Biomedical subjects

Robert Kutys

Publications and source records attributed to Robert Kutys.

11 recordsLinked to original sources

PubMed2006

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.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

PubMed2006

Pathology of drug-eluting stents in humans: delayed healing and late thrombotic risk.

OBJECTIVES: This study examined human drug-eluting stents (DES) to determine the long-term effects of these stents on coronary arterial healing and identified mechanisms underlying late stent thrombosis (LST). BACKGROUND: Although DES reduce the need for repeat revascularization compared with bare-metal stents (BMS), data suggest the window of thrombotic risk for Cypher (Cordis Corp., Miami Lakes, Florida) and Taxus (Boston Scientific Corp., Natick, Massachusetts) DES extends far beyond that for BMS. METHODS: From a registry of 40 autopsies of DES (68 stents), 23 DES cases of >30 days duration were compared with 25 matched autopsies of BMS implantation. Late stent thrombosis was defined as an acute thrombus within a stent >30 days old. RESULTS: Of 23 patients with DES >30 days old, 14 had evidence of LST. Cypher and Taxus DES showed greater delayed healing characterized by persistent fibrin deposition (fibrin score 2.3 +/- 1.1 vs. 0.9 +/- 0.8, p = 0.0001) and poorer endothelialization (55.8 +/- 26.5%) compared with BMS (89.8 +/- 20.9, p = 0.0001). Moreover, DES with LST showed more delayed healing compared with patent DES. In 5 of 14 patients suffering LST, antiplatelet therapy had been withdrawn. Additional procedural and pathologic risk factors for LST were: 1) local hypersensitivity reaction; 2) ostial and/or bifurcation stenting; 3) malapposition/incomplete apposition; 4) restenosis; and 5) strut penetration into a necrotic core. CONCLUSIONS: The Cypher and Taxus DES result in delayed arterial healing when compared with BMS of similar implant duration. The cause of DES LST is multifactorial with delayed healing in combination with other clinical and procedural risk factors playing a role.

Adult↗

PubMed2006

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.

Adult↗

PubMed2006

Identification of novel missense mutations of cardiac ryanodine receptor gene in exercise-induced sudden death at autopsy.

Mutations in the cardiac ryanodine type 2 receptor (RyR2) gene are associated with catecholaminergic polymorphic ventricular tachycardia. We hypothesized that these mutations could be detected at autopsy in cases of exercise-triggered sudden death. Fourteen sudden death patients, eight males and six females, were studied at autopsy based on apparent sudden cardiac death, without significant anatomical abnormalities. The coding regions of arrhythmia genes were amplified by polymerase chain reaction and directly sequenced. Three novel RyR2 mutations, R414C, F2331S, and R2401L, were identified in three unrelated patients (two males and one female; mean age at death, 12 +/- 2 years), all performing strenuous activity at the time of death or collapse. These mutations were located in highly conserved regions where arrhythmia-linked RyR2 mutations clustered. Although G269S in the KVLQT1 gene was detected in a female with known family history of syncope and sudden cardiac death, no other mutations were found in any of the 14 cases, and no other mutations was found in 200 controls. The absence of structural cardiac disease in physical activity-induced sudden death and the finding of three novel RyR2 mutations suggest that mutation screening in such cases should include RyR2.

Adolescent↗

PubMed2005

Role of SCN5A Y1102 polymorphism in sudden cardiac death in blacks.

BACKGROUND: The Y1102 polymorphism of the cardiac sodium channel (SCN5A) gene has been found in 13% of black Americans. It has been linked to lethal arrhythmias in black families with ventricular tachycardia. The prevalence of the Y1102 polymorphism in a series of sudden death in blacks is unknown. METHODS AND RESULTS: We investigated the incidence of the Y1102 polymorphism in a series of 289 sudden deaths in blacks by sequencing an amplified segment of DNA that contained the polymorphic site extracted from prospectively sampled frozen splenic tissue. The deaths were classified as noncardiac controls (n=107), cardiac arrhythmias with clear anatomic substrate (n=117), cardiac arrhythmias with no anatomic substrate except mild to moderate cardiac hypertrophy (n=40), and unexplained cardiac arrhythmias (n=25). Cause of death was determined after complete forensic autopsy and postmortem cardiac examination. The overall frequency of the Y1102 polymorphism was 9.0%. The frequency was 5.6% in noncardiac deaths, 4.3% in cardiac deaths with obvious anatomic substrate, 20.0% in arrhythmias with moderate hypertrophy, and 28% in unexplained arrhythmias. Adjusted for age and sex, the relative risk of an unexplained arrhythmic death was 8.4 (95% CI 2.1 to 28.6, P=0.001) with the Y1102 allele compared with noncardiac deaths. The relative risk for cardiac arrhythmias with mild cardiac hypertrophy was 4.9 (95% CI 1.3 to 13.4, P=0.01). CONCLUSIONS: The Y1102 allele is a risk factor in blacks for sudden cardiac death in the absence of obvious morphological findings or mild to moderate cardiomegaly.

