Fibrinogen and its relations to subclinical extracoronary and coronary atherosclerosis in hypercholesterolemic men

Coronary CT angiography findings based on smoking status: Do ex-smokers and never-smokers share a low probability of developing coronary atherosclerosis?

The relationship of coronary artery disease (CAD) in ex-smokers has not been elucidated, although smoking is considered to be one of the major risk factors of CAD. We investigate subclinical coronary atherosclerosis (SCA) in asymptomatic subjects with coronary computed tomography angiography (CCTA), according to smoking status, and determine whether ex-smokers share a low probability of developing CAD with never-smokers. We retrospectively enrolled 6930 self-referred asymptomatic adults who underwent both coronary artery calcium score (CACS) and CCTA. The prevalence and characteristics of SCA were assessed according to smoking status (never-, ex- and current smokers). After adjusting for variable risk factors, we used multivariate logistic regression for adjusted odds ratios (AOR) of high CACS (>100), SCA (any plaque), significant stenosis (>50 % in luminal stenosis) and each plaque type (non-calcified, mixed and calcified plaque) among the three groups. The prevalence of SCA was highest in the ex-smokers (35.4 %) and the prevalence of significant stenosis in ex-smokers (6.9 %) was as high as in current smokers (6.4 %). However, after adjusting for variable risk factors, SCA was significantly correlated with both ex-smokers (AOR; 1.21) and current smokers (AOR; 1.25), whereas significant stenosis was correlated only with current smokers (AOR; 1.91). The association between SCA and ex-smokers is as strong as with current smokers, although significant stenosis is only correlated with current smokers; thus, not only quitting smoking but also never initiating smoking would be helpful to reduce the progression of the SCA.

The NF-κB pathway: regulation of the instability of atherosclerotic plaques activated by Fg, Fb, and FDPs

Recently, the molecular mechanism responsible for the instability of atherosclerotic plaques has gradually become a hot topic among researchers and clinicians. Matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) play an important role in the processes of formation and development of atherosclerosis. In this study, we established and employed the transwell co-culture system of rabbit aortic endothelial cells and smooth muscle cells to explore the relationship between fibrin (Fb), fibrinogen (Fg), and/or their degradation products (FDPs) in relation to the instability of atherosclerotic plaques; meanwhile, we observed the effects of Fg, Fb, and FDPs on the mRNA levels of MMPs and VEGF as well as on the activation of nuclear factor-kappa B (NF-κB). We concluded that Fb, Fg, and FDPs are involved in the progression of the instability of atherosclerotic plaques via increasing the expression of MMPs and VEGF. This effect might be mediated by the NF-кB pathway.

Association between laboratory markers and presence of coronary artery disease

The aim of this paper is to elucidate the relation between laboratory markers and coronary artery disease (CAD).

METHODS

The study involved 1254 consecutive patients with suspected or known CAD referred for coronary angiography. The blood samples including blood cell count, C-reactive protein, fibrinogen, uric acid, creatinine, and lipid spectrum were obtained after overnight fasting. One hundred and thirty-three patients were excluded due to incomplete records or inacceptable laboratory values. Differences among groups were tested with one-way ANOVA and Bonferroni post-hoc test for continuous variables and with chi-square test for categorical variables. Univariate and multivariate logistic regression was adopted for the analysis of risk factors and development of models for classification of patients into clinical categories.

RESULTS

The linear logistic regression showed association of patient's biochemical markers with the presence of disease. Both acute and chronic CAD were associated with leukocyte count (Odds ratios 1.45 and 1.26), CRP (1.13; 1.05), fibrinogen (4.23; 1.95), uric acid (1.27; 1.38), creatinine (1.04; 1.04), HDL cholesterol (0.07; 0.12), triglycerides (1.4; 1.52) and glucose (1.56; 1.39). Presence of insignificant atherosclerosis was influenced only by fibrinogen (OR 1.73), creatinine (1.02), HDL cholesterol (0.5) and glucose level (1.23). There was no difference between one- and multivessel disease in laboratory values.

CONCLUSION

Leukocyte count, CRP level, triglycerides and uric acid are associated with the presence of both acute and chronic ischaemic heart disease, but not with number of stenosed vessels. In addition, glycemia, HDL cholesterol and namely fibrinogen and creatinine have relation to occurence of insignificant atherosclerosis.

Fibrinogen and left ventricular myocardial systolic function: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Increasing evidence suggests that elevated plasma fibrinogen is associated with incident heart failure. However, the underlying pathophysiological mechanisms have not been well elucidated.

