Abstract
BACKGROUND AND PURPOSE: Providers vary in their thresholds for obtaining blood cultures in patients with ischemic stroke or transient ischemic attack (TIA). We assessed the rate of missed diagnoses of infective endocarditis (IE) in patients discharged with stroke or TIA before blood culture results could have been available. METHODS: Using administrative claims data, we performed a retrospective cohort study of all patients discharged from nonfederal California emergency departments or acute care hospitals from 2005 through 2011 with stroke (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 433.x1, 434.x1, or 436 in any position) or TIA (ICD-9-CM code 435 in the primary diagnosis position). We excluded patients with a length of stay >2 days to focus on those discharged before conclusive blood culture results could have been available. Our outcome was hospitalization within 14 days with a new diagnosis of IE (ICD-9-CM codes 391.1 or 421.x in any position). RESULTS: Among 173 966 eligible patients, 24 were subsequently hospitalized for IE-a readmission rate of 1.4 per 10 000 (95% confidence interval [CI], 0.8-1.9 per 10 000). Multiple logistic regression identified the following potential associations with readmission: prosthetic valve: odds ratio (OR), 15.8 (95% CI, 1.9-129.0); other valvular disease: OR, 1.5 (95% CI, 0.2-10.8); urinary tract infection: OR, 3.5 (95% CI, 1.0-12.3; P = .05). CONCLUSIONS: In patients with acute cerebral ischemia discharged before blood culture results could have been available, the rate of subsequent IE was negligible. These findings argue against the liberal use of blood cultures for the routine evaluation of stroke or TIA.