Spontaneous coronary artery dissection epidemiology and demographics

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Nate Michalak, B.A. Arzu Kalayci, M.D. [2]

Synonyms and keywords: SCAD

The annual incidence of spontaneous coronary artery dissection is estimated at 0.26 per 100,000 persons (0.33 in women and 0.18 in men), corresponding to approximately 800 new cases per year in the United States. The true prevalence of spontaneous coronary artery dissection in the general population remains unknown; however, retrospective angiographic registries have reported a SCAD detection rate of 0.1 to 1.1% among all coronary angiograms performed. The case fatality rate of SCAD is relatively low compared with other causes of ACS, with an estimated in-hospital mortality rate of 0 to 4%. The average age at diagnosis of SCAD in females ranges from 44 to 53 years, although patients may present with SCAD in their second through ninth decades of life. SCAD has a strong predilection for young women with no or minimal traditional cardiovascular risk factors. It has been reported in all major racial and ethnic groups, with the majority of patients being white.

• The true prevalence of spontaneous coronary artery dissection (SCAD) remains unknown because it is an under-diagnosed condition.
• Missed diagnoses may be driven by a low suspicion of acute coronary syndrome (ACS) in young female even in the presence of classic manifestations, limitations of current coronary angiographic techniques, and lack of clinician familiarity with the condition.^[1]

• The prevalence of SCAD reported by retrospective angiographic registries ranges from 0.2 to 2.0% among all ACS cases and from 8.7 to 35.0% among women < 50 years with ACS.^{[2][3][4][5][6][7][8][9]}

• The annual incidence of SCAD is estimated at 0.26 per 100,000 persons (0.33 in women and 0.18 in men), corresponding to approximately 800 new cases per year in the United States.^[10]

• The case fatality rate of SCAD is relatively low compared with other causes of ACS, with an estimated in-hospital mortality rate of 0 to 4%.^[2]

• The average age at diagnosis of SCAD in females ranges from 44 to 53 years, although patients may present with SCAD in their second through ninth decades of life.^[1][11]

• The prevalence of SCAD decreases with age, and is estimated at 7.6%, 4.0%, 2.1%, and 1.2% in women below the age of 40, 50, 60, and 70, respectively.^[2]

• SCAD has a strong predilection for young women with no or minimal traditional cardiovascular risk factors.
• SCAD is one of the most common non-atherosclerotic coronary artery diseases in women <50 years of age and accounts for one-fourth of myocardial infarctions.^[12]
• The risk of SCAD has been associated with pregnancy as well as the use of oral contraceptives.^[13][14][15]
• Possible mechanisms underlying increased prevalence of SCAD in this population include structural alterations in the arterial wall secondary to hormonal change, increased shear stress during labor, fragmentation of reticulin fibers, loosening of ground substance, and hypertrophy of smooth muscle.^[16]

• SCAD has been reported in all major racial and ethnic groups, with the majority of patients being white. ^[8][17][18]
• This finding may have been influenced by referral and sampling bias as well as the demography of patients from the reporting hospitals.