Polygenic Risk Score Associates With Atherosclerotic Plaque Characteristics at Autopsy.

BACKGROUND: Polygenic risk scores (PRSs) for coronary artery disease (CAD) potentially improve cardiovascular risk prediction. However, their relationship with histopathologic features of CAD has never been examined systematically. METHODS: From 4327 subjects referred to CVPath by the State of Maryland Office Chief Medical Examiner for sudden death between 1994 and 2015, 2455 cases were randomly selected for genotyping. We generated PRS from 291 known CAD risk loci. Detailed histopathologic examination of the coronary arteries was performed in all subjects. The primary study outcome measurements were histopathologic plaque features determining severity of atherosclerosis, including %stenosis, calcification, thin-cap fibroatheromas, and thrombotic CAD. RESULTS: After exclusion of cases with insufficient DNA sample quality or with missing data, 954 cases (mean age, 48.8±14.7 years; 75.7% men) remained in the final study cohort. Subjects in the highest PRS quintile exhibited more severe atherosclerosis compared with subjects in the lowest quintile, with greater %stenosis (80.3%±27.0% versus 50.4%±38.7%; adjusted P<0.001) and a higher frequency of calcification (69.6% versus 35.8%; adjusted P=0.004) and thin-cap fibroatheroma (26.7% versus 9.5%; adjusted P=0.007). Even after adjustment for traditional CAD risk factors, subjects within the highest PRS quintile had higher odds of severe atherosclerosis (ie, ≥75% stenosis; adjusted odds ratio, 3.77 [95% CI, 2.10-6.78]; P<0.001) and plaque rupture (adjusted odds ratio, 4.05 [95% CI, 2.26-7.24]; P<0.001). Moreover, subjects within the highest quintile had higher odds of CAD-associated cause of death, especially among those aged ≤50 years (adjusted odds ratio, 4.08 [95% CI, 2.01-8.30]; P<0.001). No statistically significant associations were observed with plaque erosion after adjusting for covariates. CONCLUSIONS: This is the first autopsy study investigating associations between PRS and atherosclerosis severity at the histopathologic level in subjects with sudden death. Our pathological analysis suggests PRS correlates with plaque burden and features of advanced atherosclerosis and may be useful as a method for CAD risk stratification, especially in younger subjects.

Relationships between neighborhood disadvantage and cardiovascular findings at autopsy in subjects with sudden death.

BACKGROUND: Neighborhood disadvantage is associated with a higher risk of sudden cardiac death. However, autopsy findings have never been investigated in this context. Here, we sought to explore associations between neighborhood disadvantage and cardiovascular findings at autopsy in cases of sudden death in the State of Maryland. METHODS: State of Maryland investigation reports from 2,278 subjects within the CVPath Sudden Death Registry were screened for street addresses and 9-digit zip codes. Area deprivation index (ADI), used as metric for neighborhood disadvantage, was available for 1,464 subjects; 650 of whom self-identified as Black and 814 as White. The primary study outcome measurements were causes of death and gross and histopathologic findings of the heart. RESULTS: Subjects from most disadvantaged neighborhoods (i.e., ADI ≥ 8; n = 607) died at younger age compared with subjects from less disadvantaged neighborhoods (i.e., ADI ≤ 7; n = 857; 46.07 ± 14.10 vs 47.78 ± 13.86 years; P = 0.02) and were more likely Black or women. They were less likely to die from cardiac causes of death (61.8% vs 67.7%; P = 0.02) and had less severe atherosclerotic plaque features, including plaque burden, calcification, intraplaque hemorrhage, and thin-cap fibroatheromas. In addition, subjects from most disadvantaged neighborhoods had lower frequencies of plaque rupture (18.8% vs 25.1%, P = 0.004). However, these associations were omitted after adjustment for traditional risk factors and race. CONCLUSION: Neighborhood disadvantage did not associate with cause of death or coronary histopathology after adjustment for cardiovascular risk factors and race, implying that social determinants of health other than neighborhood disadvantage play a more prominent role in sudden cardiac death.

