Indications for low-density lipoprotein apheresis

Lateral ST-elevation myocardial infarction after donation of COVID-19 convalescent plasma in a naïve donor

A 34-year-old man presented with central chest pain heralded by bilateral arm numbness, tingling and pain soon after donation of 1000 mL of COVID-19 convalescent plasma (CP). ECG showed ST-elevation in lateral leads and coronary angiogram showed large thrombus in diagonal branch of the left anterior descending artery. The patient underwent successful thrombus aspiration and percutaneous coronary intervention of diagonal branch. In this report, we describe a case of coronary thrombosis leading to ST-elevation myocardial infarction in a naïve plasma donor after donation of COVID-19 CP.

Homozygous familial hypercholesterolemia with stenosis of the left anterior descending coronary artery successfully treated with weekly low-density lipoprotein apheresis for 16 years without percutaneous coronary intervention

We successfully treated a patient with homozygous familial hypercholesterolemia (HoFH) with stable coronary arterial disease using optimal medical therapy and low-density lipoprotein (LDL) apheresis for 16 years without percutaneous coronary intervention or bypass surgery. Intensive LDL lowering using apheresis and medication protected the patient from coronary atherosclerotic progression even in HoFH.

Intraindividual Comparison of the Impact of two Selective Apheresis Methods (DALI and HELP) on the Coagulation System

We performed an intraindividual comparison of the effect on the coagulation system of two selective apheresis procedures: Direct Adsorption of Lipoproteins (DALI) and Heparin-induced Lipoprotein Fibrinogen Precipitation (HELP). Six patients suffering from heterozygous familial hypercholesterolemia have been treated with 2 sessions of each procedure. Anticoagulation was carried out according to usual recommendations. Blood samples were taken before, immediately after and on the second day after the sessions. We assessed global coagulation tests (prothrombin time, activated partial thromboplastin time), fibrinogen, prothrombin fragment F 1 + 2 and a variety of factors (Factors II, V, VII, XIII, IX, X, XI, XII, XIIa; von Willebrand Factor; collagen-binding activity, prekallikrein, high-molecular weight kininogen) and antagonists (antithrombin III, protein S activity, free protein S). In fact, all parameters measured have been influenced by the apheresis treatment. Fibrinogen is lowered more by HELP, which also has a more definite impact on factors belonging to the prothrombin complex (II, VII, X). In contrast, the major effects of the DALI system have been seen on the intrinsic pathway of the coagulation system (IX, XI, prekallikrein, high-molecular-weight kininogen). With both systems, no increases in activated Factor XII or in prothrombin fragment F1 + 2 have been observed. These data provide a solid basis for individual adaptations of anticoagulant doses.

Lowering Low-Density Lipoprotein Particles in Plasma Using Dextran Sulphate Co-Precipitates Procoagulant Extracellular Vesicles

Plasma extracellular vesicles (EVs) are lipid membrane vesicles involved in several biological processes including coagulation. Both coagulation and lipid metabolism are strongly associated with cardiovascular events. Lowering very-low- and low-density lipoprotein ((V)LDL) particles via dextran sulphate LDL apheresis also removes coagulation proteins. It remains unknown, however, how coagulation proteins are removed in apheresis. We hypothesize that plasma EVs that contain high levels of coagulation proteins are concomitantly removed with (V)LDL particles by dextran sulphate apheresis. For this, we precipitated (V)LDL particles from human plasma with dextran sulphate and analyzed the abundance of coagulation proteins and EVs in the precipitate. Coagulation pathway proteins, as demonstrated by proteomics and a bead-based immunoassay, were over-represented in the (V)LDL precipitate. In this precipitate, both bilayer EVs and monolayer (V)LDL particles were observed by electron microscopy. Separation of EVs from (V)LDL particles using density gradient centrifugation revealed that almost all coagulation proteins were present in the EVs and not in the (V)LDL particles. These EVs also showed a strong procoagulant activity. Our study suggests that dextran sulphate used in LDL apheresis may remove procoagulant EVs concomitantly with (V)LDL particles, leading to a loss of coagulation proteins from the blood.

