Identification of Susceptibility Loci for Spontaneous Coronary Artery Dissection

The genetics of spontaneous coronary artery dissection: a scoping review

BACKGROUND

Spontaneous coronary artery dissection (SCAD) is a multifactorial process that involves predisposing factors and precipitating stressors. Genetic abnormality has been implicated to play a mechanistic role in the development of SCAD. This systematic review aims to summarize the current evidence concerning the link between SCAD and genetic abnormalities.

METHODS

We reviewed original studies published until May 2023 that reported SCAD patients with a genetic mutation by searching PubMed, Embase Ovid, and Google Scholar. Registries, cohort studies, and case reports were included if a definitive SCAD diagnosis was reported, and the genetic analysis was performed. Exclusion criteria included editorials, reviews, letters or commentaries, animal studies, meeting papers, and studies from which we were unable to extract data. Data were extracted from published reports.

RESULTS

A total of 595 studies were screened and 55 studies were identified. Among 116 SCAD patients with genetic abnormalities, 20% had mutations in the COL gene, 13.70% TLN1 gene, and 8.42% TSR1 gene. Mutations affecting the genes encoding COL and TLN1 were most frequently reported (20 and 13.7%, respectively). Interestingly, 15 genes of this collection were also reported in patients with thoracic aortic diseases as well. The genetic commonality between fibromuscular dysplasia (FMD) and SCAD was also included.

CONCLUSION

In this review, the inherited conditions and reported genes of undetermined significance from case reports associated with SCAD are collected. A brief description of the encoded protein and the clinical features associated with pathologic genes is provided. Current data suggested that the diagnostic yield of genetic studies for patients with SCAD would be low and routine genetic screening of such patients with no clinical features indicative of associated disorders remains debatable. This review can be used as a guide for clinicians to recognize inherited syndromic and nonsyndromic disorders associated with SCAD.

From Atherosclerosis to Spontaneous Coronary Artery Dissection: Defining a Clinical and Genetic Risk Spectrum for Myocardial Infarction

PURPOSE OF REVIEW

Spontaneous coronary artery dissection (SCAD) has been increasingly recognized as a significant cause of acute myocardial infarction (AMI) in young and middle-aged women and arises through mechanisms independent of atherosclerosis. SCAD has a multifactorial etiology that includes environmental, individual, and genetic factors distinct from those typically associated with coronary artery disease. Here, we summarize the current understanding of the genetic factors contributing to the development of SCAD and highlight those factors which differentiate SCAD from atherosclerotic coronary artery disease.

RECENT FINDINGS

Recent studies have revealed several associated variants with varying effect sizes for SCAD, giving rise to a complex genetic architecture. Associated genes highlight an important role for arterial cells and their extracellular matrix in the pathogenesis of SCAD, as well as notable genetic overlap between SCAD and other systemic arteriopathies such as fibromuscular dysplasia and vascular connective tissue diseases. Further investigation of individual variants (including in the associated gene PHACTR1) along with polygenic score analysis have demonstrated an inverse genetic relationship between SCAD and atherosclerosis as distinct causes of AMI. SCAD represents an increasingly recognized cause of AMI with opposing clinical and genetic risk factors from that of AMI due to atherosclerosis, and it is often associated with complex underlying genetic conditions. Genetic study of SCAD on a larger scale and with more diverse cohorts will not only further our evolving understanding of a newly defined genetic spectrum for AMI, but it will also inform the clinical utility of integrating genetic testing in AMI prevention and management moving forward.

Spontaneous coronary artery dissection (SCAD): A contemporary review

Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of myocardial infarction that most frequently affects younger women, making it an important cause of morbidity and mortality within these demographics. The evolution of intracoronary imaging, improved diagnosis with coronary angiography, and ongoing research efforts and attention via social media, has led to increasing recognition of this previously underdiagnosed condition. In this review, we provide a summary of the current body of knowledge, as well as focused updates on the pathogenesis of SCAD, insights on genetic susceptibility, contemporary diagnostic tools, and immediate, short- and long-term management.

Migraine headache in patients with spontaneous coronary artery dissection: A report of the iSCAD Registry

INTRODUCTION

Spontaneous coronary artery dissection (SCAD) is a nonatherosclerotic cause of myocardial infarction. Migraine headache has been reported to be common among patients with SCAD, but the degree of migraine-related disability has not been quantified.

METHODS

Clinical data and headache variables were obtained from the baseline assessment of the prospective, multicenter iSCAD Registry. Migraine-related disability was quantified using the self-reported Migraine Disability Assessment (MIDAS). Demographic, clinical, psychosocial, and medical characteristics from data entry forms were compared between patients with and without migraine.

RESULTS

Of the 773 patients with available data, 46% reported previous or current migraines. Those with migraines were more likely to be women (96.9% vs 90.3%, p = 0.0003). The presence of underlying carotid fibromuscular dysplasia was associated with migraine (35% vs 27%, p = 0.0175). There was not a significant association with carotid artery dissection and migraine. Current migraine frequency was less than monthly (58%), monthly (24%), weekly (16%), and daily (3%). Triptan use was reported in 32.5% of patients, and 17.5% used daily migraine prophylactic medications. Using the MIDAS to quantify disability related to migraine, 60.2% reported little or no disability, 14.4% mild, 12.7% moderate, and 12.7% severe. The mean MIDAS score was 9.9 (mild to moderate disability). Patients with SCAD had higher rates of depression and anxiety (28.2% vs 17.7% [p = 0.0004] and 35.3% vs 26.7% [p = 0.0099], respectively).

CONCLUSIONS

Migraines are common, frequent, and a source of disability in patients with SCAD. The association between female sex, anxiety, and depression may provide some insight for potential treatment modalities.

Spontaneous coronary artery dissection: review, case report and analysis of COVID-19-related cases

Spontaneous coronary artery dissection (SCAD) accounts for 1-4% of all acute coronary syndromes (ACS). Since the first description in 1931, our understanding of the disease has evolved; however, its pathophysiology and management are still a matter of debate. SCAD typically occurs in a middle-aged woman with no or few traditional cardiovascular risk factors. Two hypotheses have been proposed to explain the pathophysiology depending on the primary event: an intimal tear in the "inside-out" hypothesis and a spontaneous hemorrhage from the vasa vasorum in the "outside-in" hypothesis. Etiology appears to be multifactorial: different predisposing and precipitating factors have been identified. Coronary angiography is the gold standard for the diagnosis of SCAD. Current recommendations on the treatment of SCAD patients are based on expert opinions: a conservative strategy is preferred in hemodynamically stable SCAD patients, while urgent revascularization should be considered in hemodynamically unstable patients. Eleven cases of SCAD in COVID-19 patients have already been described: although the exact pathophysiological mechanism remains unclear, COVID-19-related SCAD is considered a combination of significant systemic inflammatory response and localized vascular inflammation. We present a literature review of SCAD, and we report an unpublished case of SCAD in a COVID-19 patient.

Spontaneous coronary artery dissection and fibromuscular dysplasia: insights into recent developments

Spontaneous coronary artery dissection (SCAD), an uncommon cause of acute coronary syndrome, continues to be a poorly understood disease predominantly affecting females. It is characterized by an abrupt separation in the coronary arterial wall due to intramural bleeding. Fibromuscular dysplasia (FMD) is a non-atherosclerotic arteriopathy manifesting in medium and small-sized arteries. It is a concomitant disease found among SCAD patients. In some studies, FMD prevalence in SCAD patients ranges between 25%-86%, which can be explained through varying screening techniques or modalities. The potential association has been elucidated in some studies; notably, not only has a genetic link been recently delineated between SCAD and FMD, but there is data to suggest that FMD not only can predispose to SCAD but can also be a potential predictor of its recurrence. However, a clear-cut correlation between the two has still not been established due to conflicting reports in the literature. To further dive into its pathology, it is crucial to highlight the importance of systematic screening in SCAD in order to identify associated risk factors and to be used as a method of FMD detection in such patients. Together, the two pathologies pose unique challenges in understanding its pathophysiology, diagnosis and management, as there is no clear evidence of a definitive treatment plan for patients with SCAD and FMD. A potentially beneficial modality of management is physical exercise, which is currently understudied in the long-term approach to treatment for patients with concomitant SCAD and FMD. Limited research in this field brings disadvantages to the understanding of the association between these two diseases, in order to give rise to better management recommendations. This mini-review aims to highlight the recent developments in the association between SCAD and FMD, its potential genetic association and some insights in screening, diagnosis, and management.

