[Myocardial perfusion under H.E.L.P. -apheresis. Objectification by PET].

Due to endothelial dysfunction (ED), coronary vasodilation capacity is reduced in patients with hypercholesterolemia. Cholesterol lowering may largely restore endothelial function. Currently, it is supposed that the onset of this therapeutic effect takes weeks or even months. However, by means of LDL apheresis, a significant LDL reduction may be achieved within hours. Dynamic quantitative positron emission tomography (PET) performed before and after LDL apheresis showed that mean global myocardial perfusion can be measured at rest and after pharmacological vasodilation with dipyridamole using N13 ammonia as tracer.A total of 35 patients (11 women and 24 men) with documented coronary heart disease and hypercholesterolemia underwent PET immediately prior to LDL apheresis and 18-20 hours thereafter. In addition to the decrease in LDL cholesterol (from 175+/-50 to 77+/-25 mg/dl) and fibrinogen (from 287+/-75 to 155+/-52 mg/dl), a significant improvement of myocardial blood flow under dipyridamole (177+/-59 vs 217+/-82 ml/min 100 g, p<0.0001), of coronary flow reserve (2.10+/-0.82 vs 2.62+/-1.02, p<0.0001) and of minimal coronary resistance (0.56+/-0.20 vs 0.44+/-0.17 mmHg 100 g min/ml, p<0.0001) were achieved. Plasma viscosity decreased only by 7.8%. Within 20 hours after single LDL apheresis a 20% improvement of coronary vasodilation capacity was noninvasively demonstrated and quantified.