Association of the PHACTR1/EDN1 Genetic Locus With 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: a case series illustrating current challenges in diagnosis and treatment

Spontaneous coronary artery dissection (SCAD) has been increasingly recognized in recent years as an important cause of acute coronary syndrome, myocardial infarction, and sudden death, especially among young women. However, due to the lack of clinical trials on SCAD, evidence-based guidance on management is currently lacking. Presented are four case studies that illustrate the recent insights and challenges in SCAD diagnosis and treatment.

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.

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.

Genetic associations of cardiovascular risk genes in European patients with coronary artery spasm

BACKGROUND

Coronary artery spasm (CAS) is a frequent finding in patients presenting with angina pectoris. Although the pathogenesis of CAS is incompletely understood, previous studies suggested a genetic contribution. Our study aimed to elucidate genetic variants in a cohort of European patients with angina and unobstructed coronary arteries who underwent acetylcholine (ACh) provocation testing.

METHODS

A candidate association analysis of 208 genes previously associated with cardiovascular conditions was performed using genotyped and imputed variants in patients grouped in epicardial (focal, diffuse) CAS (n = 119) and microvascular CAS (n = 87). Patients with a negative ACh test result (n = 45) served as controls.

RESULTS

We found no association below the genome-wide significance threshold of p < 5 × 10-8, thus not confirming variants in ALDH2, NOS3, and ROCK2 previously reported in CAS patients of Asian ancestry. However, the analysis identified suggestive associations (p < 10-05) for the groups of focal epicardial CAS (CDH13) and diffuse epicardial CAS (HDAC9, EDN1). Downstream analysis of the potential EDN1 risk locus showed that CAS patients have significantly increased plasma endothelin-1 levels (ET-1) compared to controls. An EDN1 haplotype comprising rs9349379 and rs2070698 was significantly associated to ET-1 levels (p = 0.01).

CONCLUSIONS

In summary, we suggest EDN1 as potential genetic risk loci for patients with diffuse epicardial CAS, and European ancestry. Plasma ET-1 levels may serve as a potential cardiac marker.

Angiographic patterns in spontaneous coronary artery dissection: novel diagnostic insights

INTRODUCTION

Spontaneous coronary artery dissection (SCAD) is a rare but well-recognized cause of acute coronary syndrome, especially important in women. Invasive coronary angiography (ICA) is the fundamental diagnostic technique for the confirmation of SCAD. Knowing the angiographic patterns suggestive of SCAD is essential for the correct identification of patients with this entity.

AREAS COVERED

In this narrative review, the main angiographic characteristics of SCAD lesions as detected by ICA are presented and discussed.

EXPERT OPINION

In addition to the specific angiographic classification of SCAD, several authors have described complementary angiographic patterns suggestive of SCAD. Knowledge and correct identification of these angiographic patterns is essential for the correct diagnosis of patients with clinical suspicion of SCAD.

Diagnosis and treatment of cardiovascular disease in patients with heritable connective tissue disorders or heritable thoracic aortic diseases

Patients with heritable connective tissue disorders (HCTDs), represented by Marfan syndrome, can develop fatal aortic and/or arterial complications before age 50. Therefore, accurate diagnosis, appropriate medical treatment, and early prophylactic surgical treatment of aortic and arterial lesions are essential to improve prognosis. Patients with HCTDs generally present with specific physical features due to connective tissue abnormalities, while some patients with heritable thoracic aortic diseases (HTADs) have few distinctive physical characteristics. The development of genetic testing has made it possible to provide accurate diagnoses for patients with HCTDs/HTADs. This review provides an overview of the diagnosis and treatment of HCTDs/HTADs, including current evidence on cardiovascular interventions for this population.

Spontaneous coronary artery dissection: a focus on post-dissection care for the vascular medicine clinician

Spontaneous coronary artery dissection (SCAD) is an uncommon condition which is increasingly recognized as a cause of significant morbidity. SCAD can cause acute coronary syndrome and myocardial infarction (MI), as well as sudden cardiac death. It presents similarly to atherosclerotic MI although typically in patients with few or no atherosclerotic risk factors, and particularly in women. As more patients are recognized to have this condition, there is a great need for clinician familiarity with diagnostic criteria, as well as with contemporary treatment approaches, and with appropriate patient-centered counseling, including genetic testing, exercise recommendations, and psychological care. The standard of care for patients with SCAD is rapidly evolving. This review therefore summarizes the diagnosis of SCAD, epidemiology, modern treatment, cardiac rehabilitation and preconception counseling, and the current approach to genetic testing, exercise recommendations, and psychological care, all of which are crucial to the vascular medicine specialist.

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.

