[Examination and treatment of dyslipemia after myocardial infarction--are the goals achieved?]

According to guidelines, medical treatment of dyslipidaemia in post-AMI patients should await assessment of underlying lipid disorders and the outcome of dietary treatment. The risk of patients not being treated with lipid-lowering therapy because of lack of follow-up has led to more aggressive guidelines recommending statin treatment even before discharge from hospital. In a study comprising 730 patients, we have shown that, although most patients were discharged from the coronary care unit without statin treatment, a traditional rehabilitation programme succeeded in assessing more than 95% of the patients for underlying lipid disorders, and more than 75% of patients with plasma cholesterol > or = 5.5 mmol/l received lipid-lowering therapy within the first year. Most patients were treated with statins. Statins, however, were given in smaller doses than those used in the clinical trials, and only 52% of the treated patients reached the recommended goal of plasma cholesterol lower than 5 mmol/l.

Willingness to pay for arthritis symptom alleviation. Comparison of closed-ended questions with and without follow-up

OBJECTIVE

To compare two methods of measuring willingness to pay (WTP): closed-ended questions with and without follow-up.

METHODS

A measurement experiment based on dichotomous choice contingent valuation survey data is reported. Marginal WTP estimates for alleviation of rheumatoid arthritis symptoms resulting from treatment with a novel anti-rheumatic agent, cA2 (TNF-alpha blockade), were calculated. Monte Carlo simulations were undertaken to evaluate the methods with respect to their statistical power.

RESULTS

The estimated marginal WTP values using closed-ended questions with and without follow-up were DKK 637 (US $91) and DKK 1,268 (US $181), respectively. A Wilcoxon's signed-rank test showed that the difference of DKK 631 was significant. Moreover, including a follow-up question increases the precision of the result. Monte Carlo simulations showed that trade-offs between power (i.e., the probability of a correct rejection of a false null hypothesis), efficiency, and size may exist in the two models.

CONCLUSIONS

There was a significant difference between the WTP estimates when using closed-ended questions with and without follow-up. When choosing between the models, however, power, efficiency, and size could be used as selection criteria.

Normolipidemia and hypercholesterolemia in persons heterozygous for the same 1592 + 5G --> A splice site mutation in the low-density lipoprotein receptor gene

In the present study, we have characterized a unique splice donor G to A substitution in the moderately conserved + 5 position in intron 10 of the low-density lipoprotein (LDL) receptor gene. In two Danish families, carriers of the 1592 + 5G --> A mutation display a clinical phenotype ranging from healthy normocholesterolemic persons to classical heterozygous familial hypercholesterolemia (FH) patients. Reverse transcription-polymerase chain reaction (RT-PCR) of RNA from Epstein Barr virus (EBV)-transformed lymphoblasts obtained from members of both families demonstrated abnormal splicing generating two aberrant mRNAs due to either alternative splicing and skipping of exon 10 or activation of a cryptic splice site in intron 10 inserting 66 intronic base pairs. These abnormally spliced mRNAs were predicted to encode two abnormal receptor proteins containing an in-frame deletion of 75 amino acids and an insertion of 22 novel amino acids, respectively. Results obtained by immunofluorescence staining, flow cytometry, and confocal microscopy of transfected Chang and COS-7 cells expressing normal and mutant LDL receptors were compatible with nearly complete retention of the mutant proteins in the endoplasmic reticulum. Quantitative measurements of LDL receptor mRNAs from EBV-transformed lymphoblasts, however, did not reveal any significant differences in variant mRNA contents between mutation carriers in the families that could be related to degree of hypercholesterolemia.

The clinical usefulness of glucated haemoglobin in diabetes care evaluated by use of a medical technology assessment strategy

