Risk of Intracranial Hemorrhage from Statin Use in Asians: A Nationwide Cohort Study
Background—Reports of statin usage and increased risk of intracranial hemorrhage (ICH) have been inconsistent. This study examined potential associations between statin usage and the risk of ICH in subjects without a prior history of stroke.
Methods and Results—Patients initiating statin therapy between 2005 and 2009 without a prior history of ischemic or hemorrhagic stroke were identified from Taiwan's National Health Insurance database. Participants were stratified by advanced age (≥ 70 years), sex, and diagnosed hypertension. The outcome of interest was hospital admission for ICH (ICD-9-CM codes 430, 431, 432). Cox regression models were applied to estimate the hazard ratio (HR) of ICH. The cumulative statin dosage stratified by quartile and adjusted for baseline disease risk score served as the primary variable using the lowest quartile of cumulative dosage as a reference. There were 1,096,547 statin initiators with an average follow-up of 3.3 years. The adjusted HR for ICH between the highest the lowest quartile was non-significant at 1.06 with a 95% confidence interval [CI] spanning 1.00 (0.94-1.19). Similar non-significant results were found in sensitivity analyses using different outcome definitions or model adjustments, reinforcing the robustness of the study findings. Subgroup analysis identified an excess of ICH frequency in patients without diagnosed hypertension (adjusted HR 1.36 [1.11-1.67]).
Conclusions—Generally, no association was observed between cumulative statin use and risk of ICH among subjects without a prior history of stroke. An increased risk was identified among the non-hypertensive cohort, but this finding should be interpreted with caution.
- Received August 30, 2014.
- Revision received March 23, 2015.
- Accepted April 3, 2015.