Evidence for Maximal Treatment of Atherosclerosis: Drastic Reduction of Cholesterol and Fibrinogen Restores Vascular Homeostasis

Retrospective Comparison of 5 different Methods for Long-Term LDL-Apheresis in 20 Patients between 1986 and 2001

Purpose

To compare long-term efficacy and biocompatibility of the 5 most commonly applied LDL-apheresis techniques using a specifically modified calculation method of the area under the curve (AUC) for laboratory parameters.

Design

Retrospective long-term analysis of 20 patients with homozygous or severe heterozygous familial hypercholesterolemia.

Procedures

The following 5 extra-corporeal LDL-apheresis methods were compared: IMAL (Immuno Adsorption of Lipoproteins), DSA (Dextran Sulphate Adsorption), HELP (Heparin Induced Extra-corporeal LDL Precipitation), DALI (Direct Adsorption of Lipoproteins), MDF (Membrane Differential Filtration).

Main outcome measures

AUC derived plasma concentrations (CAUC) of lipoproteins between two apheresis procedures and their long-term course. Comparison of biocompatibility and efficacy concerning the LDL-C target of < 2.6 mmol/L of 5 apheresis techniques. Progression of atherosclerosis in patients with severe hypercholesterolemia.

Main findings

The means of AUC derived average plasma concentrations (CAUC) of all treatment intervals were for LDL-C and the LDL/HDL ratio as follows: IMAL (5.59 mmol/L; ratio 4.1), DSA (3.03 mmol/L; ratio 2.0), HELP (4.06 mmol/L; ratio 2.2), DALI (3.83 mmol/L; ratio 3.3), MDF (3.26 mmol/L; ratio 3.2). Coronary heart disease and cardiac events (myocardial infarction, PTCA/ stent implantation, CABG) progressed in only 2 patients whereas atherosclerosis manifestations (sclerosis abdominal aorta, carotid artery stenosis, peripheral vascular disease) worsened in 13 patients. Mean ergometric capacity improved from 112 to 118 Watt.

Conclusions

All 5 apheresis methods (IMAL, DSA, HELP, DALI, MDF) proved to be safe and suitable for long-term treatment in patients with severe hypercholesterolemia. The introduction of the CAUC revealed that the target of LDL-C < 2.6 mmol/L was not achieved with regard to the time averaged concentration (CAUC).

LDL-apheresis in Acute Anterior Ischemic Optic Neuropathy

Acute anterior ischemic optic neuropathy (AION) is a disabling disease which impairs visual function. Standard treatment is unable to affect the outcome and the visual damage persists. We describe the case of a 64-year-old patient affected by AION, whose only known risk factor was hypercholesterolemia. After a first onset of involvement of the right eye (RE), the patient presented four weeks later with an analogous episode affecting the left eye (LE). Since standard treatment, started at involvement of the RE, had not yielded any beneficial effect, the patient underwent three sessions of LDL apheresis. The scotomatous portion of the visual field reduced even after the first session, there was further improvement after the third, and after six months the condition remained stable. Corrected vision improved from 2/10 to 6/10 after the third session. LDL cholesterol and fibrinogen decresade after the third session from 239 mg/dL to 31 mg/dL and from 289 mg/dL to 92 mg/dL, respectively. In conclusion, thanks to its effect of antagonizing hemorheologic disorders of the ocular microcirculation, LDL apheresis seems to be an efficacious treatment of AION, especially in patients suffering from hypercholesterolemia.

Increased levels of small dense low-density lipoprotein cholesterol associated with hemorheological abnormalities in untreated, early-stage essential hypertensives

Among subfractions of low-density lipoprotein cholesterol (LDL-C), small dense LDL-C (SdLDL-C) has been highlighted as the most atherogenic lipoprotein cholesterol. The present study aimed to compare the relationship of SdLDL-C with blood viscosity, a surrogate marker for cardiovascular disease, with that of other lipid fractions with blood viscosity in essential hypertensives (EHTs). In 128 untreated, early-stage EHTs, blood viscosity was measured with a falling-ball microviscometer, and serum levels of lipid fractions were determined. Blood and plasma viscosity was significantly higher in 49 patients with dyslipidemia (fasting serum level of LDL-C > 140 mg dl(-1), triglyceride > 150 mg dl(-1) or high-density lipoprotein cholesterol (HDL-C) < 40 mg dl(-1)) compared with 79 patients without dyslipidemia, although hematocrit and RBC rigidity index 'k' did not differ between the two groups. Together, SdLDL-C, LDL-C, triglyceride and large LDL-C were positively correlated with blood viscosity, but for HDL-C, the correlation was negative. After adjusting for non-lipid variables that correlated with blood viscosity (that is, the age, body mass index, resting diastolic blood pressure, sex, hematocrit, plasma viscosity and homeostasis model of assessment of insulin resistance), SdLDL-C was most strongly associated with blood viscosity among the lipid fractions. These data suggest that SdLDL-C could strongly increase blood viscosity in EHTs.

Hypercholesterolemia and LDL apheresis

Several trials have assessed the link between low-density lipoprotein cholesterol (LDL) and the development of coronary heart disease (CHD). LDL apheresis provides an effective role in treating patients with familial hypercholesterolemia (FH) and in preventing the progression of coronary artery disease (CAD). Five different techniques of LDL apheresis are in current use: immunoadsorption (IMA), dextran sulphate-cellulose adsorption (DSA), heparin extracorporeal LDL precipitation system (HELP), double filtration plasmapheresis (DFPP) or lipidfiltration and direct adsorption of lipoprotein using hemoperfusion (DALI). All methods are efficient,but their cost restricts LDL apheresis to the treatment of FH. Indications could include other diseases, but controlled trials are still lacking.