Chest Pain: Wellens Syndrome Due to Spontaneous Dissection of the Left Anterior Descending Coronary Artery - A Case Report and Literature Review

Wellens syndrome is an abnormal electrocardiographic pattern characterized by biphasic (type A) or deeply inverted (type B) T waves in leads V2-V3. It is typically caused by temporary obstruction of the left anterior descending (LAD) coronary artery due to the rupture of an atherosclerotic plaque leading to occlusion. Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and even a rarer cause of Wellens Syndrome. It occurs when an intramural hematoma forms, leading to the separation of the tunica intima from the outer layers and creating a false lumen that protrudes into the real lumen, ultimately reducing blood flow and thus resulting in myocardial infarction. Here we report a case of SCAD presenting as an acute coronary syndrome with self-resolving chest pain, slightly elevated myocardial necrosis markers and electrocardiographic changes consistent with Wellens pattern type A first, and type B afterwards, that were not present upon arrival to the emergency department.

Spontaneous coronary artery dissection in women with acute myocardial infarction: is there a new role for autoimmunity?

AIMS

Spontaneous coronary artery dissection (SCAD) is an uncommon cause of acute myocardial infarction in women and has an unclear pathophysiology. Autoantibodies (AAs) targeting angiotensin-II receptor type 1 (AT1R) and endothelin-1 receptor type A (ETAR) have known detrimental effects on endothelial function. We investigated the prevalence of these AAs in SCAD-affected female patients.

METHODS AND RESULTS

Female patients diagnosed at coronary angiography with myocardial infarction and SCAD were consecutively enrolled. Autoantibodies targeting angiotensin-II receptor type 1 and ETAR-AA titres and seropositivity prevalence were compared between SCAD patients, ST-elevation myocardial infarction (STEMI) patients, and healthy women. Ten women with SCAD and 20 age-matched controls (10 women with STEMI and 10 healthy women) were included. Six out of 10 (60%) women with myocardial infarction and SCAD were seropositive for AT1R-AAs and ETAR-AAs. In contrast, only one (10%) healthy woman and one (10%) STEMI patient were seropositive for AT1R-AAs (P = 0.03 and P = 0.03, respectively). One STEMI patient was seropositive for ETAR-AAs, while none of the healthy women was found to be seropositive (P = 0.03 and P = 0.01, respectively). The median AA titre was significantly higher in SCAD patients than in healthy women (P = 0.01 for AT1R-AAs; P = 0.02 for ETAR-AAs) and STEMI patients (P < 0.001 for AT1R-AAs; P = 0.002 for ETAR-AAs).

CONCLUSION

Autoantibodies targeting angiotensin-II receptor type 1 and ETAR-AA seropositivity is significantly higher in SCAD women with myocardial infarction than in healthy women or female patients with STEMI. Our findings, corroborated by previous data in the literature and biological plausibility, suggest a possible role for AT1R-AAs and ETAR-AAs in the pathophysiology of SCAD in women with acute myocardial infarction and should warrant further studies with larger sample sizes.

A review of the risk and precipitating factors for spontaneous coronary artery dissection

Introduction

Spontaneous coronary artery dissection (SCAD) accounts for 1%-4% of cases of acute coronary syndrome (ACS). SCAD is caused by separation occurring within or between any of the three tunics of the coronary artery wall. This leads to intramural hematoma and/or formation of false lumen in the artery, which leads to ischemic changes or infarction of the myocardium. The incidence of SCAD is higher in women than in men, with a ratio of approximately 9:1. It is estimated that SCAD is responsible for 35% of ACS cases in women under the age of 60. The high frequency is particularly observed during pregnancy and in the peripartum period (first week). Traditional risk factors are rare in patients with SCAD, except for hypertension. Patients diagnosed with SCAD have different combinations of risk factors compared with patients who have atherosclerotic changes in their coronary arteries. We presented the most common so-called "non-traditional" risk factors associated with SCAD patients.

Risk factors and precipitating disorders which are associated with SCAD

In the literature, there are few diseases frequently associated with SCAD, and they are identified as predisposing factors. The predominant cause is fibromuscular dysplasia, followed by inherited connective tissue disorders, systemic inflammatory diseases, pregnancy, use of sex hormones or steroids, use of cocaine or amphetamines, thyroid disorders, migraine, and tinnitus. In recent years, the genetic predisposition for SCAD is also recognized as a predisposing factor. The precipitating factors are also different in women (emotional stress) compared with those in men (physical stress). Women experiencing SCAD frequently describe symptoms of anxiety and depression. These conditions could increase shear stress on the arterial wall and dissection of the coronary artery wall. Despite the advancement of SCAD, we can find significant differences in the clinical presentation between women and men.

