Prospective Cardiovascular Genetics Evaluation in Spontaneous Coronary Artery Dissection

Spontaneous Coronary Artery Dissection: Insights on Rare Genetic Variation From Genome Sequencing

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Spontaneous coronary artery dissection (SCAD) occurs when an epicardial coronary artery is narrowed or occluded by an intramural hematoma. SCAD mainly affects women and is associated with pregnancy and systemic arteriopathies, particularly fibromuscular dysplasia. Variants in several genes, such as those causing connective tissue disorders, have been implicated; however, the genetic architecture is poorly understood. Here, we aim to better understand the diagnostic yield of rare variant genetic testing among a cohort of SCAD survivors and to identify genes or gene sets that have a significant enrichment of rare variants.

Spontaneous coronary artery dissection: clinical implications and diagnostic challenges. Overlooked and underappreciated in Asia?

Over the last decade, spontaneous coronary artery dissection (SCAD) has garnered much attention as a significant cause of acute coronary syndrome (ACS) and sudden cardiac death in women without classic cardiovascular risk factors. SCAD has been mostly studied in the West, with little recognition in Asia leading to under‐diagnosis and under‐representation. In this review, we highlight two distinct cases occurring at our center in Singapore, affecting two Singaporean women of Malay and Chinese descent. These 2 cases highlight that pregnancy‐associated SCAD is neither the most common nor only manifestation of SCAD. Through review of the literature, we emphasize the heterogeneity in case presentation paying particular attention to SCAD and its association with connective tissue disorders such as fibromuscular dysplasia. SCAD remains a diagnostic challenge for many cardiologists, here we shed light and dispel myths surrounding coronary angiography and review the use of intracoronary imaging. The successful treatment of this unique group of patients requires a high index of suspicion, and management within a multidisciplinary team. The development of a recovery program with access to support groups, allied health, and cardiac rehabilitation is paramount in improving outcomes for these patients in the long term. Further research and studies in our Asian population will help to enhance our understanding of this disease and develop practices to best manage our patients.

Dissection of coronary artery: A clinical overview

Spontaneous coronary artery dissection (SCAD) is a rare but life-threatening disorder. SCAD is gaining importance as an emerging cause of acute coronary syndrome (ACS), especially in otherwise healthy young women. While SCAD and ACS show similarity in presentation, the management of SCAD differs to that of ACS. If not managed properly SCAD can lead to sudden death. This review examines the pathophysiology, clinical presentation, diagnostic algorithms, and the current and future management of SCAD.

Chromosome 1q21.2 and additional loci influence risk of spontaneous coronary artery dissection and myocardial infarction

Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic cause of myocardial infarction (MI), typically in young women. We undertook a genome-wide association study of SCAD (N_cases = 270/N_controls = 5,263) and identified and replicated an association of rs12740679 at chromosome 1q21.2 (P_{discovery+replication} = 2.19 × 10⁻¹², OR = 1.8) influencing ADAMTSL4 expression. Meta-analysis of discovery and replication samples identified associations with P < 5 × 10⁻⁸ at chromosome 6p24.1 in PHACTR1, chromosome 12q13.3 in LRP1, and in females-only, at chromosome 21q22.11 near LINC00310. A polygenic risk score for SCAD was associated with (1) higher risk of SCAD in individuals with fibromuscular dysplasia (P = 0.021, OR = 1.82 [95% CI: 1.09–3.02]) and (2) lower risk of atherosclerotic coronary artery disease and MI in the UK Biobank (P = 1.28 × 10⁻¹⁷, HR = 0.91 [95% CI :0.89–0.93], for MI) and Million Veteran Program (P = 9.33 × 10⁻³⁶, OR = 0.95 [95% CI: 0.94–0.96], for CAD; P = 3.35 × 10⁻⁶, OR = 0.96 [95% CI: 0.95–0.98] for MI). Here we report that SCAD-related MI and atherosclerotic MI exist at opposite ends of a genetic risk spectrum, inciting MI with disparate underlying vascular biology.

Spontaneous coronary artery dissection (SCAD) is a cause of myocardial infarction Here, the authors present a genome-wide association study of SCAD, finding an association at 1q21.2 which potentially affects expression of ADAMTSL4.

