Characteristics of extension and de novo recurrent spontaneous coronary artery dissection.

Aims: Spontaneous coronary artery dissection (SCAD) is an under-recognised and important cause of myocardial infarction in young women. Recurrent SCAD is frequent but poorly understood. We aimed to explore the clinical and angiographic characteristics, and outcomes of recurrent SCAD.

Methods And Results: Patients with SCAD extension or recurrence prospectively followed at Vancouver General Hospital were included in this retrospective study. SCAD diagnosis was confirmed by two experienced cardiologists. Detailed medical history, baseline demographics, angiographic results, and clinical details of index SCAD and recurrent events were recorded. SCAD extension was defined as angiographic extension of a previously dissected coronary segment, and de novo recurrent SCAD was defined as new spontaneous dissection. We identified 43 patients with SCAD recurrence with mean age 48.9±8.4 years; 38/43 were women, and 32/43 had fibromuscular dysplasia. Nine patients had SCAD extension at median time of five (1-19) days, while 34 patients had de novo recurrent SCAD at median time of 1,487 (107- 6,461) days after the index SCAD event. All SCAD extension patients had worsening of the index dissected segment, with 5/9 involving extension to adjacent segments, while all de novo recurrent SCAD patients had new dissections affecting coronary segments distinct from the index dissection.

Conclusions: De novo recurrent SCAD invariably affected new segments distinct from previously dissected segments.