Spontaneous Coronary Artery Dissection Resulting in Acute Myocardial Infarction With Cardiac Rupture.

Spontaneous coronary artery dissection occurs predominantly in women and is associated with fibromuscular dysplasia. We illustrate a rare case of sudden coronary death as a result of cardiac rupture from spontaneous coronary artery dissection in a 54-year-old man without fibromuscular dysplasia. Cardiac rupture has been previously reported in 6 cases, mostly in women.

CD163+ macrophages restrain vascular calcification, promoting the development of high-risk plaque.

Vascular calcification (VC) is concomitant with atherosclerosis, yet it remains uncertain why rupture-prone high-risk plaques do not typically show extensive calcification. Intraplaque hemorrhage (IPH) deposits erythrocyte-derived cholesterol, enlarging the necrotic core and promoting high-risk plaque development. Pro-atherogenic CD163+ alternative macrophages engulf hemoglobin:haptoglobin (HH) complexes at IPH sites. However, their role in VC has never been examined to our knowledge. Here we show, in human arteries, the distribution of CD163+ macrophages correlated inversely with VC. In vitro experiments using vascular smooth muscle cells (VSMCs) cultured with HH-exposed human macrophage - M(Hb) - supernatant reduced calcification, while arteries from ApoE-/- CD163-/- mice showed greater VC. M(Hb) supernatant-exposed VSMCs showed activated NF-κB, while blocking NF-κB attenuated the anticalcific effect of M(Hb) on VSMCs. CD163+ macrophages altered VC through NF-κB-induced transcription of hyaluronan synthase (HAS), an enzyme that catalyzes the formation of the extracellular matrix glycosaminoglycan, hyaluronan, within VSMCs. M(Hb) supernatants enhanced HAS production in VSMCs, while knocking down HAS attenuated its anticalcific effect. NF-κB blockade in ApoE-/- mice reduced hyaluronan and increased VC. In human arteries, hyaluronan and HAS were increased in areas of CD163+ macrophage presence. Our findings highlight an important mechanism by which CD163+ macrophages inhibit VC through NF-κB-induced HAS augmentation and thus promote the high-risk plaque development.

Generalized Arterial Calcification of Infancy (GACI): Optimizing Care with a Multidisciplinary Approach.

It is very unusual to see evidence of arterial calcification in infants and children, and when detected, genetic disorders of calcium metabolism should be suspected. Generalized arterial calcification of infancy (GACI) is a hereditary disease, which is characterized by severe arterial calcification of medium sized arteries, mostly involving the media with marked intimal proliferation and ectopic mineralization of the extravascular tissues. It is caused by inactivating variants in genes encoding either ENPP1, in a majority of cases (70-75%), or ABCC6, in a minority (9-10%). Despite similar histologic appearances between ENPP1 and ABCC6 deficiencies, including arterial calcification, organ calcification, and cardiovascular calcification, mortality is higher in subjects carrying the ENPP1 versus ABCC6 variants (40% vs 10%, respectively). Overall mortality in individuals with GACI is high (55%) before the age of 6 months, with 24.4% dying in utero or being stillborn. Rare cases show spontaneous regression with age, while others who survive into adulthood often manifest musculoskeletal complications (osteoarthritis and interosseous membrane ossification), enthesis mineralization, and cervical spine fusion. Despite recent advances in the understanding of the genetic mechanisms underlying this disease, there is still no ideal therapy for the resolution of vascular calcification in GACI. Although bisphosphonates with anti-calcification properties have been commonly used for the treatment of CAGI, their benefit is controversial, with favorable results reported at one year and questionable benefit with delayed initiation of treatment. Enzyme replacement therapy with administration of recombinant form of ENPP1 prevents calcification and mortality, improves hypertension and cardiac function, and prevents intimal proliferation and osteomalacia in mouse models of ENPP1 deficiency. Therefore, newer treatments targeting genes are on the horizon. In this article, we review up to date knowledge of the understanding of GACI, its clinical, pathologic, and etiologic understanding and treatment in support of more comprehensive care of GACI patients.

Pathology of stent implantation in internal mammary artery.

