Aims: Spontaneous coronary artery dissection (SCAD) is an underdiagnosed entity of acute coronary syndrome (ACS). Its prevalence remains unclear due to a challenging diagnosis, particularly in instances of intramural haematoma without intimal rupture. In the present study, we aimed to: 1) estimate the prevalence of SCAD among acute coronary syndrome (ACS) patients managed in a French coronary care centre, 2) demonstrate the value of specific angiographic signs for diagnosing SCAD, and 3) confirm the incremental value of intracoronary imaging in ambiguous cases.
Methods and results: From 1999 to 2014, 55 cases of SCAD (all women, mean age 50.1 years) were diagnosed. Ignoring age, 51 (92.7%) had ≤2 cardiovascular risk factors. Thirty-six were diagnosed prospectively during the latter period (2012-2014). Among these, SCAD accounted for 35.7% of ACS (20/56) in women <60 years with ≤1 cardiovascular risk factor. Upon close investigation, five angiographic features commonly observed with SCAD were identified: 1) absence of atheroma on other coronary arteries, 2) radiolucent flap(s), 3) contrast dye staining of the arterial wall, 4) starting and/or ending of the angiographic ambiguity on a side branch, 5) long narrowing of lumen calibre: smooth and linear, or stenosis of varying severity mimicking a "stick insect" or "radish" aspect. Three of the above five signs were present in 51 (92.7%) cases. Optical computed tomography (OCT) was performed in 19 cases with no complication. All explored arteries had evidence of intramural haematoma and/or intimomedial membrane separation. An intimal rupture was observed in 10 (52.6%) patients. The diseased segment initiated or ended on a side branch in 14 (73.7%) patients.
Conclusions: SCAD accounts for approximately one third of ACS in young women with ≤1 CRF. The combination of specific angiographic signs and OCT imaging facilitates the diagnosis of ambiguous cases without intimal rupture.