Conclusion

When evaluating patients with chest pain or other ACS symptoms who have a low cardiovascular risk, particularly female patients, it is important to consider the possibility of ACS due to SCAD, particularly in conditions often associated with SCAD. This will increase the recognition of SCAD and the timely treatment of affected 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%).

Spontaneous coronary artery dissection: An underrecognized cause of ACS

ABSTRACT

Spontaneous coronary artery dissection (SCAD) is an underrecognized form of nonatherosclerotic acute coronary syndrome, mostly occurring in younger female patients. The knowledge base about the diagnosis and management of SCAD has grown over the past decade, but gaps remain in how best to approach this disease. This article reviews the research on the prevalence, presentation, and management of SCAD.

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.

Current and future strategies for targeting the endothelin pathway in cardiovascular disease

The first endothelin (ET)-1 receptor antagonist was approved for clinical use over 20 years ago, but to date this class of compounds has been limited to treating pulmonary arterial hypertension, a rare disease. Translational research over the last 5 years has reignited interest in the ET system as a therapeutic target across the spectrum of cardiovascular diseases including resistant hypertension, microvascular angina and post-coronavirus disease 2019 conditions. Notable developments include approval of a new ETA receptor antagonist and, intriguingly, combining the actions of ETA and an angiotensin II type 1 receptor antagonist within the same novel small molecule. Combinations of ET receptor blockers with other drugs, including phosphodiesterase-5 inhibitors and sodium-glucose co-transporter-2 antagonists, may drive synergistic benefits with the prospect of alleviating side effects. These new therapeutic strategies have the potential to dramatically widen the scope of indications targeting the ET-1 pathway.

Pathophysiology of spontaneous coronary artery dissection: hematoma, not thrombus

Spontaneous coronary artery dissection (SCAD) accounts for 1.7%-4% of all acute coronary syndrome presentations, particularly among young women with an emerging awareness of its importance. The demarcation of acute SCAD from coronary atherothrombosis and the proper therapeutic approach still represents a major clinical challenge. Certain arteriopathies and triggers are related to SCAD, with high variability in their prevalence, and often, the cause remains unknown. The objective of this review is to provide contemporary knowledge of the pathophysiology of SCAD and possible therapeutic solutions.

Genetic Overlap of Spontaneous Dissection of Either the Thoracic Aorta or the Coronary Arteries

Ascending thoracic aortic dissection (ATAD) is a well-known vascular cause of sudden death. Spontaneous coronary artery dissections (SCAD) are emerging as an important cause of early-onset myocardial infarction and sudden death. Genetic variants in multiple connective tissue genes have been recognized to underlie ATAD; other genetic variants have similarly been recognized to underlie SCAD. Little data are available regarding any genetic commonality between ATAD and SCAD. Our objective is to determine and characterize any genetic overlap between genes coding for ATAD and SCAD. We identified and reviewed 17 retrospective and prospective genetic studies of thoracic aortic dissection and SCAD published between 2016 and 2022 identified through PubMed and Orbis. Articles highlighting the significant plausible triggers for ATAD or SCAD individually were analyzed. No previous study reviewed both ATAD and SCAD genetics together. Separate lists of causative genes were constructed for ATAD and SCAD-and then commonalities were sought. A Venn diagram was constructed to display the genetic overlap and common physiologic pathways involved. We identified a definite, meaningful overlap of 15 independent genes based on a genome-wide association study or other genetic methods. The associated genetic pathways involved various biologic processes including elastin degradation, smooth muscle cell function, and the TGFβ-pathway. The overlapping genes included the following: COL3A1, TGFB2, SMAD3, MYLK, TGFBR2, TGFBR1, LOX, FBN1, NOTCH1, ELN, COL5A1, COL5A2, COL1A2, MYH11, and TLN1. The corresponding molecular pathways were investigated and correlated for both diseases. We are not aware of other studies searching for genetic commonalities between ATAD and SCAD. We have successfully identified overlapping genes-and their corresponding molecular pathways-for ATAD and SCAD. We hope that these insights will lead to further clinical and scientific understanding of each disease through study of their fundamental commonalities.

From Fibromuscular Dysplasia to Arterial Dissection and Back

Fibromuscular dysplasia (FMD) is an idiopathic and systemic non-inflammatory and non-atherosclerotic arterial disease. Fifteen to 25% of patients with FMD present with arterial dissection in at least one arterial bed. Conversely, a substantial number of patients with renal, carotid, and visceral dissection have underlying FMD. Also, while few patients with FMD develop coronary artery dissection, lesions suggestive of multifocal FMD have been reported in 30-80% of patients with spontaneous coronary artery dissection (SCAD), and the relation between these two entities remains controversial. The frequent association of FMD with arterial dissection, both in coronary and extra-coronary arteries raises a number of practical and theoretical questions: (i) Are FMD and arterial dissections two different facets of the same disease or distinct though related entities? (ii) Is SCAD just a manifestation of coronary FMD or a different disease? (iii) What is the risk and which are predictive factors of developing arterial dissection in a patient with FMD? (iv) What proportion of patients who experienced an arterial dissection have underlying FMD, and does this finding influence the risk of subsequent arterial complications? In this review we will address these different questions using fragmentary, mostly cross-sectional evidence derived from large registries and studies from Europe and the United States, as well as arguments derived from demographics, clinical presentation, imaging, and when available histology and genetics. From there we will derive practical consequences for nosology, screening and follow-up.

