Recent Advances on the Genetics of Spontaneous Coronary Artery Dissection

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

An unusual case of two acute coronary syndrome episodes caused by allergic and non-allergic coronary artery dissection with potential coronary vasospasm association: a case report

Background

Type I variant Kounis syndrome is characterized by coronary spasm following an allergic or anaphylactic reaction. Coronary spasm is also recognized as a contributing factor in spontaneous coronary artery dissection (SCAD).

Case summary

A 46-year-old woman presented to the emergency room with a chief complaint of chest discomfort following the ingestion of a steamed bun. A marked decrease in systolic blood pressure and a prominent rash on her forearms and groin suggested anaphylactic shock. Upon stabilization of vital signs, acute coronary syndrome (ACS) was suspected based on electrocardiogram findings and symptoms, prompting an emergency coronary angiography (CAG). The CAG revealed severe stenosis with coronary artery dissection in the right coronary artery (RCA), and a stent implantation was performed. Given the suspicion of type I variant Kounis syndrome, a spasm provocation test was performed, yielding a positive result. Six years later, she experienced chest discomfort while sleeping and was admitted to our emergency department. An electrocardiogram showed ST-segment elevation in leads II, III, and aVF. An emergency CAG identified a severely stenotic lesion with coronary artery dissection in the RCA, leading to a diagnosis of SCAD. Direct stenting was performed at the stenotic site. The patient was discharged following intensification of medication.

Discussion

This report describes a rare case of a middle-aged woman with two episodes of ACS caused by both allergic and non-allergic coronary artery dissection. These episodes suggest that a shared underlying coronary vasospasm in both conditions may be a common trigger for coronary artery dissection.

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

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

Polygenic Risk in Families With Spontaneous Coronary Artery Dissection

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposures

PRS for SCAD comprised of 7 single-nucleotide variants.

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

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.

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.

Case Report on Spontaneous Coronary Artery Dissection: A Rare Culprit of Chest Pain

Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic separation of the coronary artery wall with subsequent intramural hematoma (IMH) formation in the false lumen. It can be associated with or without an intimal tear. It is clinically divided into three types based on its angiographic appearance. Most SCAD cases are seen in young or middle-aged women, especially in a peripartum state. Additionally, SCAD patients usually have fewer cardiovascular risk factors and more commonly have predisposing conditions like fibromuscular dysplasia (FMD). Patients present with features of chest pain that radiates to the left arm or neck, shortness of breath (SOB), as well as nausea and vomiting. Coronary angiography is the most widely used first-line modality to diagnose this condition. Management is usually conservative; however, invasive procedures can be utilized for high-risk patients. We present a case of a 54-year-old woman with SCAD diagnosed using coronary angiography and treated conservatively with dual-antiplatelet therapy, culminating with resolution.

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.