Reader response: Lipid levels and the risk of hemorrhagic stroke among women

Rist et al.1 showed that patients with low-density lipoprotein cholesterol (LDL-C) levels <70 mg/dL are at increased risk of intracranial hemorrhage (ICH). While fully acknowledging their results, we, however, deem a full appreciation of the clinical relevance of these numbers to be pivotal. Because LDL-C levels are causally related to cardiovascular disease (CVD) risk, findings should be balanced against the relative contribution of LDL-C to CVD risk in the study population. The Cholesterol Treatment Trialists' Collaboration showed that every 10 mg/dL lowering of LDL-C reduces the annual CVD risk by 1.03%.2 The overall CVD risk in this cohort is reported to be 0.25% per year.3 We estimate that the low LDL-C group (<70 mg/dL) has a CVD risk of 0.24% per year (53.7 mg/dL LDL cholesterol below median in this cohort).3 The reported annual risk for ICH in the low LDL-C group is 0.04%. Therefore, the risk for CVD is approximately 6 times higher than the risk for ICH in this group.