Genetic Insights on the Relation of Vascular Risk Factors and Cervical Artery Dissection

BACKGROUND

The association between vascular risk factors and cervical artery dissections (CeADs), a leading cause of ischemic stroke (IS) in the young, remains controversial.

OBJECTIVES

This study aimed to explore the causal relation of vascular risk factors with CeAD risk and recurrence and compare it to their relation with non-CeAD IS.

METHODS

This study used 2-sample Mendelian randomization analyses to explore the association of blood pressure (BP), lipid levels, type 2 diabetes, waist-to-hip ratio, smoking, and body mass index with CeAD and non-CeAD IS. To simulate effects of the most frequently used BP-lowering drugs, this study constructed genetic proxies and tested their association with CeAD and non-CeAD IS. In analyses among patients with CeAD, the investigators studied the association between weighted genetic risk scores of vascular risk factors and the risk of multiple or early recurrent dissections.

RESULTS

Genetically determined higher systolic BP (OR: 1.51; 95% CI: 1.32-1.72) and diastolic BP (OR: 2.40; 95% CI: 1.92-3.00) increased the risk of CeAD (P < 0.0001). Genetically determined higher body mass index was inconsistently associated with a lower risk of CeAD. Genetic proxies for β-blocker effects were associated with a lower risk of CeAD (OR: 0.65; 95% CI: 0.50-0.85), whereas calcium-channel blockers were associated with a lower risk of non-CeAD IS (OR: 0.75; 95% CI: 0.63-0.90). Weighted genetic risk scores for systolic BP and diastolic BP were associated with an increased risk of multiple or early recurrent CeAD.

CONCLUSIONS

These results are supportive of a causal association between higher BP and increased CeAD risk and recurrence and provide genetic evidence for lower CeAD risk under β-blockers. This may inform secondary prevention strategies and trial design for CeAD.

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.

Cerebrovascular Fibromuscular Dysplasia - A Practical Review

Fibromuscular dysplasia (FMD) is a rare idiopathic, segmental, noninflammatory and nonatherosclerotic arteriopathy of medium-sized arteries. It is classically considered to be a disease of young and middle adulthood, with females more commonly affected than males. FMD is a systemic disease. Although historically considered to be rare, cerebrovascular FMD (C-FMD) has now been recognized to be as common as the renovascular counterpart. Extracranial carotid and vertebral arteries are the most commonly involved vascular territories in C-FMD with the clinical presentation determined by vessels affected. Common symptoms include headaches and pulsatile tinnitus, with transient ischemic attacks, ischemic stroke and subarachnoid or intracerebral hemorrhage constituting the more severe clinical manifestations. Cervical artery dissection involving carotids more often than vertebral arteries and intracranial aneurysms account for the cerebrovascular pathologies detected in C-FMD. Our understanding regarding C-FMD has been augmented in the recent past on account of dedicated C-FMD data from North American, European and other international FMD cohorts. In this review article, we provide an updated and comprehensive overview on epidemiology, clinical presentation, etiology, diagnosis and management of C-FMD.

Sex, Racial, and Ethnic Disparities in Acute Coronary Syndrome: Novel Risk Factors and Recommendations for Earlier Diagnosis to Improve Outcomes

In this review, sex, racial, and ethnic differences in acute coronary syndromes on a global scale are summarized. The relationship between disparities in presentation and management of acute coronary syndromes and effect on worse clinical outcomes in acute coronary syndromes are discussed. The effect of demographic, geographic, racial, and ethnic factors on acute coronary syndrome care disparities are reviewed. Differences in risk factors including systemic inflammatory disorders and pregnancy-related factors and the pathophysiology underlying them are discussed. Finally, breast arterial calcification and coronary calcium scoring are discussed as methods to detect subclinical atherosclerosis and start early treatment in an attempt to prevent clinical disease.

