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[Myocardial perfusion under H.E.L.P. -apheresis. Objectification by PET]
K-P Mellwig1, D Baller, H K Schmidt
1Herz- und Diabeteszentrum NRW, Kardiologische Klinik, Georgstr. 11, 32545 Bad Oeynhausen, Germany. kpmellwig@hdz-nrw.de
Insights
LDL apheresis rapidly improves coronary vasodilation in hypercholesterolemia patients. This rapid improvement in endothelial function occurs within 20 hours, challenging previous assumptions about cholesterol-lowering therapy onset.
Area of Science:
- Cardiology
- Vascular Biology
- Medical Imaging
Background:
- Endothelial dysfunction (ED) in hypercholesterolemia reduces coronary vasodilation capacity.
- Cholesterol lowering can restore endothelial function, but the therapeutic effect onset is traditionally considered slow (weeks to months).
- Lipoprotein apheresis offers rapid and significant reduction of low-density lipoprotein (LDL) cholesterol within hours.
Purpose of the Study:
- To investigate the immediate impact of LDL apheresis on coronary vasodilation capacity.
- To assess changes in myocardial blood flow and coronary flow reserve shortly after LDL apheresis.
- To challenge the established timeline for therapeutic effects of cholesterol reduction on endothelial function.
Main Methods:
- Positron emission tomography (PET) with N13 ammonia was used for dynamic quantitative myocardial perfusion imaging.
- 35 patients with coronary heart disease and hypercholesterolemia underwent PET scans before and 18-20 hours after LDL apheresis.
- Measurements included myocardial blood flow at rest and during dipyridamole-induced vasodilation, coronary flow reserve, and minimal coronary resistance.
Main Results:
- LDL apheresis significantly reduced LDL cholesterol (175 to 77 mg/dl) and fibrinogen (287 to 155 mg/dl).
- A significant improvement in myocardial blood flow under dipyridamole (177 to 217 ml/min/100g) and coronary flow reserve (2.10 to 2.62) was observed.
- Minimal coronary resistance decreased significantly (0.56 to 0.44 mmHg*100g*min/ml), indicating improved vasodilation within 20 hours.
Conclusions:
- A single LDL apheresis session rapidly improves coronary vasodilation capacity by approximately 20% within 20 hours.
- These findings demonstrate a much faster onset of therapeutic effect on endothelial function than previously assumed.
- Rapid LDL reduction via apheresis provides a potential strategy for quickly improving coronary hemodynamics in hypercholesterolemia.
Abstract:
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.