Polygenic Risk in Families With Spontaneous Coronary Artery Dissection

Importance

Spontaneous coronary artery dissection (SCAD) is a poorly understood cause of acute coronary syndrome that predominantly affects women. Evidence to date suggests a complex genetic architecture, while a family history is reported for a minority of cases.

Objective

To determine the contribution of rare and common genetic variants to SCAD risk in familial cases, the latter via the comparison of a polygenic risk score (PRS) with those with sporadic SCAD and healthy controls.

Design, Setting, and Participants

This genetic association study analyzed families with SCAD, individuals with sporadic SCAD, and healthy controls. Genotyping was undertaken for all participants. Participants were recruited between 2017 and 2021. A PRS for SCAD was calculated for all participants. The presence of rare variants in genes associated with connective tissue disorders (CTD) was also assessed. Individuals with SCAD were recruited via social media or from a single medical center. A previously published control database of older healthy individuals was used. Data were analyzed from January 2022 to October 2023.

Exposures

PRS for SCAD comprised of 7 single-nucleotide variants.

Main Outcomes and Measures

Disease status (familial SCAD, sporadic SCAD, or healthy control) associated with PRS.

Results

A total of 13 families with SCAD (27 affected and 12 unaffected individuals), 173 individuals with sporadic SCAD, and 1127 healthy controls were included. A total of 188 individuals with SCAD (94.0%) were female, including 25 of 27 with familial SCAD and 163 of 173 with sporadic SCAD; of 12 unaffected individuals from families with SCAD, 6 (50%) were female; and of 1127 healthy controls, 672 (59.6%) were female. Compared with healthy controls, the odds of being an affected family member or having sporadic SCAD was significantly associated with a SCAD PRS (where the odds ratio [OR] represents an increase in odds per 1-SD increase in PRS) (affected family member: OR, 2.14; 95% CI, 1.78-2.50; adjusted P = 1.96 × 10-4; sporadic SCAD: OR, 1.63; 95% CI, 1.37-1.89; adjusted P = 5.69 × 10-4). This association was not seen for unaffected family members (OR, 1.03; 95% CI, 0.46-1.61; adjusted P = .91) compared with controls. Further, those with familial SCAD were overrepresented in the top quintile of the control PRS distribution (OR, 3.70; 95% CI, 2.93-4.47; adjusted P = .001); those with sporadic SCAD showed a similar pattern (OR, 2.51; 95% CI, 1.98-3.04; adjusted P = .001). Affected individuals within a family did not share any rare deleterious variants in CTD-associated genes.

Conclusions and Relevance

Extreme aggregation of common genetic risk appears to play a significant role in familial clustering of SCAD as well as in sporadic case predisposition, although further study is required.

Spontaneous Coronary Artery Dissection in Clinical Practice: Pathophysiology and Therapeutic Approaches

Spontaneous coronary artery dissection (SCAD) is a cause of myocardial infarction without obstructive coronary artery disease (MINOCA). It is determined by a coronary artery wall layers separation, which occurs regardless of traumatic or iatrogenic injuries. Even if it is often a missed diagnosis, its incidence is growing along with the improvement of intracoronary imaging techniques that allow for better detection. The main angiographical classification distinguishes three different forms, with slightly different prognoses at long-term follow up. SCAD is a recurrent condition, severely hampering the life quality of affected patients. The predominantly young age of patients with SCAD and the high prevalence of females among them have made the topic increasingly important, especially regarding therapeutic strategies. According to the data, the most recommended treatment is conservative, based on the use of antiplatelet agents and supportive anti-ischemic therapy. However, there are conflicting opinions concerning the need for dual antiplatelet therapy and its duration. In the case of invasive treatment, the choice between percutaneous coronary intervention and coronary artery bypass graft depends on the patient's clinical stability and the interested vessel. The purpose of the current review is to revise the pathophysiological mechanisms underlying SCAD and the current knowledge of its treatment.

Regional and temporal variations of spontaneous coronary artery dissection care according to consensus recommendations: a systematic review and meta-analysis

AIM

The first expert consensus documents on management of patients with spontaneous coronary artery dissection (SCAD) were published in 2018. Worldwide quality of care, as measured by adherence to these recommendations, has not been systematically reviewed. We aim to review the proportion of patients with SCAD receiving consensus recommendations globally, regionally and, determine differences in practice before and after 2018.

METHODS AND RESULTS

A systematic review was performed by searching four main databases (Medline, Embase, SCOPUS, CINAHL) from their inception to 16 June 2022. Studies were selected if they included patients with SCAD and reported at least one of the consensus document recommendations. 53 studies, n=8456 patients (mean 50.1 years, 90.6% female) were included. On random effects meta-analysis, 92.1% (95% CI 89.3 to 94.8) received at least one antiplatelet, 78.0% (CI 73.5 to 82.4) received beta-blockers, 58.7% (CI 52.3 to 65.1) received ACE inhibitors or aldosterone receptor blockers (ACEIs/ARBs), 54.4% (CI 45.4 to 63.5) were screened for fibromuscular dysplasia (FMD), and 70.2% (CI 60.8 to 79.5) were referred to cardiac rehabilitation. Except for cardiac rehabilitation referral and use of ACEIs/ARBs, there was significant heterogeneity in all other quality-of-care parameters, across geographical regions. No significant difference was observed in adherence to recommendations in studies published before and after 2018, except for lower cardiac rehabilitation referrals after 2018 (test of heterogeneity, p=0.012).

CONCLUSION

There are significant variations globally in the management of patients with SCAD, particularly in FMD screening. Raising awareness about consensus recommendations and further prospective evidence about their effect on outcomes may help improve the quality of care for these patients.

[French National registry of spontaneous coronary artery dissections : ''DISCO registry'']

AIM

Spontaneous coronary artery dissection (SCAD) is a form of acute coronary syndrome (ACS). The aim of this registry is to assess the clinical and angiographic features of SCAD, to describe the therapeutic management and prognosis, and to identify links with other vascular diseases.

METHOD

From 2016 to 2018, 424 patients with a diagnosis of SCAD were included prospectively and retrospectively in 51 French cardiology centres.

RESULTS

373 patients with confirmed SCAD were included. The mean age was 51.5±10.3 years with 90.6% women. 54.7% of patients had <2 cardiovascular risk factors. ACS occurred in 96.2% of patients. 84.2% of patients were managed conservatively, 15.5% interventionally and 0.3% surgically. At 1-year follow-up, recurrence of SCAD occurred in 3.3%. No deaths occurred. The association with fibro-muscular dysplasia was found in 45% of cases and genetic analysis confirmed a strong relationship between the occurrence of SCAD and gene variations at the PHACTR1 locus.

CONCLUSION

The DISCO registry is the largest European cohort of SCAD. It confirms that this disease mainly affects young women with few cardiovascular risk factors, and that there is a strong association with the presence of fibromuscular dysplasia (45%). Conservative management should be preferred, with a favourable prognosis (no deaths at 1 year; recurrence rate of 3.3%).

Advancements in the Genetics of Spontaneous Coronary Artery Dissection

PURPOSE OF REVIEW

Spontaneous coronary artery dissection (SCAD) is a significant cause of acute myocardial infarction that is increasingly recognized in young and middle-aged women. The etiology of SCAD is likely multifactorial and may include the interaction of environmental and individual factors. Here, we summarize the current understanding of the genetic factors contributing to the development of SCAD.

RECENT FINDINGS

The molecular findings underlying SCAD have been demonstrated to include a combination of rare DNA sequence variants with large effects, common variants contributing to a complex genetic architecture, and variants with intermediate impact. The genes associated with SCAD highlight the role of arterial cells and their extracellular matrix in the pathogenesis of the disease and shed light on the relationship between SCAD and other disorders, including fibromuscular dysplasia and connective tissue diseases. While up to 10% of affected individuals may harbor a rare variant with large effect, SCAD most often presents as a complex genetic condition. Analyses of larger and more diverse cohorts will continue to improve our understanding of risk susceptibility loci and will also enable consideration of the clinical utility of genetic testing strategies in the management of SCAD.

