National French registry of spontaneous coronary artery dissections: prevalence of fibromuscular dysplasia and genetic analyses

Background: Spontaneous coronary artery dissection (SCAD) is an increasingly reported but poorly understood condition. Few European data are available.

Aims: The aims of this study were to obtain European data on SCAD, determine the prevalence of fibromuscular dysplasia (FMD) and enable genetic analyses in this population.

Methods: Data from a national French registry of SCAD cases were analysed prospectively and retrospectively. Clinical and angiographic data and management strategy were collected. Major adverse cardiovascular events (MACE) were analysed after one year of follow-up. Subjects were screened for FMD and blood was collected for DNA extraction.

Results: From June 2016 to August 2018, 373 SCAD cases were confirmed by the core lab. Mean age was 51.5 years. Patients were mostly women (90.6%) and 54.7% of cases had less than two cardiovascular risk factors. At one year, 295 patients (79.1%) were treated conservatively, the MACE rate was 12.3%, and there were no cases of mortality. The recurrence rate of SCAD was 3.3%. FMD was found at ≥1 arterial site in 45.0% of cases. We also confirmed the genetic association between the PHACTR1 locus and SCAD (odds ratio=1.66, p=7.08×10–8).

Conclusions: Here we describe the DISCO registry, the largest European SCAD cohort where FMD was found in 45% of cases and the genetic association with PHACTR1 was confirmed. This nationwide cohort is a valuable resource for future clinical and genetic investigation to understand SCAD aetiology.