Spontaneous coronary artery dissection (SCAD) is a relatively infrequent cause of acute coronary syndrome that usually affects young to middle-aged women. Mainly because of its low prevalence, until recently, most of the evidence on this condition was derived from case reports and small series. Over the last 5 years, more robust evidence has become available from larger retrospective and prospective cohorts of patients with SCAD. The increase in knowledge and recognition of this entity has led to the publication of expert consensus on both sides of the Atlantic. However, new data are continuously accumulating from larger cohorts of patients with SCAD, bringing new light to this little-understood condition. The aim of this article is to update the knowledge on SCAD, including new information from recent studies published since the consensus documents from the European Society of Cardiology and the American Heart Association.

Spontaneous coronary artery dissection (SCAD) remains an infrequent, elusive, and challenging clinical entity of unknown etiology eight decades after its initial description. Our understanding of the pathophysiology of SCAD, initially limited to information from early pathological studies, case reports, and very short series, has been enriched recently by relatively large contemporary series of patients studied prospectively. The typical presentation involves a young woman without coronary risk factors suffering an acute coronary syndrome but, actually, most patients are middle-aged and have coronary risk factors. A high number of conditions have been related to SCAD, but fibromuscular dysplasia has shown a major intriguing association with potential pathophysiological implications. SCAD may present (a) with an intimal tear and the classic angiographic 'flap' leading to the appearance of two lumens (true and false), or (b) without an intimal rupture, as an intramural hematoma. An increased clinical awareness together with new diagnostic tools have led to a major surge in the diagnosis of SCAD. High-resolution intracoronary techniques provide unique diagnostic insights into the underlying pathophysiology and facilitate identification of the disease in patients misdiagnosed previously. After the initial acute ischemic insult, most patients stabilize and have a benign clinical course and eventually experience spontaneous healing of the vessel wall during follow-up. However, recurrences may still occur in up to 10-20% of cases. Accordingly, a conservative medical management (watchful waiting strategy) has been recommended as the initial approach. Revascularization remains particularly challenging and may be associated with suboptimal results, acute complications, and poor long-term outcome. Nevertheless, in patients with ongoing or refractory ischemia and adequate anatomy, revascularization should be attempted. Some novel and attractive coronary interventions have been proposed in this uniquely challenging anatomic scenario. This review aims to present a comprehensive and contemporary update on this elusive and intriguing clinical entity.