Increased cerebral CO2 reactivity after heparin-mediated extracorporal LDL precipitation (HELP) in patients with coronary heart disease and hyperlipidemia

Background and Purpose-There is experimental and clinical evidence that hypercholesterolemia leads to an impairment of endothelial function in coronary and cerebral arteries. Using transcranial Doppler sonography, we examined CO, reactivity as a marker of cerebral vasoreactivity in patients with coronary heart disease and hyperlipidemia before and after drastic lowering of LDL cholesterol, lipoprotein(a) [Lp(a)], and fibrinogen levels by heparin-mediated extracorporal LDL precipitation (HELP). Methods-CO2 reactivity was determined in 13 patients with coronary artery disease and hyperlipidemia undergoing regular HELP therapy. Middle cerebral artery mean blood now velocity (MFV) was detected by transcranial Doppler, CO2 reactivity was calculated as the percent change of MFV during hypercapnia, induced by ventilation of carbogene (5% CO2, 95% O-2), to normocapnia. Patients with extracranial or intracranial stenoses were excluded. Other parameters such as blood viscosity, heart rate, and blood pressure were measured to control hemorheologic and systemic influences on CO2 reactivity. Results-A single HELP treatment reduced total cholesterol, LDL cholesterol, Lp(a), triglycerides, and fibrinogen levels by >50% (P<0.001). Blood viscosity significantly decreased from 1.24+/-0.04 to 1.07+/-0.02 mPa (P<0.001). Blood pressure, heart rate, and MFV did not change significantly. CO2 reactivity increased from 22% +/- 21% to 36% +/- 18% (P<0.05). Conclusions-Fast and drastic removal of LDL cholesterol, Lp(a), and fibrinogen from plasma results in an improvement of cerebrovascular reactivity in patients with coronary heart disease and hyperlipidemia. The clinical use of HELP in patients with impaired cerebrovascular reactivity might be promising.