The diagnostic and therapeutic approach to patients with non–ST-segmentelevationacute coronary syndromes (NSTE ACS — unstable angina and non-ST-segment elevation myocardial infarction) has evolved considerably over the past decade with publication of multiple landmark trials that have redefined the care of these patients and continual updating of the American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the management of NSTE ACS.^1–6 Despite these achievements, treatment patterns for these syndromes remain suboptimal.^3,7 Quality-improvement efforts are therefore needed to promote increased adherence to the ACC/AHA guidelines and overcome challenges that limit the use of beneficial therapies for NSTE ACS.³

The first challenge involves accurately identifying patients with NSTE ACS from the much larger population of patients who present to emergency departments with suspected ischemic symptoms. Whereas patients with acute ST-segment elevation myocardial infarction usually present with clear chest pain symptoms and often are identified rapidly from the initial electrocardiogram (ECG), patients with NSTE ACS often do not have definitive symptoms or clear ischemic ECG changes on presentation.^8,9 Thus, determination of risk status for patients with NSTE myocardial infarction relies heavily on documentation of elevated cardiac biomarkers such as troponins, but interpretation of troponin results often is uncertain in clinical practice given limitations of the available troponin assays and disagreements on what level of troponin elevation should be used to guide therapeutic decision making.^10–12

The second challenge involves promoting practice guideline recommendations among all specialties that typically care for patients with NSTE ACS. A recent analysis demonstrated that almost one half of high-risk patients with NSTE ACS in U.S. hospitals are cared for by non-cardiologists who use guideline-recommended therapies and interventions less frequently than cardiologists.¹³ Similar disparities in care by specialty have been demonstrated in patients with acute myocardial infarction or congestive heart failure.^14,15 Explanations for differential care patterns by specialty have not been defined clearly, but may relate to the availability of cardiology services and invasive procedures (especially at community hospitals), poor cooperation among specialties, and inadequate dissemination of guideline recommendations to non-cardiology specialties. Therefore, improved collaboration among specialties is needed to increase adherence to guidelines.

The third challenge involves defining and demonstrating success with quality-improvement efforts. Achievable benchmarks of care such as thresholds for ideal use of aspirin and heparin (designated by treatment patterns at hospitals that have the highest adherence to practice guidelines) have been used as performance indicators to successfully motivate changes in practice. However, benchmarks for the use of medications and procedures are difficult to delineate given uncertainties about contraindications to specific therapies and disagreement among physicians about the benefits of certain medications.¹⁶ Results from quality-improvement studies often are questioned because of methodologic limitations that restrict the applicability of the findings to diverse practice environments.¹⁷ Nonetheless, key components to successful quality-improvement efforts appear to include developing a consensus about the goals of interventions, administrative support, leadership from physician champions, and regular performance feedback.¹⁸ There is no “right” formula for quality improvement, but sustained enthusiasm and flexibility regarding performance improvement approaches may be the best starting points.

Despite the challenges of improving the quality of care for patients with NSTE ACS, there should be a strong impetus for changing current practice patterns because improved performance is associated with a lower risk of mortality.^19–22 Specifically, in the ongoing Can Rapid Risk Stratification of Unstable Angina Patients Suppress ADverse Outcomes with Early Implementation of the ACC/AHA Guidelines (CRUSADE) national quality-improvement initiative involving more than 400 hospitals in the United States, in-hospital mortality rates were almost 50 percent lower in hospitals with the best overall adherence to the ACC/AHA guidelines for NSTE ACS compared with hospitals that had the worst adherence to guidelines.²² Therefore, multidisciplinary quality-improvement strategies are needed to promote use of these guidelines, ensuring sustained improvements in care.