Rationale and design of a multicenter, international and collaborative coronary artery aneurysm registry (CAAR)

Coronary artery aneurysm has been classically defined as a coronary dilation that exceeds the diameter of normal adjacent segments or the diameter of the patient’s largest coronary vessel by 1.5×. Termed by Bourgon,1 it is an uncommon disease that has been diagnosed with increasing occurrence since the advent of coronary angiography.2,3 The incidence has been reported to vary from 1.5% to 5%, with suggested male dominance and a predilection for the right coronary artery.2,3 Although several causes have been shown, atherosclerosis accounts for ≥50% of coronary aneurysms in adults. Reported complications include thrombosis and distal embolization, vasospasm, and rupture, producing ischemia, heart failure, or arrhythmias. The natural history and long-term outcomes remain unclear, as definitive data are lacking. In addition, controversies persist regarding the use of medical treatment (antithrombotic therapy) or interventional/surgical procedures.1–5