Spontaneous Coronary Artery Dissection: A Call for Consensus and Research Advancement

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.

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

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

Fibromuscular dysplasia: A comprehensive review on evaluation and management and role for multidisciplinary comprehensive care and patient input model

Fibromuscular dysplasia is a nonatherosclerotic, under-recognized disorder primarily seen in middle-aged women. It can lead to several complications, such as hypertension, headaches, dissections, aneurysms, myocardial infarctions, and cerebrovascular accidents, to name a few. This article provides a comprehensive review of current literature on epidemiology, etiology, diagnosis, treatment, and long-term surveillance and fibromuscular dysplasia management. In addition, it renders the role of education and prevention for patients living with this condition and family screening. Lastly, it emphasizes the importance of a comprehensive multidisciplinary care model and patient input, given the complexity of this disease and its systemic presence and protean manifestations.

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.