Abstract
Coronary artery fistula is a rare cardiac abnormality, occurring more frequently in young patients and treated with cardiac surgery or percutaneous interventions in most cases. We present the case of a 63-year-old man with an incidental diagnosis of coronary artery fistula, treated with conservative strategy. (Level of Difficulty: Intermediate.)
Key Words: angio-computed tomography, coronary angiogram, coronary artery fistula, transesophageal echocardiography
Abbreviations and Acronyms: CAF, coronary artery fistula; CT, computed tomography
Central Illustration
A 63-year-old man, with an anamnesis positive for diabetes mellitus, dyslipidemia, and hypertension, presented to our hospital with a transient ischemic attack during a hypertensive crisis, symptomatic for lower lip paresthesia. Vital signs and physical examination were normal. Electrocardiogram revealed a sinus rhythm and no sign of ischemia. Chest X-ray showed neither cardiomegaly nor pulmonary congestion. No critical stenosis were detected at ultrasonography of the supra-aortic trunks. Brain computed tomography (CT) showed an arachnoid cyst in right posterior cerebellar site.
Transthoracic echocardiographic showed normal wall motion with a left ventricular ejection fraction of 66%. Transesophageal echocardiography was performed for evaluation of potential patent foramen ovale revealing a fistulous aneurysmal formation arising from the left main coronary artery (Figures 1A and 1B, Videos 1 to 4). Angio-CT confirmed a coronary artery fistula (CAF) between distal left main coronary artery and right atrium (Figure 1D), with a retro-aortic serpiginous course and an ectasic vascular structure (>8.35 mm); this pathologic vessel also had an aneurismatic formation of maximum diameter of 1 cm. CT scan detected also a 50% soft eccentric plaque in mid-circumflex coronary artery and a <50% soft eccentric plaque in the right coronary artery.
Figure 1.
Multimodality Imaging of CAF
(A and B) Transesophageal echocardiography: (A) short axis of the valve plane, and (B) long axis of the ascending aorta with color Doppler showing the flow inside the CAF (white arrow). (C) Angio-CT follow-up, showing the stability of the CAF. (D) Angio-CT with 3-dimensional reconstruction of CAF (3 arrows) and of LM and CX. (E) Coronary angiogram of CAF showing the ectasic vessel as well as a focal aneurism (white arrow). CAF = coronary artery fistula; CT = computed tomography; CX = circumflex coronary artery; LM = left main coronary artery.
Coronary angiography revealed no significant coronary atherosclerotic disease and confirmed the CAF with its convoluted course (Figure 1E, Video 5). Cardiac magnetic resonance demonstrated a normal biventricular dimension and systolic function without valvular abnormalities. No left-to-right shunt was found either in cardiac magnetic resonance (Qp/Qs close to 1) or right-sided heart catheterization. Maximal stress test with cycloergometer was negative for clinical and electrocardiographic inducible ischemia (120 W).
CAF is an uncommon vascular abnormality, present in 0.002% of the general population, characterized by a connection between a coronary artery and a cardiac chamber or a great vein vessel, therefore bypassing the myocardial capillary bed. CAFs occur in isolation in 55% to 80% of cases, with 10% of cases accompanied by a coronary artery aneurysm.1
These CAFs are usually asymptomatic in the first 2 decades, especially when they are hemodynamically small, and a small number may close spontaneously. The CAFs may increase in size over time, although this does not occur invariably, and indications for treatment include: presence of a large or increasing left-to-right shunt, left ventricular volume overload, myocardial ischemia, left ventricular dysfunction, congestive cardiac failure, and prevention of endocarditis/endarteritis.2
The surgical indication for asymptomatic patients is controversial and most surgeons will operate on those with a significant shunt.3 Considering the age, the absence of clinical symptoms, and the absence of hemodynamically significant left-to-right shunt at invasive assessment, a conservative strategy was chosen, so the patient had strict follow-up, with clinical and echocardiographic assessment every 6 months, and with annual CT scan and stress test. During these 9 years of follow-up, the CAF remained stable, with a maximum diameter dimension of 8.35-8.39 mm (Figure 1C), with no impact on cardiac chambers and on symptoms. This case emphasizes the importance of an individual case-by-case multidisciplinary management of CAF as suggested by recent American Heart Association/American College of Cardiology guidelines.4
Funding Support and Author Disclosures
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Footnotes
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
Appendix
For supplemental videos, please see the online version of this paper.
Appendix
Transesophageal Echo Video
Short-axis view at the plane of aortic valve, showing the convoluted course of the CAF. CAF = coronary artery fistula.
Transesophageal Echo Video
Short-axis view at the plane of ascending aorta, showing the convoluted course of the CAF. CAF = coronary artery fistula.
Transesophageal Echo Video
Long-axis view at the plane of aortic valve and ascending aorta, showing the convoluted course of the CAF. CAF = coronary artery fistula.
Transesophageal Echo Video
Long-axis view at the plane of aortic valve and ascending aorta, with color-Doppler showing the blood flow inside the convoluted course of the CAF. CAF = coronary artery fistula.
Coronary Angiography
Showing the origin and the convoluted course of the CAF. CAF = coronary artery fistula.
References
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Associated Data
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Supplementary Materials
Transesophageal Echo Video
Short-axis view at the plane of aortic valve, showing the convoluted course of the CAF. CAF = coronary artery fistula.
Transesophageal Echo Video
Short-axis view at the plane of ascending aorta, showing the convoluted course of the CAF. CAF = coronary artery fistula.
Transesophageal Echo Video
Long-axis view at the plane of aortic valve and ascending aorta, showing the convoluted course of the CAF. CAF = coronary artery fistula.
Transesophageal Echo Video
Long-axis view at the plane of aortic valve and ascending aorta, with color-Doppler showing the blood flow inside the convoluted course of the CAF. CAF = coronary artery fistula.
Coronary Angiography
Showing the origin and the convoluted course of the CAF. CAF = coronary artery fistula.