Newer concepts for imaging anomalous aortic origin of the coronary arteries in adults

Abstract

Of the different kinds of coronary anomalies observed in adults, anomalous origin of a coronary artery from the opposite sinus of Valsalva with an "interarterial" course (ACAOS) entails a high risk of clinical consequences related to the intramural course of the ectopic coronary artery. We review current imaging modalities for differentiating this condition from generally benign coronary anomalies and for quantifying the severity of individual cases. For identifying ACAOS, noninvasive modalities (echocardiography, computed tomographic angiography, and coronary magnetic resonance angiography) are preferred: the favored modalities are transthoracic echocardiography in children and multidetector computed tomography in adults. For evaluating the pathophysiologic mechanisms of ischemia in ACAOS and subclassifying the severity of individual forms, coronary intravascular ultrasonography provides enhanced temporal and spatial resolution. The critical quantifiable features of the coronary anatomy in ACAOS seem to be hypoplasia, lateral compression at the level of the intramural course, and possibly exercise-related further narrowing of the proximal ectopic segment. Definitive guidelines are being developed for the optimal workup and treatment of ACAOS.

Coronary artery anomalies detected by MSCT-coronary angiography in the adult

“…Angelini and co-workers found a prevalence of 1.07% by invasive coronary angiography. 25 Recently Cademartiri and colleagues reported a prevalence for ACAOS of 1.5% as detected by MSCT-CA in a series of 543 patients. 26 According to the authors, the number of detected CAAs in this study was positively influenced by selection bias.…”

“…24 3D capabilities of MSCT facilitate an accurate description of coronary artery anatomy including collateral flow, even in the hands of operators not specifically trained in diagnosing CAAs. 25 This may facilitate the diagnosis of ALCAPA, especially if symptoms are less pronounced and/or variable, as in adults.…”

“…Echocardiography is highly accurate in detecting these CAAs without the use of ionising radiation or potentially nephrotoxic contrast agents. 25 Unfortunately, at older age, when the BMI increases, transthoracic echocardiography becomes progressively less accurate and more operator dependant. Furthermore, evaluation by echocardiography is limited to the proximal part of the coronary arteries.…”

“…28 Furthermore coronary magnetic resonance angiography (CMRA) allows 3D visualisation of the main coronary arteries in their topographic environment, thereby circumventing an important drawback of invasive coronary angiography. 25 However, its use is more time consuming as compared with MSCT-CA, repetitive (for some patients strenuous) breath-holds are required that are crucial for image quality and visualisation of the coronary arteries is incomplete, especially for the distal segments. 29,30 With the use of CMRA, the intramural course and degree of compression inside the aortic wall in case of ACAOS can only be guessed at.…”

Improper aortic sinus-connected coronary artery: Ascertaining the course is essential (Comment on Ann Saudi Med 2010;1:81-3)

“…An improper aortic sinus-connected coronary artery can take several courses to reach its dependent territory; these include the prepulmonic, interarterial, intraseptal and retroaortic 23. Accurate delineation of the course of ectopic coronary arteries is essential provided its pathophysiological, surgical and prognostic implications.…”