Microthrombi as a Major Cause of Cardiac Injury in COVID-19: A Pathologic Study.

BACKGROUND: Cardiac injury is common in patients who are hospitalized with coronavirus disease 2019 (COVID-19) and portends poorer prognosis. However, the mechanism and the type of myocardial damage associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain uncertain. METHODS: We conducted a systematic pathological analysis of 40 hearts from hospitalized patients dying of COVID-19 in Bergamo, Italy, to determine the pathological mechanisms of cardiac injury. We divided the hearts according to presence or absence of acute myocyte necrosis and then determined the underlying mechanisms of cardiac injury. RESULTS: Of the 40 hearts examined, 14 (35%) had evidence of myocyte necrosis, predominantly of the left ventricle. Compared with subjects without necrosis, subjects with necrosis tended to be female, have chronic kidney disease, and have shorter symptom onset to admission. The incidence of severe coronary artery disease (ie, >75% cross-sectional narrowing) was not significantly different between those with and without necrosis. Three of 14 (21.4%) subjects with myocyte necrosis showed evidence of acute myocardial infarction, defined as ≥1 cm2 area of necrosis, whereas 11 of 14 (78.6%) showed evidence of focal (>20 necrotic myocytes with an area of ≥0.05 mm2 but <1 cm2) myocyte necrosis. Cardiac thrombi were present in 11 of 14 (78.6%) cases with necrosis, with 2 of 14 (14.2%) having epicardial coronary artery thrombi, whereas 9 of 14 (64.3%) had microthrombi in myocardial capillaries, arterioles, and small muscular arteries. We compared cardiac microthrombi from COVID-19-positive autopsy cases to intramyocardial thromboemboli from COVID-19 cases as well as to aspirated thrombi obtained during primary percutaneous coronary intervention from uninfected and COVID-19-infected patients presenting with ST-segment-elevation myocardial infarction. Microthrombi had significantly greater fibrin and terminal complement C5b-9 immunostaining compared with intramyocardial thromboemboli from COVID-19-negative subjects and with aspirated thrombi. There were no significant differences between the constituents of thrombi aspirated from COVID-19-positive and -negative patients with ST-segment-elevation myocardial infarction. CONCLUSIONS: The most common pathological cause of myocyte necrosis was microthrombi. Microthrombi were different in composition from intramyocardial thromboemboli from COVID-19-negative subjects and from coronary thrombi retrieved from COVID-19-positive and -negative patients with ST-segment-elevation myocardial infarction. Tailored antithrombotic strategies may be useful to counteract the cardiac effects of COVID-19 infection.

APOL1 Genetic Variants Are Associated With Increased Risk of Coronary Atherosclerotic Plaque Rupture in the Black Population.

[Figure: see text].

Pathology of self-expanding transcatheter aortic valves: Findings from the CoreValve US pivotal trials.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has recently become an alternative to surgical aortic valve replacement for patients with severe aortic stenosis. However, paravalvular leaks, possible leaflet thrombosis, and device durability following TAVR remain unresolved issues. METHODS AND RESULTS: We conducted the first systematic microscopic and macroscopic pathologic analysis of self-expanding CoreValve transcatheter aortic valves removed at autopsy or surgically from the U.S. pivotal trial of extreme- and high-risk patients. Implants were evaluated for histopathologic changes in the valve frame and leaflets. Thrombus/neointima on the leaflets was graded depending on the leaflet thickness and the extent of leaflet involvement. Inflammation, calcification, and structural integrity were also assessed. A total of 21 cases (median age 86.0 years [IQR, 79.0-91.0]), with median duration of implant duration of 17.0 days ranged from 0 to 503 days were evaluated. No valve frame fracture was observed and severe paravalvular gaps were uncommon. Inflammation and thrombus in the valve frame was minimal, but neointimal growth increased overtime. Symptomatic valve thrombosis was observed in one case (5%) and subclinical moderate leaflet thrombus was observed in four additional cases (19%). Inflammation of the leaflets was mild, while structural changes were minimal, and one case had infective endocarditis. Pannus or leaflet calcification were not observed. CONCLUSIONS: This first systematic macroscopic and microscopic pathologic analysis of self-expanding transcatheter aortic valves demonstrates favorable short-term pathologic findings. However, our finding of subclinical leaflet thrombus formation confirms prior observations and warrants further investigation.