Spontaneous Coronary Artery Dissection: Review of Possible Pathophysiological Risk Factors

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome (ACS) that typically affects the younger and healthier female population without the typical ACS risk factors such as hypertension, diabetes, or hyperlipidemia. The clinical presentation of SCAD can be diverse and the diagnosis is typically by coronary angiography but also can require advanced imaging such as intravascular ultrasound or optical coherence tomography. Past studies have shown the atypical patient characteristics of SCAD patients among ACS patients. The main challenge is that the exact pathophysiology of SCAD is unknown. Potential pathophysiological risk factors are discussed including fibromuscular dysplasia, other arteriopathies, pregnancy and female sex hormone changes, migraines, inflammatory conditions, and stress. The current understanding of these risk factors along with potential pathophysiological mechanisms are discussed. There still remain many areas of additional investigation in understanding this rare cause of ACS.

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.

Genetics of spontaneous cervical and coronary artery dissections

Objectives

Spontaneous cervical artery dissections (SCeAD) and coronary artery dissections (SCoAD) are major causes of neurovascular and cardiovascular morbidity in young adults. Although multiple aspects of their etiology are still unknown, most consensuses are focused on the presence of constitutional genetic aspects and environmental triggers. Since recent evidence of genetic contribution points to a possible overlap between these conditions, we aimed to describe current information on SCeAD and SCoAD genetics and their potential shared pathological aspects.

Materials and methods

A narrative review is presented. Publications in English and Spanish were queried using database search. The articles were evaluated by one team member in terms of inclusion criteria. After collecting, the articles were categorized based on scientific content.

Results

Given that patients with SCeAD and SCoAD rarely present connective tissue disorders, other genetic loci are probably responsible for the increased susceptibility in some individuals. The common variant rs9349379 at PHACTR1 gene is associated with predisposition to pathologies of the arterial wall, likely mediated by variations in Endothelin-1 (ET-1) levels. The risk of arterial dissection may be increased for those who carry the rs9349379(A) allele, associated with lower expression levels of ET-1; however, the local effect of this vasomotor imbalance remains unclear. Sex differences seen in SCeAD and SCoAD support a role for sex hormones that could modulate risk, tilting the delicate balance and forcing vasodilator actions to prevail over vasoconstriction due to a reduction in ET-1 expression.

Conclusions

New evidence points to a common gene variation that could explain dissection in both the cervical and coronary vasculatures. To further confirm the risk conferred by the rs9349379 variant, genome wide association studies are warranted, hopefully in larger and ethnically diverse populations.

Multiomic Analysis and CRISPR Perturbation Screens Identify Endothelial Cell Programs and Novel Therapeutic Targets for Coronary Artery Disease

Endothelial cells (EC) are an important mediator of atherosclerosis and vascular disease. Their exposure to atherogenic risk factors such as hypertension and serum cholesterol leads to endothelial dysfunction and many disease-associated processes. Identifying which of these multiple EC functions is causally related to disease risk has been challenging. There is evidence from in vivo models and human sequencing studies that dysregulation of nitric oxide production directly affects risk of coronary artery disease. Human genetics can help prioritize the other EC functions with causal relationships because germline mutations are acquired at birth and serve as a randomized test of which pathways affect disease risk. Though several coronary artery disease risk variants have been linked to EC function, this process has been slow and laborious. Unbiased analyses of EC dysfunction using multiomic approaches promise to identify the causal genetic mechanisms responsible for vascular disease. Here, we review the data from genomic, epigenomic, and transcriptomic studies that prioritize EC-specific causal pathways. New methods that CRISPR (clustered regularly interspaced short palindromic repeats) perturbation technology with genomic, epigenomic, and transcriptomic analysis promise to speed up the characterization of disease-associated genetic variation. We summarize several recent studies in ECs which use high-throughput genetic perturbation to identify disease-relevant pathways and novel mechanisms of disease. These genetically validated pathways can accelerate the identification of drug targets for the prevention and treatment of atherosclerosis.

Using Machine Learning Methods in Identifying Genes Associated with COVID-19 in Cardiomyocytes and Cardiac Vascular Endothelial Cells

Corona Virus Disease 2019 (COVID-19) not only causes respiratory system damage, but also imposes strain on the cardiovascular system. Vascular endothelial cells and cardiomyocytes play an important role in cardiac function. The aberrant expression of genes in vascular endothelial cells and cardiomyocytes can lead to cardiovascular diseases. In this study, we sought to explain the influence of respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the gene expression levels of vascular endothelial cells and cardiomyocytes. We designed an advanced machine learning-based workflow to analyze the gene expression profile data of vascular endothelial cells and cardiomyocytes from patients with COVID-19 and healthy controls. An incremental feature selection method with a decision tree was used in building efficient classifiers and summarizing quantitative classification genes and rules. Some key genes, such as MALAT1, MT-CO1, and CD36, were extracted, which exert important effects on cardiac function, from the gene expression matrix of 104,182 cardiomyocytes, including 12,007 cells from patients with COVID-19 and 92,175 cells from healthy controls, and 22,438 vascular endothelial cells, including 10,812 cells from patients with COVID-19 and 11,626 cells from healthy controls. The findings reported in this study may provide insights into the effect of COVID-19 on cardiac cells and further explain the pathogenesis of COVID-19, and they may facilitate the identification of potential therapeutic targets.

