCI or emergency coronary artery bypass grafting (CABG) for patients younger than 75 has become a class 1 recommendation for patients who have failed to achieve sufficient reperfusion with thrombolytics, especially in the presence of shock, heart failure, or other conditions of compromised cardiac output, the update observes.
Facilitated PCI — that is, planned PCI after reduced-dose thrombolytic therapy — isn't recommended as a routine strategy, Antman observed. "But we do leave open the door to the possibility that there may be certain clinical situations where the patient may have a low risk of bleeding, a high-risk infarct, and an anticipated very long time for transportation to a PCI center," when facilitated PCI may be useful. Using full-dose thrombolytics in facilitated PCI, according to the update, "may be harmful."
Antithrombotic agents: So many choices
Much space in the document is devoted to changes in anticoagulation protocols and how to handle the different antithrombin agents now available.
The update recommends that anticoagulation be maintained for at least 48 hours after the initiation of thrombolytic therapy and preferably throughout the entire hospitalization. If anticoagulation runs longer than 48 hours, an agent other than unfractionated heparin (UFH) should be used. The document specifies appropriate regimens for UFH, enoxaparin, bivalirudin, and fondaparinux in the PCI and non-PCI settings.
"It's very important that hospitals and teams caring for patients with STEMI discuss in advance what their preferred approach would be with respect to anticoagulation," Antman said. "If you have multiple physicians making independent choices, there can be errors, confusion, and worse: double dosing with the anticoagulant."
The indication for adding clopidogrel to aspirin at PCI has been strengthened and now calls for 12 months of clopidogrel following drug-eluting-stent PCI and for a minimum of one month up to 12 months if bare-metal stents are used.
After reperfusion therapy by means other than stents, clopidogrel is recommended for at least 14 days, and a treatment period of one year "is reasonable" in all STEMI patients, whether or not they receive reperfusion therapy, according to the update.
Ancillary treatments
A new class 1 recommendation calls for any STEMI patient on cyclooxygenase-2 (COX-2) inhibitors or NSAIDs, except for aspirin, to discontinue them "because of the increased risk of mortality, reinfarction, hypertension, heart failure, and myocardial rupture associated with their use." Avoiding them during the hospitalization is a class 3 recommendation; there is guidance on the postdischarge use of medications for pain relief, which progresses stepwise according to associated risk, beginning with acetaminophen.
Also, the update clarifies and specifies how intravenous (IV) beta blockers should be used in acute STEMI; a class 1 recommendation, they should be given during the first 24 hours except in patients with heart failure, risk factors for cardiogenic shock, or relative contraindications to the drugs.
Antman is a senior investigator with the Thrombosis in Myocardial Infarction group, which receives grants from a long list of companies, which are listed in the original guidelines article. He has received honoraria from or being on the speakers bureau for Eli Lilly and Sanofi-Aventis, and being a consultant or advisor to Sanofi-Aventis. The complete list of disclosures is available in the original article.
Source
Antman EM, Hand M, Armstrong PW, et al. 2007 focused update of the ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Group to Review New Evidence and Update the ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction). Circulation. Published online before print December 11, 2007. 2008;117:XXX–XXX. DOI: 10.1161/CIRCULATIONAHA.107.188209 http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.107.188209.