The internal mammary artery (IMA) is the most durable conduit for bypassing the left anterior descending (LAD) coronary artery in patients undergoing coronary artery bypass graft surgery (CABG). However, little is known about how the IMA reacts histologically to stent implantation. From CVPath stent registry (1048 lesions, 614 cases), we obtained 4 stent lesions (2 bare metal stents, 2 drug-eluting stents) involving IMA grafts. The mean age of our patients was 63 years and the duration of stent implantation in the IMA ranged from 5 days to 5 years. Stented arteries were dissected from hearts and embedded in plastic, segmented at 3 mm intervals, sectioned at 4-6 microns and stained with H&E and Movat pentachrome stains. Histological observations were performed. Majority of stents (3 of 4) were implanted in anastomosis between IMA and LAD while 1 stent was implanted in IMA body. One stent with duration of 5 days showed stent thrombosis while others were all patent with fully coverage by varying degrees of neointima. Foamy macrophage, lipid pool and calcification in neointima were observed in 1 stent with duration of 5 years but it was limited only to the distal LAD part within the stented segment. Overall, in this small pathologic series, the majorities of stents were implanted in IMA-to-LAD anastomosis site and demonstrated acceptable pathologic responses.

Quantitative measurement of lipid rich plaque by coronary computed tomography angiography: A correlation of histology in sudden cardiac death.

BACKGROUND AND AIMS: Recent advancements in coronary computed tomography angiography (CCTA) have allowed for the quantitative measurement of high-risk lipid rich plaque. Determination of the optimal threshold for Hounsfield units (HU) by CCTA for identifying lipid rich plaque remains unknown. We aimed to validate reliable cut-points of HU for quantitative assessment of lipid rich plaque. METHODS: 8 post-mortem sudden coronary death hearts were evaluated with CCTA and histologic analysis. Quantitative plaque analysis was performed in histopathology images and lipid rich plaque area was defined as intra-plaque necrotic core area. CCTA images were analyzed for quantitative plaque measurement. Low attenuation plaque (LAP) was defined as any pixel < 30, 45, 60, 75, and 90 HU cut-offs within a coronary plaque. The area of LAP was calculated in each cross-section. RESULTS: Among 105 cross-sections, 37 (35.2%) cross-sectional histology images contained lipid rich plaque. Although the highest specificity for identifying lipid rich plaque was shown with <30 HU cut-off (88.2%), sensitivity (e.g. 55.6% for <75 HU, 16.2% for <30 HU) and negative predictive value (e.g. 75.9% for <75 HU, 65.9% for <30 HU) tended to increase with higher HU cut-offs. For quantitative measurement, <75 HU showed the highest correlation coefficient (0.292, p = 0.003) and no significant differences were observed between lipid rich plaque area and LAP area between histology and CT analysis (Histology: 0.34 ±â€¯0.73 mm2, QCT: 0.37 ±â€¯0.71 mm2, p = 0.701). CONCLUSIONS: LAP area by CCTA using a <75 HU cut-off value demonstrated high sensitivity and quantitative agreement with lipid rich plaque area by histology analysis.

CD163+ macrophages promote angiogenesis and vascular permeability accompanied by inflammation in atherosclerosis.

Intake of hemoglobin by the hemoglobin-haptoglobin receptor CD163 leads to a distinct alternative non-foam cell antiinflammatory macrophage phenotype that was previously considered atheroprotective. Here, we reveal an unexpected but important pathogenic role for these macrophages in atherosclerosis. Using human atherosclerotic samples, cultured cells, and a mouse model of advanced atherosclerosis, we investigated the role of intraplaque hemorrhage on macrophage function with respect to angiogenesis, vascular permeability, inflammation, and plaque progression. In human atherosclerotic lesions, CD163+ macrophages were associated with plaque progression, microvascularity, and a high level of HIF1α and VEGF-A expression. We observed irregular vascular endothelial cadherin in intraplaque microvessels surrounded by CD163+ macrophages. Within these cells, activation of HIF1α via inhibition of prolyl hydroxylases promoted VEGF-mediated increases in intraplaque angiogenesis, vascular permeability, and inflammatory cell recruitment. CD163+ macrophages increased intraplaque endothelial VCAM expression and plaque inflammation. Subjects with homozygous minor alleles of the SNP rs7136716 had elevated microvessel density, increased expression of CD163 in ruptured coronary plaques, and a higher risk of myocardial infarction and coronary heart disease in population cohorts. Thus, our findings highlight a nonlipid-driven mechanism by which alternative macrophages promote plaque angiogenesis, leakiness, inflammation, and progression via the CD163/HIF1α/VEGF-A pathway.