With the introduction of measurements of glycated haemoglobin in a single blood sample as an index of long-term blood glucose control, the clinically usefulness of these measurements was questioned. The aim of this study was to evaluate measurements of glycated haemoglobin as a new test for metabolic regulation in diabetes management by use of a medical technology assessment strategy. Technology assessment in medicine has been defined as "the art and science of evaluating medical practices", but the strategy has to be adjusted to the medical technology in question always including the following three stages: (a) problem definition and identification of medical technology, (b) analysis by testing the technology with consideration to its benefit and harm, its costs, and its social consequences, and (c) synthesis of the accumulated knowledge about the technology. Based on the out-put from the problem definition we found it necessary to investigate some of the identified problems ourselves before implementation of routine measurements of glycated haemoglobin. Several studies were accomplished to validate the laboratory technology in terms of analytical reliability and its clinical usefulness. We wanted to (1) define goals of analytical quality of assays of glycated haemoglobin based on clinical goals, (2) establish a laboratory method for measurements of glycated haemoglobin fulfilling the defined goals, (3) investigate the ability of measurements of glycated haemoglobin to characterize impaired glucose tolerance, (4) evaluate the clinical usefulness of measurements of glycated haemoglobin in the assessment of metabolic regulation in non-insulin-dependent diabetes mellitus (NIDDM), (5) compare physicians' assessment of metabolic control in insulin-dependent diabetes mellitus (IDDM) with measurements of glycated haemoglobin and determine whether knowledge of glycated haemoglobin values would result in improved metabolic control, and (6) evaluate the organizational and economical consequences of introducing regular measurements of glycated haemoglobin. The analysis required a multi-disciplinary approach. Based on our own studies and the available data information we found that measurements of glycated haemoglobin should be regarded the most clinically appropriate test of long-term glycemia and should be introduced into routine management of adult patients with IDDM and NIDDM with the following guidelines concerning methodologies, clinical utility, organizational consequences. The individual laboratory has to establish and secure its own method since at present we are still without an internationally accepted reference method or reference material. The method should measure HbA1c without measuring the labile intermediate pre-HbA1c and provide separate detection of haemoglobin variants. We investigated the analytical goals for the performance characteristics of assays based on biological variation and on the clinical significance of a certain change in concentrations in the individual. Different strategies lead to different analytical goals of CVA between 2-4%. An oral glucose tolerance test is still required to establish the diagnosis of diabetes. Measurements of glycated haemoglobin have been suggested as an alternative but a considerable overlap between the WHO-defined groups of normal and impaired glucose tolerance was observed. In patients with IDDM our studies demonstrated the limitations of traditional clinical judgement and the laboratory procedures in providing an accurate assessment of blood glucose control and that knowledge of HbA1c values allowed the clinician to identify patients in poor glycemic control and lead to improvement in glycemic control. In patients with NIDDM our study showed that measurements of HbA1c provided information that was otherwise not obtainable in the usual clinical setting in primary health care. Measurements of glycated haemoglobin were easily accepted by patients with diabetes. (ABSTRACT TRUNCA

Dyslipidemia and coronary artery disease. Prevalence and treatment in patients referred for coronary arteriography

A reduction in serum total cholesterol (T-C) levels has been shown to reduce mortality in patients with coronary artery disease and to decrease the need for revascularization. To examine the prevalence and treatment of lipid disorders in patients referred for their first coronary angiogram, medical history and fasting blood samples were collected in 108 consecutive patients. Ninety-one patients (84.3%) fulfilled the criteria for dyslipidemia. Hypercholesterolemia had previously been demonstrated in 53 patients (49.1%), and 34 (64.2%) of these patients still had T-C > 6.0 mmol/l at the time of admission. Among 55 patients who were unaware of any lipid disorders at admission, 28 (50.9%) had T-C > 6.0 mmol/l.

CONCLUSION

The majority of patients referred for their first coronary angiogram and possible revascularization suffered from dyslipidemia. Many patients with previously recognized dyslipidemia were insufficiently treated.

Phenotypic presentation of the FH-Cincinnati type 5 low density lipoprotein receptor mutation

Familial hypercholesterolaemia (FH) is an autosomal dominant hereditary disease of lipid metabolism that in most families is caused by mutations in the low density lipoprotein receptor (LDLR) gene. Though more than 150 mutations are known, the clinical picture associated with most of these is not known. Genetic FH diagnosis may soon become routine in the setting of genetic counselling, and therefore thorough information on the phenotype-genotype relationship of different mutations is now important. In this study, index patients from each of 14 Danish FH families were screened for mutations in exon 2 of the LDLR gene using a denaturing gradient gel electrophoresis (DGGE)-based mutation screening assay. A deviating DGGE pattern identified two index patients, where subsequent sequencing revealed heterozygosity for the FH Cincinnati type 5 Trp23-to-Stop LDLR mutation. Data from three generations of the families allowed the first clinical and biochemical description of this mutation. Evidence that genetic analysis adds independent diagnostic information compared to traditional clinical/biochemical FH diagnosis was documented by demonstrating the presence of the FH Cincinnati mutation in a family member with a completely normal lipid profile. By comparison to non-FH family members, it was documented that carrier status for the FH Cincinnati mutation is associated with a significant risk of cardiovascular disease. Thus, genetic analysis may improve diagnostic precision and help to define more precisely which of the members of FH families are in need of preventive interventions and may aid in establishing phenotype-genotype relationships allowing more refined genetic counselling in FH.

