Unstable angina and progression of coronary atherosclerosis

We studied the progression of atherosclerotic coronary lesions in 38 patients who had previously undergone angiography and were later hospitalized for an episode of unstable angina pectoris, and in 38 matched patients with stable angina who had also undergone prior catheterization. Patients with unstable angina and those with stable angina were similar in terms of age (mean, 49 and 50 years, respectively), number of risk factors (1.5 per patient in both groups), interval between studies (mean +/- S.D., 44 +/- 31 and 35 +/- 31 months, respectively), number of diseased vessels on the first angiogram (1.52 in both groups), and initial ejection fraction (65 and 63 per cent, respectively). Progression of coronary lesions was demonstrated in 29 of the 38 patients with unstable angina, as compared with 12 of the 38 with stable angina (P less than 0.0005). Progression to 70 per cent or more stenosis was recorded in 21 of the patients with unstable angina but in only 5 of those with stable angina (P less than 0.0005). Also more frequent in the patients with unstable angina were multifocal progression (11 vs. 2, P less than 0.01) and progression of the left main or preseptal left anterior descending artery or both (9 vs. 1, P less than 0.01). Thus, we have demonstrated by angiography that unstable angina is associated with progression in the extent and severity of coronary atherosclerosis.     

Subendocardial ischemic myocardial lesions associated with severe coronary atherosclerosis.

Morphologic changes in the subendocardial myocardium that appeared to be caused by severe, chronic subendocardial ischemia were studied in patients with fatal ischemic heart disease admitted to the Specialized Center of Research for Ischemic Heart Disease at the University of Alabama in Birmingham in the period 1970--1977. Thirteen patients were selected for this report on the basis that they had the lesions in the subendocardial myocardium we believe to have been caused by subendocardial ischemia and had no evidence of acute or remote myocardial infarction or other conditions that may have contributed to their terminal illness or death. Clinical findings were unstable angina, congestive heart failure, usually no increase in plasma enzymes indicative of myocardial damage, and electrocardiographic changes consistent with subendocardial ischemia. All 13 patients had 75% or greater stenosis of the three major coronary arteries; none had acute thrombotic or embolic coronary artery occlusion. The left ventricle in all cases was hypertrophied. The subendocardial myocardium showed circumferential pallor, hyperemia, or focal fibrosis without perceptible loss of volume in papillary muscles or trabeculae carneae. Microscopically, acute lesions showed one to two layers of preserved myofibers adjacent to the endocardium, vacuolar change in the deeper fibers, and focal areas of coagulation necrosis of variable size in the myocardium external to the fibers with vacuolar change. Coagulation necrosis was extensive in some cases and usually was not associated with infiltration of neutrophils. The repair reaction involved removal of necrotic sarcoplasm by mononuclear phagocytes, resulting in a reticular-appearing tissue without evidence of stromal collapse. Granulation tissue was not seen. Collagen fibers appeared to be deposited within the area of previous sarcolemmal sheaths. The distribution and morphology of subendocardial myocardial lesions associated with severe coronary atherosclerosis are distinctive and can be distinguished from myocardial necrosis or fibrosis associated with acute total occlusion of a coronary artery.     

Atherogenic lipoproteins found in the blood of patients with coronary atherosclerosis are desialylated low-density lipoproteins

Institute of Experimental Cardiology, All-Union Cardiologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Smirnov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 8, pp. 138–140, August, 1990.     

The mainstream hypothesis that LDL cholesterol drives atherosclerosis may have been falsified by non-invasive imaging of coronary artery plaque burden and progression

That LDL cholesterol drives atherosclerosis is a widely if not almost universally held belief, and this belief strongly influences the mainstream approach to coronary heart disease. However heart disease has a number of stages, and in terms of primary prevention, the initiation and progression of silent or sub-clinical atherosclerosis is clearly fundamental. However, studies that address the efficacy of interventions and practices aimed at the primary prevention of heart disease almost always use event-based endpoints such as fatal or non-fatal myocardial infarction or unstable angina. These endpoints do not directly relate to the primary prevention of silent atherosclerosis and to apply these results to asymptomatic individuals in this context involves an extrapolation.The advent of non-invasive imaging techniques which allow the determination of coronary artery plaque burden and progression of plaque has provided a unique opportunity to examine the relationship between both traditional and emerging risk factors and the extent of sub-clinical coronary artery disease and in particular allow the testing of the hypothesis that LDL cholesterol drives coronary atherosclerosis. Consistent with earlier autopsy studies, the use of electron beam tomography and contrast enhanced CT angiography techniques have created a large body of evidence which appears to falsify this hypothesis. The large number of null results for the association between serum LDL cholesterol levels and the prevalence or progression of both calcified and non-calcified plaque in the appropriate vascular bed and involving large numbers of men and women over a wide range of age, ethnic background, plaque burden and cholesterol levels cannot be easily dismissed. If the hypothesis is false, this has a significant impact on currently held views regarding risk factors and therapeutic interventions in the case of individuals who are asymptomatic, that is, issues associated with primary prevention. Also, if the hypothesis is false, then the use of changes in LDL as a surrogate marker for judging the importance of various risk factors for silent atherosclerosis and thus coronary artery disease can be called into question.     