Current Treatment of Familial Hypercholesterolaemia

Familial hypercholesterolaemia is an autosomal-dominant disorder associated with mutations in the LDL receptor gene resulting in markedly elevated plasma low-density lipoprotein cholesterol levels. FH is significantly underrecognised with as many as 1 in 300 having the heterozygous form and 1 in 1 million having the homozygous form of the disease. Early diagnosis and treatment of FH is paramount to reduce the risk of premature atherosclerotic cardiovascular disease and death. The goal of treatment is to reduce LDL-C by 50 % from baseline levels with lifestyle modification, pharmacologic lipid-lowering therapy, LDL apheresis and in rare cases, liver transplantation. Pharmacologic treatment ranges from statin medications to newer agents such as lomitapide, mipomersin and PCSK9 inhibitors. Combination therapy is frequently required to achieve goal lipoprotein level reductions and prevent complications.

Primary hemostasis in patients treated with LDL-apheresis for severe familiar hypercholesterolemia: A prospective pilot trial using PFA-100 analysis to rationalize therapeutic LDL-apheresis procedure

LDL-apheresis is a method of extracorporeal elimination of serum LDL-cholesterol used for treating patients with severe hyperlipidemia resistant to diet and pharmacotherapy. A practically applicable marker that may possibly be used to ascertain the efficacy of this treatment in lowering the activity of atherosclerosis are still to be found and remains an unresolved problem. Activity of primary hemostasis plays an important role in the process of developing atherosclerotic complications. This fact led us to hypothesize that the investigation of primary hemostatic activity might be a useful marker for monitoring LDL-apheresis efficacy. The aim of this work was to verify this hypothesis.

METHODS AND PATIENTS

Commercial analyzer Dade Behring PFA-100, Germany (PFA, platelet function analysis) was used for all investigations. This analyzer enables quantitative measurement of platelet-mediated hemostasis in uncoagulated (citrated) blood. The method simulates platelet activation by mechanical stress (shear stress), and also simulates contact of platelets with collagen. A total of nine long-term treated patients with familial hypercholesterolemia were included in the study group (4 females and 5 males). Ages ranged from 17 to 59 years (average 46.4, median 55). Two patients had homozygous hypercholesterolemia. Eighteen sample pairs were examined using collagen/epinephrine (COL/EPI) membrane and 17 pairs were examined using collagen/ADP (COL/ADP) membrane, the total number of samples amounted to 70.

RESULTS

Closure time (CT) values were prolonged after separation in all cases but CT prolongation was not statistically significant (p < 0.14). No differences between homozygous and heterozygous patients were found (p < 0.05).

CONCLUSION

Investigation of primary hemostasis using PFA-100 analyzer is not a suitable marker and should not be used to determine the optimal intensity of individual LDL-apheresis procedures.

Safety and Tolerability of Long Lasting LDL-apheresis in Familial Hyperlipoproteinemia

The aim of this work is to arbitrate the incidence of side effects and tolerability of long lasting LDL-apheresis in familial hyperlipoproteinemia. 1200 procedures were performed and the last 463 of them were evaluated. An immunoadsorption method of LDL-apheresis was used (continuous blood cell separator Cobe Spectra; secondary device: automated adsorption-desorption ADA, Medicap; absorption columns: Lipopak). As a whole, 6.26% adverse events were found and subsequently resolved by standard symptomatic therapy. Vaso-vagal reactions (symptoms of neurovegetative lability) were the most common adverse effects, presented as malaise, weakness, slight and short-term drop in blood pressure or other general signs. They were all well controlled by symptomatic therapy. We conclude that LDL-apheresis in the hands of experienced personnel is a safe procedure. An acceptable procedure duration limit, balancing the possibility to achieve a targeted cholesterol level while still maintaining an acceptable patient tolerance, was confirmed to be 4 hours.

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.

