March 28th, 2011
Updated Unstable Angina/Non-STEMI Guidelines Released by ACC & AHA
The AHA and ACC have released a focused update of the 2007 guidelines for the management of unstable angina and non-STEMI. The guidelines incorporate new information from recent clinical trials, and deal with controversial topics such as the choice of antiplatelet agents, the use of platelet-function and genetic tests with antiplatelet agents, and the timing and indication for invasive therapy.
The document endorses the FDA label for prasugrel that states “it is reasonable to consider selective use of prasugrel before catheterization in subgroups of patients for whom a decision to proceed to angiography and PCI has already been established for any reason” but also cautions clinicians about the “potential bleeding risks from prasugrel compared with clopidogrel.” The update also notes that another oral antiplatelet agent, ticagrelor, has not yet been approved by the FDA and is therefore not recommended for use but acknowledges that “it may have a future role in patients with [unstable angina and non-STEMI].”
The update includes a full discussion of platelet function and genetic testing for CYP2C19 allelles but does not include a recommendation for their use. Noting the absence of clinical trials to support platelet function tests, the update states that “the lack of evidence does not mean lack of efficacy or potential benefit, but the prudent physician should maintain an open yet critical mind-set about the concept until data are available from ≥1 of the ongoing randomized clinical trials examining this strategy.”
Regarding the use of PPIs with clopidogrel, the update agrees with a recent ACC statement that “does not prohibit the use of PPI agents in appropriate clinical settings, yet highlights the potential risks and benefits from use of PPI agents in combination with clopidogrel.”
An early invasive strategy within 12 to 24 hours of admission is recommended only for initially stabilized high-risk patients. For patients at lower risk, a delayed invasive approach is “reasonable.”
The document also clarifies the use of dual antiplatelet therapy versus triple antiplatelet therapy and the role of invasive therapies in patients with advanced renal dysfunction.