Risk of Mortality After an Arterial Ischemic Event Among Intracerebral Hemorrhage Survivors

Abstract

Background and Purpose: The impact of arterial ischemic events after intracerebral hemorrhage (ICH) on outcomes is unclear. This study aimed to evaluate the risk of death among ICH survivors with and without an incident arterial ischemic event. Methods: We performed a retrospective cohort study using claims data from Medicare beneficiaries with a non-traumatic ICH from January 2008 to October 2015. Our exposure was an arterial ischemic event, a composite of acute ischemic stroke or myocardial infarction (MI), identified using validated ICD-9-CM diagnosis codes. The outcome was mortality. We used marginal structural models to analyze the risk of death among ICH patients with and without an arterial ischemic event, after adjusting for confounders as time-varying covariates. Results: Among 8,804 Medicare beneficiaries with ICH, 2,371 (26.9%) had an arterial ischemic event. During a median follow-up time of 1.9 years (interquartile range, 0.7-3.9), ICH patients with an arterial ischemic event had a mortality rate of 21.7 (95% confidence interval [CI], 20.4-23.0) per 100 person-years compared to a rate of 15.0 (95% CI, 14.4-15.6) per 100 person-years in those without. In the marginal structural model, an arterial ischemic event was associated with an increased risk of death (hazard ratio [HR], 1.8; 95% confidence interval [CI], 1.6-1.9). In secondary analyses, the mortality risk was elevated after an ischemic stroke (HR, 1.7; 95% CI, 1.5-1.8), and MI (HR, 3.0; 95% CI, 2.4-3.8). Conclusions: We found that elderly patients who survived an ICH had an increased risk of death after a subsequent ischemic stroke or MI.