Association of Pregnancy With Recurrence of Spontaneous Coronary Artery Dissection Among Women With Prior Coronary Artery Dissection

IMPORTANCE

Spontaneous coronary artery dissection (SCAD) is a notable cause of acute coronary syndrome in women of childbearing age.

OBJECTIVE

To test the hypothesis that pregnancy after SCAD is associated with recurrent SCAD.

DESIGN, SETTING, AND PARTICIPANTS

Three study designs were implemented: a case series of women with pregnancy after SCAD; a nested case-control study comparing patients with recurrent SCAD to matched controls without recurrent SCAD; and a cohort study. Women with SCAD who were of childbearing potential and enrolled into the Mayo Clinic SCAD Registry from August 30, 2011, to April 4, 2019, were included in the study. Patients with coronary dissections associated with iatrogenesis, trauma, or atherosclerosis were not enrolled.

EXPOSURES

Pregnancy after SCAD.

MAIN OUTCOMES AND MEASURES

The primary outcome was SCAD recurrence, defined as an acute coronary syndrome or cardiac arrest due to new SCAD. Other demographic measures collected included age, year of SCAD occurrence, and comorbidities.

RESULTS

The cohort included 636 women of childbearing potential. Twenty-three of those women had a total of 32 pregnancies after SCAD. The median (interquartile range) age of women with pregnancy after SCAD was 38 years (34-40 years), and 20 (87%) were White. In the nested case-control study, 92 cases of recurrent SCAD were matched to 158 controls. There was no significant difference in exposure to subsequent pregnancies in the women with recurrent SCAD as compared with matched controls (2 of 92 [2%] vs 13 of 158 [8%]; P = .06). In the overall cohort of 636 patients, recurrent SCAD was present in 122 patients with a Kaplan-Meier 5-year SCAD recurrence estimate of 14.8%. The Cox analysis showed no significant association between subsequent pregnancy and SCAD recurrence with a nonsignificant hazard ratio of 0.38 (95% CI, 0.09-1.6) when controlling for age at first SCAD, year of first SCAD, and fibromuscular dysplasia.

CONCLUSIONS AND RELEVANCE

This study found that most women tolerated pregnancy and lactation after SCAD without evidence for increased risk of SCAD recurrence when compared with women with a history of SCAD who did not experience pregnancy. Although this study is reassuring and indicates complex contributors to SCAD recurrence, the results need to be interpreted prudently because of study selection bias and the small total number of women who became pregnant after SCAD. The notable hemodynamic changes that occur with pregnancy and severe presentation of pregnancy-associated SCAD are reasons for concern when considering pregnancy after SCAD.

Spontaneous Coronary Artery Dissection and Fibromuscular Dysplasia: Vasculopathies With a Predilection for Women

The burden of cardiovascular disease in women is being increasingly appreciated. Nevertheless, both clinicians and the general public are largely unaware that cardiovascular disease is the leading cause of death worldwide in women in all countries and that outcomes after a heart attack are worse for women than men. Of note, certain types of cardiovascular disease have a predilection for women, including spontaneous coronary artery dissection (SCAD) and fibromuscular dysplasia (FMD). Although uncommon, SCAD is being increasingly recognised as the cause of an acute coronary syndrome (ACS) and can recur. It is a potentially fatal, under-diagnosed condition that affects relatively young women, who often have few traditional risk factors, and is the commonest cause of a myocardial infarction associated with pregnancy. In contrast, FMD often remains silent but when manifested can also cause major sequelae, including renal infarction, stroke, cervical artery dissection and gut infarction. Here we provide an update on the diagnosis, aetiology and management of these important disorders that overwhelmingly affect women.

Pregnancy and cardiovascular disease

Cardiovascular disease complicates 1-4% of pregnancies - with a higher prevalence when including hypertensive disorders - and is the leading cause of maternal death. In women with known cardiovascular pathology, such as congenital heart disease, timely counselling is possible and the outcome is fairly good. By contrast, maternal mortality is high in women with acquired heart disease that presents during pregnancy (such as acute coronary syndrome or aortic dissection). Worryingly, the prevalence of acquired cardiovascular disease during pregnancy is rising as older maternal age, obesity, diabetes mellitus and hypertension become more common in the pregnant population. Management of cardiovascular disease in pregnancy is challenging owing to the unique maternal physiology, characterized by profound changes to multiple organ systems. The presence of the fetus compounds the situation because both the cardiometabolic disease and its management might adversely affect the fetus. Equally, avoiding essential treatment because of potential fetal harm risks a poor outcome for both mother and child. In this Review, we examine how the physiological adaptations during pregnancy can provoke cardiometabolic complications or exacerbate existing cardiometabolic disease and, conversely, how cardiometabolic disease can compromise the adaptations to pregnancy and their intended purpose: the development and growth of the fetus.

