The writing committee of the 2012 UA/NSTEMI guideline constructed additional evidence-based recommendations regarding measures to diminish contrast-induced nephropathy in ACS patients undergoing cardiac catheterization, including administration of adequate preparatory hydration and the calculation of the contrast volume to CrCl ratio to predict the maximum volume of contrast media that can be given safely.1
The writing committee also emphasized the importance of standardized quality-of-care data registries to track and measure outcomes, complications, and adherence to evidence-based processes of care for ACS and endorsed the participation in these registries as a reasonable strategy.1
The writing committee also advocated the use of an insulin-based regimen to achieve and maintain blood glucose levels <180 mg/dL while avoiding hypoglycemia for hospitalized UA/NSTEMI patients as a reasonable approach.18
An important addition to the 2012 ACCF/AHA guidelines update pertains to aspirin dosing. Previously, the 2007 UA/NSTEMI guidelines endorsed medium-to-high doses of aspirin selectively, with variability in dose and duration of therapy according to the type of stent utilized. Nevertheless, the saturability of the antiplatelet effect of aspirin at low doses, the lack of dose-response relationship in studies evaluating its clinical efficacy, and the dose-dependence response of its side effects all support the use of a low dose of aspirin (e.g., the 81-mg dosage form available in the United States).19
Therefore, the 2012 ACCF/AHA guidelines update maintained that it is reasonable to use 81-mg daily aspirin in preference to higher maintenance doses after PCI (irrespective of stent type), which is concordant with the recently released 2011 ACCF/AHA PCI guidelines.21
The 2012 ACCF/AHA UA/NSTEMI guideline update did not provide recommendations on the use of proton pump inhibitors (PPIs) in patients on dual antiplatelet therapy (DAPT). Despite experimental and registry data suggesting diminished effectiveness of clopidogrel with the use of a PPI, the COGENT trial showed no increase in adverse cardiovascular outcomes and decreased GI bleeding from the combination of clopidogrel and omeprazole.22
The 2012 ACCF/AHA PCI guidelines, on the other hand, recommended the use of PPIs in patients with a history of prior GI bleeding who require dual antiplatelet therapy.21
In addition, the 2012 ACCF/AHA guideline update did address the use of anticoagulant therapies (such as the new oral factor Xa inhibitors, apixaban and rivaroxaban), anti-ischemic therapies (such as ranolazine), or new diagnostic modalities and biomarkers in patients with ACS.