Therapeutic Apheresis-State of the Art in the Year 2005

Therapeutic apheresis is an extracorporeal blood purification method for the treatment of diseases in which pathological proteins or cells have to be eliminated. Selective plasma processing is more efficient in pathogen removal than unselective plasma exchange and does not require a substitution fluid like albumin. This overview presents the various selective devices for the treatment of plasma (plasmapheresis) and blood cells (leukocyte apheresis). Prospective randomized trials were performed for the treatment of age-related macular degeneration (Rheopheresis), sudden hearing loss (heparin-induced lipoprotein precipitation [HELP]), rheumatoid arthritis (Prosorba), dilative cardiomyopathy (Ig-Therasorb, Immunosorba), acute-on-chronic liver failure (molecular adsorbent recirculating system [MARS]), and ulcerative colitis (Cellsorba). Prospective non-randomized controlled trials were carried out treating hypercholesterolemia (Liposorber) and crossmatch-positive recipients before kidney transplantation (Immunosorba). Uncontrolled studies were done for ABO-incompatibility in living donor kidney transplantation (KT) (Glycosorb), acute humoral rejection after KT (Immunosorba) and acute liver failure (Prometheus). According to the 2002 International Apheresis Registry covering 11428 sessions in 811 patients, 79% of the patients showed an improvement of their condition by apheresis and only a few sessions were fraught with adverse effects (AE). The major AE were blood access difficulties (3.1%) and hypotension (1.6%). In summary, therapeutic apheresis is a safe and effective procedure for the treatment of diseases refractory to drug therapy.

Hyperlipidemia

Over the past 20 years, a link between lipoprotein disorders and atherosclerosis, and its clinical manifestations of myocardial infarction, stroke, and sudden cardiac death, has been conclusively demonstrated. This article reviews lipoprotein metabolism, its pathophysiology, describes an approach for the management of patients with lipid disorders and discusses therapy using the ATP III guidelines.

Role of low-density lipoprotein apheresis

Low-density lipoprotein (LDL) apheresis has been shown to reduce plasma levels of total cholesterol, LDL cholesterol, and lipoprotein(a). In addition to these lipoprotein changes, LDL apheresis induces atherosclerosis regression, improves myocardial perfusion and endothelial function, and may reduce cardiovascular event rates.

LDL apheresis

Low density lipoprotein (LDL) apheresis provides a safe and effective means of treating patients with homozygous familial hypercholesterolaemia (FH). It also has a role in preventing the progression of coronary artery disease in heterozygotes and others with severe dyslipidaemia who are refractory to or intolerant of high doses of lipid-lowering drugs. Established methods involve either adsorption of apolipoprotein B-containing lipoproteins by affinity columns containing anti-apolipoprotein B antibodies or dextran sulphate, or their precipitation at low pH by heparin, in each instance after first separating plasma from blood cells with a cell separator. The most recently developed method enables lipoproteins to be adsorbed directly from whole blood, using polyacrylate columns. All 4 methods have proved to be similarly efficient when used weekly or biweekly to lower LDL cholesterol and Lp(a) without unduly reducing HDL cholesterol. Economic constraints restrict the use of LDL apheresis to the treatment of potentially fatal disorders such as FH, where there is clear evidence of benefit compared with conventional therapy. Widening the indications to include the treatment of other dyslipidaemic disorders such as steroid-resistant nephrotic syndrome, post-transplant donor vessel disease, stroke and prevention of re-stenosis after coronary angioplasty requires evidence from controlled trials that is currently lacking.

Six years of treatment with the HELP system of a patient with familial hypercholesterolemia

The purpose of the present report is to demonstrate the long-term efficacy and safety of heparin-induced extracorporeal lipoprotein precipitation (HELP) of LDL-c and fibrinogen in the management of familial hypercholesterolemia. From June 1992 to June 1998 a 22-year-old young male patient with familial hypercholesterolemia (double heterozygote for C660X and S305C) resistant to medication and diet and with symptomatic coronary artery disease (angina) was treated weekly with 90-min sessions of the HELP system. The patient had also been previously submitted to right coronary artery angioplasty. The efficacy of the method was evaluated by comparing the reduction of total cholesterol, LDL-c and fibrinogen before and after the sessions and before and after initiation of the study (data are reported as averages for each year). During the study, angina episodes disappeared and there were no detectable adverse effects of the treatment. Total cholesterol (TC), fibrinogen, and LDL-c decreased significantly after each session by 59.6, 66.1 and 64%, respectively. HDL-c showed a nonsignificant reduction of 20.4%. Comparative mean values pre- and post-treatment values in the study showed significant differences: TC (488 vs 188 mg/dl), LDL-c (416.4 vs 145 mg/dl), and fibrinogen (144.2 vs 57.4 mg/dl). There was no significant change in HDL-c level: 29.4 vs 23 mg/dl. These data show that the HELP system, even for a long period of time, is a safe and efficient mode of treatment of familial hypercholesterolemia and is associated with disappearance of angina symptoms.