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.

Cardiac CT assessment of tissue thickness at the ostium of the left atrial appendage predicts acute success of radiofrequency ablation.

BACKGROUND: Tissue thickness at the site of ablation is a determinant of lesion transmurality. We reported the feasibility, safety, and efficacy of longstanding persistent atrial fibrillation ablation, incorporating deliberate left atrial appendage (LAA) isolation and occlusion, and identified systematic differences in ostial LAA tissue thickness in a matched cohort of cadaveric specimens. METHODS: Preprocedural cardiac computed tomography (CCT) scans were acquired from 22 patients undergoing LAA isolation and subsequent occlusion. Using a novel CCT wall thickness algorithm, LAA ostial wall thickness was assessed in vivo, compared with measurements from the cadaveric specimens, and analyzed for differences between regions that demonstrated acute electrical reconnection and those that did not. RESULTS: Mean tissue thickness calculated for each LAA ostial quadrant was 2.1 (±0.6) mm (anterior quadrant), 1.9 (±0.4) mm (superior quadrant), 1.5 (±0.4) mm (posterior quadrant), and 1.8 (±0.7) mm (inferior quadrant). Tissue was significantly thicker in the anterior (P  =  0.004) and superior quadrants (P  =  0.014) than the posterior quadrant. Higher thickness measurements were recorded from quadrants demonstrated to be thicker from histology. Tissue was significantly thicker in regions that demonstrated acute electrical reconnection (1.9 (±0.6) mm) when compared with those that did not (1.6 (±0.5) mm) (P  =  0.008). CONCLUSIONS: CCT imaging may be used to detect differences in wall thickness at different atrial locations and success of LAA ablation may be affected by local tissue thickness. Atrial wall thickness may need to be considered as a metric to guide titration of radiofrequency energy for safe and successful ablation.

Neoatherosclerosis: overview of histopathologic findings and implications for intravascular imaging assessment.

Despite the reduction in late thrombotic events with newer-generation drug-eluting stents (DES), late stent failure remains a concern following stent placement. In-stent neoatherosclerosis has emerged as an important contributing factor to late vascular complications including very late stent thrombosis and late in-stent restenosis. Histologically, neoatherosclerosis is characterized by accumulation of lipid-laden foamy macrophages within the neointima with or without necrotic core formation and/or calcification. The development of neoatherosclerosis may occur in months to years following stent placement, whereas atherosclerosis in native coronary arteries develops over decades. Pathologic and clinical imaging studies have demonstrated that neoatherosclerosis occurs more frequently and at an earlier time point in DES when compared with bare metal stents, and increases with time in both types of implant. Early development of neoatherosclerosis has been identified not only in first-generation DES but also in second-generation DES. The mechanisms underlying the rapid development of neoatherosclerosis remain unknown; however, either absence or abnormal endothelial functional integrity following stent implantation may contribute to this process. In-stent plaque rupture likely accounts for most thrombotic events associated with neoatherosclerosis, while it may also be a substrate of in-stent restenosis as thrombosis may occur either symptomatically or asymptomatically. Intravascular optical coherence tomography is capable of detecting neoatherosclerosis; however, the shortcomings of this modality must be recognized. Future studies should assess the impact of iterations in stent technology and risk factor modification on disease progression. Similarly, refinements in imaging techniques are also warranted that will permit more reliable detection of neoatherosclerosis.

Pathology of second-generation everolimus-eluting stents versus first-generation sirolimus- and paclitaxel-eluting stents in humans.

