Most cases of SCAD can’t be traced back to apparent risk factors

Though it’s been linked tenuously in the past to psychological stressors and genetics, the majority of cases of spontaneous coronary artery dissection (SCAD) can’t be traced back to a concomitant arteriopathy, inflammatory disorder or evident risk factor, according to research published in the American Journal of Cardiology Oct. 29.

SCAD, a heterogeneous clinical syndrome commonly associated with systemic arteriopathies, inflammatory diseases and illicit drug use, is often identified when men and women present to the hospital with an acute coronary syndrome (ACS), corresponding author Deepak L. Bhatt, MD, MPH, and colleagues wrote in AJC. It’s also been tied to Crohn’s disease, systemic lupus, Marfan syndrome, Ehler-Danlos, fibromuscular dysplasia, migraines, and cocaine, amphetamine and steroid abuse.

“Despite advances in diagnosis using angiography, intravascular ultrasound and optical coherence tomography, the pathogenesis of SCAD remains unknown,” Bhatt, of Brigham and Women’s Hospital and Harvard Medical School, and coauthors wrote. “Interestingly, SCAD patients tend not to have typical risk factors for ACS such as diabetes, smoking, dyslipidemia or obesity.”

Instead, it looks like the pathophysiology of SCAD is heterogenous, the authors said, likely involving a host of genetic and hormonal factors.

To evaluate phenotypes of SCAD in the U.S., Bhatt et al. extracted data from 66,360 SCAD patients enrolled in the National Inpatient Sample between January 2004 and September 2015. A little under half of the pool were women, and on average patients were 63 years old.

The researchers said most cases of SCAD showed few connections to concomitant arteriopathies, inflammatory disorders or apparent risk factors, but they did identify a handful of factors that might have influenced the progression of the condition.

The strongest link existed between SCAD and depression—5.14 percent of patients presented with both conditions. One percent had rheumatoid arthritis, 0.96 percent had anxiety, 0.82 had a migraine disorder and 0.66 percent said they used steroids. SCAD patients also presented with:

  • Malignant hypertension (0.58 percent)
  • Systemic lupus erythematosus (0.42 percent)
  • Cocaine abuse (0.38 percent)
  • Hypertensive heart or renal disease (0.32 percent)
  • Coronary spasm (0.19 percent)

“Although in some case reports and small studies SCAD has been previously reported with several conditions such as psychological stress, autoimmune and inflammatory conditions, or cocaine and amphetamine use, our results did not show those associated conditions were higher in SCAD than non-SCAD ACS patients,” Bhatt and colleagues wrote. “However, our results are consistent with previous reports that SCAD is associated with genetic arteriopathies, fibromuscular dysplasia, both anabolic steroid and corticosteroid use, migraine and some autoimmune and inflammatory conditions.”

In the study, SCAD was also associated with small percentages of Crohn’s disease, celiac disease, hormone replacement therapy, adult autosomal dominant polycystic kidney disease, sarcoidosis, Marfan Syndrome and Kawasaki disease.

“There were two main findings,” the authors wrote. “First, consistent with previously published case reports, we demonstrated that SCAD was associated with a variety of heterogeneous conditions, many of which are not associated with traditional ACS. Second, our study highlighted the use of a large database potentially to characterize an uncommon disease such as SCAD.”