Anomalous Circumflex Coronary Artery Injury Caused by Mitral Annuloplasty: Role of 64-Multislice Computed Tomography

From the Cardiovascular Institute, San Carlos University Hospital, Madrid, Spain. The authors report no conflicts of interest regarding the content herein. Manuscript submitted March 14, 2009, provisional acceptance given April 11, 2009, and final version accepted May 18, 2009. Address for correspondence: David Vivas, MD, Cardiovascular Institute (Department of Cardiology), San Carlos University Hospital, Profesor Martin Lagos, s/n Postal Code: 28040, Madrid, Spain. E-mail: dvivas@secardiologia.es

_______________________________________________

J INVASIVE CARDIOL 2009;21:E204-E205 Anomalous origin of the coronary arteries is an uncommon anomaly frequently detected as an incidental finding during coronary angiography.1,2 Injury of an anomalous coronary artery during valvular surgery is a very unusual complication.3 We report the case of a patient with occlusion of an anomalous circumflex coronary artery (Cx) after mitral annuloplasty who required urgent revascularization by coronary artery bypass grafting (CABG). Imaging with 64-multislice computed tomography (MSCT) showed external compression of the Cx. Case Report. A 69-year-old female presented to the emergency room with severe progressive dyspnea. On physical examination a IV/VI holosystolic murmur, best heard over the axilla, was noted. Two-dimensional echocardiography showed severe mitral regurgitation due to mitral valve prolapse and a normal left ventricular ejection fraction (LVEF). Preoperative coronary angiography exhibited an anomalous Cx origin from the right sinus of Valsalva, with a retroaortic course. No significant angiographic stenoses were observed (Figure 1A). The patient underwent mitral valve repair and placement of a 32 mm Carpentier-Edwards Physio annuloplasty ring (Edwards Lifesciences, Irvine, California). However, 3 hours after surgery she developed hemodynamic instability and the electrocardiogram (ECG) showed a 3 mm ST-segment elevation on the inferolateral leads. An echocardiogram revealed severely reduced LVEF. The mitral valve ring was well-seated and no paravalvular leak was observed. Coronary angiography showed a total occlusion in the proximal segment of the anomalous Cx (Figure 1B). Percutaneous intervention was attempted, without success, due to failure to cross the occluded segment despite the use of different guidewires. The patient underwent emergency CABG (saphenous vein grafts to the first and second obtuse marginals). A 64-MSCT revealed an external mechanical compression of the anomalous Cx, probably by a periannular hematoma rather than as the result of suture injury (Figure 2). Her subsequent clinical course was uneventful and she was discharged in stable condition. Discussion. Coronary artery anomalies are detected in 1–2% of patients.1 A retroaortic course of the Cx has been found in asymptomatic patients, but has also been associated with sudden death.2 Special consideration requires valvular surgery, where the coronary artery could be damaged by occlusion of the coronary ostium by the prosthesis or direct suture of the arterial wall.3 Our patient suffered an unusual injury of the anomalous Cx following mitral annuloplasty. Although the the priority is always to restore coronary flow, it is also important to clarify the cause of coronary occlusion. Previous reports have suggested the use of intravascular ultrasound in patients referred for urgent coronary angiography to distinguish suture injury from an atherosclerotic lesion.4 In our experience, MSCT may be useful in identifying patients at high risk before valvular surgery. MSCT accurately visualizes the anatomic relationship between the mitral annulus and the anomalous Cx artery, avoiding complications in the postoperative period. A distance Conclusion Special surgical considerations must be made when performing valvular replacements in patients with an anomalous circumflex coronary artery. MSCT should be considered as an integral part of the preoperative study to guide the surgeon during the mitral annuloplasty procedure and to avoid coronary injury.

2. Taylor AJ, Byers JP, Cheitlin MD, Virmani R. Anomalous right or left coronary artery from the contralateral coronary sinus: “High-risk” abnormalities in the initial coronary artery course and heterogeneous clinical outcomes. Am Heart J 1997;133:428–435.

3. Cornu E, Lacroix PH, Christides C, Laskar M. Coronary artery damage during mitral valve replacement. J Cardiovasc Surg 1995;36:261–264.

4. Wykrzykowska J, Cohen D, Zimetabum P. Mitral annuloplasty causing left circumflex injury and infarction: Novel use of intravascular ultrasound to diagnose suture injury. J Invasive Cardiol 2006;18:505–508.

5. Sato Y, Inoue F, Matsumoto N, et al. Detection of anomalous origins of the coronary artery by means of multislice computed tomography. Circ J 2005;69:320–324.