METHODS

We examined the relationship between plasma fibrinogen level and peak systolic midwall circumferential strain (Ecc) at the base, mid cavity, and apex of the left ventricle measured by magnetic resonance imaging myocardial tagging in 1096 participants without clinical cardiovascular disease enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA).

RESULTS

After adjustment for demographics, established risk factors and body mass index, elevated fibrinogen was independently associated with reductions in absolute Ecc indicative of impaired systolic function in all regions (all P < or = .015). The relationships were consistently significant upon further adjustment for measures of atherosclerosis (all P < .024) and were modestly attenuated with regional heterogeneity after additional adjustment for other inflammatory biomarker and N-terminal pro-brain natriuretic peptide. In this fully-adjusted model, every 1-SD (74 mg/dL) increment in plasma fibrinogen was independently associated with a reduction in left ventricular absolute Ecc of 0.29% (95% CI 0.03%-0.59%, P = .048) at the base, 0.22% (95% CI 0.006%-0.43%, P = .044) at mid cavity, 0.20% (95% CI = -0.035% to 0.43%, P = .097) at the apex, and 0.24% (95% CI = 0.05%-0.43%, P = .015) overall.

CONCLUSIONS

Among asymptomatic individuals without clinical cardiovascular disease, elevated fibrinogen is independently associated with impaired myocardial systolic function. These findings support roles of inflammation, procoagulation, and hyperviscosity underlying hyperfibrinogenemia in the pathogenesis of incipient myocardial dysfunction.

Subclinical atherosclerosis modeling: Integration of coronary artery calcium score to Framingham equation

Medical prevention consists to identify as soon as possible apparently healthy individuals who develop a disease and to engage them for active preventive treatment. Several cross-sectional studies of general populations or high cardiovascular risk have shown that coronary calcium score (coronary artery calcium, CAC) was positively associated with traditional risk factors (hypertension, dyslipidemia, diabetes, and smoking) and some new risk factors (fibrinogen). In this work, we first calculated, among 618 men, the risk of 10-years cardiovascular heart disease (CHD) according to the Framingham risk model, and then we calculated the probability that the CAC score of an individual falls in all four CAC categories (0, 1-100, 101-400 and > 400). We obtained risk factors adjusted relative risk (RR) estimates from a meta-analysis comparing the risk of coronary heart disease in individuals with CAC scores of 1-100 (RR = 1.7), 101 - 400 (RR = 3.0) and > 400 (RR = 4.3) with the risk of a person with a CAC score zero. The new model for the risk of CHD for each CAC score category were then calculated assuming an average 1-year risk of CHD and risk assessment of the four CAC score categories, weighted by the probability that scores fall into each category. The combination of modeling the CCA with the modeling of conventional risk factors allows obtaining a remarkable predictive value that can improve the assessment of overall risk Framingham through the reclassification of the risk of CHD to an extent which may be clinically important.

Association of C-Reactive Protein with the Presence and Extent of Angiographically Verified Coronary Artery Disease

Prospective studies have demonstrated that markers of inflammation, such as high-sensitivity C-reactive protein (hsCRP) and fibrinogen, predict future cardiovascular disease risk. However, the association between the hsCRP and fibrinogen levels and the extent of coronary stenosis in patients with coronary artery disease (CAD) remains controversial. The aim of our case-control study was to assess the association of inflammatory markers with the occurrence and extent of CAD. Serum hsCRP and plasma fibrinogen levels were measured in 138 patients with angiographically assessed CAD and in 183 healthy subjects matched according to age and gender. According to the number of significantly stenosed (>or= 50%) vessels, the patients were classified in four groups: those without stenosis (0-vessel disease) and those with 1, 2 or 3-vessel disease. The hsCRP and fibrinogen levels were significantly higher in patients than in controls (p < 0.001). Although the hsCRP and fibrinogen levels tended to increase with the number of stenotic vessels, the differences were only significant for hsCRP (p < 0.01). Regression analysis indicated hsCRP as an independent predictor for the presence (OR = 3.573, p < 0.05) and extent of CAD (beta = 1.095, p < 0.05). In conclusion, the present study is the first report concerning the frequency distribution of hsCRP in Serbian healthy subjects and CAD patients. We have shown that elevated levels of hsCRP are associated with the presence and extent of CAD.