PHACTR1 modulates vascular compliance but not endothelial function: a translational study

AIMS

The non-coding locus at 6p24 located in Intron 3 of PHACTR1 has consistently been implicated as a risk allele in myocardial infarction and multiple other vascular diseases. Recent murine studies have identified a role for Phactr1 in the development of atherosclerosis. However, the role of PHACTR1 in vascular tone and in vivo vascular remodelling has yet to be established. The aim of this study was to investigate the role of PHACTR1 in vascular function.

METHODS AND RESULTS

Prospectively recruited coronary artery disease (CAD) patients undergoing bypass surgery and retrospectively recruited spontaneous coronary artery dissection (SCAD) patients and matched healthy volunteers were genotyped at the PHACTR1 rs9349379 locus. We observed a significant association between the PHACTR1 loci and changes in distensibility in both the ascending aorta (AA = 0.0053 ± 0.0004, AG = 0.0041 ± 0.003, GG = 0.0034 ± 0.0009, P < 0.05, n = 58, 54, and 7, respectively) and carotid artery (AA = 12.83 ± 0.51, AG = 11.14 ± 0.38, GG = 11.69 ± 0.66, P < 0.05, n = 70, 65, and 18, respectively). This association was not observed in the descending aorta or in SCAD patients. In contrast, the PHACTR1 locus was not associated with changes in endothelial cell function with no association between the rs9349379 locus and in vivo or ex vivo vascular function observed in CAD patients. This finding was confirmed in our murine model where the loss of Phactr1 on the pro-atherosclerosis ApoE-/- background did not alter ex vivo vascular function.

CONCLUSION

In conclusion, we have shown a role for PHACTR1 in arterial compliance across multiple vascular beds. Our study suggests that PHACTR1 has a key structural role within the vasculature.

Recurrent spontaneous coronary artery dissection

Spontaneous coronary artery dissection (SCAD) is a significant cause of myocardial infarction (MI) and is more prevalent in pregnancy. The disease is being increasingly appreciated and diagnosed with the development and application of coronary angiography and intravascular imaging. Recurrent spontaneous coronary artery dissection (R-SCAD) is relatively common, with recurrence rates ranging from 8 to 27%. R-SCAD usually involves anatomical sites different from the original SCAD lesion and can cause MI, ventricular arrhythmias, and cardiogenic shock. This study aims to conduct a comprehensive review of R-SCAD to identify early risk factors and guide prevention policies and interventions. In addition, the risk of R-SCAD in subsequent pregnancies in women with a history of SCAD is discussed.

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.

The Australian New Zealand Spontaneous Coronary Artery Dissection (ANZ-SCAD) Registry - A Multi-Centre Cohort Study: Protocol, Background and Significance

INTRODUCTION

Spontaneous coronary artery dissection (SCAD) is an under-recognised cause of acute coronary syndrome (ACS) with a strong female predominance. There are currently limited prospective studies and no randomised controlled trials that inform on SCAD's best clinical care. Little is also known about predictors of acute SCAD deterioration or recurrence. We describe the study design of a multi-centre prospective and historical cohort study recruiting patients with SCAD across 15-20 sites in Australia/New Zealand (NZ). The primary aim is to describe the clinical presentation, management and outcomes along with predictors of acute deterioration and recurrence in a large Australian/NZ SCAD cohort, with international data pooling.

METHODS AND ANALYSIS

Consented patients diagnosed with SCAD during a hospital admission for an ACS will be prospectively followed at 30 days then yearly, for up to 5 years. Each recruiting site will also retrospectively identify historical cases of SCAD from the proceeding 10 years, with a waiver of consent. For historical cases, data will be collected in a de-identified manner with date of last follow-up or death obtained from the medical records. All cases undergo core laboratory adjudication of coronary angiography and any accompanying imaging to confirm SCAD diagnosis. The primary endpoint will be occurrence of major adverse cardiovascular events; a composite of all-cause mortality, recurrent myocardial infarction (including SCAD recurrence), stroke/transient ischaemic attack, heart failure, cardiogenic shock, cardiac arrest/ventricular arrhythmia, heart transplantation and, repeat/unplanned revascularisation. Secondary endpoints will include each individual primary outcome as well as acute SCAD extension and quality of life/Seattle Angina Score in prospectively recruited participants. Endpoints will be assessed at the end of the hospital admission and at 30-days, 1 year, and median long-term follow-up.

