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Background and Purpose: Since the 2011 publication of an update to the 2007 guidelines on the management of unstable angina and non–ST-segment-elevation myocardial infarction (UA/NSTEMI; (JW Cardiol Apr 20 2011), medical management of acute coronary syndromes has continued to advance rapidly. New findings from several trials and the approval of another antiplatelet drug (ticagrelor) have led to a new focused update to replace the 2011 one.
1. Based on the results of the PLATO trial (JW Cardiol Sep 2 2009), ticagrelor joins prasugrel as a reasonable alternative to clopidogrel in all UA/NSTEMI patients, but particularly those at high risk and those for whom percutaneous coronary intervention is planned (Class I). The guidelines do not endorse any P2Y12 receptor inhibitor over another. However, clinicians should note that prasugrel is associated with increased bleeding risk in specific patient subsets (history of stroke or transient ischemic attack, age ≥75, body weight <60 kg), and that ticagrelor has shown reduced efficacy in patients taking high maintenance doses of aspirin (81 mg daily of aspirin is preferred with ticagrelor).
2. With the usual caution about premature discontinuation of dual antiplatelet therapy in stent recipients, the guidelines recommend halting P2Y12 receptor-inhibitor therapy when coronary artery bypass grafting is planned (clopidogrel or ticagrelor, 5 days; prasugrel, 7 days), if surgery can be delayed (Class I).
3. Recognizing the availability of genetic and functional testing for reduced clopidogrel responsiveness as well as the lack of prospective study data supporting a clinical benefit of testing, the authors walk a middle ground, stating that a selective, limited testing strategy may be reasonable (Class IIb).
4. A new recommendation has been added to consider a lower international normalized ratio target (e.g., 2.0–2.5) of oral anticoagulation therapy in patients with UA/NSTEMI who are also taking aspirin and a P2Y12 receptor inhibitor (Class IIb; level of evidence, C).
Jneid H et al. 2012 ACCF/AHA focused update of the guideline for the management of patients with unstable angina/non–ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 focused update): A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2012 Aug 14; 60:645.
Comment
These guidelines were updated quickly, primarily to address the appropriate use of prasugrel and ticagrelor in clinical practice. The recommendations are reasonable and will be welcomed by clinicians who are faced with a sometimes bewildering array of therapeutic choices for UA and NSTEMI patients.