Association of Short- and Medium-Term Particulate Matter Exposure with Risk of Mortality after Spontaneous Intracerebral Hemorrhage

Objective: We investigated the association of short- and medium-term particulate matter (I'M) exposure with risk of mortality in patients with spontaneous intracerebral hemorrhage (ICH) identified according to strict etiologic criteria. Methods: We conducted a retrospective analysis of prospectively collected data from consecutive patients with spontaneous ICH admitted to the emergency department of the University Hospital of Verona from March 2011 to December 2014. Outcome measures were mortality within 1 month after ICH and significant hematoma expansion (HE) defined as an absolute growth of more than 12.5 mL or a relative increase of more than 50% from baseline to follow-up computed tomography scan. Results: A final number of 308 patients were included. In the adjusted model, higher PM2.5 and PK10 values in the last 3 days (odds ratio [OR] 1.827, 95% confidence interval [CI] 1.057-3.159, P = .031 and OR 1.949, 95% CI 1.025-3.704, P = .042, respectively) and in the last 4 weeks (OR 4.975, 95% CI 2.174-11.381, P < .001 and OR 9.781, 95% CI 3.425-27.932, P< .001, respectively) before ICH were associated with higher mortality rate. No association was found between PM exposure and significant HE. Conclusions: PM exposure in the short- and medium-term before spontaneous ICH was associated with risk of 1-month mortality, independent of predictors such as age, sex, stroke severity, intraventricular hemorrhage, ICH volume, ICH location, ICH etiologic subtype, significant HE, antithrombotic therapy, atrial fibrillation, and blood glucose levels.