Low Level of Low-Density Lipoprotein Cholesterol Increases Hemorrhagic Transformation in Large Artery Atherothrombosis but Not in Cardioembolism

Background and Purpose-Low cholesterol level is known to be associated with increased cerebral hemorrhage. However, the associations of hemorrhagic transformation (HTf) after acute ischemic stroke and the low levels of total cholesterol (TC) or low-density lipoprotein cholesterol (LDLC) are largely undiscovered. Methods-Of the 1034 patients with acute ischemic stroke who were consecutively admitted to our hospital, 377 patients with stroke attributable to large artery atherothrombosis (LAA; n=210) or cardioembolism (n=167) were selected for this study. Demographic and clinical information was collected and HTf was evaluated through follow-up T2*-weighted gradient-echo MRI performed usually within 1 week after stroke. Measurement of lipid parameters included TC, LDLC, high-density lipoprotein cholesterol, and triglyceride. Results-Of the 377 patients, HTf was noted in 74 patients (19.6%). When patients were divided into 4 groups according to their TC and LDLC levels, the incidence of HTf was significantly elevated in the lowest quartile of each TC (P<0.01) and LDLC (P<0.01) level in LAA subgroup, but not in cardioembolism. After adjusting covariates, a low level of LDLC (OR, 0.46 per 1 mmol/L-increase; 95% CI, 0.22-0.98) was independently associated with HTf in LAA, but not in cardioembolism. There was no significant association between low levels of TC (OR, 0.63 per 1 mmol/L-increase; 95% CI, 0.35-1.15) and HTf in LAA. Conclusions-Low levels of LDLC, and possibly TC, are associated with greater risk of hemorrhagic transformation after acute ischemic stroke attributable to LAA. (Stroke. 2009; 40: 1627-1632.)