Atheroembolism

The many manifestations of atheroembolism are apparent in all specialties. However, with increasing intervention in older patients with atherosclerotic disease, it has become an important renal clinical problem. Atheroembolic disease is widely recognized as a cause of acute catastrophic renal dysfunction and recent important data have suggested that effective management protocols can improve outcome. It is probable that the clinical course is insidious in the majority of patients with severe atherosclerotic aortic disease. The management of these patients is less clear and at present rests on small anecdotal reports.

Comparison of two filter combinations for low-density lipoprotein apheresis by membrane differential filtration: a prospective crossover controlled clinical study

Membrane differential filtration is an accepted procedure for the extracorporeal removal of low-density lipoprotein (LDL). Reduction rates largely depend on the nature of the membranes and are ideally evaluated in a crossover study design. Four patients who had been treated by LDL apheresis for at least 6 months were included. Six consecutive weekly sessions (40 ml plasma/kg body weight) were scheduled per system (Plasmacure PS06/Evaflux Eval 5A [Kuraray] versus Plasmaflo OP05W/Cascadeflo AC1770 [Asahi]). Laboratory measurements indicated reductions of plasma concentrations for fibrinogen (37% [Kuraray] versus 44% [Asahi]), IgG (15% versus 20%), IgA (24% versus 28%), IgM (63% versus 53%), and total protein (11% versus 16%). Total cholesterol was eliminated by 52% versus 49%, LDL by 67% versus 66%, triglycerides by 56% versus 41%, and high-density lipoprotein by 10% versus 20%. Three therapies employing the Asahi filter combination were terminated prematurely due to saturation of the plasma fractionator. In conclusion, despite similar physical properties, the membranes differ significantly concerning selectivity and sensitivity to saturation.

Low-density lipoprotein apheresis for the treatment of refractory hyperlipidemia

The advent of treatment with 3-hydroxy-3-methylglutaryl coenzyme A inhibitors has meant that, with a combination of diet and drug therapy, adequate control of serum cholesterol concentrations can be achieved in most patients with hypercholesterolemia. However, some patients, primarily those with familial hypercholesterolemia (FH), may require additional therapy to lower their cholesterol levels. In recent years, low-density lipoprotein (LDL) apheresis has emerged as an effective method of treatment in these patients. The criteria for commencement of LDL apheresis are LDL cholesterol levels of 500 mg/dL or higher for homozygous FH patients, 300 mg/dL or higher for heterozygous FH patients in whom medical therapy has failed, and 200 mg/dL or higher for heterozygous FH patients with documented coronary disease and in whom medical therapy has failed. In addition to cholesterol lowering in patients with FH, other indications for LDL apheresis are emerging. These include its use in the treatment of graft vascular disease in patients receiving cardiac transplants as well as in the treatment of certain glomerulonephritides. This review examines the role of LDL apheresis in the management of lipid disorders and the evidence available to support its use in clinical practice.

Gene therapy for lipid disorders

Lipid disorders are associated with atherosclerotic vascular disease, and therapy is associated with a substantial reduction in cardiovascular events. Current approaches to the treatment of lipid disorders are ineffective in a substantial number of patients. New therapies for refractory hypercholesterolemia, severe hypertriglyceridemia, and low levels of high-density lipoprotein cholesterol are needed: somatic gene therapy is one viable approach. The molecular etiology and pathophysiology of most of the candidate diseases are well understood. Animal models exist for the diseases and in many cases preclinical proof-of-principle studies have already been performed. There has been progress in the development of vectors that provide long-term gene expression. New clinical gene therapy trials for lipid disorders are likely to be initiated within the next few years.

