Statins and Risk of Intracerebral Hemorrhage in Individuals With a History of Stroke.

Background and Purpose- It has been suggested that statins increase the risk of intracerebral hemorrhage in individuals with a history of stroke, which has led to a precautionary principle of avoiding statins in patients with prior intracerebral hemorrhage. However, such prescribing reticence may be unfounded and potentially harmful when considering the well-established benefits of statins. This study is so far the largest to explore the statin-associated risk of intracerebral hemorrhage in individuals with prior stroke. Methods- We conducted a population-based, propensity score-matched cohort study using information from Danish national registers. We included all individuals initiating statin treatment after a first-time stroke diagnosis (intracerebral hemorrhage, N=2728 or ischemic stroke, N=52 964) during 2002 to 2016. For up to 10 years of follow-up, they were compared with a 1:5 propensity score-matched group of statin nonusers with the same type of first-time stroke. The difference between groups was measured by adjusted hazard ratios for intracerebral hemorrhage calculated by type of first-time stroke as a function of time since statin initiation. Results- Within the study period, 118 new intracerebral hemorrhages occurred among statin users with prior intracerebral hemorrhage and 319 new intracerebral hemorrhages in users with prior ischemic stroke. The risk of intracerebral hemorrhage was similar for statin users and nonusers when evaluated among those with prior intracerebral hemorrhage, and it was reduced by half in those with prior ischemic stroke. These findings were consistent over time since statin initiation and could not be explained by concomitant initiation of other medications, by dilution of treatment effect (due to changes in exposure status over time), or by healthy initiator bias. Conclusions- This large study found no evidence that statins increase the risk of intracerebral hemorrhage in individuals with prior stroke; perhaps the risk is even lower in the subgroup of individuals with prior ischemic stroke.