Conditional risk factors for atherosclerosis

Although most patients who experience a coronary heart disease (CHD) event have one or more of the conventional risk factors for atherosclerosis, so do many people who have not yet experienced such an event. Therefore, predictive models based on conventional risk factors have a lower than desired accuracy, providing a stimulus to search for new tools to refine CHD risk prediction. In particular, there is intense interest in evaluating circulating biomarkers related to the atherosclerotic process that might add to our ability to better predict CHD risk. One such group of biomarkers was termed conditional risk factors in an American Heart Association/American College of Cardiology statement in 1999. The conditional risk factors include homocysteine, fibrinogen, lipoprotein(a), low-density lipoprotein particle size, and C-reactive protein. This review updates the conditional risk factors. The main focus is on the potential utility of these risk factors, which are currently available to clinicians, in the prediction of CHD risk in asymptomatic persons. The putative mechanisms of risk, available assays, evidence for association with CHD, and the clinical implications thereof are discussed for each of the risk factors.

Non-invasive assessment of coronary calcification

Electron-beam tomography (EBT) and multi-detector computed tomography (MDCT) enable the noninvasive assessment of coronary calcification. The amount of coronary calcification, as detected by EBT, has a close relation with the amount of coronary atherosclerosis, which is the substrate for the occurrence of myocardial infarction and sudden cardiac death. Calcification of the coronary arteries can be seen as a cumulative measure of life-time exposure to cardiovascular risk factors. Several studies have shown that the amount of coronary calcification is associated with the risk of coronary heart disease. Therefore, coronary calcification is a promising method for non-invasive detection of asymptomatic subjects at high risk of developing coronary heart disease. Whether measurement of coronary calcification also increases the predictive power of coronary events based on cardiovascular risk factors is topic of current research.

Oxidatively modified fibrinogen modulates blood rheological parameters

We studied the effect of UV-oxidized fibrinogen with oxidation degrees of 10 and 20% on rheological parameters of the blood. The effect of fibrinogen with 10% oxidation degree was moderate and variable, which attests to its partial compensation with the pool of natural antioxidants. The effect of fibrinogen with 20% oxidation degree was more pronounced. It dramatically decreased deformability of erythrocytes, delayed formation of linear aggregates, accelerated formation of 3D-aggregates, enhanced the total hydrodynamic strength of aggregates, but decreased stability of the largest aggregates. It did not increase plasma viscosity, but enhanced viscosity of the blood at all shear rates. At both degrees of oxidation, suspension stability of the blood decreased, the Caisson viscosity did not change, and the difference between the values of Caisson and asymptotic viscosities markedly increased. On the whole, oxidative fibrinogen produces negative changes in blood rheological parameters, and its effect depends on the degree of oxidation.

Effect of oxidized fibrinogens on blood coagulation

We studied the effect of UV-irradiated fibrinogen on blood coagulation. Fibrinogen with oxidation degree of 10% moderately activated the intrinsic pathway, but inhibited the extrinsic pathway of blood coagulation. Fibrinogen with oxidation degree of 20% inhibited both the extrinsic and intrinsic blood coagulation pathways. We revealed disturbances in the formation of fibrin clot with oxidized fibrinogen, suppression of platelet aggregation mediated by collagen receptors, and inhibition of aggregation associated with von Willebrand factor activity. ADP initiated platelet aggregation, which was in direct proportion to the degree of fibrinogen oxidation. Our results indicate that oxidized fibrinogen produces a dysregulatory effect on platelets.

HMG-CoA reductase inhibitors are associated with decreased serum neopterin levels in stable coronary artery disease

Neopterin, a marker of stimulated cellular immune response, is increased in unstable angina, acute myocardial infarction and possibly stable coronary artery disease. 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have anti-inflammatory properties, but their effect on neopterin is largely unknown. Neopterin was measured in 232 patients undergoing elective coronary angiography and compared to the degree of atherosclerosis, use of concomitant medications and demographics. Neopterin was lower in subjects using statins (n = 66) compared to those not taking statins (median (range): 6.65 (4.1-18.3) vs. 7.70 (3.6-29.1) nmol/l, p < 0.0001). This association was also found in the subgroup of patients with coronary artery disease (1-3-vessel disease, n = 164; 6.60 (4.1-18.3) vs. 7.80 (3.6-29.1) nmol/l, p = 0.0012), whereas only a slight tendency toward lower neopterin levels was found in the group without atherosclerosis (6.90 (5.1-16.0) vs. 7.60 (4.0-18.5) nmol/l, p = 0.17). In patients with coronary atherosclerosis, neopterin concentrations were lower in smokers (n = 105) compared to non-smokers (7.20 (3.6-29.1) vs. 7.90 (4.4-18.6) nmol/l, p < 0.02), confirming previous observations. However, use of statins was associated with lower neopterin levels in both non-smokers and smokers (6.70 (4.1-18.3) vs. 7.60 (3.6-29.1) nmol/l, p < 0.05, and 6.20 (5.2-16.0) vs. 7.80 (4.4-18.6) nmol/l, p < 0.05, respectively). Overall, similar serum neopterin concentrations were found in patients with coronary atherosclerosis and those without. In accordance with their anti-inflammatory effects, the use of statins is associated with lower neopterin levels in patients undergoing elective coronary angiography.

