Woven coronary anomaly leading to silent myocardial infarction: A case report.

RATIONALE: Woven coronary artery is an extremely unusual congenital anomaly with unknown etiology. Because of normal flow after anomalous segment, this anomaly is considered to be benign. PATIENT CONCERNS: A 51-year-old man was admitted to our hospital with exertional dyspnea that he had experienced for half a year. Woven coronary artery was found in coronary angiography. DIAGNOSES: The patient was diagnosed with mitral regurgitation and woven coronary. Silent myocardial infarction was found in cardiac surgery.
INTERVENTIONS: Coronary artery bypass grafting was performed in the process of cardiac surgery. OUTCOMES: At 4 weeks follow-up, he was well and without symptoms. LESSONS: Although most woven coronary arteries are considered to be benign, myocardial ischemia even myocardial infarction can be caused by this anomaly.

Introduction

Woven coronary artery is an extremely unusual congenital anomaly with unknown etiology. In this anomaly, the coronary artery is divided into many small arteries along the anomalous axis. These small arteries merge again in the distal. Because of normal flow after anomalous segment, this anomaly is considered to be benign. However, we reported a patient with woven coronary anomaly developing silent myocardial infarction.

Case report

The ethics committee of Second Xiangya Hospital has approved the study. A 51-year-old man was admitted to our hospital with exertional dyspnea that he had experienced for half a year. He had no risk factor for atherosclerosis. He was diagnosed with mitral regurgitation and planned to accept mitral valve repair. Coronary angiography before surgery showed that left circumflex coronary artery (LCX) divided into 2 tortuous small arteries and merged again into the distal lumen with TIMI 3 blood flow (Fig. 1). For a better anatomical characterization of the LCX, computed tomography angiography was performed. Computed tomography angiography showed that LCX divided in multiple thin and reticular arteries and reassembled in the distal (Fig. 2). We could find vascular mass in the middle of LCX. Akinesia and scar formation were found in the left ventricular posterior wall in surgery, which usually meant silent myocardial infarction. However, electrocardiogram did not show the classic changes of old myocardial infarction. Mitral valve repair and coronary artery bypass grafting was performed. At 4 weeks follow-up, he was well and without symptoms.

Figure 1

Woven coronary artery anomaly at the proximal portion of the left circumflex coronary artery (LCX) in the right anterior oblique view with caudal angulation. There was a normal blood flow in the distal segment of the anomaly.

Figure 2

(A) Cross-sectional images at the lesion site showed twisting and multiple small channels. (B) Three-dimensional reconstruction revealed a vascular mass in the proximal left circumflex coronary artery (LCX).

Discussion

The woven coronary is an extremely rare congenital anomaly in which epicardial coronary arteries are divided into thin tunnel-like channels that reassemble again into the distal lumen. Woven coronary artery, which was usually an incidental finding in the process of coronarography, was first described by Sane and Vidaillet in 1988.[ Woven coronary anomaly should be distinguished with intracoronary thrombus, spontaneous coronary artery dissection, or chronic total occlusion with bridging collaterals. CTA was crucial in doing the differential diagnosis. A vascular mass without bridging collaterals was observed in the middle of coronary artery. Unlike intracoronary thrombus and spontaneous coronary artery dissection, the diameter of vascular mass was much larger and the structure was more complex. Intravascular ultrasound and optical coherence tomography can be useful in establishing a definitive diagnosis as well.[ Multiple thin and tortuous epicardial arterial conduits were shown in intravascular ultrasound or optical coherence tomography, reassembling again into a single lumen in the distal segment of the RCA without thrombus or dissection flaps.[ The woven coronary artery is thought to be a benign condition in most cases; however, it was associated with myocardial infarction and ischemia in some case reports.[ The presence of this malformation can make cardiac catheterization procedures more difficult. Coronary artery bypass grafting may be a better alternative.

Conclusion

Although most woven coronary arteries are considered to be benign, myocardial ischemia even myocardial infarction can be caused by this anomaly.