Genetic diagnosis with the denaturing gradient gel electrophoresis technique improves diagnostic precision in familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant inherited disorder of lipid metabolism caused by mutations in the LDL receptor gene. FH is characterized clinically by elevated LDL cholesterol level and premature coronary disease. Diagnosing FH on clinical grounds may be difficult, and previous genetic methods are too cumbersome for routine use except in the few populations with FH-founder mutations. A simple mutation screening technique based on denaturing gradient gel electrophoresis (DGGE) has been highly useful in detecting mutations in other genes, and in the present study we evaluated the diagnostic potential of this method for the diagnosis of FH.

METHODS AND RESULTS

Conditions for screening exon 3 of the LDL receptor gene using the DGGE technique were established and 14 Danish FH families were examined. An index patient from 1 family had an abnormal DGGE pattern; consequently, an examination of exon 3 of the LDL receptor gene in 21 members of this patient's family was done. The DGGE pattern was seen only in patients with a definite clinical diagnosis of FH. Subsequent sequencing of exon 3 of the LDL receptor gene in these individuals revealed the presence of the French-Canadian type 4 Trp66-Gly mutation. However, in 4 of 11 cases in which a definite clinical diagnosis of FH had been made, the inheritance of the French-Canadian type 4 mutation could be rejected on the basis of genetic analysis.

CONCLUSIONS

Introduction of a simple genetic analysis based on DGGE may improve the precision of diagnosis in FH families.

Detection of a single base deletion in codon 424 of the low density lipoprotein receptor gene in a Danish family with familial hypercholesterolemia

We performed a screening of exon 9 of the low density lipoprotein receptor (LDLR) gene in 14 Danish families with familial hypercholesterolemia (FH) using the denaturing gradient gel electrophoresis (DGGE) technique. In one of the probands from these families an abnormal band pattern in the gradient gel was detected. Subsequent DGGE analysis of the family of this index patient revealed that the DGGE pattern cosegregated with the disease in this family. Sequencing of the exon showed a deletion of a C in codon 424 of the LDLR gene resulting in a frame shift with the introduction of a stop codon 5 codons further downstream. The mutation is referred to as FH-Odense. The predicted truncated receptor protein consists of the 428 amino terminal amino acids. Consequently, the cytosolic and membrane spanning parts of the mature LDL receptor, which normally secure the receptor in the plasma membrane, are missing. The FH-Odense mutation results in severe premature coronary atherosclerosis as shown by the clinical expression in 5 generations of the affected family.

Comparative effects of gemfibrozil and clofibrate in type III hyperlipoproteinemia

Type III hyperlipoproteinemia (dysbetalipoproteinemia) is characterized by elevated concentrations of plasma cholesterol and triglycerides due to an increase in very low density lipoprotein (VLDL) remnant lipoproteins. In a retrospective analysis we observed that in 12 patients with this disorder, gemfibrozil reduced concentrations of total cholesterol, VLDL cholesterol and triglycerides by 48%, 72% and 68%, respectively. These changes were greater than those reported in a similar number of patients treated with clofibrate. Comparative data on the efficacy of different fibrates in this disorder are very limited; to assess this further we have compared the hypolipidemic effects of gemfibrozil (600 mg twice daily) and clofibrate (1 g twice daily) in six patients with well-characterized type III hyperlipoproteinemia. Baseline values were obtained after at least 8 weeks on diet and treatment values were obtained after 6 and 8 weeks of treatment with each drug. Treatment with clofibrate and gemfibrozil both resulted in significant reductions in the plasma concentrations of total cholesterol (40% and 54%), VLDL cholesterol (59% and 79%) and total triglycerides (48% and 70%), as well as a significant increase in HDL cholesterol (9% and 7%). Gemfibrozil was, however, significantly (P < 0.05) more effective in reducing plasma concentrations of total cholesterol, VLDL cholesterol and triglycerides than was clofibrate, in the same patients.

Intraventricular streptokinase increases cerebrospinal fluid D dimer in preterm infants with posthaemorrhagic ventricular dilatation

Failure to lyse multiple small blood clots in the cerebrospinal fluid (CSF) reabsorption pathways may be one of the mechanisms leading to posthaemorrhagic ventricular dilatation (PHVD). It has been suggested that intraventricular administration of streptokinase may resolve PHVD but it is not known whether such treatment produces an increase in fibrin degradation products in the CSF. Ventricular CSF was collected from six infants with PHVD before and during intraventricular treatment with streptokinase 1000 units/h. In all six infants, CSF D dimer increased during streptokinase treatment. Median D dimer before treatment was 1642 micrograms/l and during treatment 5440 micrograms/l (p < 0.05). Undetectable D dimer levels in plasma during streptokinase treatment ruled out the possibility that D dimer had merely diffused into the CSF. This augmentation of local fibrinolysis may have therapeutic potential. There was no evidence of systemic fibrinolysis.