Spontaneous coronary artery dissection: an overview

The prevalence of spontaneous coronary artery dissection (SCAD) has increased over the last decades in young adults presenting with acute coronary syndrome. Although the diagnostic tools, including intracoronary imaging, have permitted a more accurate diagnosis of SCAD, the prognosis and overall outcomes remain dismal. Furthermore, the disproportionate sex distribution affecting more women and the underdiagnosis in many parts of the world render this pathology a persistent clinical challenge, particularly since the management remains largely supportive with a limited and controversial role for percutaneous or surgical interventions. The purpose of this review is to summarize the available literature on SCAD and to provide insights into the gaps in knowledge and areas requiring further investigation.

MINOCA biomarkers: Non-atherosclerotic aspects

Myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) is an important subtype of myocardial infarction. Although comprising less than 50% stenosis in the main epicardial coronary arteries, it constitutes a severe health risk. A variety of approaches have been recommended, but definitive diagnosis remains elusive. In addition, the lack of a comprehensive understanding of underlying pathophysiology makes clinical management difficult and unpredictable. This review highlights ongoing efforts to identify relevant biomarkers in MINOCA to improve diagnosis, individualize treatment and better predict outcomes.

Identification of Rare Genetic Variants in Familial Spontaneous Coronary Artery Dissection and Evidence for Shared Biological Pathways

Rare familial spontaneous coronary artery dissection (SCAD) kindreds implicate genetic disease predisposition and provide a unique opportunity for candidate gene discovery. Whole-genome sequencing was performed in fifteen probands with non-syndromic SCAD who had a relative with SCAD, eight of whom had a second relative with extra-coronary arteriopathy. Co-segregating variants and associated genes were prioritized by quantitative variant, gene, and disease-level metrics. Curated public databases were queried for functional relationships among encoded proteins. Fifty-four heterozygous coding variants in thirteen families co-segregated with disease and fulfilled primary filters of rarity, gene variation constraint, and predicted-deleterious protein effect. Secondary filters yielded 11 prioritized candidate genes in 12 families, with high arterial tissue expression (n = 7), high-confidence protein-level interactions with genes associated with SCAD previously (n = 10), and/or previous associations with connective tissue disorders and aortopathies (n = 3) or other vascular phenotypes in mice or humans (n = 11). High-confidence associations were identified among 10 familial SCAD candidate-gene-encoded proteins. A collagen-encoding gene was identified in five families, two with distinct variants in COL4A2. Familial SCAD is genetically heterogeneous, yet perturbations of extracellular matrix, cytoskeletal, and cell-cell adhesion proteins implicate common disease-susceptibility pathways. Incomplete penetrance and variable expression suggest genetic or environmental modifiers.

Assessment of extra-coronary peripheral arteriopathy in spontaneous coronary dissection: state of the art in non-invasive imaging techniques and future perspectives

Spontaneous coronary artery dissection (SCAD) has been recognized as an important cause of acute coronary syndrome in women ≤ 50 years old, and up to 43% of pregnancy-associated myocardial infarction. SCAD has a strong association with extra-coronary arteriopathies, including either more common entities such as dissections, intracranial or other aneurysms, and extra-coronary and coronary arterial tortuosity or less common inherited vascular disorders such as Ehlers-Danlos syndrome, Marfan syndrome, and Loeys-Dietz syndrome, leading to the conclusion that systemic arterial disorders may underlie SCAD. Fibromuscular dysplasia is the most common extra-coronary vascular abnormality identified among these patients, also sharing a common genetic variant with SCAD. The American Heart Association, in a scientific statement regarding the management of SCAD, recommends that patients with SCAD should undergo additional evaluation with imaging techniques including either computed tomography angiography (CTA) or magnetic resonance angiography (MRA). MRA has been shown to have sufficient diagnostic accuracy in identifying extra-coronary arterial abnormalities, almost equal to CTA and conventional angiography. The aim of this review is to appraise the most recent important evidence of extra-coronary arteriopathy in the setting of SCAD and to discuss the strengths and weaknesses of various non-invasive imaging methods for screening of extra-coronary arteriopathies in patients with SCAD.

Association of single nucleotide polymorphisms with dyslipidemia and risk of metabolic disorders in the State of Qatar

BACKGROUND

Dyslipidemia is recognized as one of the risk factors of cardiovascular diseases (CVDs), type 2 diabetes mellitus (T2DM), and non-alcoholic fatty liver disease (NAFLD).

OBJECTIVE

The study aimed to investigate the association between selected single nucleotide polymorphisms (SNPs) with dyslipidemia and increased susceptibility risks of CVD, NAFLD, and/or T2DM in dyslipidemia patients in comparison with healthy control individuals from the Qatar genome project.

METHODS

A community-based cross-sectional study was conducted among 2933 adults (859 dyslipidemia patients and 2074 healthy control individuals) from April to December 2021 to investigate the association between 331 selected SNPs with dyslipidemia and increased susceptibility risks of CVD, NAFLD and/or T2DM, and covariates.

RESULTS

The genotypic frequencies of six SNPs were found to be significantly different in dyslipidemia patients subjects compared to the control group among males and females. In males, three SNPs were found to be significant, the rs11172113 in over-dominant model, the rs646776 in recessive and over-dominant models, and the rs1111875 in dominant model. On the other hand, two SNPs were found to be significant in females, including rs2954029 in recessive model, and rs1801251 in dominant and recessive models. The rs17514846 SNP was found for dominant and over-dominant models among males and only the dominant model for females. We found that the six SNPs linked to gender type had an influence in relation to disease susceptibility. When controlling for the four covariates (gender, obesity, hypertension, and diabetes), the difference between dyslipidemia and the control group remained significant for the six variants. Finally, males were three times more likely to have dyslipidemia in comparison with females, hypertension was two times more likely to be present in the dyslipidemia group, and diabetes was six times more likely to be in the dyslipidemia group.

CONCLUSION

The current investigation provides evidence of association for a common SNP to coronary heart disease and suggests a sex-dependent effect and encourage potential therapeutic applications.

Genome-wide association meta-analysis of spontaneous coronary artery dissection identifies risk variants and genes related to artery integrity and tissue-mediated coagulation

Spontaneous coronary artery dissection (SCAD) is an understudied cause of myocardial infarction primarily affecting women. It is not known to what extent SCAD is genetically distinct from other cardiovascular diseases, including atherosclerotic coronary artery disease (CAD). Here we present a genome-wide association meta-analysis (1,917 cases and 9,292 controls) identifying 16 risk loci for SCAD. Integrative functional annotations prioritized genes that are likely to be regulated in vascular smooth muscle cells and artery fibroblasts and implicated in extracellular matrix biology. One locus containing the tissue factor gene F3, which is involved in blood coagulation cascade initiation, appears to be specific for SCAD risk. Several associated variants have diametrically opposite associations with CAD, suggesting that shared biological processes contribute to both diseases, but through different mechanisms. We also infer a causal role for high blood pressure in SCAD. Our findings provide novel pathophysiological insights involving arterial integrity and tissue-mediated coagulation in SCAD and set the stage for future specific therapeutics and preventions.

Arterial dissections: Common features and new perspectives

Arterial dissections, which involve an abrupt tear in the wall of a major artery resulting in the intramural accumulation of blood, are a family of catastrophic disorders causing major, potentially fatal sequelae. Involving diverse vascular beds, including the aorta or coronary, cervical, pulmonary, and visceral arteries, each type of dissection is devastating in its own way. Traditionally they have been studied in isolation, rather than collectively, owing largely to the distinct clinical consequences of dissections in different anatomical locations - such as stroke, myocardial infarction, and renal failure. Here, we review the shared and unique features of these arteriopathies to provide a better understanding of this family of disorders. Arterial dissections occur commonly in the young to middle-aged, and often in conjunction with hypertension and/or migraine; the latter suggesting they are part of a generalized vasculopathy. Genetic studies as well as cellular and molecular investigations of arterial dissections reveal striking similarities between dissection types, particularly their pathophysiology, which includes the presence or absence of an intimal tear and vasa vasorum dysfunction as a cause of intramural hemorrhage. Pathway perturbations common to all types of dissections include disruption of TGF-β signaling, the extracellular matrix, the cytoskeleton or metabolism, as evidenced by the finding of mutations in critical genes regulating these processes, including LRP1, collagen genes, fibrillin and TGF-β receptors, or their coupled pathways. Perturbances in these connected signaling pathways contribute to phenotype switching in endothelial and vascular smooth muscle cells of the affected artery, in which their physiological quiescent state is lost and replaced by a proliferative activated phenotype. Of interest, dissections in various anatomical locations are associated with distinct sex and age predilections, suggesting involvement of gene and environment interactions in disease pathogenesis. Importantly, these cellular mechanisms are potentially therapeutically targetable. Consideration of arterial dissections as a collective pathology allows insight from the better characterized dissection types, such as that involving the thoracic aorta, to be leveraged to inform the less common forms of dissections, including the potential to apply known therapeutic interventions already clinically available for the former.

