Association Between Inpatient Echocardiography Use and Outcomes in Adult Patients With Acute Myocardial Infarction

IMPORTANCE: Guidelines recommend that patients with acute myocardial infarction (AMI) undergo echocardiography for assessment of cardiac structure and ejection fraction, but little is known about the association between echocardiography as used in routine clinical management of AMI and patient outcomes. OBJECTIVE: To examine the association between risk-standardized hospital rates of transthoracic echocardiography and outcomes. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study of data from 397 US hospitals that contributed to the Premier Healthcare Informatics inpatient database from January 1, 2014, to December 31, 2014, used International Classification of Diseases, Ninth Revision (ICD-9) codes to identify 98 999 hospital admissions for patients with AMI. Data were analyzed between October 2017 and January 2019. EXPOSURES: Rates of transthoracic echocardiography. MAIN OUTCOMES AND MEASURES: Inpatient mortality, length of stay, total inpatient costs, and 3-month readmission rate. RESULTS: Among the 397 hospitals with more than 25 admissions for AMI in 2014, a total of 98 999 hospital admissions for AMI were identified for analysis (38.2% women; mean [SD] age, 66.5 [13.6] years), of which 69 652 (70.4%) had at least 1 transthoracic echocardiogram performed. The median (IQR) hospital risk-standardized rate of echocardiography was 72.5% (62.6%-79.1%). In models that adjusted for hospital and patient characteristics, no difference was found in inpatient mortality (odds ratio [OR], 1.02; 95% CI, 0.88-1.19) or 3-month readmission (OR, 1.01; 95% CI, 0.93-1.10) between the highest and lowest quartiles of echocardiography use (median risk-standardized echocardiography use rates of 83% vs 54%, respectively). However, hospitals with the highest rates of echocardiography had modestly longer mean lengths of stay (0.23 days; 95% CI, 0.04-0.41; P = .01) and higher mean costs ($3164; 95% CI, $1843-$4485; P