Improved coronary risk assessment with electron beam computed tomography in an asymptomatic female with familial hypercholesterolemia

An asymptomatic 36-year-old woman had high cholesterol levels due to heterozygous familial hypercholesterolemia (FHC) and a family history of coronary artery disease (CAD) but no other risk factors. Exercise testing showed no signs of ischemia. Conventional drug therapy did not lower lipid levels adequately. However, low-density lipoprotein (LDL) apheresis, which effectively reduces cholesterol levels in patients with heterozygous FHC, was not indicated, according to current guidelines. Electron beam computed tomography demonstrated exceptionally high amounts of coronary calcium for the patient's age and sex. A subsequent coronary angiogram revealed advanced CAD, which justified the initiation of LDL apheresis to reduce her cholesterol levels. In patients with heterozygous FHC refractory to conventional lipid-lowering therapy, the presence of coronary calcium in the highest percentiles for age and sex (i.e., > 75th percentile) may warrant aggressive clinical management to improve prognosis, even if no symptoms or signs of ischemia are present.

Gene therapy for dyslipidemia: clinical prospects

Current approaches to the treatment of lipid disorders are inadequate for a substantial number of patients with severe hyperlipoproteinemia, isolated low high-density lipoprotein (HDL) cholesterol levels, or other molecular disorders of lipoprotein metabolism. Therefore, dyslipidemias remain important targets for the development of novel therapies. Gene therapy is a logical therapeutic approach to monogenic lipoprotein disorders, such as homozygous familial hypercholesterolemia, familial lipoprotein lipase deficiency, familial lecithin-cholesterol acyltransferase deficiency, and abetalipoproteinemia, for which current therapies are inadequate. Gene therapy could also be used to increase expression of certain proteins, such as apolipoprotein A-I as a strategy to raise HDL cholesterol levels or apoE as a strategy for severe combined hyperlipidemia. With further progress in the development of vectors, gene therapy for severe dyslipidemia is likely to become a clinical reality.

Lipoproteins and atherogenesis

Like many complex disease processes, atherogenesis represents the interaction of an array of genetic and environmental factors. From nonhuman animal models to the investigation of epidemiologic factors in man, no single, overriding cause for the development of this indolent vascular disease has been identified. However, the cholesterol-enriched lipoprotein particles are closely tied to the development of the disease. The genetic and environmental influences on the concentrations of specific lipoprotein subspecies provide a context for identifying patients at risk as well as for developing effective therapeutic strategies to influence and prevent the sequelae of atherogenesis.

Long-term effects of low-density lipoprotein apheresis using an automated dextran sulfate cellulose adsorption system. Liposorber Study Group

The short-term effectiveness of low-density lipoprotein (LDL) apheresis using a dextran sulfate cellulose adsorption column technique was previously examined in a 9-center, 22-week controlled trial in 64 patients with familial hypercholesterolemia (FH) who did not adequately respond to diet and drug therapy. Forty-nine patients (40 treatment, 9 controls) subsequently received LDL apheresis procedures as part of an optional follow-up phase. This study reports on the long-term safety, lipid lowering, and clinical efficacy of LDL apheresis for the 5-year period that includes both the initial controlled study and follow-up phase. During this time, patients received a total of 3,902 treatments of which 3,314 treatments were given during the follow-up phase. Adverse events were infrequent, occurring in 142 procedures (3.6%). Immediate reduction in LDL cholesterol was 76% both in homozygotes and in heterozygotes. Patients with homozygous FH had a progressive decrease in pretreatment LDL cholesterol level along with an increase in high-density lipoprotein (HDL) cholesterol level. There was no appreciable change in pretreatment lipoprotein level over time in heterozygotes. The rate of cardiovascular events during therapy with LDL apheresis and lipid-lowering drugs was 3.5 events per 1,000 patient-months of treatment compared with 6.3 events per 1,000 patient-months for the 5 years before LDL apheresis therapy. These findings support the long-term safety and clinical efficacy of LDL apheresis in patients with heterozygous and homozygous FH who are inadequately controlled with drug therapy.