ETHICS

Multicentre ethics approval has been granted from the Western Sydney Local Health District Human Research Ethics Committee (2021/ETH00040).

DISSEMINATION OF RESULTS

The analysed results will be published in peer-reviewed journals on completion of the historical data collection and then on completion of the prospective data collection.

REGISTRATION DETAILS

The ANZ-SCAD registry has been prospectively registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12621000824864).

Genome-Wide Transcriptional Profiling Reveals PHACTR1 as a Novel Molecular Target of Resveratrol in Endothelial Homeostasis

Atherosclerosis is a chronic inflammatory vascular disease in which endothelial cells play an important role in maintaining vascular homeostasis. Endotheliitis caused by endothelial dysfunction (ED) is the key cause for the development of cardiovascular and cerebrovascular diseases as well as other vascular system diseases. Resveratrol (RES), a multi-functional polyphenol present in edible plants and fruits, prevents cardiovascular disease by regulating a variety of athero-relevant signaling pathways. By transcriptome profiling of RES-treated human umbilical vein endothelial cells (HUVECs) and in-depth bioinformatic analysis, we observed that differentially expressed genes (DEGs) were enriched in KEGG pathways of fluid shear stress and atherosclerosis, suggesting that the RES may serve as a good template for a shear stress mimetic drug that hold promise in combating atherosclerosis. A heat map and multiple datasets superimposed screening revealed that RES significantly down-regulated phosphatase and actin modulator 1 (PHACTR1), a pivotal coronary artery disease risk gene associated with endothelial inflammation and polyvascular diseases. We further demonstrate that RES down-regulated the gene and protein expression of PHACTR1 and inhibited TNF-α-induced adhesion of THP-1 monocytes to activated endothelial cells via suppressing the expression of PHACTR1. Taken together, our study reveals that PHACTR1 represents a new molecular target for RES to maintain endothelial cell homeostasis and prevent atherosclerotic cardiovascular disease.

Spontaneous coronary artery dissection: A review of diagnostic methods and management strategies

Spontaneous coronary artery dissection (SCAD) is a rare non-atherosclerotic cause of acute coronary syndromes defined as non-iatrogenic, non-traumatic separation of the coronary artery wall. The most common profile is a middle-aged woman between 44 and 53 years with few cardiovascular risk factors. SCAD is frequently linked with predisposing factors, such as postpartum, fibromuscular dysplasia or other vasculopathies, connective tissue disease and hormonal therapy, and it is often triggered by intense physical or emotional stress, sympathomimetic drugs, childbirth and activities increasing shear stress of the coronary artery walls. Patients with SCAD usually present at the emergency department with chest discomfort, chest pain, and rapid heartbeat or fluttery. During the last decades, the most common problem of SCAD was the lack of awareness about this condition which has led to significant underdiagnosis and misdiagnosis. However, modern imaging techniques such as optical coherence tomography, intravascular ultrasound, coronary angiography or magnetic resonance imaging have contributed to the early diagnosis of the disease. Treatment of SCAD remains controversial, especially during the last years, where invasive techniques are being used more often and in more emergent cardiac syndromes. Although conservative treatment combining aspirin and beta-blocker remains the recommended strategy in most cases, revascularization could also be suggested as a method of treatment in specific indications, but with a higher risk of complications. The prognosis of SCAD is usually good and long-term mortality seems to be low in these patients. Follow-up should be performed on a regular basis.

Differences in Demographics and Outcomes Between Men and Women With Spontaneous Coronary Artery Dissection

BACKGROUND

Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of myocardial infarction (MI) that most frequently affects women. The characteristics of men with SCAD are less well described.

OBJECTIVES

The aim of this study was to describe the characteristics of men with SCAD.

METHODS

We compared baseline demographics, clinical presentation, angiographic findings and cardiovascular outcomes of men and women in the Canadian SCAD Study. Major adverse cardiovascular events (MACE) were composite of death, MI, stroke or transient ischemic attack, heart failure hospitalization, and revascularization.

RESULTS

Of 1,173 patients with SCAD, 123 (10.5%) were men. Men with SCAD were younger than women (mean age 49.4 ± 9.6 years vs 52.0 ± 10.6 years; P = 0.01). Men had lower rate of prior MI than women (0.8% vs 7.0%; P = 0.005). Men were less likely to have fibromuscular dysplasia (FMD) (27.8% vs 52.7%; P = 0.001), depression (9.8% vs 20.2%; P = 0.005), emotional stress (35.0% vs 59.3%; P < 0.001), or high score on the Perceived Stress Scale (3.5% vs 11.0%; P = 0.025) but were more likely to report isometric physical stress (40.2% vs 24.0%; P = 0.007). There was no difference in angiographic types of SCAD, but men had more circumflex artery (44.4% vs 30.9%; P = 0.001) and fewer right coronary artery (11.8% vs 21.7%; P = 0.0054) dissections. At median follow-up of 3.0 (IQR: 2.0-3.8) years, men had fewer hospital presentations with chest pain (10.6% vs 24.8%; P < 0.001). There were no differences in in-hospital events or follow-up MACE (7.3% vs 12.7%; P = 0.106).

