Computed Tomography Derived Coronary Triangulated Orifice Area—Deduction of a New Parameter for Follow-up After Surgical Correction of Anomalous Aortic Origin of Coronary Arteries and Call for Validation

Abstract

Introduction: Anomalous aortic origin of a coronary artery (AAOCA) from the opposite sinus of Valsalva is a rare congenital abnormality. Computed tomography angiography (CTA) is primarily used as a diagnostic tool to evaluate the anatomy and identify potentially malignant AAOCA variants. Limited data is available on the role of CTA during postoperative follow-up. We aimed to develop an objective CTA derived parameter for diagnostic evaluation and follow-up after surgical correction of AAOCA and correlate the anatomical features to the postoperative outcome.Methods: All consecutive patients who underwent surgical repair of AAOCA from 2001 to 2018 and had pre and postoperative CTA imaging available were included. A retrospective analysis of the pre- and postoperative CTA and the outcomes was performed. The origin and course of the anomalous coronary artery and the ostial dimensions were evaluated and correlated with restenosis of operated coronary artery. To allow an accurate evaluation of the effective orifice area at diagnosis and after surgical repair we deduce and propose a new parameter—the coronary triangulated orifice area (CTOA).Results: Out of the 54 patients who underwent surgical treatment for AAOCA, 11 fulfilled the inclusion criteria. The median follow-up was 19 months [IQR 3;42]. The mean age at surgery was 41 ± 16 years, with six patients (55%) being male. Postoperatively, the angle between the proximal coronary artery and the aortic wall increased from 20 ± 5° to 28 ± 9° (p < 0.01) and ostial diameter in the transversal plane increased from 4.1 ± 2.5 mm to 6.2 ± 2.7 mm (p < 0.01). The median CTOA increased significantly from 1.6 mm2 [IQR 0.9;4.9] to 5.5 mm2 [IQR 3;11.8] (p < 0.005). During follow-up, in three patients a restenosis of the operated coronary artery was suspected. In these patients, the CTOA only showed a limited postoperative increase of ≤ 1.4 mm2.Conclusions: CTA can play an important role in the evaluation of the pre- and postoperative anatomy in AAOCA patients. CTOA may be of use in conjunction with the acute angle take-off and ostial diameter order to comprehensively evaluate the operated ostium after unroofing or patch angioplasty.

Anomalous origin of the coronary artery: prevalence and coronary artery disease in adults undergoing coronary tomographic angiography

“…Specifically, myocardial ischemia can be attributed to fixed extent component (e.g. slit-like ostium), proximal narrowing, acute take-off angle and intramural course with an elliptic vessel shape [ 16 – 19 ], as well as dynamic component (e.g., lateral compression) that are accentuated during exercise [ 12 , 20 – 22 ]. In this study, coronary stenosis was mostly found in the middle or distal segments of coronary arteries.…”

“…The various pathological aspects associated with malignant AAOCA collectively contribute to a significantly reduced functional ostial area in the anomalous coronary artery, leading to ischemia and potentially fatal arrhythmias [ 16 ]. The potential mechanisms underlying AAOCA-induced ischemia may be resulted from the origin, the anatomy of the origin [ 16 – 19 ], the angulation, and the dynamic compression [ 12 , 20 – 22 ].…”

A comprehensive analysis of the intramural segment in interarterial anomalous coronary arteries using computed tomography angiography

“…Coronary artery motion during the CTA produces temporal and spatial blurring that can effectively result in a lower spatial resolution than intended. 18 Thus, it would be advisable to use a slice thickness of 0.5 mm on CTA in all cases for the evaluation of the ILS to obtain the most reliable results. In the current study, CTAs were performed in the different referring hospitals following local protocols; therefore, not all scans included in this study were performed according to the same scanning protocol.…”

“…Images were rotated to a view perpendicular to the horizontal plane of the aortic valve annulus according to previously described methods. 18 In this view, the distance between the aortic lumen and coronary artery lumen [further referred to as ‘interluminal space’ (ILS)] was measured at consecutive 2 mm intervals along the length of the intramural segment that was measured peroperatively by the surgeon. The surgical measurements were used as the reference to define the length of the intramural segment ( Figure 1B ).…”