Very Late Pathological Responses to Cobalt-Chromium Everolimus-Eluting, Stainless Steel Sirolimus-Eluting, and Cobalt-Chromium Bare Metal Stents in Humans.

BACKGROUND: The "very late" clinical outcomes for durable polymer drug-eluting stents and bare metal stents (BMSs) have been shown to be dissimilar in clinical studies. Conceptually, the long-term vascular compatibility of BMSs is still regarded to be superior to drug-eluting stents; however, no pathologic study to date has specifically addressed this issue. We evaluated the very late (≥1 year) pathologic responses to durable polymer drug-eluting stents (cobalt-chromium [CoCr] everolimus-eluting stents [EESs] and stainless steel sirolimus-eluting stents [SS-SESs]) versus BMSs (CoCr-BMSs). METHODS AND RESULTS: From the CVPath stent registry, we studied a total of 119 lesions (40 CoCr-EESs, 44 SS-SESs, 35 CoCr-BMSs) from 92 autopsy cases with a duration ranging from 1 to 5 years. Sections of stented coronary segments were pathologically analyzed. Inflammation score and the percentage of struts with giant cells were lowest in CoCr-EESs (median inflammation score: 0.6; median percentage of struts with giant cells: 3.8%) followed by CoCr-BMSs (median inflammation score: 1.3 [P<0.01]; median percentage of struts with giant cells: 8.9% [P=0.02]) and SS-SESs (median inflammation score: 1.7 [P<0.01]; median percentage of struts with giant cells: 15.3% [P<0.01]). Polymer delamination was observed exclusively in SS-SESs and was associated with increased inflammatory and giant cell reactions. The prevalence of neoatherosclerosis with CoCr-EESs (50%) was significantly less than with SS-SESs (77%, P=0.02) but significantly greater than with CoCr-BMSs (20%, P<0.01). CONCLUSIONS: CoCr-EESs, SS-SESs, and BMSs each demonstrated distinct vascular responses. CoCr-EESs demonstrated the least inflammation, near-equivalent healing to BMSs, and lower neointimal formation. These results challenge the belief that BMSs have superior biocompatibility compared with some polymeric coated drug-eluting stents and may have implications for future stent design.

Pathology of balloon-expandable transcatheter aortic valves.

BACKGROUND: The Placement of AoRtic TraNscathetER Valves trials (PARTNER) showed favorable safety and efficacy versus medical or surgical therapy in inoperable, high, and intermediate surgical risk patients with severe aortic stenosis. However, the biological responses to transcatheter aortic valves have not been well characterized. OBJECTIVES: The aim of this study was to perform pathologic assessment of Edwards SAPIEN transcatheter aortic valves removed either at autopsy or surgically during the PARTNER I and II clinical trials. METHODS: Explanted valves and frame were evaluated for pathologic responses including extent of thrombus, inflammation, neointima, and leaflet degeneration/calcification according to semiquantitative grading by implant duration (≤30 days; 31-90 days; >90 days). RESULTS: A total of 22 cases (median age 82.0 years, 45% men) were included, with a duration of implantation that ranged from 0 to 1739 days (median duration 16.5 days [interquartile range, 2.8-68.3]). Valve thrombosis resulting in severe aortic stenosis was observed in one case. Moderate leaflet thrombus was seen in 14% of cases (n = 3) and all were asymptomatic. Calcification was seen in two valves: one with severe leaflet calcification had severe aortic stenosis requiring surgical replacement, while the other showed early calcification. Mild structural leaflet changes were exclusively seen in valve implants >90 days. Valve inflammation and thrombus formation was mild in majority of the cases. CONCLUSIONS: Overall, our study demonstrates moderate thrombus formation in 14% and calcification in only 2 valves, ≥4 years duration. In this short-duration study, acceptable durability and biocompatibility of the Edwards SAPIEN transcatheter valve system was demonstrated; however, further studies are required to confirm the significance and application of our findings.