Hypertriglyceridemia and low HDL: therapeutic considerations

The recently revised guidelines for cholesterol management in Europe and the USA have focused attention on triglycerides and HDL cholesterol as risk factors for coronary heart disease. In the present review, I shall discuss therapeutic considerations in the treatment of patients with hypertriglyceridemia or low HDL cholesterol in the context of these new recommendations. I shall also consider recent studies in which the effect of triglyceride-lowering drugs on the concentrations and metabolism of lipoproteins in patients with dyslipidemia are evaluated.

Drug treatment of dyslipoproteinemia

This article has focused on the appropriate indications for lipid-lowering drugs in adult patients with different lipoprotein disorders, which we have divided into primary hypercholesterolemia, combined hyperlipidemia,and hypertriglyceridemia. The mechanism of action, efficacy, and safety profile of the major drugs have been reviewed, and based on this information, we have presented our views on the appropriate drugs of first choice and appropriate second-choice agents for treatment of adult patients with different dyslipidemias. The rationale for the use of hypolipidemic drugs is strongest in patients with hyperlipidemia who concurrently have evidence for coronary or peripheral vascular disease, in whom the goal of secondary prevention is to retard further progression of atherosclerosis and potentially induce some regression, whereas in selected high-risk patients without evidence of atherosclerosis, the goals of therapy are to prevent the premature development of CAD or, in patients with severe hypertriglyceridemia, prevent the adverse sequelae of hepatomegaly, splenomegaly, and potentially pancreatitis. We have focused on the use of hypolipidemic drugs in adult patients, and the guidelines discussed are not appropriate for use in children with hyperlipidemia, in whom drug therapy should be undertaken selectively and in consultation with a lipid specialist. Many areas of controversy in the use of lipid-lowering drugs remain to be addressed by future studies; these include the use of lipid-lowering drugs in patients with secondary causes of hyperlipidemia (e.g., the nephrotic syndrome), the use of lipid-lowering drugs in women, and recommendations for drug therapy in older patients.

[Treatment of primary hypercholesterolemia with pravastatin. A placebo-controlled trial]

We present the results of a multicentre, placebo-controlled, randomized double-blind comparison of the treatment of primary hypercholesterolaemia with pravastatin (Pravachol), an HMG-CoA-reductase inhibitor. The study was conducted in both general practice and hospital settings. Two hundred and eighty-six patients who despite oral and written dietary instructions and advice on healthy living had elevated total serum cholesterol levels of between six and eight mmol/l were randomized to treatment with either parvastatin (Pravachol) or placebo. The study showed a significant reduction in both total serum cholesterol (of 16%) and serum LDL-cholesterol among those treated with pravastatin (Pravachol), as well as a small increase tin serum HDL-cholesterol of six percent. Advice on diet and healthy living resulted in a reduction of serum cholesterol of only 1.5%. There were no important differences between those treated from the hospital and those treated in general practice. The incidence of side-effects was low and comparable to placebo levels, and only two percent of the pravastatin (Pravachol) treated patients had to have the treatment stopped. All side-effects were reversible. No side-effects relating to the central nervous system were registered, and no elevations of serum creatinine phosphokinase were observed amongst the pravastatin treated patients, presumably because of the drug's selective inhibitory effect on cholesterol synthesis in the liver.

Analytical Goal-Setting for Monitoring Patients When Two Analytical Methods are Used

Serial results from an individual are often obtained using more than one method. Results should be transferable over time and locale. Every method has inherent analytical error, and goals are required to delineate the maximum allowable random (imprecision) and systematic (inaccuracy, bias) errors to facilitate optimal patient care. Based on Harris's proposal [Am J Clin Pathol 1979;72:374-82] that desirable imprecision should be less than or equal to one-half the within-subject biological variation, if the methods have negligible imprecision, then the maximum allowable bias between two methods used for monitoring is one-third of the within-subject biological variation. A more general model has been developed that relates the analytical imprecisions of two methods, and the bias between them, to biological variation. Applying the general formula derived in specific clinical monitoring situations in which a known change in serial results (occurring at a stated probability) stimulates clinical action allows goals for the imprecisions of the two methods and allows the difference in bias between them to be determined quantitatively.

