Carl-Göran Ericsson

Treatment effects on serum lipoprotein lipids, apolipoproteins and low density lipoprotein particle size and relationships of lipoprotein variables to progression of coronary artery disease in the Bezafibrate Coronary Atherosclerosis Intervention Trial (BECAIT) ☆

OBJECTIVES To investigate the mechanisms by which bezafibrate retarded the progression of coronary lesions in the Bezafibrate Coronary Atherosclerosis Intervention Trial (BECAIT), we examined the relationships of on-trial lipoproteins and lipoprotein subfractions to the angiographic outcome measurements. BACKGROUND BECAIT, the first double-blind, placebo-controlled, randomized serial angiographic trial of a fibrate compound, showed that progression of focal coronary atherosclerosis in young survivors of myocardial infarction could be retarded by bezafibrate treatment. METHODS A total of 92 dyslipoproteinemic men who had survived a first myocardial infarction before the age of 45 years were randomly assigned to treatment for 5 years with bezafibrate (200 mg three times daily) or placebo; 81 patients underwent baseline and at least one post-treatment coronary angiography. RESULTS In addition to the decrease in very low density lipoprotein (VLDL) cholesterol (-53%) and triglyceride (-46%) and plasma apolipoprotein (apo) B (-9%) levels, bezafibrate treatment resulted in a significant increase in high density lipoprotein-3 (HDL3) cholesterol (+9%) level and a shift in the low density lipoprotein (LDL) subclass distribution toward larger particle species (peak particle diameter +032 nm). The on-trial HDL3 cholesterol and plasma apo B concentrations were found to be independent predictors of the changes in mean minimum lumen diameter (r=-0.23, p < 0.05), and percent (%) stenosis (r = 0.30, p < 0.01), respectively. Decreases in small dense LDL and/or VLDL lipid concentrations were unrelated to disease progression. CONCLUSIONS Our results suggest that the effect of bezafibrate on progression of focal coronary atherosclerosis could be at least partly attributed to a rise in HDL3 cholesterol and a decrease in the total number of apo B-containing lipoproteins.

Serum matrix metalloproteinase-3 concentration is influenced by MMP-3 )1612 5A/6A promoter genotype and associated with myocardial infarction

Objectives.  Matrix metalloproteinase‐3 (MMP‐3) is implicated in the formation of atherosclerotic plaques, and the MMP‐3 −1612 5A/6A polymorphism is associated with myocardial infarction (MI) and stable coronary artery disease (CAD). The present study examined whether the −1612 5A/6A polymorphism in the promoter region of the MMP‐3 gene influences serum concentrations of MMP‐3 and whether serum concentrations of MMP‐3 are related to extent of coronary atherosclerosis and risk of MI.

Effect of bezafibrate treatment over five years on coronary plaques causing 20% to 50% diameter narrowing (The Bezafibrate Coronary Atherosclerosis Intervention Trial [BECAIT])

Recent reports indicate that most coronary events originate from plaques causing <50% diameter stenosis. A subgroup analysis of the Bezafibrate Coronary Atherosclerosis Intervention Trial (BECAIT) data was undertaken to determine the effects of bezafibrate in relation to baseline narrowing. BECAIT included 92 male postacute myocardial infarction patients <45 years of age. Each received double-blind treatment with bezafibrate (200 mg 3 times daily) or placebo for 5 years, together with a low-fat diet. Coronary angiography was performed at baseline and after 2 and 5 years. The mean minimum lumen diameter of lesions causing 20% to <50% diameter stenosis at baseline did not narrow over 5 years in the bezafibrate group and decreased by 0.15 mm in the placebo group (p <0.05). In segments with > or =50% diameter stenosis at baseline, no change was seen in either of the 2 groups. In the analysis including only segments with 20% to <50% stenosis at baseline, coronary events were seen in 7 of 40 patients with a progression in minimum lumen diameter of more than the median value and in 3 of 41 patients with a change less than the median value. Thus, bezafibrate had a preferential effect in slowing the progression of narrowings causing <50% stenosis at baseline in young men followed up for a 5-year period after acute myocardial infarction.

