Quality Measure Adherence and One-year Mortality in Patients with Non-ST-Elevation Myocardial Infarction

Does adherence to ACC/AHA guideline therapies in patients with non-ST-elevation myocardial infarction (NSTEMI) result in reductions in one-year post-discharge mortality rates?

As part of the "Unstable Angina, NSTEMI, and STEMI: Risk Markers and Outcomes" Abstract Oral Session presented Tuesday, November 16, at the American Heart Association Scientific Sessions 2009, Bimal R. Shah, from the Duke Clinical Research Institute at Duke University Medical Center, presented "Association between Hospital Process Performance and One-year Post-discharge Mortality in Patients with Non-ST Elevation Myocardial Infarction: Results from 35,918 Patients," which evaluated the association between hospitals' adherence to performance measures for evidence-based NSTEMI care and long-term mortality.

Using data from the CRUSADE registry, researchers identified nearly 36,000 patients treated for NSTEMI at 268 hospitals. Exclusion criteria included patients with in-hospital death and hospitals that had participated in CRUSADE for less than one year, among other variables.

Researchers created a "composite adherence score" for each hospital based on that institution's "composite adherence to 9 Class I ACC/AHA guideline therapies (antiplatelet, beta-blocker, any heparin, and GP IIB/IIIA within 24 hours; antiplatelet, beta-blocker, clopidogrel, ACEI/ARB, and lipid-lowering agent at discharge)."

Mean composite adherence score was 81%, with hospitals grouped into four quartiles: 73% (the "lagging centers"); 79%, 83%, and 88%. The researchers reported no significant clinical differences among patients in four hospital quartiles. They also found a gradual increase in evidence-based therapy use among quartiles, but variance in some measures was as high as 30%.

The authors report that "greater composite performance adherence was strongly associated with reduction in 1-year mortality," which was 21% in this cohort. Unadjusted mortality rates (from lowest to highest by adherence score quartile) were 24%, 22%, 19%, and 19%. This association persisted after adjusting for 13 baseline clinical factors.

The researchers conclude that "hospital adherence to ACC/AHA AMI guideline therapies is strongly associated with improved long-term mortality, further supporting the use of these metrics for measuring and improving" the care of patients with acute myocardial infarction.