Burden of Rare Genetic Variants in Spontaneous Coronary Artery Dissection With High-risk Features

Importance

The emerging genetic basis of spontaneous coronary artery dissection (SCAD) has been defined as both partially complex and monogenic in some patients, involving variants predominantly in genes known to underlie vascular connective tissue diseases (CTDs). The effect of these genetic influences has not been defined in high-risk SCAD phenotypes, and the identification of a high-risk subgroup of individuals may help to guide clinical genetic evaluations of SCAD.

Objective

To identify and quantify the burden of rare genetic variation in individuals with SCAD with high-risk clinical features.

Design, Setting, and Participants

Whole-exome sequencing (WES) was performed for subsequent case-control association analyses and individual variant annotation among individuals with high-risk SCAD. Genetic variants were annotated for pathogenicity by in-silico analysis of genes previously defined by sequencing for vascular CTDs and/or SCAD, as well as genes prioritized by genome-wide association study (GWAS) and colocalization of arterial expression quantitative trait loci. Unbiased genome-wide association analysis of the WES data was performed by comparing aggregated variants in individuals with SCAD to healthy matched controls or the Genome Aggregation Database (gnomAD). This study was conducted at a tertiary care center. Individuals in the Canadian SCAD Registry genetics study with a high-risk SCAD phenotype were selected and defined as peripartum SCAD, recurrent SCAD, or SCAD in an individual with family history of arteriopathy.

Main Outcomes and Measures

Burden of genetic variants defined by DNA sequencing in individuals with high-risk SCAD.

Results

This study included a total of 336 participants (mean [SD] age, 53.0 [9.5] years; 301 female participants [90%]). Variants in vascular CTD genes were identified in 17.0% of individuals (16 of 94) with high-risk SCAD and were enriched (OR, 2.6; 95% CI, 1.6-4.2; P = 7.8 × 10-4) as compared with gnomAD, with leading significant signals in COL3A1 (OR, 13.4; 95% CI, 4.9-36.2; P = 2.8 × 10-4) and Loeys-Dietz syndrome genes (OR, 7.9; 95% CI, 2.9-21.2; P = 2.0 × 10-3). Variants in GWAS-prioritized genes, observed in 6.4% of individuals (6 of 94) with high-risk SCAD, were also enriched (OR, 3.6; 95% CI, 1.6-8.2; P = 7.4 × 10-3). Variants annotated as likely pathogenic or pathogenic occurred in 4 individuals, in the COL3A1, TGFBR2, and ADAMTSL4 genes. Genome-wide aggregated variant testing identified novel associations with peripartum SCAD.

Conclusions and Relevance

In this genetic study, approximately 1 in 5 individuals with a high-risk SCAD phenotype harbored a rare genetic variant in genes currently implicated for SCAD. Genetic screening in this subgroup of individuals presenting with SCAD may be considered.

Spontaneous Coronary Artery Dissection Associated With Infertility Treatment

Assisted conception involving hormonals is a risk factor for spontaneous coronary artery dissection (SCAD), and pregnant women with spontaneous coronary artery dissection are more likely to have had treatment for subfertility. Increasingly, there is a risk of maternal death in women after assisted conception, and so, the need to assess the cardiovascular sequelae after assisted conception is imperative. This is an illustrative case of spontaneous coronary artery dissection shortly after a repeat cycle of in vitro fertilisation (IVF).

The aetiology of spontaneous coronary artery dissection is believed to be multi-factorial, affecting mostly young women, a population similar to women requiring assisted conception. The oestrogen and progesterone used in in vitro fertilisation are believed to trigger structural weakening in the coronary blood vessels, leading to vascular rupture. Repeat in vitro fertilisation cycles and successful conception are thought to increase spontaneous coronary artery dissection risk by increasing hormonal exposure.

The management of spontaneous coronary artery dissection is dependent on if pregnancy has been achieved or not, and a multi-disciplinary approach to its management is essential.

More research is needed to identify women at higher risk of this life-threatening event.

Reconstruction and analysis of potential biomarkers for hypertrophic cardiomyopathy based on a competing endogenous RNA network

Hypertrophic cardiomyopathy (HCM) is a common heritable cardiomyopath. Although considerable effort has been made to understand the pathogenesis of HCM, the mechanism of how long noncoding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) network result in HCM remains unknown. In this study, we acquired a total of 520 different expression profiles of lncRNAs (DElncRNAs) and 371 messenger RNAs (mRNA, DEGs) by microarray and 33 microRNAs (DEmiRNAs) by sequencing in plasma of patients with HCM and healthy controls. Then lncRNA–miRNA pairs were predicted using miRcode and starBase and crossed with DEmiRNAs. MiRNA–mRNA pairs were retrieved from miRanda and TargetScan and crossed with DEGs. Combined with these pairs, the ceRNA network with eight lncRNAs, three miRNAs, and 22 mRNAs was constructed. lncRNA RP11-66N24.4 and LINC00310 were among the top 10% nodes. The hub nodes were analyzed to reconstruct a subnetwork. Furthermore, quantitative real-time polymerase chain reaction results showed that LINC00310 was significantly decreased in patients with HCM. For LINC00310, GO analysis revealed that biological processes were enriched in cardiovascular system development, sprouting angiogenesis, circulatory system development, and pathway analysis in the cGMP-PKG signaling pathway. These results indicate that the novel lncRNA-related ceRNA network in HCM and LINC00310 may play a role in the mechanism of HCM pathogenesis, which could provide insight into the pathogenesis of HCM.

The complex genetic basis of fibromuscular dysplasia, a systemic arteriopathy associated with multiple forms of cardiovascular disease

Artery stenosis is a common cause of hypertension and stroke and can be due to atherosclerosis accumulation in the majority of cases and in a small fraction of patients to arterial fibromuscular dysplasia (FMD). Artery stenosis due to atherosclerosis is widely studied with known risk factors (e.g. increasing age, male gender, and dyslipidemia) to influence its etiology, including genetic factors. However, the causes of noninflammatory and nonatherosclerotic stenosis in FMD are less understood. FMD occurs predominantly in early middle-age women, a fraction of the population where cardiovascular risk is different and understudied. FMD arteriopathies are often diagnosed in the context of hypertension and stroke and co-occur mainly with spontaneous coronary artery dissection, an atypical cause of acute myocardial infarction. In this review, we provide a comprehensive overview of the recent advances in the understanding of molecular origins of FMD. Data were obtained from genetic studies using complementary methodological approaches applied to familial, syndromic, and sporadic forms of this intriguing arteriopathy. Rare variation analyses point toward mechanisms related to impaired prostacyclin signaling and defaults in fibrillar collagens. The study of common variation, mainly through a recent genome-wide association study, describes a shared genetic link with blood pressure, in addition to point at potential risk genes involved in actin cytoskeleton and intracellular calcium homeostasis supporting impaired vascular contraction as a key mechanism. We conclude this review with future strategies and approaches needed to fully understand the genetic and molecular mechanisms related to FMD.

Exploring the Genetic Architecture of Spontaneous Coronary Artery Dissection Using Whole-Genome Sequencing

Background:

Spontaneous coronary artery dissection (SCAD) is a cause of acute coronary syndrome that predominantly affects women. Its pathophysiology remains unclear but connective tissue disorders (CTD) and other vasculopathies have been observed in many SCAD patients. A genetic component for SCAD is increasingly appreciated, although few genes have been robustly implicated. We sought to clarify the genetic cause of SCAD using targeted and genome-wide methods in a cohort of sporadic cases to identify both common and rare disease-associated variants.

Methods:

A cohort of 91 unrelated sporadic SCAD cases was investigated for rare, deleterious variants in genes associated with either SCAD or CTD, while new candidate genes were sought using rare variant collapsing analysis and identification of novel loss-of-function variants in genes intolerant to such variation. Finally, 2 SCAD polygenic risk scores were applied to assess the contribution of common variants.

