Background: Guidelines recommend that patients with AMI undergo universal echocardiography for the assessment of cardiac structure and ejection fraction, despite modest diagnostic yield.
Study design: Retrospective cohort.
Setting: 397 U.S. hospitals contributing to the Premier Healthcare Informatics inpatient database.
Synopsis: ICD-9 codes were used to identify 98,999 hospitalizations with a discharge diagnosis of AMI. Of these, 70.4% had at least one transthoracic echocardiogram performed. Patients who underwent echocardiogram were more likely than patients without an echocardiogram to have heart failure, pulmonary disease, and intensive care unit stays and require interventions such as noninvasive and invasive ventilation, vasopressors, balloon pumps, and inotropic agents.
Risk-standardized echocardiography rates varied significantly across hospitals, ranging from a median of 54% in the lowest quartile to 83% in the highest quartile. The authors found that use of echocardiography was most strongly associated with the hospital, more so than individual patient factors. In adjusted analyses, no difference was seen in inpatient mortality (odds ratio, 1.02; 95% CI, 0.88-1.99) or 3-month readmission (OR, 1.01; 95% CI, 0.93-1.10), but slightly longer mean length of stay (0.23 days; 95% CI, 0.04-0.41; P = .01) and higher mean costs ($3,164; 95% CI, $1,843-$4,485; P < .001) were found in patients treated at hospitals with the highest quartile of echocardiography use, compared with those in the lowest quartile.
Limitations include lack of information about long-term clinical outcomes, inability to adjust for ejection fraction levels, and reliance on administrative data for AMI and procedure codes.
Bottom line: In a cohort of patients with AMI, higher rates of hospital echocardiography use did not appear to be associated with better clinical outcomes but were associated with longer length of stay and greater hospital costs.
Citation: Pack QR et al. Association between inpatient echocardiography use and outcomes in adult patients with acute myocardial infarction. JAMA Intern Med. 2019 Jun 17. doi: 10.1001/jamainternmed.2019.1051.
Dr. Liu is a hospitalist at Vanderbilt University Medical Center, Nashville, Tenn.