Heart transplantation in the Ehlers-Danlos syndrome

Spontaneous Coronary Artery Dissection: An Updated Comprehensive Review

Spontaneous coronary artery dissection (SCAD) is defined as a non-iatrogenic, non-traumatic separation of the coronary artery wall, which has gained considerable recognition as an important cause of acute coronary syndrome. Despite the emerging evidence, it is still frequently missed and requires a high index of suspicion, as failure to accurately identify SCAD promptly could prove fatal. SCAD is most prevalent among middle-aged women, although it can also be found in men and postmenopausal women. Risk factors of SCAD include exogenous hormone use, physical and emotional stressors, pregnancy, and several inflammatory and connective tissue disorders. COVID-19 also contributes to the prevalence of SCAD. SCAD is classified into four main types based on the angiographic findings - type 1, type 2, type 3, and type 4. The gold standard for diagnosis is coronary angiography; however, intracardiac imaging is useful if diagnostic doubts persist. Despite the increasing recognition of this disease, there is a paucity in the guidelines on the management of SCAD. Management may be conservative, medical, or interventional. Cardiac rehabilitation is also necessary in the management of patients with SCAD. In light of the gaps in evidence, the authors aim to provide a comprehensive review of the existing literature, outlining the pathophysiology, classification, and, most importantly, the evidence and pitfalls circulating diagnosis, acute, and long-term management of SCAD.

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.

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.

Successful Heart Transplantation in a Patient With Loeys-Dietz Syndrome

Our patient is a 45-year-old woman with a history of Loeys-Dietz syndrome, vertebral artery dissection, stroke, prior atrial septal defect repair, and spontaneous left main coronary artery dissection that was revascularized with coronary artery bypass grafting who progressed to end-stage heart failure. She was listed for cardiac transplantation, and a suitable organ became available. She underwent heart transplantation more than 1 year ago successfully. This is the first reported case of a successful heart transplantation in an individual with Loeys-Dietz syndrome.

The spectrum of spontaneous coronary artery dissection: illustrated review of the literature

Spontaneous coronary artery dissection or SCAD is a rare and challenging disease that is increasingly diagnosed. It is characterized by a non-traumatic, non-iatrogenic separation of the coronary artery wall and occurs predominantly in young and middle-aged women without traditional cardiovascular risk factors. SCAD is often associated with predisposing conditions such as the peripartum period, systemic inflammatory disease and heritable connective tissue disease. More recently, independent investigators have demonstrated an important association with fibromuscular dysplasia. Extreme emotional or physical stress as well as intense hormonal therapy or drug abuse have been pointed out as precipitating factors. The diagnosis of SCAD can be challenging and starts with clinical suspicion. Advanced imaging techniques such as intravascular ultrasound and optical coherence tomography are useful for the differentiation from atherosclerotic disease and are increasingly used for this indication. The proposed treatment in the acute setting is based on findings from single-centre retrospective series: in stable patients with a TIMI-flow ≥2 a conservative management is proposed because of the high risk of procedural failure and complications as well as a high probability of spontaneous healing. Long-term treatment is comparable to that in non-SCAD acute coronary syndromes (ACS) but dual antiplatelet therapy should only be started in case of stenting and should be kept as short as possible in patients with vascular Ehlers-Danlos syndrome. Prognosis seems to be better compared to non-SCAD ACS but there is a reasonable risk of recurrence. In this review, we discuss the current knowledge of SCAD and provide a clinical pathway for the diagnosis, management and work-up of SCAD patients.