Fibrinogen--marker or mediator of vascular disease?

Fibrinogen plays a key role in platelet aggregation, the final step of the coagulation cascade, i.e. the formation of fibrin, and it is a major determinant of plasma viscosity and erythrocyte aggregation. It is both constitutively expressed and inducible during an acute phase reaction. Increased plasma fibrinogen levels are associated with an increased risk of coronary heart disease and myocardial infarction. The question as to whether fibrinogen is only a marker of the inflammatory process involved in atherosclerosis or a mediator, i.e. a pathogenic factor, has not yet been answered. Human in vivo studies do not permit a conclusive answer to this question. If it is a pathogenic factor, fibrinogen lowering would be a therapeutic option. Selective fibrinogen-lowering agents do not exist however. All agents that lower fibrinogen also have other cardiovascular effects such as a decrease in cholesterol or inflammation. Newer information stems from molecular biology. Polymorphisms in the human fibrinogen gene with higher fibrinogen levels do not increase the risk for myocardial infarction. Fibrinogen knockout mice crossed with an atherosclerosis-susceptible strain (apoprotein E null mice) did not show a decreased extent of atherosclerosis despite the absence of fibrinogen, and a mouse strain over-expressing fibrinogen did not show an increased degree of atherosclerosis. Thus, fibrinogen seems to be a marker rather than a mediator of vascular disease, which would make selective fibrinogen lowering a useless preventive or therapeutic strategy.

Stress and the inflammatory response: a review of neurogenic inflammation

The subject of neuroinflammation is reviewed. In response to psychological stress or certain physical stressors, an inflammatory process may occur by release of neuropeptides, especially Substance P (SP), or other inflammatory mediators, from sensory nerves and the activation of mast cells or other inflammatory cells. Central neuropeptides, particularly corticosteroid releasing factor (CRF), and perhaps SP as well, initiate a systemic stress response by activation of neuroendocrinological pathways such as the sympathetic nervous system, hypothalamic pituitary axis, and the renin angiotensin system, with the release of the stress hormones (i.e., catecholamines, corticosteroids, growth hormone, glucagons, and renin). These, together with cytokines induced by stress, initiate the acute phase response (APR) and the induction of acute phase proteins, essential mediators of inflammation. Central nervous system norepinephrine may also induce the APR perhaps by macrophage activation and cytokine release. The increase in lipids with stress may also be a factor in macrophage activation, as may lipopolysaccharide which, I postulate, induces cytokines from hepatic Kupffer cells, subsequent to an enhanced absorption from the gastrointestinal tract during psychologic stress. The brain may initiate or inhibit the inflammatory process. The inflammatory response is contained within the psychological stress response which evolved later. Moreover, the same neuropeptides (i.e., CRF and possibly SP as well) mediate both stress and inflammation. Cytokines evoked by either a stress or inflammatory response may utilize similar somatosensory pathways to signal the brain. Other instances whereby stress may induce inflammatory changes are reviewed. I postulate that repeated episodes of acute or chronic psychogenic stress may produce chronic inflammatory changes which may result in atherosclerosis in the arteries or chronic inflammatory changes in other organs as well.

Determinants of progression of coronary artery calcifications in asymptomatic men at high cardiovascular risk