BACKGROUND: Clinical trials have demonstrated that the second-generation cobalt-chromium everolimus-eluting stent (CoCr-EES) is superior to the first-generation paclitaxel-eluting stent (PES) and is noninferior or superior to the sirolimus-eluting stent (SES) in terms of safety and efficacy. It remains unclear whether vascular responses to CoCr-EES are different from those to SES and PES because the pathology of CoCr-EES has not been described in humans. METHODS AND RESULTS: A total of 204 lesions (SES=73; PES=85; CoCr-EES=46) from 149 autopsy cases with duration of implantation >30 days and ≤3 years were pathologically analyzed, and comparison of vascular responses was corrected for duration of implantation. The observed frequency of late and very late stent thrombosis was less in CoCr-EES (4%) versus SES (21%; P=0.029) and PES (26%; P=0.008). Neointimal thickness was comparable among the groups, whereas the percentage of uncovered struts was strikingly lower in CoCr-EES (median=2.6%) versus SES (18.0%; P<0.0005) and PES (18.7%; P<0.0005). CoCr-EES showed a lower inflammation score (with no hypersensitivity) and less fibrin deposition versus SES and PES. The observed frequency of neoatherosclerosis, however, did not differ significantly among the groups (CoCr-EES=29%; SES=35%; PES=19%). CoCr-EES had the least frequency of stent fracture (CoCr-EES=13%; SES=40%; PES=19%; P=0.007 for CoCr-EES versus SES), whereas fracture-related restenosis or thrombosis was comparable among the groups (CoCr-EES=6.5%; SES=5.5%; PES=1.2%). CONCLUSIONS: CoCr-EES demonstrated greater strut coverage with less inflammation, less fibrin deposition, and less late and very late stent thrombosis compared with SES and PES in human autopsy analysis. Nevertheless, the observed frequencies of neoatherosclerosis and fracture-related adverse pathological events were comparable in these devices, indicating that careful long-term follow-up remains important even after CoCr-EES placement.

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.

Human autopsy study of drug-eluting stents restenosis: histomorphological predictors and neointimal characteristics.

AIMS: Restenosis in drug-eluting stents (DESs) occurs infrequently, however, it remains a pervasive clinical problem. We interrogated our autopsy registry to determine the underlying mechanisms of DES restenosis, and further we investigated the neointimal characteristics of DESs and compared with bare metal stents (BMSs). METHODS AND RESULTS: Coronary lesions from patients with DES implants (n = 82) were categorized into four groups based on cross-sectional area narrowing: patent (<50%), intermediate (50-74%), restenotic (≥ 75% with residual lumen), and total occlusion (organized thrombus within the stent). Restenosis and occlusion were significantly dependent on the total stented length: restenosis (26.7 mm) and occlusion (25.7 mm) compared with patent DESs (17.3 mm). Further, restenotic and occluded lesions were located more distally in the coronary arteries and had greater vessel injury and uneven strut distribution suggesting local drug gradient. Multivariate analysis revealed that normalized maximum inter-strut distance was associated with DES restenosis (OR: 17.4, P = 0.04) while medial tear length was a predictor of DES occlusion (OR: 5.1, P = 0.03). No differences were observed between different DESs (sirolimus-, paclitaxel-, and everolimus-eluting stents) for restenosis and occlusion. Further, neointimal compositions of restenotic DESs demonstrated greater proteoglycan deposition and less smooth muscle cellularity over time, when compared with BMS with greater cell density and collagen deposition. CONCLUSIONS: Our study indicates the impacts of inadequate drug concentration due to wider inter-strut distance and vessel injury as primary mechanisms of DES restenosis and occlusion, respectively. Moreover, the differences in neointimal compositions between DESs and BMSs might serve as a potential target for the suppression of late neointima growth via inhibition of proteoglycans in DESs.

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.

Mechanisms of Medial Wall Thinning in Chronic Total Occlusion.