Accelerated atherosclerosis in ApoE deficient lupus mouse models

The accelerated development of atherosclerosis with increased risk of cardiovascular disease in systemic lupus erythematosus (SLE) patients is not well understood. An appropriate mouse model would greatly help to understand the mechanisms of this association. We have therefore combined the ApoE(-/-) model of atherosclerosis with three different murine models of SLE. We found that induction of cGVH in B6.ApoE(-/-) mice, breeding a Fas null gene onto the B6.ApoE(-/-) mice, and breeding the ApoE(-/-) defect onto MRL/lpr mice all caused a modest increase of atherosclerosis at 24 weeks of age compared to B6.ApoE(-/-) controls. B cells in B6.ApoE(-/-) mice had certain phenotypic differences compared to congenic C57BL/6 mice, as indicated by high expression of MHC II, Fas, CD86, and by increased number of cells bearing marginal zone phenotype. Furthermore, B6ApoE(-/-) mice had significant titers of anti-oxLDL and anti-cardiolipin autoantibodies compared to their B6 counterparts. Our studies also indicate that, following induction of cGVH, marginal zone B cells in B6.ApoE(-/-) are depleted, and there is considerable increase in anti-oxLDL and anti-cardiolipin abs along with secretion of lupus-specific autoantibodies, such as anti-dsDNA and anti-chromatin abs. Histological sections showed that cGVH and/or Fas deficiency could exacerbate atherosclerosis. The production of anti-oxLDL and anti-cardiolipin in ApoE(-/-) mice was also increased. These observations define a connection between induction of lupus-like symptoms and development of severe atherosclerosis in ApoE deficient lupus mouse models.     

Anti-endothelial cell antibodies in patients with coronary atherosclerosis

Anti-endothelial cell antibodies (AECA) have been shown to possess endothelial cell activation properties and to harbor pathogenic potential in experimental animal models of autoimmune systemic disorders. Atherosclerosis is a form of an inflammatory condition in which the immune system has been shown to be involved. The aim of the present study was to assess the presence of AECA in patients with coronary atherosclerosis. A total of 134 patients admitted for chest pain of suspected anginal origin were evaluated for coronary artery atherosclerosis by angiography. Sera were drawn prior to the procedure for the determination of AECA employing cyto-ELISA. AECA positive sera were further evaluated for its ability to promote in vitro E-selectin expression by HUVEC using a cell-based ELISA. Patients with no coronary artery involvement had levels of AECA that did not differ from those obtained for patients with confirmed coronary atherosclerosis (one, two or three vessel disease). Furthermore, AECA positive sera from patients, with or without coronary atherosclerosis displayed similar capacity of inducing E-selectin expression by endothelial cells. AECA may not stand as an optimal mean of discriminating atherosclerotic from non-atherosclerotic patients. The ability of AECA to activate endothelial cells is also not unique to patients with atherosclerosis and is evident also in age-matched control subjects.     

Diet, lipoproteins, and the progression of coronary atherosclerosis. The Leiden Intervention Trial

We studied the relation between diet, serum lipoproteins, and the progression of coronary lesions in 39 patients with stable angina pectoris in whom coronary arteriography had shown at least one vessel with 50 per cent obstruction before intervention. Intervention consisted of a two-year vegetarian diet that had a ratio of polyunsaturated to saturated fatty acids of at least 2 and that contained less than 100 mg of cholesterol per day. Dietary changes were associated with a significant increase in linoleic acid content of cholesteryl esters and a significant lowering of body weight, systolic blood pressure, serum total cholesterol, and the ratio of total to high-density lipoprotein (total/HDL) cholesterol. Angiographic examination was performed after 24 months; angiograms were assessed visually (with blinding) and by computer-assisted image analysis. Both types of assessment indicated progression of disease in 21 of 39 patients but no lesion growth in 18. Coronary lesion growth correlated with total/HDL cholesterol (r = 0.50, P = 0.001) but not with blood pressure, smoking status, alcohol intake, weight, or drug treatment. Disease progression was significant in patients who had values for total/HDL cholesterol that were higher than the median (greater than 6.9) throughout the trial period. No coronary-lesion growth was observed in patients who had lower values for total/HDL cholesterol (less than 6.9) throughout the trial or who initially had higher values (greater than 6.9) that were significantly lowered by dietary intervention.     

Clonality analysis suggests that STK11 gene mutations are involved in progression of lobular endocervical glandular hyperplasia (LEGH) to minimal deviation adenocarcinoma (MDA)

Lobular endocervical glandular hyperplasia (LEGH) is a benign proliferative disease of cervical glands. Although histological resemblance of minimal deviation adenocarcinoma (MDA) to LEGH and frequent association of LEGH with MDA have been reported, it still remains unclear whether LEGH is a precancerous lesion of MDA. The present study was undertaken to examine the pathogenetic relationship between LEGH and MDA using a clonality analysis and mutational analyses of the STK11 gene, of which mutations have been reported in MDA. Of nine cases of LEGH only, four were polyclonal and five were monoclonal in composition. Of six LEGH lesions associated with MDA or adenocarcinoma, two were polyclonal and four were monoclonal. In cases of MDA or adenocarcinoma coexisting with LEGH, the patterns of X chromosome inactivation in malignant lesions were identical to those in coexisting LEGH lesions. A mutation of STK11 was only identified in one MDA, but not in LEGH. These results indicate that a subset of LEGH may be a precursor to malignant tumors including MDA and that a mutation of STK11 may be involved in progression of LEGH to MDA.