Results:

We identified 10 cases with at least one rare, likely disease-causing variant in CTD-associated genes, although only one had a CTD phenotype. No genes were significantly associated with SCAD from genome-wide collapsing analysis, however, enrichment for TGF (transforming growth factor)-β signaling pathway genes was found with analysis of 24 genes harboring novel loss-of-function variants. Both polygenic risk scores demonstrated that sporadic SCAD cases have a significantly elevated genetic SCAD risk compared with controls.

Conclusions:

SCAD shares some genetic overlap with CTD, even in the absence of any major CTD phenotype. Consistent with a complex genetic architecture, SCAD patients also have a higher burden of common variants than controls.

Sex-dimorphic gene effects on survival outcomes in people with coronary artery disease

Background:

Ischemic coronary heart disease (IHD) is the leading cause of death worldwide. Genetic variation is presumed to be a major factor underlying sex differences for IHD events, including mortality. The purpose of this study was to identify sex-specific candidate genes associated with all-cause mortality among people diagnosed with coronary artery disease (CAD).

Methods:

We performed a sex-stratified, exploratory genome-wide association (GWAS) screen using existing data from CAD-diagnosed males (n = 510) and females (n = 174) who reported European ancestry from the Duke Catheterization Genetics biorepository. Extant genotype data for 785,945 autosomal SNPs generated with the Human Omni1-Quad BeadChip (Illumina, CA, USA) were analyzed using an additive inheritance model. We estimated instantaneous risk of all-cause mortality by genotype groups across the 11-year follow-up using Cox multivariate regression, covarying for age and genomic ancestry.

Results:

The top GWAS hits associated with all-cause mortality among people with CAD included 8 SNPs among males and 15 among females (p = 1 × 10⁻⁶ or 10⁻⁷), adjusted for covariates. Cross-sex comparisons revealed distinct candidate genes. Biologically relevant candidates included rs9932462 (EMP2/TEKT5) and rs2835913 (KCNJ6) among males and rs7217169 (RAP1GAP2), rs8021816 (PRKD1), rs8133010 (PDE9A), and rs12145981 (LPGAT1) among females.

Conclusions:

We report 20 sex-specific candidate genes having suggestive association with all-cause mortality among CAD-diagnosed subjects. Findings demonstrate proof of principle for identifying sex-associated genetic factors that may help explain differential mortality risk in people with CAD. Replication and meta-analyses in larger studies with more diverse samples will strengthen future work in this area.

Genome-Wide Identification of Associations of Circulating Molecules With Spontaneous Coronary Artery Dissection and Aortic Aneurysm and Dissection

Circulating proteins play functional roles in various biological processes and disease pathogenesis. The aim of this study was to highlight circulating proteins associated with aortic aneurysm and dissection (AAD) and spontaneous coronary artery dissection (SCAD). We examined the associations of circulating molecule levels with SCAD by integrating data from a genome-wide association study (GWAS) of CanSCAD and 7 pQTL studies. Mendelian randomization (MR) analysis was applied to examine the associations between circulating molecule levels and AAD by using data from UK Biobank GWAS and pQTL studies. The SCAD-associated SNPs in 1q21.2 were strongly associated with circulating levels of extracellular matrix protein 1 (ECM1) and 25 other proteins (encoded by CTSS, CAT, CNDP1, KNG1, SLAMF7, TIE1, CXCL1, MBL2, ESD, CXCL16, CCL14, KCNE5, CST7, PSME1, GPC3, MAP2K4, SPOCK3, LRPPRC, CLEC4M, NOG, C1QTNF9, CX3CL1, SCP2D1, SERPINF2, and FN1). These proteins were enriched in biological processes such as regulation of peptidase activity and regulation of cellular protein metabolic processes. Proteins (FGF6, FGF9, HGF, BCL2L1, and VEGFA) involved in the Ras signaling pathway were identified to be related to AAD. In addition, SCAD- and AAD-associated SNPs were associated with cytokine and lipid levels. MR analysis showed that circulating ECM1, SPOCK3 and IL1b levels were associated with AAD. Circulating levels of low-density lipoprotein cholesterol and small very-low-density lipoprotein particles were strongly associated with AAD. The present study found associations between circulating proteins and lipids and SCAD and AAD. Circulating ECM1 and low-density lipoprotein cholesterol may play a role in the pathology of SCAD and AAD.

Optical Coherence Tomography and Coronary Dissection: Precious Tool or Useless Surplus?

Spontaneous coronary artery dissection (SCAD) is a rare clinical condition, but frequently manifested as acute myocardial infarction. In this particular setting, in recent years, optical coherence tomography (OCT) has been established as a possible diagnostic method due to the high spatial resolution (10–20 μm), which can visualize the different layers of coronary vessels. OCT can better analyze the “binary” or double lumen morphology, typical of this entity. Furthermore, it can identify the entrance breach and the circumferential and longitudinal extension of the lesion. However, we have to emphasize that this technique is not free from complications. OCT could further aggravate a dissection or exacerbate a new intimal tear. Therefore, the use of OCT in the evaluation of SCAD should be defined by balancing the diagnostic benefits versus procedural risks. Moreover, we underline that as SCAD is a rare condition and OCT is a recently introduced technique in clinical practice, limited data is available in literature.

Fibrillar Collagen Variants in Spontaneous Coronary Artery Dissection

IMPORTANCE

Spontaneous coronary artery dissection (SCAD) is an increasingly recognized nonatherosclerotic cause of acute myocardial infarction enriched among individuals with early-onset myocardial infarction but is of unclear etiology.

OBJECTIVE

To assess which genes contribute to the development of SCAD.

DESIGN, SETTING, AND PARTICIPANTS

To prioritize genes influencing risk for SCAD, whole-exome sequencing was performed among individuals with SCAD in the discovery and replication cohorts from a tertiary care hospital outpatient specialty clinic, and gene set enrichment analyses were also performed for disruptive coding variants. All patients were sequentially enrolled beginning July 2013. Aggregate prevalence of rare disruptive variants for prioritized gene sets was compared between individuals with SCAD with population-based controls comprising 46 468 UK Biobank participants with whole-exome sequencing. Complementary mice models were used for in vivo validation. Analysis took place between June 2020 and January 2021.

MAIN OUTCOMES AND MEASURES

The frequency and identity of rare genetic variants in individuals with SCAD.

RESULTS

Of 130 patients, 109 (83.8%) were female (26 of 32 [81.2%] in the discovery cohort and 83 of 98 [84.7%] in the replication cohort) with mean (SD) age at first SCAD event of 48.41 (8.76) years in the discovery cohort and 47.74 (10.09) years in the replication cohort. Across all patients with SCAD, rare disruptive variants were found within 10 collagen genes (COL3A1, COL5A1, COL4A1, COL6A1, COL5A2, COL12A1, COL4A5, COL1A1, COL1A2, and COL27A1) were 17-fold (P = 1.5 × 10-9) enriched among individuals with SCAD compared with a background of 2506 constrained genes expressed in coronary artery. Furthermore, compared with individuals from the UK Biobank, individuals with SCAD were 1.75-fold (P = .04) more likely to carry disruptive rare variants within fibrillar collagen genes. Complementary mice models haploinsufficient for Col3a1 or Col5a1, the 2 most common collagen gene variants identified in SCAD cases, demonstrated increased risk of arterial dissection and increased size of arterial diameters especially in female mice, with resulting changes in collagen fibril organization and diameter.

CONCLUSIONS AND RELEVANCE

Unbiased gene discovery in patients with SCAD with independent human and murine validation highlights the role of the extracellular matrix dysfunction in SCAD.

Association of Circulating Cathepsin B Levels With Blood Pressure and Aortic Dilation

Hypertension is a key risk factor for spontaneous coronary artery dissection (SCAD) and aortic dilation. Circulating proteins play key roles in a range of biological processes and represent a major source of druggable targets. The aim of this study was to identify circulating proteins that were associated with blood pressure (BP), SCAD and aortic dilation. We identified shared genetic variants of BP and SCAD in genome-wide association studies, searched for circulating protein affected by these variants and examined the association of circulating protein levels with BP, aortic aneurysm and dissection (AAD) and aortic diameters by integrating data from circulating protein quantitative trait loci (pQTL) studies and genome wide association study (GWAS) in individuals from the UK Biobank using two-sample Mendelian randomization analysis methods. Single nucleotide polymorphisms (SNPs) in JAG1, ERI1, ULK4, THSD4, CMIP, COL4A2, FBN1, FAM76B, FGGY, NUS1, and HNF4G, which were related to extracellular matrix components, were associated with both BP and SCAD. We found 49 significant pQTL signals among these SNPs. The regulated proteins were encoded by MMP10, IL6R, FIGF, MMP1, CTSB, IGHG1, DSG2, TTC17, RETN, POMC, SCARF2, RELT, and GALNT16, which were enriched in biological processes such as collagen metabolic process and multicellular organism metabolic process. Causal associations between BP and AAD and aortic diameters were detected. Significant associations between circulating levels of cathepsin B, a well-known prorenin processing enzyme, and BP and aortic diameters were identified by using several Mendelian randomization analysis methods and were validated by independent data.