Histopathological Differential Diagnosis of Optical Coherence Tomographic Image Interpretation After Stenting.

OBJECTIVES: The aim of this study was to identify histological features that correlate with terms commonly used to describe optical coherence tomographic (OCT) and optical frequency-domain imaging (OFDI) images of stented vessels, by means of a histopathological validation study using stented human coronary arteries. BACKGROUND: OCT imaging and OFDI are used to evaluate vascular responses to stent implantation. Descriptive terms such as "peristrut low attenuation" and "heterogeneous" have been used to describe neointimal characteristics that may have clinical relevance. However, only limited histopathological correlations are available. METHODS: Using the CVPath stent registry, 19 cases were identified in whom implantation duration was >30 days and OCT imaging or OFDI and histological findings were available. Consecutive OCT or OFDI frames (n = 1,063) of stented coronary arteries were categorized according to their predominant imaging features in 1-mm intervals. Coregistration of OCT or OFDI frames and histopathological cross sections was performed in 111 frames. RESULTS: Seven distinct OCT or OFDI patterns were found: homogenous (45%), layered (15%), high intensity with high attenuation (14%), intraluminal protruding masses (8%), peristrut low attenuation (7%), heterogeneous (2%), and honeycomb (1%). Histopathologically, the homogenous pattern correlated most often with smooth muscle cells within collagenous/proteoglycan matrix and less often with organized thrombus. The layered pattern correlated with healed neointimal rupture or erosion, peristrut neovascularization, or smooth muscle cells within collagen/proteoglycan matrix. High intensity with high attenuation correlated with superficial macrophage accumulation in the majority of cases, but with other histological findings in 30% of cases. The diagnostic accuracy was greater in restenotic lesions. The only OCT or OFDI finding that had a single histological feature was the honeycomb pattern. CONCLUSIONS: This study suggests a lack of correlation between OCT image patterns and distinct histological tissue characteristics.

Comparison of pathology of chronic total occlusion with and without coronary artery bypass graft.

AIMS: The aim of our study was to investigate chronic total occlusion (CTO) in human coronary arteries to clarify the difference between CTO with prior coronary artery bypass graft (CABG) and those without prior CABG. METHODS AND RESULTS: A total of 95 CTO lesions from 82 patients (61.6 ± 14.0 years, male 87.8%) were divided into the following three groups: CTO with CABG (n = 34) (CTO+CABG), CTO without CABG--of long-duration (n = 49) (LD-CTO) and short-duration (n = 12) (SD-CTO). A histopathological comparison of the plaque characteristics of CTO, proximal and distal lumen morphology, and negative remodelling between groups was performed. A total of 1127 sections were evaluated. Differences in plaque characteristics were observed between groups as follows: necrotic core area was highest in SD-CTO (18.6%) (LD-CTO: 7.8%; CTO+CABG: 4.5%; P = 0.02); calcified area was greatest in CTO+CABG (29.2%) (LD-CTO: 16.8%; SD-CTO: 12.1%; P = 0.009); and negative remodelling was least in SD-CTO [remodelling index (RI) 0.86] [CTO+CABG (RI): 0.72 and LD-CTO (RI): 0.68; P < 0.001]. Approximately 50% of proximal lumens showed characteristics of abrupt closure, whereas the majority of distal lumen patterns were tapered (79%) (P < 0.0001). CONCLUSION: These pathological differences in calcification, negative remodelling, and presence of necrotic core along with proximal and distal tapering, which has been associated with greater success, help explain the differences in success rates of percutaneous coronary intervention in CTO patients with and without CABG.

Adventitial lymphocytic inflammation in human coronary arteries with intimal atherosclerosis.