Extended coronary artery calcifications (CAC) are predictive for cardiovascular complications but little is known about factors likely to influence CAC deposit. An analysis was undertaken to assess the cardiovascular risk factors that are capable of predicting CAC change over time. A retrospective analysis of CAC change was carried out in 55 asymptomatic men who underwent sequential electron beam computed tomographic measurement of CAC score a mean of 3.3 years apart. To ensure maximal accuracy in CAC change analysis, patients were included who had an initial CAC score of 10 or greater and with difference between both scores of 20% or greater of the initial score. The annual change rate in CAC score was calculated by dividing the change in CAC score by the interval between scores. Subjects' risk factors were analyzed and included body mass index, blood pressure, blood lipids and glucose, plasma lipoprotein(a) and fibrinogen, smoking status, and family history of coronary heart disease. The annual change rate in CAC score correlated positively with lipoprotein(a) (r = 0.42, p<0.01) and with initial CAC score (r = 0.46, p<0.001) and these associations persisted in multivariate analysis (p = 0.01, p = 0.001 respectively, R2 = 0.31). In contrast, no association existed between annual CAC change and baseline values and follow-up changes of other risk factors. The association of lipoprotein(a) with CAC progression in symptom-free patients with preexisting coronary calcifications provides new insights into the progression of coronary artery disease and may be useful for planning therapy and follow-up.

Stress, inflammation and cardiovascular disease

Various psychosocial factors have been implicated in the etiology and pathogenesis of certain cardiovascular diseases such as atherosclerosis, now considered to be the result of a chronic inflammatory process. In this article, we review the evidence that repeated episodes of acute psychological stress, or chronic psychologic stress, may induce a chronic inflammatory process culminating in atherosclerosis. These inflammatory events, caused by stress, may account for the approximately 40% of atherosclerotic patients with no other known risk factors. Stress, by activating the sympathetic nervous system, the hypothalamic-pituitary axis, and the renin-angiotensin system, causes the release of various stress hormones such as catecholamines, corticosteroids, glucagon, growth hormone, and renin, and elevated levels of homocysteine, which induce a heightened state of cardiovascular activity, injured endothelium, and induction of adhesion molecules on endothelial cells to which recruited inflammatory cells adhere and translocate to the arterial wall. An acute phase response (APR), similar to that associated with inflammation, is also engendered, which is characterized by macrophage activation, the production of cytokines, other inflammatory mediators, acute phase proteins (APPs), and mast cell activation, all of which promote the inflammatory process. Stress also induces an atherosclerotic lipid profile with oxidation of lipids and, if chronic, a hypercoagulable state that may result in arterial thromboses. Shedding of adhesion molecules and the appearance of cytokines, and APPs in the blood are early indicators of a stress-induced APR, may appear in the blood of asymptomatic people, and be predictors of future cardiovascular disease. The inflammatory response is contained within the stress response, which evolved later and is adaptive in that an animal may be better able to react to an organism introduced during combat. The argument is made that humans reacting to stressors, which are not life-threatening but are "perceived" as such, mount similar stress/inflammatory responses in the arteries, and which, if repetitive or chronic, may culminate in atherosclerosis.

Arterial stiffening and vascular calcifications in end-stage renal disease

BACKGROUND

Epidemiological studies have identified aortic stiffness as an independent predictor of cardiovascular mortality in end-stage renal disease (ESRD) patients. In these patients, aortic pulse wave velocity (PWV) was associated with mediacalcosis, but the influence of arterial calcifications on the viscoelastic properties of large arteries was not well characterized. The purpose of the present study was to analyse the influence of arterial calcifications on arterial stiffness in stable haemodialysed patients.

METHODS

We studied 120 stable ESRD patients on haemodialysis. All patients underwent B-mode ultrasonography of common carotid artery (CCA), aorta, and femoral arteries to determine CCA distensibility, the elastic incremental modulus (Einc), and the presence of vascular calcifications. All patients underwent measurement of aortic PWV and echocardiogram. The presence of calcifications was analysed semiquantitatively as a score (0 to 4) according to the number of arterial sites with calcifications.

RESULTS

Our observations indicate that arterial and aortic stiffness is significantly influenced by the presence and extent of arterial calcifications. The extent of arterial calcifications is in part responsible for increased left ventricular afterload, and is inversely correlated with stroke volume. The influence of calcifications is independent of the role of ageing and blood pressure. Arterial calcifications density increases with age, duration of haemodialysis, the fibrinogen level, and the prescribed dose of calcium-based phosphate binders.

CONCLUSIONS

The results of this study showed that the presence of vascular calcifications in ESRD patients was associated with increased stiffness of large capacity, elastic-type arteries, like the aorta and CCA. The extent of arterial calcifications increased with the use of calcium-based phosphate-binders.