CONCLUSIONS

Ten percent of SCAD patients were men. Men were younger and more likely to have a physical trigger but were less likely to have FMD, depression, or an emotional trigger. Men had less recurrent chest pain but no significant difference in MACE.

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.

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.

PHACTR1, a coronary artery disease risk gene, mediates endothelial dysfunction

Genome-wide association studies (GWAS) have recently identified phosphatase and actin regulator-1 (PHACTR1) as a critical risk gene associated with polyvascular diseases. However, it remains largely unclear how PHACTR1 is involved in endothelial dysfunction. Here, by mining published datasets of human stable and vulnerable/ruptured plaque tissues, we observed upregulated expression of PHACTR1 in vulnerable/ruptured plaques. Congruent with these data, we demonstrated increased Phactr1 gene expression in aortic endothelium from ApoE^-/- mice fed a western type diet compared with that in normal C57BL/6J mice. Relevantly, PHACTR1 gene expression was upregulated by pro-inflammatory and pro-atherogenic stimuli, including TNF-α, IL-1β and oxidized LDL (oxLDL). By employing next-generation RNA sequencing, we demonstrate that PHACTR1 overexpression disrupts pathways associated with endothelial homeostasis. Cell biological studies unravel that PHACTR1 mediates endothelial inflammation and monocyte adhesion by activating NF-κB dependent intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1) expression. In addition, overexpression of PHACTR1 also reduces the generation of nitric oxide (NO) by inhibiting Akt/eNOS activation. In-house compound screening of vasoprotective drugs identifies several drugs, including lipid-lowering statins, decreases PHACTR1 gene expression. However, PHACTR1 gene expression was not affected by another lipid-lowering drug-fenofibrate. We also performed a proteomic study to reveal PHACTR1 interacting proteins and validated that PHACTR1 can interact with heat shock protein A8 (HSPA8) which was reported to be associated with coronary artery disease and eNOS degradation. Further studies are warranted to confirm the precise mechanism of PHACTR1 in driving endothelial dysfunction. In conclusion, by using systems biology approach and molecular validation, we disclose the deleterious effects of PHACTR1 on endothelial function by inducing endothelial inflammation and reducing NO production, highlighting the potential to prevent endothelial dysfunction and atherosclerosis by targeting PHACTR1 expression. The precise role of endothelial cell PHACTR1 in polyvascular diseases remains to be validated in diseased conditions.

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.

Factors associated with recurrent spontaneous coronary artery dissection: a systematic review and meta-analysis

BACKGROUND

The risk of recurrent spontaneous coronary artery dissection (SCAD) is a major concern to SCAD patients and clinicians. Identifying the high-risk subsets of recurrent SCAD remains an ongoing challenge. The meta-analysis aimed to assess the potential predictors for SCAD recurrence.

METHODS

A literature search was performed in PubMed to collect studies that assessed potential factors associated with recurrence of SCAD among angiographically confirmed SCAD patients, including pregnancy, ventricular arrhythmia at presentation, history of hypertension, migraine, fibromuscular dysplasia (FMD), extracoronary vascular abnormalities (EVA), recent emotional or physical stress, and use of thienopyridine, beta-blocker, or statin. A meta-analytic approach was employed to estimate the relative risk (RR) with a 95% confidence interval (CI) by fitting random-effects models using the generic inverse variance weighted method.

RESULTS

A total of 14 studies representing 4206 SCAD patients were included. Hypertension (RR, 1.49; 95% CI, 1.05-2.12; P = 0.0247) and FMD (RR, 2.02; 95% CI, 1.03-3.94; P = 0.0404) were associated with a greater risk of SCAD recurrence. The use of beta-blocker (RR, 0.51; 95% CI, 0.33-0.77; P = 0.0013) was associated with a lower risk of SCAD recurrence. Pregnancy, ventricular arrhythmia at presentation, migraine, EVA, recent emotional or physical stress, and use of thienopyridine or statin were not significantly associated with recurrent SCAD (P > 0.05).

CONCLUSION

SCAD patients with hypertension or FMD were at a higher risk of recurrence, whereas beta-blocker usage was related to a reduced risk. These findings may provide insights into risk prediction and management after the SCAD episode.