BACKGROUND: The relationship between adventitial inflammation, plaque type, and culprit plaque morphology in the epicardial arterial circulation has not been studied in detail. METHODS: We studied semiserial sections of coronary arteries at autopsy from patients dying with severe coronary disease, 81 men (age 50 + or - 12 years) and 13 women (age 52 + or - 13 years). Lesions were classified at 3- to 5-mm segments according to modified AHA criteria. Adventitial lymphocyte aggregates were assessed at every 5-mm interval and graded semiquantitatively. Macrophage density in the adventitial fat and intima was assessed with anti-CD68 staining. RESULTS: Adventitial lymphocytic inflammation increased with percent stenosis (P<.0001) and not calcification (P>.2). Hemorrhage into late core, rupture, erosion, and thin caps all had greater adventitial lymphocytic inflammation independent of percent stenosis (P<.0001). Peri-adventitial adipose macrophage density was increased in plaques with atheromas (206 + or - 22 mm(2) vs. 121 + or - 15 mm(2) in fibrous plaques; P=.02) and correlated positively with adventitial lymphocytes (P<.0001) and intimal macrophage content (P<.0001). CONCLUSIONS: Features associated with plaque instability are associated with significantly greater degrees of adventitial lymphocytic inflammation, both as lymphocyte aggregates and as adipocyte-derived macrophages. Further study is required to determine the nature of the association between intimal and adventitial lymphocytic inflammation.

Cardiac inflammatory myofibroblastic tumor: a "benign" neoplasm that may result in syncope, myocardial infarction, and sudden death.

Cardiac tumors other than myxomas are rare. We report a series of 10 intracavitary polypoid myofibroblastic proliferations in children and young adults emphasizing gross, histologic, and clinical features. There were 6 females and 4 males, with a mean age of 10 years (range 5 wk to 21 y). All lesions were endocardial-based, located in the right atrium (1), right ventricular inflow/tricuspid valve (1), right ventricular outflow (3), mitral valve (3), aortic valve/left coronary sinus (1), and left ventricular free wall (1). Symptoms included shortness of breath or dyspnea (3), syncope (2), chest pain (1), transient ischemic attacks (1), and fever with myalgias (1). All tumors were surgical resections, except 1 tumor that resulted in sudden coronary death and that was diagnosed at autopsy, and 1 tumor that embolized into the coronary artery and was treated by cardiac transplant. Two tumors, present in the aortic and mitral valves, respectively, caused cardiac ischemia. The tumors were polypoid or filiform and histologically resembled inflammatory myofibroblastic tumors of extracardiac sites, with loose spindle cell growth with sparse inflammation. Although there were frequent collagen bundles interspersed among the tumor cells, there were no large areas of dense fibrosis. Surface fibrin was present on the polypoid projections in 7 cases. Symptoms resulted from prolapse into coronary ostia or embolization, but no patient developed metastasis. Long-term follow-up in 2 patients demonstrated no evidence of disease or recurrence. Although metastatic potential was not identified, these tumors may result in serious symptoms, including myocardial infarct, syncope, and sudden death. These cardiac myofibroblastic tumors are readily distinguished from other endocardial-based cardiac tumors, including papillary fibroelastoma and myxoma, which may present clinically in the same manner.

Characterization of intimal changes in coronary artery specimens with MR microscopy.

PURPOSE: To determine if magnetic resonance (MR) microscopy can yield images sufficient for discriminating early progressive atherosclerotic lesions from nonprogressive atherosclerotic lesions in human coronary arteries. MATERIALS AND METHODS: Institutional review board approval and informed consent were not required. Seventeen coronary artery segments (mean diameter, 2.8 mm +/- 1.0 [standard deviation]) were collected within 36 hours after death from 11 cadavers (six men, five women; age range at death, 33-65 years). Quantitative T1, T2, intensity-weighted (IW), and magnetization transfer (MT) maps were acquired with a 9.4-T vertical-bore magnet. Coronary artery lesions were classified as adaptive intimal thickening (AIT), pathologic intimal thickening (PIT), or intimal xanthoma (IXA). Internal anatomic fiducial landmarks and stains were applied to proximal and epicardial vessel surfaces and used to register histologic sections with MR images and thus enable comparison of MR images and Movat pentachrome-stained histologic specimens. Unique 0.0012-0.0287-cm(2) regions of interest were visually identified on quantitative T1, T2, MT, and IW maps of AIT, IXA, and PIT lesions. Distributions of T1, T2, MT, and IW values were compared with Student t and Wilcoxon two-sample tests. RESULTS: MR microscopic images of nonprogressive AIT and IXA lesions revealed two intimal layers. The luminal intima had higher T1 and T2 values and lower MT values than did the medial intima; these findings were consistent with compositional differences observed in histologic sections. In the IXA lesion, T2 values of both intimal layers were markedly reduced when compared with T2 values of AIT lesions because of the accumulation of lipid-laden macrophages in both layers. Progressive PIT lesions had a typical multilayered appearance or foci with a short T2 relaxation time and low IW values; these features were not observed in AIT or IXA lesions. CONCLUSION: MR microscopy enabled identification of morphologic arterial wall features that enable discrimination of progressive PIT lesions from nonprogressive AIT or IXA lesions.

