Ruptured arteriovenous malformation mortality: Incidence, risk factors, and inpatient outcome score

Background: Limited literature exists on the morbidity and mortality of AVM associated intracerebral hemorrhage (ICH) compared with non-AVM ICH. Objective: We examine morbidity and mortality in cAVM in a large nationwide inpatient sample to create a prognostic inpatient ruptured AVM mortality score. Methods: This retrospective cohort study from 2008 to 2014 compares outcomes in cAVM related hemorrhages and ICH utilizing the National Inpatient Sample database. Diagnostic codes for ICH and AVM underlying ICH were identified. We compared case fatality according to medical complications. Multivariate analysis was used to derive hazard ratios and 95% confidence intervals to assess odds of mortality. Results: We identified 6496 patients with ruptured AVMs comparing them to 627,185 admitted with ICH. Mortality was lower for ruptured AVMs (11%) compared to ICH (22%) [p < 0.01]. Mortality associated factors were liver disease (OR 2.64, CI 1.81–3.85, p <.001), diabetes mellitus (OR 2.42, CI 1.38–4.22, p = 0.002), alcohol abuse (OR 1.81, CI 1.31–2.49, p = 0.001), hydrocephalus (OR 3.35 CI 2.81–4.00, p < 0.001), cerebral edema (OR 1.5, 1.25–1.85, p < 0.001), cardiac arrest (OR 15, CI 7.9–30, p < 0.001), and pneumonia (OR 1.93, CI 1.51–2.47, p < 0.001). A 0–5 ruptured AVM mortality score was developed: Cardiac arrest (=3), age >60 (=1), Black race (=1), chronic liver failure (=1) diabetes mellitus (=1), pneumonia (=1), alcohol abuse (=1) and cerebral edema (=1). Mortality increased with score. No patient with 5 or more points survived. Conclusion: The Ruptured AVM Mortality Score allows for risk stratification on patients with ICH due to ruptured AVM. This scale could prove useful in prognostication and patient education.