Treatment of homozygous familial hypercholesterolemia with low density lipoprotein apheresis: a 4 year follow-up study

Hypercholesterolemia and elevated lipoprotein (a) (Lp[a]) levels are considered to be risk factors for the development and progression of premature atherosclerosis. The purpose of our report is to describe the effects of low density lipoprotein (LDL) apheresis (Liposorber system, Kanegafuchi Chemical Industrial Company LTD, Osaka, Japan) on serum lipoprotein concentrations and the clinical status in 2 male patients with homozygous familial hypercholesterolemia. Compared with pretreatment values, the posttreatment concentrations of total cholesterol, LDL cholesterol, and Lp(a) were significantly reduced by 50-60% (p < 0.0001). The concentration of high density lipoprotein (HDL) cholesterol was slightly affected. After one treatment session, LDL cholesterol and Lp(a) were decreased on average by 65% and then increased to reach about 70-75% of the pretreatment values before the next session. Prior to the treatment with LDL apheresis, each patient had suffered one myocardial infarction and had had 2 coronary angiographies. After treatment with LDL apheresis, neither cardiac complaints nor myocardial infarction were observed. The xanthomas were much decreased during the treatment or disappeared. We conclude that LDL apheresis can be continued safely and without major technical problems for several years. Apheresis effectively lowers the serum levels of total and LDL cholesterol. Furthermore, it reduces Lp(a), which is not influenced by lipid-lowering drugs. The reduction of LDL cholesterol and Lp(a) may delay the progression of the atherosclerotic process, thereby helping to reduce the risk of new episodes of coronary heart disease and thus extending the life expectancy in these patients.

The role of low density lipoprotein apheresis in the treatment of familial hypercholesterolemia

The chief indication for low density lipoprotein (LDL) apheresis is the treatment of homozygous familial hypercholesterolemia (FH), a potentially fatal condition that responds poorly to conventional therapy. Dextran sulfate/cellulose adsorption columns (Kaneka) and on-line heparin precipitation (HELP) are the most popular systems used in LDL apheresis. Weekly or biweekly procedures plus concomitant drug therapy enable LDL cholesterol to be maintained at 30-50% of its untreated level, with regression of xanthomas, arrest of progression of coronary atherosclerosis, and improved life expectancy. However, aortic stenosis may progress despite apheresis and necessitate valve replacement. Better control of hypercholesterolemia results from combining apheresis with a new 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, atorvastatin. LDL apheresis can also be useful in treating drug-resistant FH heterozygotes with coronary disease. However, the FH Regression Study showed no evidence that reduction by apheresis of both LDL and lipoprotein(a), was more advantageous than reduction by combination drug therapy of LDL alone.

Gene therapy for atherosclerosis

Although considerable progress has been made in the prevention and treatment of atherosclerotic cardiovascular disease, new therapeutic strategies are still needed. Atherosclerosis is a systemic disease and represents an attractive target for the development of somatic gene transfer intended to modulate systemic factors with the goal of inhibiting disease progression. This approach should be differentiated from localized vascular gene delivery to isolated atherosclerotic lesions such as that intended to prevent restenosis. Systemic gene therapy for atherosclerosis can involve either: 1) gene replacement therapy in patients with defined genetic disorder causing premature atherosclerosis, or 2) overexpression of proteins which directly or indirectly inhibit atherosclerosis or stabilize vulnerable lesions. The former is conceptually straightforward, and a pilot clinical gene therapy trial for one of these diseases, homozygous familial hypercholesterolemia, has already been reported. The latter has significant potential for eventual application to a large number of patients at risk for progressive atherosclerosis, independent of the specific cause. However, substantial progress in vector development and the demonstration of efficacy in relevant animal models will be required before gene therapy for atherosclerosis becomes a clinical reality.

Low density lipoprotein apheresis improves regional myocardial perfusion in patients with hypercholesterolemia and extensive coronary artery disease. LDL-Apheresis Atherosclerosis Regression Study (LAARS)

OBJECTIVES

In a randomized study we evaluated the effect of biweekly low density lipoprotein (LDL) apheresis plus simvastatin versus medication alone on regional myocardial perfusion.