Lipoprotein-associated phospholipase A2 protein expression in the natural progression of human coronary atherosclerosis.

OBJECTIVE: Although lipoprotein-associated phospholipase A2 (Lp-PLA2) has received recent attention as a biomarker of inflammation and risk for acute coronary events, its relative expression in coronary plaque phenotypes, including unstable lesions, has not been established. METHODS AND RESULTS: Coronary segments (n=30) were prospectively collected from 25 sudden coronary death patients for immunolocalization of Lp-PLA2. Lesion morphologies were classified as pathologic intimal thickening, fibroatheromas, thin-cap fibroatheromas (fibrous cap thicknesses <65 microm), and rupture. The expression of Lp-PLA2 was detected using a specific monoclonal antibody. Apoptosis was identified by DNA end-labeling using terminal deoxynucleotidyl transferase (TdT). Lp-PLA2 staining in early plaques was absent or minimally detected. In contrast, thin-cap fibroatheromas and ruptured plaques showed intense Lp-PLA2 expression within necrotic cores and surrounding macrophages including those in the fibrous cap. The degree of macrophage apoptosis was greater in thin-cap fibroatheroma and ruptures compared with less advanced plaques with additional double labeling studies showing Lp-PLA2 present in apoptotic cells in regions of high macrophage density. CONCLUSIONS: Lp-PLA2 is strongly expressed within the necrotic core and surrounding macrophages of vulnerable and ruptured plaques, with relatively weak staining in less advanced lesions. These findings together with the association of Lp-PLA2 in apoptotic macrophages suggest a potential role in promoting plaque instability.

Left ventricular noncompaction: a pathological study of 14 cases.

Left ventricular noncompaction (LVNC) has been recently proposed as a specific form of cardiomyopathy. There have been few pathological series describing gross and microscopic findings of this entity, especially in children. We present findings of 14 hearts (13 autopsy and 1 explant) with LVNC (isolated and associated with congenital heart disease), defined by poorly developed left ventricular (LV) papillary muscles and a noncompact inner LV myocardial layer comprising more than 50% of the LV thickness. The mean age at death/explant was 3.6 years (median, 2.5 months); there were 6 boys and 8 girls. The symptoms were sudden unexpected death (10) and heart failure (4). The diagnosis was suspected before death in only 1 of 13 autopsy cases. Right ventricular involvement (> 75% ventricular thickness comprised of noncompacted area with recess adjacent to tricuspid valve) was seen in 6 of 14 hearts. One patient had a sibling with pulmonary stenosis, but there was no other known familial cardiomyopathy. Endocardial fibroelastosis was a characteristic histological feature, as well as anastomosing or polypoid endocardial trabeculations, which resulted in staghorn-shaped, endocardial-lined recesses. There was a high rate of other cardiac anomalies, which often coexisted and were not clearly related to the LVNC, present in 8 cases (nonisolated LVNC): ventricular septal defect (4/14), anomalous venous pulmonary veins (1/14), coronary ostial stenosis (1/14), histiocytoid cardiomyopathy (1/14), polyvalvar dysplasia (2/14), and pulmonary stenosis (2/14). In the 6 isolated LVNC, there were 2 malformed atrioventricular valves (1 mitral and 1 tricuspid), which appeared part of the ventricular maldevelopment. There were no differences in histological or gross patterns of the noncompacted regions between the isolated and nonisolated LVNC. LVNC is frequently associated with other cardiac defects, especially when causing sudden death in infants and children. A clear-cut morphological distinction between "isolated" and "secondary" LVNC was not apparent. The pathologist should be aware of the entity because the diagnosis is often first established at autopsy.

Multiple spontaneous coronary artery dissections in association with anomalous origin of right coronary and intramural coronary artery dysplasia.

