Hemorrhagic Transformation Rates following Contrast Media Administration in Patients Hospitalized with Ischemic Stroke

BACKGROUND AND PURPOSE: Hemorrhagic transformation is a critical complication associated with ischemic stroke and has been associated with contrast media administration. The objective of our study was to use real-world in-hospital data to evaluate the correlation between contrast media type and transformation from ischemic to hemorrhagic stroke. MATERIALS AND METHODS: We obtained data on inpatient admissions with a diagnosis of ischemic stroke and a record of either iso-osmolar or low-osmolar iodinated contrast media for a stroke-related diagnostic test and a treatment procedure (thrombectomy, thrombolysis, or angioplasty). We performed multivariable regression analysis to assess the relationship between contrast media type and the development of hemorrhagic transformation during hospitalization, adjusting for patient characteristics, comorbid conditions, procedure type, a threshold for contrast media volume, and differences across hospitals. RESULTS: Inpatient visits with exclusive use of either low-osmolar (n?=?38,130) or iso-osmolar contrast media (n?=?4042) were included. We observed an overall risk reduction in hemorrhagic transformation among patients who received iso-osmolar compared with low-osmolar contrast media, with an absolute risk reduction of 1.4% (P?=?.032), relative risk reduction of 12.5%, and number needed to prevent harm of 70. This outcome was driven primarily by patients undergoing endovascular thrombectomy (n?=?9211), in which iso-osmolar contrast media was associated with an absolute risk reduction of 4.6% (P?=?.028), a relative risk reduction of 20.8%, and number needed to prevent harm of 22, compared with low-osmolar contrast media. CONCLUSIONS: Iso-osmolar contrast media was associated with a lower rate of hemorrhagic transformation compared with low-osmolar contrast media in patients with ischemic stroke.