Clinical and genetic data of 22 new patients with SMAD3 pathogenic variants and review of the literature

Background

Pathogenic SMAD3 variants are responsible for a cardiovascular phenotype, mainly thoracic aortic aneurysms and dissections. Precocious identification of the vascular risk such as aortic dilatation in mutated patients has a major impact in terms of management, particularly to avoid dissection and sudden death. These vascular damages are classically associated with premature osteoarthritis and skeletal abnormalities. However, variable expressivity and incomplete penetrance are common with SMAD3 variants.

Methods

To investigate the clinical variability observed within SMAD3 patients, we reviewed the phenotypic and genetic data of 22 new patients from our Centre and of 133 patients reported in the literature. From this cohort of 155 mutated individuals, we first aimed to delineate an estimated frequency of the main clinical signs associated with SMAD3 pathogenic variants and, then, to look for genotype‐phenotype correlations, mainly to see if the aortic phenotype (AP) could be predicted by the SMAD3 variant type.

Results

We showed, herein, the absence of correlation between the SMAD3 variant type and the occurrence of an AP in patients.

Conclusion

Therefore, this report brings additional data for the genotype‐phenotype correlations of SMAD3 variants and the need to explore in more detail the effects of genetic modifiers that could influence the phenotype.

Association of the PHACTR1/EDN1 Genetic Locus With Spontaneous Coronary Artery Dissection

BACKGROUND

Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of acute coronary syndromes (ACS) afflicting predominantly younger to middle-aged women. Observational studies have reported a high prevalence of extracoronary vascular anomalies, especially fibromuscular dysplasia (FMD) and a low prevalence of coincidental cases of atherosclerosis. PHACTR1/EDN1 is a genetic risk locus for several vascular diseases, including FMD and coronary artery disease, with the putative causal noncoding variant at the rs9349379 locus acting as a potential enhancer for the endothelin-1 (EDN1) gene.

OBJECTIVES

This study sought to test the association between the rs9349379 genotype and SCAD.

METHODS

Results from case control studies from France, United Kingdom, United States, and Australia were analyzed to test the association with SCAD risk, including age at first event, pregnancy-associated SCAD (P-SCAD), and recurrent SCAD.

RESULTS

The previously reported risk allele for FMD (rs9349379-A) was associated with a higher risk of SCAD in all studies. In a meta-analysis of 1,055 SCAD patients and 7,190 controls, the odds ratio (OR) was 1.67 (95% confidence interval [CI]: 1.50 to 1.86) per copy of rs9349379-A. In a subset of 491 SCAD patients, the OR estimate was found to be higher for the association with SCAD in patients without FMD (OR: 1.89; 95% CI: 1.53 to 2.33) than in SCAD cases with FMD (OR: 1.60; 95% CI: 1.28 to 1.99). There was no effect of genotype on age at first event, P-SCAD, or recurrence.

CONCLUSIONS

The first genetic risk factor for SCAD was identified in the largest study conducted to date for this condition. This genetic link may contribute to the clinical overlap between SCAD and FMD.

Spontaneous coronary artery dissection of the proximal left circumflex artery: a case report

Background

Spontaneous coronary artery dissection (SCAD) has gained attention as an important cause of acute coronary syndrome and sudden cardiac death (SCD) among women. Management strategies of SCAD differ from those of atherosclerotic disease. There is an elevated risk of complications and suboptimal outcomes in patients with SCAD undergoing percutaneous coronary interventions (PCIs).