We present a case of sudden death due to spontaneous acute coronary artery dissection. In addition, there was a healing spontaneous coronary dissection, intramural coronary artery dysplasia, and an anomalous origin of the right coronary artery from the pulmonary trunk. The coincidence of multiple spontaneous coronary dissections, coronary arterial dysplasia, and anomalous origin of the right coronary artery is unique.

Intraplaque hemorrhage and progression of coronary atheroma.

BACKGROUND: Intraplaque hemorrhage is common in advanced coronary atherosclerotic lesions. The relation between hemorrhage and the vulnerability of plaque to disruption may involve the accumulation of free cholesterol from erythrocyte membranes. METHODS: We stained multiple coronary lesions from 24 randomly selected patients who had died suddenly of coronary causes with an antibody against glycophorin A (a protein specific to erythrocytes that facilitates anion exchange) and Mallory's stain for iron (hemosiderin), markers of previous intraplaque hemorrhage. Coronary lesions were classified as lesions with pathologic intimal thickening, fibrous-cap atheromas with cores in an early or late stage of necrosis, or thin-cap fibrous atheromas (vulnerable plaques). The arterial response to plaque hemorrhage was further defined in a rabbit model of atherosclerosis. RESULTS: Only traces of glycophorin A and iron were found in lesions with pathologic intimal thickening or fibrous-cap atheromas with cores in an early stage of necrosis. In contrast, fibroatheromas with cores in a late stage of necrosis or thin caps had a marked increase in glycophorin A in regions of cholesterol clefts surrounded by iron deposits. Larger amounts of both glycophorin A and iron were associated with larger necrotic cores and greater macrophage infiltration. Rabbit lesions with induced intramural hemorrhage consistently showed cholesterol crystals with erythrocyte fragments, foam cells, and iron deposits. In contrast, control lesions from the same animals had a marked reduction in macrophages and lipid content. CONCLUSIONS: By contributing to the deposition of free cholesterol, macrophage infiltration, and enlargement of the necrotic core, the accumulation of erythrocyte membranes within an atherosclerotic plaque may represent a potent atherogenic stimulus. These factors may increase the risk of plaque destabilization.

Elevated C-reactive protein values and atherosclerosis in sudden coronary death: association with different pathologies.

BACKGROUND: Elevations in serum C-reactive protein measured by high-sensitivity assay (hs-CRP) have been associated with unstable coronary syndromes. There have been no autopsy studies correlating hs-CRP to fatal coronary artery disease. METHODS AND RESULTS: Postmortem sera from 302 autopsies of men and women without inflammatory conditions other than atherosclerosis were assayed for hs-CRP. There were 73 sudden deaths attributable to atherothrombi, 71 sudden coronary deaths with stable plaque, and 158 control cases (unnatural sudden deaths and noncardiac natural deaths without conditions known to elevate CRP). Atherothrombi were classified as plaque ruptures (n=55) and plaque erosion (n=18); plaque burden was estimated in each heart. Total cholesterol, high-density lipoprotein cholesterol, diabetes, smoking history, and body mass index were also determined. Immunohistochemical stains for CRP and numbers of thin cap atheromas per heart were quantitated in coronary deaths with hs-CRP in the highest and lowest quintiles. The median hs-CRP was 3.2 microg/mL in acute rupture, 2.9 microg/mL in plaque erosion, 2.5 microg/mL in stable plaque, and 1.4 microg/mL in controls. Mean log hs-CRP was higher in rupture (P<0.0001), erosion (P=0.005), and stable plaque (P=0.0003) versus controls. By multivariate analysis, atherothrombi (P=0.02), stable plaque (P=0.003), and plaque burden (P=0.03) were associated with log hs-CRP independent of age, sex, smoking, and body mass index. Mean staining intensity for CRP of macrophages and lipid core in plaques was significantly greater in cases with high hs-CRP than those with low CRP (P=0.0001), as were mean numbers of thin cap atheromas (P<0.0001). CONCLUSIONS: hs-CRP is significantly elevated in patients dying suddenly with severe coronary artery disease, both with and without acute coronary thrombosis, and correlates with immunohistochemical staining intensity and numbers of thin cap atheroma.