Left ventricular ejection fraction assessment among patients with acute myocardial infarction and its association with hospital quality of care and evidence-based therapy use

Abstract

Background: The left ventricular ejection fraction (LVEF) has prognostic and therapeutic utility after acute myocardial infarction (AMI). Although LVEF assessment is a key performance measure among AMI patients, contemporary rates of in-hospital assessment and its association with therapy use have not been well characterized.

Methods and results: We examined rates of in-hospital LVEF assessment among 77 982 non-ST-elevation myocardial infarction patients and 50 863 ST-elevation myocardial infarction patients in Acute Coronary Treatment and Intervention Outcomes Network Registry-Get With The Guidelines between January 2007 and September 2009, after excluding patients who died in-hospital or who were transferred to another acute care facility, discharged to end-of-life care, or had missing LVEF assessment status. LVEF assessment increased significantly over time, with higher rates among ST-elevation myocardial infarction than non-ST-elevation myocardial infarction patients (95.1% versus 91.6%; P<0.001). Excluding patients with prior heart failure did not alter these observations. Significant interhospital variability in LVEF assessment rates was observed. Compared with patients with in-hospital LVEF assessment, patients who did not have LVEF assessed were older and more likely to have clinical comorbidities. In multivariable modeling, lower overall hospital quality of AMI care was also associated with lower likelihood of LVEF assessment (odds ratio for failure to assess LVEF, 1.09; 95% confidence interval, 1.05-1.13 per 10% decrease in defect-free care). Patients with in-hospital LVEF assessment were more likely to be discharged on evidence-based secondary prevention medication therapies compared with patients without LVEF assessment.

Conclusions: The assessment of LVEF among patients with AMI has improved significantly over time, yet significant interhospital variability exists. Patients who did not have in-hospital LVEF assessment were less likely to receive evidence-based medications at discharge. These patients represent targets for future quality improvement efforts.