Background: Few population-level data exist regarding functional outcomes after intracerebral hemorrhage (ICH) caused by a ruptured cerebral arteriovenous malformation (AVM). Our aim was to compare outcomes after ICH from AVM rupture versus other causes of ICH.
Methods: We performed a retrospective population-based study using data from the Nationwide Inpatient Sample (NIS), a nationally representative survey of hospitalizations across the U.S. We used previously validated International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis codes to identify ICH cases in the NIS from 2002 through 2011. We also performed a confirmatory analysis in a prospective cohort of patients hospitalized with ICH at our medical center from 2011 through 2015. Our predictor variable was a documented AVM. Our primary outcomes were inpatient mortality and home discharge. We used logistic regression to compare outcomes between ICH patients with and without AVM, while adjusting for demographics and medical comorbidities. In the confirmatory analysis of ICH patients at our institution, we additionally adjusted for hematoma size, hematoma location, and the Glasgow Coma Scale score.
Results: Among 619,167 ICH patients in the NIS, the 4,485 patients (0.7%) with an AVM were younger and had fewer medical comorbidities than patients without AVM. After adjustment for demographics and comorbidities, patients with AVM had lower odds of death (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.40-0.71) and higher odds of home discharge (OR, 2.03; 95% CI, 1.38-2.98) than patients without AVM. In a confirmatory analysis of 342 ICH patients at our institution, the 34 patients (9.9%) with a ruptured AVM had significantly higher odds of independent ambulation at discharge (OR, 4.39, 95% CI, 1.47-13.06) compared to ICH patients without AVM.
Conclusion: Patients with ICH due to ruptured AVM have more favorable outcomes than patients with other causes of ICH, even after adjustment for demographics, comorbidities, and traditional measures of ICH severity.