BACKGROUND: The success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is lower and the risk for complications higher compared with other non-CTO PCI. Although interventionalists focus on intimal plaque characteristics, the coronary media is an important (especially for techniques involving antegrade dissection and re-entry) but poorly understood structure in CTO PCI. OBJECTIVES: The aim of the present study was to investigate coronary medial wall thinning in CTO lesions and determine how this thinning might affect CTO PCI. METHODS: A total of 2,586 sections were investigated, from arteries with evidence of CTO from 54 subjects (n = 1,383 sections) and arteries without evidence of CTO from 54 subjects with non-coronary-related deaths (n = 1,203 sections) after matching for age, gender, body weight, and body height. RESULTS: The medial thickness in subjects with CTO was lower than that in those with non-coronary-related death (P < 0.001). In subjects with CTO, CTO lesions had thinner medial walls compared with those with lower luminal narrowing (P < 0.001). At the CTO distal segments, the 6- to 12-mm distal segment from the distal end of the CTO had significantly less luminal narrowing (P < 0.001), and similar medial thickness, compared with the distal end of the CTO. Immunohistochemical analysis revealed that short-duration CTO had more cleaved caspase-3-positive cells in media and had significantly more CD3+, CD4+, CD8+, and CD4+CD28null T cells compared with long-duration CTO. CONCLUSIONS: CTO lesions demonstrated coronary medial thinning compared with non-CTO lesions. Further investigation of the cause-and-effect relationship among inflammation, apoptosis, and coronary medial wall thinning is warranted in future mechanistic studies.

Polygenic Risk Score Associates with Atherosclerotic Plaque Characteristics at Autopsy.

Background: Polygenic risk scores (PRS) for coronary artery disease (CAD) potentially improve cardiovascular risk prediction. However, their relationship with histopathologic features of CAD has never been examined systematically. Methods: From 4,327 subjects referred to CVPath by the State of Maryland Office Chief Medical Examiner (OCME) for sudden death between 1994 and 2015, 2,455 cases were randomly selected for genotyping. We generated PRS from 291 known CAD risk loci. Detailed histopathologic examination of the coronary arteries was performed in all subjects. The primary study outcome measurements were histopathologic plaque features determining severity of atherosclerosis, including %stenosis, calcification, thin-cap fibroatheromas (TCFA), and thrombotic CAD. Results: After exclusion of cases with insufficient DNA sample quality or with missing data, 954 cases (mean age 48.8±14.7; 75.7% men) remained in the final study cohort. Subjects in the highest PRS quintile exhibited more severe atherosclerosis compared to subjects in the lowest quintile, with greater %stenosis (80.3%±27.0% vs. 50.4%±38.7%; adjusted p<0.001) and a higher frequency of calcification (69.6% vs. 35.8%; adjusted p=0.004) and TCFAs (26.7% vs. 9.5%; adjusted p=0.007). Even after adjustment for traditional CAD risk factors subjects within the highest PRS quintile had higher odds of severe atherosclerosis (i.e., ≥75% stenosis; adjusted OR 3.77; 95%CI 2.10-6.78; p<0.001) and plaque rupture (adjusted OR 4.05; 95%CI 2.26-7.24; p<0.001). Moreover, subjects within the highest quintile had higher odds of CAD-associated cause of death, especially among those aged 50 years and younger (adjusted OR 4.08; 95%CI 2.01-8.30; p<0.001). No associations were observed with plaque erosion. Conclusions: This is the first autopsy study investigating associations between PRS and atherosclerosis severity at the histopathologic level in subjects with sudden death. Our pathological analysis suggests PRS correlates with plaque burden and features of advanced atherosclerosis and may be useful as a method for CAD risk stratification, especially in younger subjects. Highlights: In this autopsy study including 954 subjects within the CVPath Sudden Death Registry, high PRS correlated with plaque burden and atherosclerosis severity.The PRS showed differential associations with plaque rupture and plaque erosion, suggesting different etiologies to these two causes of thrombotic CAD.PRS may be useful for risk stratification, particularly in the young. Further examination of individual risk loci and their association with plaque morphology may help understand molecular mechanisms of atherosclerosis, potentially revealing new therapy targets of CAD. Graphic Abstract: A polygenic risk score, generated from 291 known CAD risk loci, was assessed in 954 subjects within the CVPath Sudden Death Registry. Histopathologic examination of the coronary arteries was performed in all subjects. Subjects in the highest PRS quintile exhibited more severe atherosclerosis as compared to subjects in the lowest quintile, with a greater plaque burden, more calcification, and a higher frequency of plaque rupture.

