Abstract T P176: Readmission for Infective Endocarditis after Ischemic Stroke or Transient Ischemic Attack

Abstract

Background: Guidelines recommend blood cultures for the evaluation of cerebral ischemia when infective endocarditis (IE) is the suspected cause, but given the absence of more specific guidance, providers likely have significantly varying thresholds for obtaining blood cultures in patients with cerebral ischemia. To explore the utility of blood cultures in these patients, we assessed rates of missed diagnoses of IE in patients discharged after stroke or TIA before blood culture results could have been available. Methods: Using administrative claims data, we retrospectively identified consecutive patients discharged from all nonfederal emergency departments (ED) or hospitals in California from 2005 through 2011 with a diagnosis of ischemic stroke (defined as ICD-9-CM codes 433.x1, 434.x1, or 436 in any diagnosis code position) or TIA (ICD-9-CM code 435 in the primary diagnosis position). Our primary outcome was a subsequent hospitalization within 14 days with any diagnosis of IE (ICD-9-CM code 391.1 or 421.x in any position). Patients with a diagnosis of IE before or at the time of their first stroke or TIA were excluded. To target patients discharged without conclusive blood culture results, only patients discharged directly from the ED or within 2 days of admission were included. A subgroup analysis was performed in patients diagnosed with TIA and discharged home from the ED. Results: Among 172,666 patients discharged with stroke or TIA, 24 were subsequently hospitalized for IE, equating to a readmission rate of 1.4 per 10,000 (95% CI, 0.8-2.0 per 10,000). Subgroup analysis of 39,019 patients diagnosed with TIA and discharged home from the ED revealed a readmission rate of 0.8 per 10,000 (95% CI, 0.1-1.6 per 10,000). Multiple logistic regression identified valvular disease (OR, 7.0; 95% CI, 2.9-17.2), chronic kidney disease (OR, 3.7; 95% CI, 1.3-10.4), and possibly drug abuse (OR, 5.0; 95% CI, 0.7-38.3) as risk factors for readmission with IE after discharge for stroke or TIA. Conclusions: In a cohort of 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 in the routine evaluation of ischemic stroke or TIA.