The prevalence of CAAs is close to 0.5% with coronary angiography and 1% with coronary CT [5]. The circumflex artery is the most involved (50% of cases) versus 30% for the RCA and 20% for the left main and the left anterior descending artery (LAD) [6].

The position between the aorta and the pulmonary artery puts the coronary arteries at risk for compression particularly during strenuous activity and may significantly limit the reservoir capacity of the epicardial coronary system [7].  In addition, the angulation of coronary artery at its origin from the opposite sinus causes an acute closure in its ostium responsible for the symptoms especially during hard activities [8].

The clinical presentation can include angina or equivalent, lipothymia, syncope, heart failure, documented myocardial ischemia, severe ventricular rhythm disturbances (tachycardia or fibrillation), recovered cardiac arrest and sudden death. Yet coronary anomalies may also be asymptomatic.

Adults are not well suited for coronary analysis by transthoracic echocardiogram. Only the first few millimeters of an ectopic coronary artery can be visualized and precise diagnosis cannot be made on ultrasound imaging alone.

Frequently involved in the diagnosis in adults, coronary angiography is no longer considered the gold standard for classifying CAA. It does not allow sufficient analysis of the ectopic orifice and the initial pathway.

Coronary CT has become the reference examination when a risky form is suspected or when an initial ectopic path is uncertain. CT is particularly useful in determining the path of the ectopic vessel.

Cardiac MRI has the advantage of not using contrast agents and is non-irradiating. However, because of its low spatial resolution, this technique is currently less helpful in evaluating the distal coronary system [9,10].

CAAs with an intraarterial pathway and/or intramural connection, and those with a pulmonary connection are the recognized CAAs at risk [11].

The course of action is often difficult in adults for CAAs at risk. Several decision algorithms have been proposed [12,13].

Practices are quite heterogeneous, explained by still limited knowledge on the natural or corrected history of CAAs [14,15].

The benefit/risk ratio of surgical correction has not yet been clearly evaluated. In cases of recovered cardiac arrest or symptomatic left-sided CAA, the indication for correction is clear. The current lack of a score stratifying individual risk of sudden death complicates management [16]. The same anatomic shape may be responsible for early sudden death or be perfectly tolerated until old age.

If myocardial ischemia is the main mechanism of symptoms, the place of coronary angioplasty deserves to be evaluated in adults where placing a stent seems possible without major risk.

Empirically, a beta-blocker treatment can be proposed in case of ischemic symptomatology. Monitoring alone may be an acceptable initial strategy depending on the context.

Given the current state of knowledge and uncertainty, it seems preferable that the decision to correct or not to correct a CAA be made by a specialized multidisciplinary team. There are recommendations to this effect [17].