Limitations of using cardiac catheterization rates to assess the quality of care for patients with non-ST-segment elevation myocardial infarction

Background: An early invasive management strategy is recommended for patients with non-ST-segment elevation myocardial infarction (NSTEMI) who do not have a contraindication to cardiac catheterization (CCC). However, the frequency of CCC reporting has not been delineated, and the relationship of CCC reporting to hospital-level guidelines adherence for NSTEMI has not been investigated. Methods: We used the American College of Cardiology National Cardiovascular Data Registry Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines database to evaluate variations in hospital-level reporting of CCC for 111,320 patients with NSTEMI admitted to 370 hospitals with revascularization capabilities in the United States from 2007 to 2010 and how these variations were associated with guideline adherence and in-hospital mortality. Hospitals were grouped into tertiles based on rates of reported CCCs. Treatment patterns and in-hospital mortality rates were evaluated across hospital tertiles separately for patients with and without a reported CCC. Results: A total of 18,290 (16.4%) of 111,320 patients with NSTEMI had a reported CCC, but hospital-level CCC reporting varied considerably (low tertile 0%-8.2%, intermediate tertile >8.2%-18.8%, and high tertile >18.8%-75.6%). Patients with a reported CCC had more comorbidities and high-risk features compared with patients without a CCC. The use of most guideline-recommended medications and in-hospital mortality rates were similar across hospital tertiles - both for patients with and without a reported CCC. Conclusions: The reporting of CCC among patients with NSTEMI varies widely across US hospitals and does not appear to be related to guidelines adherence or in-hospital mortality rates. These findings suggest that it will be a challenge to standardize the reporting of CCC and thus use invasive management to assess the quality of NSTEMI care.