Case summary

A 48-year-old woman without any traditional cardiovascular risk factors was admitted with severe central chest pain with associated dyspnoea and diaphoresis. The patient had a strong family history of SCD, affecting three female members in their 40s and 50s. Cardiac troponins were elevated. Coronary angiogram showed moderate to severe stenosis of the proximal circumflex coronary artery. Optical coherence tomography confirmed SCAD with sub-intimal haematoma. Despite significant stenosis in the proximal segment of a relatively large artery, a decision was made not to proceed with PCI. The follow-up angiogram demonstrated normal coronaries. Magnetic resonance imaging of renal arteries showed features suggestive of fibromuscular dysplasia affecting the right renal artery. Subsequent genetic counselling and gene testing were unremarkable.

Discussion

Conservative management of SCAD is recommended because the large majority of SCAD lesions heal naturally, whereas PCI is associated with increased risk of complications and adverse outcomes. Whether SCAD is associated with the sudden death events in our patient’s family remains unclear. It certainly raises concerns as to an inheritable condition. In the absence of post-mortem findings in her family members, we can only speculate about this representing a possible inheritable form of SCAD.

Familial Spontaneous Coronary Artery Dissection and the SMAD-3 Mutation

Spontaneous coronary artery dissection (SCAD) is a cause of about 4% of acute coronary syndrome. The pathophysiology of SCAD is not yet fully understood. Loeys-Dietz syndrome is a connective tissue disorder characterized by aortic aneurysms, arterial tortuosity, and aortic dissections. It is caused by mutations in the genes affecting the transforming growth factor β pathway. We describe a family with a SMAD3 gene mutation and Loeys-Dietz syndrome presenting with recurrent SCAD episodes.

Rare genetic variants in patients with cervical artery dissection

Introduction

The potential role of genetic alterations in cervical artery dissection (CeAD) pathogenesis is poorly understood. We aimed to identify pathogenic genetic variants associated with cervical artery dissection by using whole exome sequencing.

Patients and methods

CeAD-patients with either a family history of cervical artery dissection (f-CeAD) or recurrent cervical artery dissection (r-CeAD) from the CeAD-databases of two experienced stroke centres were analysed by whole exome sequencing.Variants with allele frequency <0.05 and classified as pathogenic by predicting algorithms (SIFT or Polyphen-2) or the ClinVar database were explored. First, we analysed a panel of 30 candidate genes associated with arterial dissection (any site) or aneurysm according to the OMIM (online Mendelian Inheritance of Men) database. Second, we performed a genome-wide search for pathogenic variants causing other vascular phenotypes possibly related to cervical artery dissection.Findings were classified as CeAD-causing (pathogenic variants in genes from the arterial dissection or aneurysm panel) or suggestive (pathogenic variants in genes associated with other vascular phenotypes and variants of unknown significance in genes from the arterial dissection or aneurysm panel). All other variants were classified as benign/uncertain.

Results

Among 43 CeAD-patients, 28 patients (17 pedigrees) had f-CeAD and 15 had r-CeAD. No CeAD-causing variants were identified in r-CeAD patients. Among f-CeAD-patients, 5/17 pedigrees carried CeAD-causing variants in COL3A1, COL4A1, COL4A3, COL4A4, COL5A1, COL5A2 and FBN1. Suggestive variants in ABCC6, COL3A1, COL5A2, MEF2A, and RNF213 were detected in three pedigrees with f-CeAD and six patients with r-CeAD.Discussion and conclusion: CeAD-causing variants were rare and exclusively found in f-CeAD-patients, suggesting differences between the genetic architectures of f-CeAD and r-CeAD. The identified variants indicate a high genetic heterogeneity of the study sample.

Spontaneous coronary artery dissection: etiology and recurrence

Introduction: Spontaneous coronary artery dissection (SCAD) is an increasingly appreciated cause of acute myocardial infarction (AMI) and sudden cardiac death most often affecting young to middle-aged women with few conventional cardiovascular risk factors. Areas covered: A literature search was performed using MedLine, PubMed, and Google Scholar (dating to 04/30/2019). Authors review the key clinical features of SCAD and highlight what is known regarding its pathophysiology and associated factors. The relationship between SCAD and other systemic vasculopathies, notably fibromuscular dysplasia (FMD) is also discussed. Authors also mention the management of acute SCAD along with considerations for long term follow-up such as chest pain syndrome, extracoronary vasculopathy screening, and recurrent SCAD. Expert opinion: Our understanding regarding the association of SCAD and other arteriopathies such as FMD is anticipated to grow. In addition, progress is likely to be made in our efforts to predict recurrent SCAD risk and define potential preventative strategies, possibly through the incorporation of adjunctive imaging.