Analytical goal-setting for monitoring patients when two analytical methods are used

Serial results from an individual are often obtained using more than one method. Results should be transferable over time and locale. Every method has inherent analytical error, and goals are required to delineate the maximum allowable random (imprecision) and systematic (inaccuracy, bias) errors to facilitate optimal patient care. Based on Harris's proposal [Am J Clin Pathol 1979;72:374-82] that desirable imprecision should be less than or equal to one-half the within-subject biological variation, if the methods have negligible imprecision, then the maximum allowable bias between two methods used for monitoring is one-third of the within-subject biological variation. A more general model has been developed that relates the analytical imprecisions of two methods, and the bias between them, to biological variation. Applying the general formula derived in specific clinical monitoring situations in which a known change in serial results (occurring at a stated probability) stimulates clinical action allows goals for the imprecisions of the two methods and allows the difference in bias between them to be determined quantitatively.

[Leadership and professionalism]

In 1990 a new organizational structure based on decentralization and team leadership, where the leader (usually a doctor) is responsible for the final decision, was introduced at the regional and university hospital of Tromsø. This structure replaces the traditional dual structure of leadership where the leaders (a doctor and a nurse) did not share responsibility for the whole department. In order to analyze organizational practices after the reform we constructed three different organization models of the hospital: the hierarchical model, the professional model and the workshop model. Of five teams, one functioned hierarchically, three resembled the professional model, and the fifth came close to the workshop model. The leader of the hierarchical team behaves autocratically and the employees are dissatisfied. In the three remaining teams conditions have changed very little compared with the situation before the reorganization. In the workshop team decisions are reached jointly. This team functions in an innovative way. Even though the new organizational structure has quite divergent consequences and some leaders have problems, the majority of the hospital employees support the new structure.

Extrinsic pathway inhibitor (EPI) released to the blood by heparin is a more powerful coagulation inhibitor than is recombinant EPI

EPI released to the blood after injection of heparin, as well as recombinant EPI (r-EPI) added to normal plasma prolonged both the dilute Tissue Thromboplastin (TTP) time and the Activated Partial Thromboplastin Time (APTT). It is known that EPI inhibits both factor Xa and the factor VIIa-TTP complex. The prolongation of the APTT by EPI reflects only its inhibition of factor Xa. Addition of anti-EPI immunoglobulins (IgG) to normal plasma shortened the dilute TTP time 7.3 seconds (p less than 0.001) and the APTT by 0.7 seconds (p less than 0.001). In postheparin plasma, with polybrene added to neutralize the direct effect of heparin, the TTP was about 26 seconds longer and the APTT about 9 seconds longer than baseline values. These effects were completely abolished by anti-EPI IgG, as were the effects of r-EPI. The EPI activity (chromogenic substrate-assay) of this postheparin plasma was 1.7 U/ml. The EPI activity of the plasma spiked with r-EPI to obtain comparable effects on clotting were much higher; about 22 U/ml for the TTP effect and about 5 U/ml for the APTT effect. The findings indicate that r-EPI is considerably less potent than postheparin EPI as inhibitor of plasma coagulation. This is most striking when coagulation is initiated through the extrinsic pathway. Possibly, the anticoagulant effect of r-EPI mainly depends on its Xa inhibitory effect.

Chromogenic substrate assay of extrinsic pathway inhibitor (EPI): levels in the normal population and relation to cholesterol

A two-stage chromogenic substrate assay was standardized to measure extrinsic pathway inhibitor (EPI) activity in plasma and serum samples. In the first stage, diluted plasma or serum (0-0.8%) was incubated with factor VIIa (25 pM), tissue thromboplastin (tissue factor, TF, 1% v/v) with excess binding sites for factor VIIa, and factor Xa (0.8 nM). In the second stage, excess factor X and chromogenic substrate were added as substrate for residual TF/factor VIIa catalytic activity. Heating the samples at 56 degrees C for 15 min before assay removed greater than 95% of the factor VII amidolytic activity of the samples, defibrinated the plasma, and produced only slight reduction of EPI activity. The coefficient of variation for the same sample assayed on different days was 8.7-10.6% and the intra-assay coefficient of variation was 5.0%. Addition of anti-EPI immunoglobulin to normal plasma completely abolished the EPI activity of the sample. EPI activity was stable in plasma samples stored at -20 degrees C, but in serum, some samples lost greater than 50% activity after 3 months at -70 degrees C. Median EPI activity of umbilical cord blood was 45% (range 33-93%). In a cohort of healthy blood donors (n = 176) EPI activity was significantly correlated with age; the regression line was y = 68% + 0.60x (r = 0.39). The approximated standard deviation for the regression line was 17.9% and the age-adjusted reference limits were determined. Equal levels were seen in males and females.(ABSTRACT TRUNCATED AT 250 WORDS)