BACKGROUND

In patients with severe hypercholesterolemia, diet and lipid-lowering drugs are often insufficient to achieve optimal LDL cholesterol values. Low density lipoprotein apheresis is a very effective lipid-lowering therapy. Assessment of regional myocardial perfusion enables evaluation of the functional state of the coronary circulation.

METHODS

We studied 42 patients with severe hypercholesterolemia and extensive coronary artery disease who were randomized to diet and simvastatin with or without biweekly LDL apheresis. Regional myocardial perfusion was assessed by digital subtraction angiography with videodensitometric calculation of hyperemic mean transit time (HMTT) of contrast medium at baseline and after 2 years of therapy.

RESULTS

Low density lipoprotein cholesterol decreased by 63% (to 3.0 mmol/liter) in the LDL apheresis group and by 47% (to 4.1 mmol/liter) in the medication group. Paired HMTT measurements were assessed in 43 regions in the LDL apheresis group and 35 regions in the medication group. In the LDL apheresis group, regional HMTT decreased over 2 years from 3.35 +/- 1.18 (mean +/- SD) to 2.87 +/- 0.82 s (-14%, p = 0.001), whereas no change in the medication group was observed: 2.95 +/- 1.06 to 2.96 +/- 0.90 s (p = NS). In the patient-based comparison, the mean change in HMTT was -0.45 s (-14%, p = 0.01) in the LDL apheresis group and -0.05 s (-2%, p = NS) in the medication group, respectively. Only exercise-induced ischemia improved in the LDL apheresis group.

CONCLUSIONS

Biweekly LDL apheresis plus simvastatin decreased time-averaged LDL cholesterol levels by an additional 31% (1.1 mmol/liter) compared with medication alone. After 2 years of therapy, regional myocardial perfusion improved in the LDL apheresis group and remained unchanged in the medication group. Thus, aggressive reduction of LDL cholesterol has a favorable effect on regional myocardial perfusion and alleviates ischemia.

Familial hypercholesterolaemia with severe cardiac involvement in a boy: successful management and mid-term follow-up

A 13-year-old boy with double heterozygosity for familial hypercholesterolaemia with a 90% left coronary artery main stem stenosis is reported. The patient's cholesterol levels were effectively controlled with weekly sessions of selective low-density lipoprotein cholesterol removal through immunoadsorption by use of an extracorporeal system. Left main coronary artery stenosis was successfully treated with percutaneous transluminal balloon dilation. At 30 months after the intervention and still under treatment with weekly sessions of low-density lipoprotein apheresis the patient is free of cardiac symptoms. He shows normal exercise capacity and normal myocardial perfusion. It is concluded that aggressive management is justified in such patients and may result in a near-normal quality of life.

Preregistration house officers in general practice

OBJECTIVES

To obtain from house officers who had rotated through general practice in their pre-registration year their views about their experience; and, separately, to compare the overall hours and type of work performed by hospital based and general practice based house officers.

DESIGN

Postal questionnaire; and self recording of working hours and duties during four consecutive weeks.

SETTING

Inner London teaching hospital and nearby general practice.

PARTICIPANTS

28 preregistration house officers in general practice, 1981-91; and 12 preregistration house officers, four each in medicine, surgery, and general practice.

RESULTS

26 out of 28 questionnaires were returned (response rate 93%). Twelve respondents were following or thinking of following a career in general practice. Twenty five respondents were satisfied with the clinical and educational aspects of the general practice rotation and would recommend the rotation, and 25 thought four months was about the right length of time in general practice. With regard to hours and type of work performed, hospital based house officers worked on average 55.5 hours a week (excluding on call), with an average of 12.5 hours (22.5%) spent in clinical activities; general practice based house officers worked about 41 hours a week, of which 24 hours (58%) were in clinical activities. House officers in hospital received less than one hour's specific teaching a week; those in general practice received nearly three hours' a week.

CONCLUSIONS

A preregistration rotation in general practice is a popular alternative to the hospital based rotation. Although this is a limited study, other medical schools should consider introducing general practice options for preregistration house officers.