Diagnostic Performance of High-Resolution Vessel Wall Magnetic Resonance Imaging and Digital Subtraction Angiography in Intracranial Vertebral Artery Dissection

Purpose: Intracranial vertebral artery dissection (VAD) is being increasingly recognized as a leading cause of Wallenberg syndrome and subarachnoid hemorrhage. Conventional angiography is considered the standard diagnostic modality, but the diagnosis of VAD remains challenging. This study aimed to compare the diagnostic performance of high-resolution vessel wall imaging (HR-VWI) with digital subtraction angiography (DSA) for intracranial VAD. Materials and methods: Twenty-four patients with 27 VADs, who underwent both HR-VWI and DSA within 2 weeks, were consecutively enrolled in the study from March 2016 to September 2020. HR-VWI and DSA were performed to diagnose VAD and to categorize its angiographic features as either definite dissection or suspicious dissection. Features of HR-VWI were used to evaluate direct arterial wall imaging. The reference standard was set from the clinicoradiologic diagnosis. Two independent raters evaluated the angiographic features, dissection signs, and interrater agreement. Each subject was also dichotomized into two groups (suspicious or definite VAD) in each modality, and diagnosis from HR-VWI and DSA was compared with the final diagnosis by consensus. Results: HR-VWI had higher agreement (90.6% vs. 53.1%) with the final diagnosis and better interrater reliability (kappa value (κ) = 0.91; 95% confidence interval (CI) = 0.64–1.00) compared with DSA (κ = 0.58; 95% CI = 0.35–1.00). HR-VWI provided a more detailed identification of dissection signs (77.7% vs. 22.2%) and better reliability (κ = 0.88; 95% CI = 0.58–1.00 vs. κ = 0.75; 95% CI = 0.36–1.00), compared to DSA. HR-VWI was comparable to DSA for the depiction of angiographic features for VAD. Conclusions: HR-VWI may be useful to evaluate VAD, with better diagnostic confidence compared to DSA.

Migraine, Stroke, and Cervical Arterial Dissection: Shared Genetics for a Triad of Brain Disorders With Vascular Involvement

BACKGROUND AND OBJECTIVES

Migraine, stroke, and cervical artery dissection (CeAD) represent a triad of cerebrovascular disorders with pairwise comorbid relationships and vascular involvement. Larger samples and recent advances in methodology invite systematic exploration of their shared genetics.

METHODS

Genetic analyses leveraged summary statistics from genome-wide association studies of the largest available samples of each disorder, including subtypes of stroke (ischemic stroke, large artery stroke, small vessel stroke, and cardioembolic stroke) and migraine (with aura and without aura). For each pair of disorders, genetic correlation was assessed both on a genome-wide basis and within independent segments across the genome including known specific loci for each disorder. A cross-trait meta-analysis was used to identify novel candidate loci. Finally, potential causality of migraine susceptibility on stroke and CeAD was assessed by Mendelian randomization.

RESULTS

Among all pairs of disorders, genome-wide genetic correlation was observed only between CeAD and migraine, particularly MO. Local genetic correlations were more extensive between migraine and CeAD than those between migraine and stroke or CeAD and stroke and revealed evidence for novel CeAD associations at rs6693567 (ADAMTSL4/ECM1), rs11187838 (PLCE1), and rs7940646 (MRVI1) while strengthening prior subthreshold evidence at rs9486725 (FHL5) and rs650724 (LRP1). At known migraine loci, novel associations with stroke had concordant risk alleles for small vessel stroke at rs191602009 (CARF) and for cardioembolic stroke at rs55884259 (NKX2-5). Known migraine loci also revealed novel associations but with opposite risk alleles for all stroke, ischemic stroke, and small vessel stroke at rs55928386 (HTRA1), for large artery stroke at rs11172113 (LRP1), and for all stroke and ischemic stroke at rs1535791 and rs4942561 (both LRCH1), respectively. rs182923402 (near PTCH1) was a novel concordant locus for migraine and cardioembolic stroke. Mendelian randomization supported potential causal influences of migraine on CeAD (odds ratio [95% confidence interval] per doubling migraine prevalence = 1.69 [1.24-2.3], p = 0.0009) with concordant risk, but with opposite risk on large artery stroke (0.86 [0.76-0.96], p = 0.0067).

DISCUSSION

The findings emphasize shared genetic risk between migraine and CeAD while identifying loci with likely vascular function in migraine and shared but opposite genetic risk between migraine and stroke subtypes, and a central role of LRP1 in all 3 cerebrovascular disorders.

Spontaneous Coronary Artery Dissection: New Insights into This Not-So-Rare Condition

Spontaneous coronary artery dissection (SCAD) is an uncommon but increasingly recognized cause of acute myocardial infarction (MI) among young and middle-aged women and is an important cause of pregnancy-associated MI. Over 90% of SCAD patients are women. Compared to patients with MI caused by atherosclerosis, SCAD patients have fewer cardiovascular risk factors but more often have systemic arteriopathy, most commonly fibromuscular dysplasia. Angiographically, SCAD is characterized by the presence of an intramural hematoma with or without an intimal tear. Accurate recognition of characteristic findings on coronary angiography is critical, as there are important differences in the acute and long-term management of MI caused by SCAD versus atherosclerosis. Acutely, most SCAD patients should be managed conservatively, since percutaneous revascularization is associated with more complications and SCAD-affected vessels usually heal without intervention. Randomized clinical trials and other prospective evaluations are needed, especially to clarify optimal treatment and prevention strategies.

Is there a genetic basis for spontaneous coronary artery dissection?

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Recent Advances on the Genetics of Spontaneous Coronary Artery Dissection

Spontaneous coronary artery dissection (SCAD) has been acknowledged as a significant cause of acute myocardial infarction, predominantly in young to middle-aged women. SCAD often occurs in patients with fewer cardiovascular risk factors than atherosclerotic acute myocardial infarction. Unfortunately, SCAD remains underdiagnosed due to a lack of awareness among health care providers leading to misdiagnosis. The underlying pathophysiological mechanisms of SCAD are not well understood. SCAD occurring in members of the same family has been described, suggesting a potentially identifiable genetically triggered cause in at least some cases. However, thus far, the search for highly penetrant mutations in candidate pathways has had a low yield, often pointing to genes involved in other clinically undiagnosed hereditary syndromes manifesting as SCAD. Recent exploratory efforts using exome sequencing and genome-wide association studies have provided several interesting leads toward understanding the pathogenesis of SCAD. Here, we review recent publications where rare and common genetic factors were reported to associate with a predisposition to SCAD and indicate suggestions for the future strategies and approaches needed to fully address the genetic basis of this intriguing and atypical cause of acute myocardial infarction.