Adolescent↗

PubMed2005

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.

Autopsy↗

PubMed2003

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.

Animals↗

PubMed2002

Differential accumulation of proteoglycans and hyaluronan in culprit lesions: insights into plaque erosion.

OBJECTIVE: The importance of the extracellular matrix molecules versican, biglycan, decorin, and hyaluronan in plaque instability has not been recognized. METHODS AND RESULTS: Coronary lesions with acute thrombi and stable plaques were examined for the accumulation and distribution of specific proteoglycans and hyaluronan at culprit sites. The cell surface receptor for hyaluronan, CD44, and smooth muscle (SM) cell maturation markers were also assessed. Proteoglycans and hyaluronan accumulated in distinct patterns depending on plaque type. The fibrous cap of stable lesions was enriched in versican and biglycan, with considerably less staining for decorin and hyaluronan, whereas picrosirius red revealed a heavy accumulation of collagen type I. In contrast, intense staining for hyaluronan and versican was found in erosions at the plaque/thrombus interface, with weak staining for biglycan and decorin; collagen content was predominantly type III. Rupture sites showed little immunoreactivity for proteoglycans or hyaluronan. CD44 was localized along the plaque/thrombus interface in erosions, whereas in ruptures and stable plaques, it was mostly confined to inflammatory cells. Positive immunostaining for immature SM cells (SM myosin heavy chain SM1 and SMemb) was present in stable and eroded plaques, whereas the presence of SM2 and smoothelin was weak or nonexistent. CONCLUSIONS: Specific accumulation of versican, hyaluronan, and CD44 at the sites of plaque erosion implicates an involvement of these molecules in events associated with acute coronary thrombosis.

Adult↗

PubMed2002

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.

C-Reactive Protein↗

PubMed2002

Traditional risk factors and the incidence of sudden coronary death with and without coronary thrombosis in blacks.

BACKGROUND: Blacks have a high rate of sudden coronary death (SCD). We determined the rate of SCD in men and women 30 to 69 years of age in a 6-year period recorded at a state Medical Examiner's Office. METHODS AND RESULTS: In a subset of 327 whites and 130 blacks, hearts were systematically studied to determine the extent of coronary disease, presence and type of thrombus (acute rupture, acute erosion, stable plaque), and heart weight. These parameters were correlated with the presence of conventional risk factors. The estimated rate of SCD in blacks was similar to that in whites under the age of 40 years but increased compared with whites with advancing age, becoming 1.5 times the rate for whites in the 7th decade (95% of the increase in the 6th decade was due to sudden death with stable plaque). Among the autopsied group with severe coronary atherosclerosis, HDL cholesterol was higher and hypertension more prevalent in blacks, but there was no difference in the prevalence of healed infarcts, plaque burden, heart weight, acute thrombi, or rates of diabetes, cigarette smoking, and total cholesterol. CONCLUSIONS: When compared with a control autopsy group of 568 deaths, multivariate analysis showed a significant association in blacks between stable plaque and left ventricular hypertrophy (risk ratio, 7.6), type 1 diabetes (risk ratio, 3.6), hypertension (risk ratio, 3.5), elevated total cholesterol (risk ratio, 3.1) and type 2 diabetes (risk ratio, 2.9). Because these risk factors are associated with SCD in blacks, they may be important targets for reducing the disparately high rate of SCD in blacks as compared with whites.

Adult↗

PubMedDate not supplied

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.

Adult↗