Human Evidence That the Cystatin C Gene Is Implicated in Focal Progression of Coronary Artery Disease

Objective—Overexpression of elastolytic cysteine and aspartic proteases, known as cathepsins, is implicated in atherogenesis. The potential significance of imbalance in expression between cathepsins and their inhibitor cystatin C in cardiovascular disease has been highlighted by the demonstration of cystatin C deficiency in human atherosclerosis and abdominal aortic aneurysms. Methods and Results—We identified and characterized physiologically relevant polymorphisms in the promoter region of the cystatin C gene that influence cystatin C production and used these polymorphisms as a tool to examine the significance of cystatin C in coronary atherosclerosis in vivo in humans. Seven polymorphisms, all in strong-linkage disequilibrium, were identified in the cystatin C gene, of which 2 promoter polymorphisms (−82G/C and −78T/G) were functional in vitro in electromobility shift and transient transfection assays. Genotyping of 1105 individuals (237 survivors of a first myocardial infarction before age 60 and 2 independent groups comprising a total of 868 healthy individuals) revealed that the plasma cystatin C concentration was significantly lower in carriers of the mutant haplotype. Furthermore, the mutant haplotype was associated with a higher average number of stenoses per coronary artery segment in unselected postinfarction patients (N=237) undergoing routine coronary angiography. Conclusions—These results provide human evidence for an important role of cystatin C in coronary artery disease.

Serum insulin-like growth factor-I level is independently associated with coronary artery disease progression in young male survivors of myocardial infarction: beneficial effects of bezafibrate treatment ☆

OBJECTIVES We investigated whether the effect of bezafibrate on progression of coronary atherosclerosis in the BEzafibrate Coronary Atherosclerosis Intervention Trial (BECAIT) was related to insulin-like growth factor (IGF)-I and glucose-insulin homeostasis. BACKGROUND BECAIT, the first double-blind, placebo-controlled, randomized, serial angiographic trial of a fibrate compound, demonstrated that progression of focal coronary atherosclerosis in young patients after infarction could be retarded by bezafibrate treatment. METHODS The treatment effects on serum concentrations of IGF-I and insulin-like growth factor binding protein (IGFBP)-1, as well as on basal and postload glucose and insulin levels, were examined, and on-trial determinations were related to the angiographic outcome measurements. RESULTS Bezafibrate treatment resulted in a significant reduction of serum IGF-I levels, both at two and five years, and on-trial serum IGF-I levels were directly related to changes in both minimal lumen diameter (r = 0.25, p < 0.05) and mean segment diameter (r = 0.29, p < 0.05). In contrast, none of the available indexes of insulin resistance (homeostasis model assessment estimate, basal and postload plasma insulin concentrations and serum IGFBP-1 levels) were related to the angiographic changes, nor were they significantly affected by bezafibrate treatment. Multiple stepwise regression analysis showed that the relation between on-trial serum IGF-I level and coronary artery disease (CAD) progression was independent of baseline angiographic score, age, body mass index, serum lipoprotein and plasma fibrinogen concentrations and measures of glucose-insulin homeostasis. CONCLUSIONS IGF-I could be implicated in the progression of premature CAD, and a reduction of serum IGF-I concentration could account partly for the effect of bezafibrate on progression of focal coronary atherosclerosis.