Whole-exome sequencing reveals a role of HTRA1 and EGFL8 in brain white matter hyperintensities

White matter hyperintensities (WMH) are among the most common radiological abnormalities in the ageing population and an established risk factor for stroke and dementia. While common variant association studies have revealed multiple genetic loci with an influence on their volume, the contribution of rare variants to the WMH burden in the general population remains largely unexplored. We conducted a comprehensive analysis of this burden in the UK Biobank using publicly available whole-exome sequencing data (n up to 17 830) and found a splice-site variant in GBE1, encoding 1,4-alpha-glucan branching enzyme 1, to be associated with lower white matter burden on an exome-wide level [c.691+2T>C, β = -0.74, standard error (SE) = 0.13, P = 9.7 × 10-9]. Applying whole-exome gene-based burden tests, we found damaging missense and loss-of-function variants in HTRA1 (frequency of 1 in 275 in the UK Biobank population) to associate with an increased WMH volume (P = 5.5 × 10-6, false discovery rate = 0.04). HTRA1 encodes a secreted serine protease implicated in familial forms of small vessel disease. Domain-specific burden tests revealed that the association with WMH volume was restricted to rare variants in the protease domain (amino acids 204-364; β = 0.79, SE = 0.14, P = 9.4 × 10-8). The frequency of such variants in the UK Biobank population was 1 in 450. The WMH volume was brought forward by ∼11 years in carriers of a rare protease domain variant. A comparison with the effect size of established risk factors for WMH burden revealed that the presence of a rare variant in the HTRA1 protease domain corresponded to a larger effect than meeting the criteria for hypertension (β = 0.26, SE = 0.02, P = 2.9 × 10-59) or being in the upper 99.8% percentile of the distribution of a polygenic risk score based on common genetic variants (β = 0.44, SE = 0.14, P = 0.002). In biochemical experiments, most (6/9) of the identified protease domain variants resulted in markedly reduced protease activity. We further found EGFL8, which showed suggestive evidence for association with WMH volume (P = 1.5 × 10-4, false discovery rate = 0.22) in gene burden tests, to be a direct substrate of HTRA1 and to be preferentially expressed in cerebral arterioles and arteries. In a phenome-wide association study mapping ICD-10 diagnoses to 741 standardized Phecodes, rare variants in the HTRA1 protease domain were associated with multiple neurological and non-neurological conditions including migraine with aura (odds ratio = 12.24, 95%CI: 2.54-35.25; P = 8.3 × 10-5]. Collectively, these findings highlight an important role of rare genetic variation and the HTRA1 protease in determining WMH burden in the general population.

Spontaneous Coronary Artery Dissection: An Underdiagnosed Clinical Entity-A Primer for Cardiac Imagers

Spontaneous coronary artery dissection (SCAD) is a nonatherosclerotic cause of myocardial infarction in young and middle-aged women that has gained increasing awareness in recent years. Its diagnosis presents a challenge. Invasive coronary angiography is the primary imaging modality for diagnosing SCAD; however, it carries risk in these patients, who have an increased predisposition to complications. Advances in CT technology enable robust noninvasive evaluation of the coronary arteries at low radiation doses and have been increasingly utilized for the diagnosis or resolution of SCAD, in hemodynamically stable patients or when diagnosis of SCAD is uncertain at invasive angiography, particularly in proximal vessels. However, criteria for the diagnosis of SCAD with use of coronary CT angiography (CCTA) have not been currently established, and sensitivity and specificity for diagnosis have not yet been defined. The appearance of SCAD at CCTA can be subtle and can be missed, especially in distal small-caliber coronary arteries; hence utilization of other noninvasive imaging multimodalities may help solve this diagnostic challenge. Accurate and prompt diagnosis is vital, as management of SCAD differs significantly from that of traditional atherosclerotic acute coronary syndromes, with conservative management preferred for the majority of SCAD patients, and invasive treatment reserved for those with ongoing or recurrent ischemia, heart failure, or hemodynamic compromise. The goal of this review is twofold: (a) to discuss the potential role of CCTA in the diagnosis of SCAD, and (b) to discuss the role of multimodality imaging that may improve diagnostic yield, guide management, and enable subsequent surveillance. An invited commentary by Ordovas is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

Genetic investigation of fibromuscular dysplasia identifies risk loci and shared genetics with common cardiovascular diseases

Fibromuscular dysplasia (FMD) is an arteriopathy associated with hypertension, stroke and myocardial infarction, affecting mostly women. We report results from the first genome-wide association meta-analysis of six studies including 1556 FMD cases and 7100 controls. We find an estimate of SNP-based heritability compatible with FMD having a polygenic basis, and report four robustly associated loci (PHACTR1, LRP1, ATP2B1, and LIMA1). Transcriptome-wide association analysis in arteries identifies one additional locus (SLC24A3). We characterize open chromatin in arterial primary cells and find that FMD associated variants are located in arterial-specific regulatory elements. Target genes are broadly involved in mechanisms related to actin cytoskeleton and intracellular calcium homeostasis, central to vascular contraction. We find significant genetic overlap between FMD and more common cardiovascular diseases and traits including blood pressure, migraine, intracranial aneurysm, and coronary artery disease.

National French registry of spontaneous coronary artery dissections: prevalence of fibromuscular dysplasia and genetic analyses

BACKGROUND

Spontaneous coronary artery dissection (SCAD) is an increasingly reported but poorly understood condition. Few European data are available.

AIMS

The aims of this study were to obtain European data on SCAD, determine the prevalence of fibromuscular dysplasia (FMD) and enable genetic analyses in this population.

METHODS

Data from a national French registry of SCAD cases were analysed prospectively and retrospectively. Clinical and angiographic data and management strategy were collected. Major adverse cardiovascular events (MACE) were analysed after one year of follow-up. Subjects were screened for FMD and blood was collected for DNA extraction.

RESULTS

From June 2016 to August 2018, 373 SCAD cases were confirmed by the core lab. Mean age was 51.5 years. Patients were mostly women (90.6%) and 54.7% of cases had less than two cardiovascular risk factors. At one year, 295 patients (79.1%) were treated conservatively, the MACE rate was 12.3%, and there were no cases of mortality. The recurrence rate of SCAD was 3.3%. FMD was found at ≥1 arterial site in 45.0% of cases. We also confirmed the genetic association between the PHACTR1 locus and SCAD (odds ratio=1.66, p=7.08×10-8).

CONCLUSIONS

Here we describe the DISCO registry, the largest European SCAD cohort where FMD was found in 45% of cases and the genetic association with PHACTR1 was confirmed. This nationwide cohort is a valuable resource for future clinical and genetic investigation to understand SCAD aetiology.

Spontaneous Coronary Artery Dissection: Pitfalls of Angiographic Diagnosis and an Approach to Ambiguous Cases

Spontaneous coronary artery dissection (SCAD) is a pathophysiologically distinct cause of acute coronary syndromes (ACS). It is increasingly recognized that optimal management is different from that for atherosclerotic ACS and that a SCAD diagnosis has specific long-term prognostic and therapeutic implications. Accurate diagnosis is therefore essential to ensure the best treatment of patients. At present this relies on the recognition of typical features of SCAD identified on invasive coronary angiography. Although most SCAD can be readily distinguished angiographically from alternative causes of ACS, false positive and false negative diagnoses remain common. In particular, sometimes non-SCAD presentations, including atherothrombosis, takotsubo cardiomyopathy, coronary embolism, coronary vasospasm, contrast streaming, and myocardial infarction with nonobstructive coronary arteries, can mimic angiographic features usually associated with SCAD. The authors present the combined experience from European and US SCAD referral centers reviewing the classical angiographic appearances of SCAD, presenting potential diagnostic pitfalls and exemplars of SCAD mimickers. The authors further review the benefits and limitations of intracoronary imaging in the context of SCAD. Finally, the authors discuss the investigation of ambiguous cases and an approach to minimize misdiagnosis in difficult cases.

Genome-Wide Identification of RNA Modifications for Spontaneous Coronary Aortic Dissection

RNA modification plays important roles in many biological processes such as gene expression control. Genetic variants that affect RNA modification may have functional roles in aortic dissection. The aim of this study was to identify RNA modifications related to spontaneous coronary artery dissection (SCAD). We examined the association of RNA modification-associated single-nucleotide polymorphisms (RNAm-SNPs) with SCAD in summary data from a genome-wide association study (GWAS) of European descent (270 SCAD cases and 5,263 controls). Furthermore, we performed expression quantitative loci (eQTL) and protein quantitative loci (pQTL) analyses for the RNAm-SNPs using publicly available data. Functional enrichment and protein–protein interaction analyses were performed for the identified proteins. We found 11,464 unique RNAm-SNPs in the SCAD GWAS dataset, and 519 were nominally associated with SCAD. Nine RNAm-SNPs were associated with SCAD at p < 0.001, and among them, seven were N⁶-methyladenosine (m⁶A) methylation-related SNPs, one (rs113664950 in HLA-DQB1) was m⁷G-associated SNP, and one [rs580060 in the 3′-UTR of Mitochondrial Ribosomal Protein S21 (MRPS21)] was A-to-I modification SNP. The genome-wide significant SNP rs3818978 (SCAD association p = 5.74 × 10^–10) in the 5′-UTR of MRPS21 was related to m⁶A modification. These nine SNPs all showed eQTL effects, and six of them were associated with circulating protein or metabolite levels. The related protein-coding genes were enriched in specific Gene Ontology (GO) terms such as extracellular space, extracellular region, defense response, lymphocyte migration, receptor binding and cytokine receptor binding, and so on. The present study found the associations between RNAm-SNPs and SCAD. The findings suggested that RNA modification may play functional roles in SCAD.