Association of plasma viscosity and carotid thickening in a French working cohort

Plasma viscosity and intima-media thickness (IMT) are frequently associated with cardiovascular disease and its risk factors. We evaluated the association of rheologic and vascular factors in asymptomatic subjects. Plasma viscosity (coaxial cylinder viscometry) and both preintrusive and intrusive atherosclerosis in the carotid arteries (ultrasonography) were investigated in 246 men and 337 women aged 17 to 65 years from the AXA study, a prospective cohort of healthy workers. Plasma viscosity was positively related to age-adjusted mean bifurcation carotid artery IMT (P < .01 for men; P < .04 for women) and maximum carotid artery IMT (P < .01 for men; P < .02 for women), but not to mean common carotid artery IMT. Multivariate adjustment affected these relations to a greater extent in men than in women. The odds ratio (range) of having intrusive atherosclerosis in relation to 1 SD greater plasma viscosity was 2.27 (1.52 -3.38) in men and 1.63 (1.17-2.26) in women. Adjustment of age, waist-to-hip ratio, smoking, hypercholesterolemia, hypertension, diabetes, and fibrinogen had very little effect on the magnitude of these odds ratios. Thus, plasma viscosity was associated with carotid thickening, suggesting that rheologic factors are involved in the subclinical phase of atherosclerosis.

Statin + fibrate combination therapy fluvastatin with bezafibrate or ciprofibrate in high risk patients with vascular disease

We evaluated the use of combination therapy (ciprofibrate 100 mg or bezafibrate 400 mg plus fluvastatin 40 mg) in 23 patients (n = 13 in the ciprofibrate group) with established cardiovascular disease. Both treatments achieved a significant (P< or =0.01) decrease in the total cholesterol (TC) (32 and 21%), triglycerides (TG) (53 and 46%) and low-density lipoprotein (LDL) (36 and 26%) levels and the TC/high-density lipoprotein (HDL) (42 and 31%) and LDL/HDL (46 and 35%) ratios. HDL levels were increased (19% for both treatment groups), but this rise only achieved significance (P=0.01) in the ciprofibrate group. Although the two patient groups were not strictly matched, the reduction in serum TC and LDL levels was greater with ciprofibrate (32 and 36%, respectively; P< or =0.001) than with bezafibrate (21 and 26%, respectively; P< or =0.01). There was a significant reduction in plasma fibrinogen levels (36.4 and 13.5% in the ciprofibrate and bezafibrate group, respectively). None of the patients reported myalgia or had abnormal creatine kinase activity or liver function tests. Combination therapy is worth considering in high-risk patients because of the advantages associated with this option. Combination therapy is competitively priced when compared with high doses of statins. An end-point-based trial is needed.

Effect of HMG-CoA reductase inhibitors on coronary artery disease as assessed by electron-beam computed tomography

BACKGROUND

Angiographic studies of the regression of coronary artery disease are invasive and costly, and they permit only limited assessment of changes in the extent of atherosclerotic disease. Electron-beam computed tomography (CT) is noninvasive and inexpensive. The entire coronary-artery tree can be studied during a single imaging session, and the volume of coronary calcification as quantified with this technique correlates closely with the total burden of atherosclerotic plaque.

METHODS

We conducted a retrospective study of 149 patients (61 percent men and 39 percent women; age range, 32 to 75 years) with no history of coronary artery disease who were referred by their primary care physicians for screening electron-beam CT. All patients underwent base-line scanning and follow-up assessment after a minimum of 12 months (range, 12 to 15), and a volumetric calcium score was calculated as an estimate of the total burden of plaque. Treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors was begun at the discretion of the referring physician. Serial measurements of low-density lipoprotein (LDL) cholesterol were obtained, and the change in the calcium-volume score was correlated with average LDL cholesterol levels.

RESULTS

One hundred five patients (70 percent) received treatment with HMG-CoA reductase inhibitors, and 44 patients (30 percent) did not. At follow-up, a net reduction in the calcium-volume score was observed only in the 65 treated patients whose final LDL cholesterol levels were less than 120 mg per deciliter (3.10 mmol per liter) (mean [+/-SD] change in the score, -7+/-23 percent; P=0.01). Untreated patients had an average LDL cholesterol level of at least 120 mg per deciliter and at the time of follow-up had a significant net increase in mean calcium-volume score (mean change, +52+/-36 percent; P<0.001). The 40 treated patients who had average LDL cholesterol levels of at least 120 mg per deciliter had a measurable increase in mean calcium-volume score (25+/-22 percent, P<0.001), although it was smaller than the increase in the untreated patients.

CONCLUSIONS

The extent to which the volume of atherosclerotic plaque decreased, stabilized, or increased was directly related to treatment with HMG-CoA reductase inhibitors and the resulting serum LDL cholesterol levels. These changes can be determined noninvasively by electron-beam CT and quantified with use of a calcium-volume score.