High plasma concentrations of autoantibodies against native peptide 210 of apoB-100 are related to less coronary atherosclerosis and lower risk of myocardial infarction

AIMS We examined whether antibodies against peptides 45 and 210 of apoB-100 are related to myocardial infarction (MI) and severity of coronary atherosclerosis. METHODS AND RESULTS Three hundred and eighty-seven survivors of a first MI (aged <60 years) and 387 sex- and age-matched controls were characterized in detail. IgG and IgM autoantibodies against native and malondialdehyde (MDA)-modified peptides 45 and 210 of apoB-100 (amino acids 661-680 and 3136-3155) were quantified in plasma and quantitative coronary angiography was performed in 243 patients. Post-infarction patients had significantly lower IgG against the native peptide 210 (IgG-p210(nat)) and higher IgM against the MDA-modified peptide 210 (IgM-p210(MDA)) compared with controls, whereas no differences were found for other antibodies. Plasma concentrations of IgG-p210(nat), but not IgM-p210(MDA), were independently and inversely related to the degree of coronary atherosclerosis in patients. In multiple logistic regression analysis (including established risk indicators), MI risk was 0.55 (95%CI: 0.37-0.81) for individuals in the IgG-p210(nat) upper quartile compared with the remaining individuals. CONCLUSION Circulating IgG antibodies against the native peptide 210 of apoB-100 are inversely related to the severity of coronary atherosclerosis and associated with lower risk of MI. Epitope 210 of apoB-100 emerges as a target for immunization against atherosclerosis in humans.

Accumulation of Apolipoprotein C-I–Rich and Cholesterol-Rich VLDL Remnants During Exaggerated Postprandial Triglyceridemia in Normolipidemic Patients With Coronary Artery Disease

BACKGROUND Exaggerated postprandial triglyceridemia is common in normolipidemic patients with coronary artery disease (CAD). Alterations in the composition of triglyceride-rich lipoproteins (TRLs) are likely to underlie this metabolic disturbance. However, the composition of very-low-density lipoproteins (VLDLs), which are the most abundant postprandial TRLs, has never been defined in CAD patients. METHODS AND RESULTS We examined postprandial changes in the number and composition of VLDLs in middle-aged, normolipidemic CAD patients and control subjects. TRLs from 14 patients and 14 control subjects aged 45 to 55 years were subfractionated by density gradient ultracentrifugation into Svedberg flotation rate (Sf) fractions >400, 60 to 400, and 20 to 60. The VLDLs were separated from chylomicron remnants by immunoaffinity chromatography. In CAD patients, the postprandial concentrations of triglycerides and large (Sf 60 to 400) VLDL particles were elevated. In addition, their postprandial large VLDLs were enriched in apolipoprotein (apo) C-I and their postprandial small (Sf 20 to 60) VLDL remnants were enriched with apo C-I and cholesterol. CONCLUSIONS Perturbed handling of postprandial triglycerides in normolipidemic CAD patients involves the accumulation of apo C-I-rich large VLDL particles and the generation of small, apo C-I- and cholesterol-rich VLDL remnants.

Contribution of haplotypes across the fibrinogen gene cluster to variation in risk of myocardial infarction

Fibrinogen has consistently been recognized as an independent predictor of myocardial infarction (MI). Multiple mechanisms link fibrinogen to MI; therefore disentangling the factors underlying variation in plasma fibrinogen concentration is essential. Candidate regions in the fibrinogen gamma (FGG), alpha (FGA) and beta (FGB) genes were screened for single nucleotide polymorphisms (SNPs). Several novel SNPs were detected in the FGG and FGA genes in addition to the previously known SNPs in the fibrinogen genes. Tight linkage disequilibrium extending over various physical distances was observed between most SNPs. Consequently, eight SNPs were chosen and determined in 377 postinfarction patients and 387 healthy individuals. None of the SNPs were associated with plasma fibrinogen concentration or MI. Haplotype analyses revealed a consistent pattern of haplotypes associated with variation in risk of MI. Of the four haplotypes inferred using the FGA -58G>A and FGG 1299 +79T>C SNPs, the most frequent haplotype, FGG-FGA*1 (prevalence 46.6%), was associated with increased risk of MI (OR 1.51; 95%CI 1.18, 1.93), whereas the least frequent haplotype, FGG-FGA*4 (11.8%), was associated with lower risk of MI (OR 0.79 95%CI 0.64, 0.98). In conclusion, fibrinogen haplotypes, but not SNPs in isolation, are associated with variation in risk of MI.