FMD and SCAD: Sex-Biased Arterial Diseases With Clinical and Genetic Pleiotropy

Multifocal fibromuscular dysplasia (FMD) and spontaneous coronary artery dissection are both sex-biased diseases disproportionately affecting women over men in a 9:1 ratio. Traditionally known in the context of renovascular hypertension, recent advances in knowledge about FMD have demonstrated that FMD is a systemic arteriopathy presenting as arterial stenosis, aneurysm, and dissection in virtually any arterial bed. FMD is also characterized by major cardiovascular presentations including hypertension, stroke, and myocardial infarction. Similar to FMD, spontaneous coronary artery dissection is associated with a high prevalence of extracoronary vascular abnormalities, including FMD, aneurysm, and extracoronary dissection, and recent studies have also found genetic associations between the two diseases. This review will summarize the relationship between FMD and spontaneous coronary artery dissection with a focus on common clinical associations, histopathologic mechanisms, genetic susceptibilities, and the biology of these diseases. The current status of disease models and critical future research directions will also be addressed.

Contribution of lncRNA CASC8, CASC11, and PVT1 Genetic Variants to the Susceptibility of Coronary Heart Disease

ABSTRACT

The purpose of this study was to explore the relationship between lncRNA CASC8, CASC11, and plasmacytoma variant translocation 1 (PVT1). genetic variants and coronary heart disease (CHD) susceptibility among a Chinese Han population. Five single nucleotide polymorphisms were genotyped by Agena MassARRAY platform among 464 CHD patients and 510 healthy controls. Binary logistic regression models by calculating odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association between selected single nucleotide polymorphisms and CHD risk. Multifactor dimensionality reduction analysis was performed to analyze gene-gene interaction. PVT1 rs4410871 (OR = 0.77, P = 0.040) was associated with a reduced risk of CHD occurrence in the Chinese population. CASC11 rs9642880 (OR = 1.49, P = 0.021) was a risk factor for increased CHD susceptibility in subjects over 60 years old, and PVT1 rs4410871 was a protective factor for CHD susceptibility in males (OR = 0.67, P = 0.015) and smokers (OR = 0.62, P = 0.047). Complications (hypertension or diabetes) of CHD influenced the association between CASC8, CASC11, and PVT1 genetic polymorphisms and CHD predisposition. Moreover, CASC8, CASC11, and PVT1 polymorphisms were related to the number of pathological branches and Gensini score in CHD patients. The study displayed the contribution of CASC8, CASC11, and PVT1 genetic polymorphisms to CHD predisposition, and these variants could serve as potential biomarkers of CHD susceptibility. These findings contribute to enhancing the understanding of the role of lncRNA polymorphisms in CHD risk.

The molecular mechanism of LRP1 in physiological vascular homeostasis and signal transduction pathways

Interactions between vascular smooth muscle cells (VSMCs), endothelial cells (ECs), pericytes (PCs) and macrophages (MФ), the major components of blood vessels, play a crucial role in maintaining vascular structural and functional homeostasis. Low-density lipoprotein (LDL) receptor-related protein-1 (LRP1), a transmembrane receptor protein belonging to the LDL receptor family, plays multifunctional roles in maintaining endocytosis, homeostasis, and signal transduction. Accumulating evidence suggests that LRP1 modulates vascular homeostasis mainly by regulating vasoactive substances and specific intracellular signaling pathways, including the plasminogen activator inhibitor 1 (PAI-1) signaling pathway, platelet-derived growth factor (PDGF) signaling pathway, transforming growth factor-β (TGF-β) signaling pathway and vascular endothelial growth factor (VEGF) signaling pathway. The aim of the present review is to focus on recent advances in the discovery and mechanism of vascular homeostasis regulated by LRP1-dependent signaling pathways. These recent discoveries expand our understanding of the mechanisms controlling LRP1 as a target for studies on vascular complications.

Recurrent spontaneous coronary artery dissection

Introduction: Spontaneous coronary artery dissection (SCAD) is a cause of non-atherosclerotic acute coronary syndrome and sudden cardiac death that predominantly impacts young and middle-aged women. In addition to the challenges of acute SCAD including arrhythmias, heart failure, and recurrent chest pain, de novo recurrent SCAD occurs in 5-29% of patients. Recurrent SCAD presents both a psychological burden and a significant cardiac risk to patients. Research regarding SCAD recurrence risk has been growing and can guide providers and patients alike.Areas covered: This review provides up-to-date information about many aspects of SCAD with a focus on SCAD recurrence. PubMed articles were reviewed through October 2020, with particular focus on clinical studies and original research. The resulting literature was scrutinized for information on SCAD recurrence. SCAD-associated conditions, genetic data, clinical characteristics, medications, and aspects of post-SCAD care are summarized.Expert Opinion: SCAD recurrence poses a concerning risk for patients with SCAD. Conditions such as hypertension and severe coronary tortuosity may be associated with recurrence. More research is needed to further elucidate risk factors for recurrence and clarify interventions, such as beta blocker therapy, that may reduce recurrence risk.

Lack of Association of Spontaneous Coronary Artery Dissection With Autoimmune Disease

BACKGROUND

Case reports and referral-based studies suggest spontaneous coronary artery dissection (SCAD) is associated with autoimmune diseases and causes 2% to 4% of acute coronary syndromes.

OBJECTIVES

This study determined the association of SCAD with autoimmune diseases, together with incidence and recurrence, in a population-based study.

METHODS

This case-control study took place from 1995 to 2018 within the Rochester Epidemiology Project. The study identified cases with SCAD from diagnosis codes and verified them using coronary angiography images, matching each case to 3 control subjects on age, sex, county, and years of medical history. Autoimmune disease history came from a validated, code-based definition. A multivariable logistic regression model calculated the odds ratio (OR) for SCAD among patients with a history of autoimmune disease, adjusting for race and body mass index.

RESULTS

The study identified 114 cases with SCAD (mean age 51 years and 90% women) and 342 matched control subjects. Autoimmune disease occurred in 13 (11%) cases with SCAD and 40 (12%) control subjects (p = 0.93). Even after adjustment, autoimmune diseases were not associated with SCAD (OR: 0.81; 95% confidence interval [CI]: 0.40 to 1.66). SCAD incidence between 2010 and 2018 (2.7 per 100,000; 95% CI: 1.7 to 3.7) was 10-fold higher than the incidence between 1995 and 2009 (0.3 per 100,000; 95% CI: 0.0 to 0.6). SCAD recurrence was 10% (95% CI: 3% to 16%) at 5 years.

CONCLUSIONS

These findings suggested SCAD pathogenesis is noninflammatory and screening for autoimmune diseases based on SCAD alone is not warranted. The code-based incidence of SCAD has increased over time, highlighting the importance of considering SCAD among patients with acute coronary syndromes.

Spontaneous Coronary Artery Dissection: JACC State-of-the-Art Review

Over the past decade, spontaneous coronary artery dissection (SCAD) has emerged as an important cause of myocardial infarction, particularly among younger women. The pace of knowledge acquisition has been rapid, but ongoing challenges include accurately diagnosing SCAD and improving outcomes. Many SCAD patients experience substantial post-SCAD symptoms, recurrent SCAD, and psychosocial distress. Considerable uncertainty remains about optimal management of associated conditions, risk stratification and prevention of complications, recommendations for physical activity, reproductive planning, and the role of genetic evaluations. This review provides a clinical update on the diagnosis and management of patients with SCAD, including pregnancy-associated SCAD and pregnancy after SCAD, and highlight high-priority knowledge gaps that must be addressed.

Spontaneous coronary artery dissection: Overview of pathophysiology

The growing use of imaging examinations has led to increased detection of spontaneous coronary artery dissection (SCAD) as a non-atherosclerotic cause of acute coronary syndrome (ACS). Since a greater awareness of pathophysiologic mechanisms has relevant implications in clinical practice, we aim to provide an update to current knowledge of SCAD pathophysiology. We discuss the most common conditions associated with SCAD, including predisposing factors and triggers, and focus on potential mechanisms leading to SCAD development. Furthermore, we report the main genetic research findings that have shed further light on SCAD pathophysiology. Finally, we summarize practical considerations in SCAD management based on pathophysiologic insights.