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.

Cardiovascular pathology in Hutchinson-Gilford progeria: correlation with the vascular pathology of aging.

OBJECTIVE: Children with Hutchinson-Gilford progeria syndrome (HGPS) exhibit dramatically accelerated cardiovascular disease (CVD), causing death from myocardial infarction or stroke between the ages of 7 and 20 years. We undertook the first histological comparative evaluation between genetically confirmed HGPS and the CVD of aging. METHODS AND RESULTS: We present structural and immunohistological analysis of cardiovascular tissues from 2 children with HGPS who died of myocardial infarction. Both had features classically associated with the atherosclerosis of aging, as well as arteriolosclerosis of small vessels. In addition, vessels exhibited prominent adventitial fibrosis, a previously undescribed feature of HGPS. Importantly, although progerin was detected at higher rates in the HGPS coronary arteries, it was also present in non-HGPS individuals. Between the ages of 1 month and 97 years, progerin staining increased an average of 3.34% per year (P<0.0001) in coronary arteries. CONCLUSIONS: We find concordance among many aspects of cardiovascular pathology in both HGPS and geriatric patients. HGPS generates a more prominent adventitial fibrosis than typical CVD. Vascular progerin generation in young non-HGPS individuals, which significantly increases throughout life, strongly suggests that progerin has a role in cardiovascular aging of the general population.

Genetic Variants Associated With Unexplained Sudden Cardiac Death in Adult White and African American Individuals.

Importance: Unexplained sudden cardiac death (SCD) describes SCD with no cause identified. Genetic testing helps to diagnose inherited cardiac diseases in unexplained SCD; however, the associations between pathogenic or likely pathogenic (P/LP) variants of inherited cardiomyopathies (CMs) and arrhythmia syndromes and the risk of unexplained SCD in both White and African American adults living the United States has never been systematically examined. Objective: To investigate cases of unexplained SCD to determine the frequency of P/LP genetic variants of inherited CMs and arrhythmia syndromes. Design, Setting, and Participants: This genetic association study included 683 African American and White adults who died of unexplained SCD and were included in an autopsy registry. Overall, 413 individuals had DNA of acceptable quality for genetic sequencing. Data were collected from January 1995 to December 2015. A total of 30 CM genes and 38 arrhythmia genes were sequenced, and variants in these genes, curated as P/LP, were examined to study their frequency. Data analysis was performed from June 2018 to March 2021. Main Outcomes and Measures: The frequency of P/LP variants for CM or arrhythmia in individuals with unexplained SCD. Results: The median (interquartile range) age at death of the 413 included individuals was 41 (29-48) years, 259 (62.7%) were men, and 208 (50.4%) were African American adults. A total of 76 patients (18.4%) with unexplained SCD carried variants considered P/LP for CM and arrhythmia genes. In total, 52 patients (12.6%) had 49 P/LP variants for CM, 22 (5.3%) carried 23 P/LP variants for arrhythmia, and 2 (0.5%) had P/LP variants for both CM and arrhythmia. Overall, 41 P/LP variants for hypertrophic CM were found in 45 patients (10.9%), 9 P/LP variants for dilated CM were found in 11 patients (2.7%), and 10 P/LP variants for long QT syndrome were found in 11 patients (2.7%). No significant difference was found in clinical and heart characteristics between individuals with or without P/LP variants. African American and White patients were equally likely to harbor P/LP variants. Conclusions and Relevance: In this large genetic association study of community cases of unexplained SCD, nearly 20% of patients carried P/LP variants, suggesting that genetics may contribute to a significant number of cases of unexplained SCD. Our findings regarding both the association of unexplained SCD with CM genes and race-specific genetic variants suggest new avenues of study for this poorly understood entity.