Epistatic and pleiotropic effects of polymorphisms in the fibrinogen and coagulation factor XIII genes on plasma fibrinogen concentration, fibrin gel structure and risk of myocardial infarction

An intricate interplay between the genes encoding fibrinogen gamma (FGG), alpha (FGA) and beta (FGB), coagulation factor XIII (F13A1) and interleukin 6 (IL6) and environmental factors is likely to influence plasma fibrinogen concentration, fibrin clot structure and risk of myocardial infarction (MI). In the present study, the potential contribution of SNPs harboured in the fibrinogen, IL6 and F13A1 genes to these biochemical and clinical phenotypes was examined. A database and biobank based on 387 survivors of a first MI and population-based controls were used. Sixty controls were selected according to FGG 9340T > C [rs1049636] genotype for studies on fibrin clot structure using the liquid permeation method. The multifactor dimensionality reduction method was used for interaction analyses. We here report that the FGA 2224G > A [rs2070011] SNP (9.2%), plasma fibrinogen concentration (13.1%) and age (8.1%) appeared as independent determinants of fibrin gel porosity. The FGA 2224G > A SNP modulated the relation between plasma fibrinogen concentration and fibrin clot porosity. The FGG-FGA*4 haplotype, composed of the minor FGG 9340C and FGA 2224A alleles, had similar effects, supporting its reported protective role in relation to MI. Significant epistasis on plasma fibrinogen concentration was detected between the FGA 2224G > A and F13A1 Val34Leu [rs5985] SNPs (p < 0.001). The FGG 9340T > C and FGB 1038G > A [rs1800791] SNPs appeared to interact on MI risk, explaining the association of FGG-FGB haplotypes with MI in the absence of effects of individual SNPs. Thus, epistatic and pleiotropic effects of polymorphisms contribute to the variation in plasma fibrinogen concentration, fibrin clot structure and risk of MI.

Gender specific associations between matrix metalloproteinases and inflammatory markers in post myocardial infarction patients.

OBJECTIVE Atherothrombotic disease in the coronary arteries leads to myocardial infarction (MI) through plaque rupture or erosion of the endothelium, the former mechanism predominating in men and the latter in women. Inflammation is a key feature of these processes, and the interplay between inflammation and matrix metalloproteinases (MMPs) in this context is not fully understood. In this study, we investigated the association between inflammatory markers and MMPs in men and women. METHODS Blood samples were drawn 3 months after a first MI in 387 patients and 387 sex- and age-matched controls (82% men). C-reactive protein (CRP), interleukin-6 (IL-6), IL-8, -18, tumour necrosis factor-alpha (TNF-alpha), macrophage chemoattractant protein-1 (MCP-1), MMP-1, -3 and -9 were measured. Coronary angiography was performed in 243 of the patients, and they were classified into 0-, 1-, 2- or 3-vessel disease groups. RESULTS CRP, IL-6, -8, -18 and TNF-alpha were higher, and MMP-3 and -9 were lower, in patients than in controls. A greater proportion of women (49%) had 0-vessel disease than men (16%, p<0.0001). A gender specific pattern of associations between inflammatory markers and MMPs was found as IL-6 (r(S)=0.29, p<0.05), IL-18 (r(S)=0.34, p<0.01) and MCP-1 (r(S)=0.35, p<0.01) correlated with MMP-3 in female patients, whereas CRP (r(S)=0.23, p<0.0001), IL-6 (r(S)=0.13, p<0.05) and IL-8 (r(S)=-0.21, p<0.01) correlated with MMP-9 in male patients. CONCLUSIONS The present study demonstrates different patterns of association between inflammatory markers and MMPs in men and women, strengthening the hypothesis of gender specific differences in pathophysiological mechanisms of MI.