Spontaneous coronary artery dissection and associated myocardial bridging: Current evidence from cohort study and case reports

Spontaneous coronary artery dissection (SCAD) is a relatively uncommon and under-diagnosed disease characterized by the dissociation of intima and media of coronary artery wall due to an intimal tear or intramural hemorrhage. The exact pathophysiology of SCAD remains elusive and may involve multiple predisposing or precipitating factors including genetic abnormalities, inherited or acquired vasculopathies, hormonal influences, inflammation, intense exercise, emotional stress, and recreational drugs. Accruing reports, including five case reports and one cohort study, have recently addressed the concurrence of SCAD and myocardial bridging (MB), an anatomic variant in which a segment of the epicardial coronary descends and traverses in the myocardium. Among the patients with coexisting MB and SCAD, the left anterior descending artery was the only artery that harbors both pathologies, with SCAD locating either within the tunneled segment or distal to the MB. No other predisposing factors or precipitating stressors for SCAD were noted. It is hypothesized that the predilection for vasospasm, impaired endothelial function, and disturbed coronary flow dynamics associated with MB bridging could collectively contribute to the development of SCAD. Future studies are warranted to explore the mechanistic implications of MB in patients with SCAD.

Conditions and Factors Associated With Spontaneous Coronary Artery Dissection (from a National Population-Based Cohort Study)

The pathophysiology of spontaneous coronary artery dissection (SCAD) is heterogeneous, associated with systemic arteriopathies and inflammatory diseases, and often compounded by environmental precipitants, genetics, or stressors. However, the frequency of these associated conditions with SCAD on a population level remains unknown. Therefore, the objective of this analysis was to evaluate heterogeneous phenotypes of SCAD in the United States using data from the Nationwide Inpatient Sample collected from January 1, 2004, to September 31, 2015. Among 66,360 patients diagnosed with SCAD, the mean age was 63.1 ± 13.2 years and 44.2% were women. A total of 3,415 (5.14%) had depression, 670 (1.0%) had rheumatoid arthritis, 640 (0.96%) had anxiety, 545 (0.82%) had a migraine disorder, 440 (0.66%) used steroids, 385 (0.58%) had malignant hypertension, 280 (0.42%) had systemic lupus erythematosus, 250 (0.38%) had cocaine abuse, 215 (0.32%) had hypertensive heart or renal disease, 130 (0.19%) had coronary spasm, 105 (0.16%) had fibromuscular dysplasia, 85 (0.13%) had Crohn's disease, 75 (0.11%) had celiac disease, 60 (0.09%) had adult autosomal dominant polycystic kidney disease, 60 (0.09%) had hormone replacement therapy, 55 (0.08%) had sarcoidosis, 55 (0.08%) had amphetamine abuse, 15 (0.02%) had granulomatosis polyangiitis, 10 (0.02%) had α1-antitrypsin deficiency, 10 (0.02%) had Marfan syndrome, 10 (0.02%) had Ehlers-Danlos syndrome, 10 (0.02%) had Kawasaki disease, 10 (0.02%) had polyarteritis nodosa, and 5 (0.01%) had multiparity. In conclusion, most cases of SCAD had no apparent concomitant arteriopathy, inflammatory disorder, or evident risk factor.

Spontaneous coronary artery dissection: contemporary aspects of diagnosis and patient management

Spontaneous coronary artery dissection is an increasingly recognised cause of acute coronary syndromes, especially in young and middle-age women. Recognising its particularities and differences with atherosclerotic disease is central for appropriately identifying and approaching these patients. The authors review the current state of knowledge on spontaneous coronary artery dissection and provide practical recommendations for the diagnosis and management of this condition, both in the acute and convalescence phases.

Update in Spontaneous Coronary Artery Dissection

There has been increased awareness in the understanding and recognition of spontaneous coronary artery disease. Diagnosing this condition is of paramount importance as the treatment strategy differs greatly from traditional acute coronary syndrome patient. We review here the current state of management of spontaneous coronary artery disease.