Improvement of coronary vasodilatation capacity through single LDL apheresis

Abstract

A concomitant phenomenon of hypercholesterolemia is reduced coronary vasodilatation capacity due to disturbed endothelial function. Endothelial function can be partially or completely normalized by reducing cholesterol levels through drug therapy, but it is still unclear how rapidly this desired effect is achieved. An interval of between weeks and months has been presumed. LDL apheresis (LDL-A) is capable of achieving a high-degree LDL cholesterol reduction within hours. With positron emission tomography (PET), carried out immediately before and after LDL-A, changes in coronary reserve due to this abrupt LDL cholesterol reduction could be measured both quantitatively and non-invasively. In nine patients (six women, three men) with documented coronary artery disease and hypercholesterolemia, PET was carried out immediately before and 18–20 h after LDL-A. A reduction in LDL cholesterol (from 194±38 to 81±20 mg/dl), facilitated significant improvement in myocardial blood flow (MBF) (173±63 versus 226±79 ml/min per 100 g) after pharmacologic recruitment of coronary flow capacity (dipyridamole stress), coronary flow reserve (CFR) (1.91±0.68 versus 2.48±0.68) and minimum coronary resistance (MCR) (0.61±0.18 versus 0.43±0.16 mmHg/100 g per min per ml) within 24 h. Plasma viscosity was reduced slightly, by 6.6%. Probably for the first time, a 30% improvement in coronary vasodilatation capacity could be demonstrated quantitatively and non-invasively by PET after a single LDL-A within 24 h.