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Incidental Finding of a Coronary Artery Fistula in a Patient with Anterolateral ST-Elevation Myocardial Infarction

Open AccessPublished:November 05, 2022DOI:https://doi.org/10.1016/j.cjco.2022.11.004

      Case

      A 67-year-old male with a past medical history of hypertension, dyslipidemia, and a previous myocardial infarction presented to the emergency department with complaints of acute substernal chest pain at rest. He was a non-smoker and had no family history of premature coronary artery disease. In triage, the patient collapsed and became unresponsive due to a ventricular fibrillatory arrest, which required several rounds of CPR, epinephrine, amiodarone, and defibrillation. He was resuscitated successfully, and subsequently intubated, and transported to the intensive care unit (ICU). An electrocardiogram (ECG) showed new anterolateral ST elevations (Fig 1, A) and troponins were markedly elevated. He was taken to the catheterization lab for a coronary angiogram, revealing triple vessel coronary artery disease (CAD) with an identifiable left anterior descending artery (LAD) to pulmonary artery (PA) fistula (Fig 1, B).
      Figure thumbnail gr1
      Figure 1(A) Initial ECG showing ST elevations in anterolateral leads. (B) Coronary angiogram revealing proximal LAD disease (yellow) with LAD to PA fistula (red) and left circumflex artery (green). (LAD: left anterior descending, PA: pulmonary artery). (C) Repeat ECG following medical therapy and patient stabilization.
      The patient remained intubated for the first 24 hours and was stabilized with intravenous Nitroglycerin, unfractionated Heparin and standard acute coronary syndrome therapy. Repeat ECG showed resolution of ST elevations and troponins continued to trend downward (Fig 1, C). He did not have a recurrence of ventricular fibrillation or other dysrhythmias while in ICU. Due to the significance of the patients coronary artery disease, it was determined that complete surgical revascularization would be most appropriate with intraoperative ligation of the fistula. The patient was extubated after 48 hours, though he remained relatively drowsy and weak. Therefore, he spent a further 2 days recovering. Once his neurologic status was confirmed to be back to baseline, he was taken to the operating room 5 days after his initial cardiac arrest.
      Preoperative transesophageal echocardiogram (TEE), showed an ejection fraction of 59% and normal biventricular function with no wall motion or valvular abnormalities. There was evidence of left-to-right shunting due to the LAD to PA fistula. A CT coronary angiogram was performed to further elucidate the coronary anatomy. This showed tortuous vessels near the course of the LAD and the PA with no definitive fistula identified, and a high total coronary artery calcium score (Fig 2, A).
      Figure thumbnail gr2
      Figure 2(A) Axial and sagittal CT images demonstrating dilated tortuous vessels entering the pulmonary trunk, having a very thin tortuous communication with the LAD. (B) Ligated fistula (black) with visualization of left atrial appendage (blue).
      In the operating room, the anomalous artery was visualized overlying the lateral surface of the PA, just above the left atrial appendage (Video 1). The fistula was ligated and transected intraoperatively (Fig 2, B; Video 2). The surgeons then continued with coronary artery bypass grafting (CABG) in standard fashion. A CABG x3 with left internal mammary artery to the LAD, vein graft to the diagonal and vein graft to the right coronary artery, and ligation and division of the LAD to PA fistula was successfully achieved. The intraoperative TEE showed preserved biventricular function with no new wall motion abnormalities. Post-operative CT coronary angiogram showed three patent grafts, and no further communication between the LAD and PA. The patient had an uneventful post-operative course and went home 5 days later.

      Discussion

      Coronary artery fistulas (CAF) are inappropriate connections between a coronary artery and a cardiac chamber, like the atria or ventricles, or other vascular structures such as the vena cava, pulmonary artery, pulmonary veins and aorta. These anomalous malformations are extremely rare, reported in 0.1 to 0.2% of patients.

      Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation 2019;139:e833-e834.

      Most CAFs are congenital in origin, while some may be acquired due to iatrogenic injury following a range of cardiovascular interventions.
      • El-Sabawi B.
      • Al-Hijji M.A.
      • Eleid M.F.
      • et al.
      Transcatheter closure of coronary artery fistula: A 21-year experience.
      ,
      • Battisha A.
      • Madoukh B.
      • Sheikh O.
      • et al.
      Coronary Fistula Between Left Anterior Descending Artery (LAD) and Pulmonary Artery (PA) Leading to Sudden Cardiac Death: Case Report with Literature Review.
      Patients with a CAF may present with symptoms, but the majority are asymptomatic, making it difficult to ascertain their prevalence accurately. Chest pain, dyspnea, palpitations, and syncope are common presenting symptoms.
      • El-Sabawi B.
      • Al-Hijji M.A.
      • Eleid M.F.
      • et al.
      Transcatheter closure of coronary artery fistula: A 21-year experience.
      As this presentation is non-specific and mimics many medical conditions, the presumptive diagnosis of coronary artery fistula is difficult to make. Arrythmias, heart failure or sudden cardiac death may arise as consequences of untreated CAFs.
      • Härle T.
      • Kronberg K.
      • Elsässer A.
      Coronary artery fistula with myocardial infarction due to steal syndrome.
      Hence, early detection is the most important factor in deciding the most appropriate form of management, whether conservative, or choosing to close the fistula via percutaneous or surgical techniques.
      Diagnosis of CAFs relies on physical examination, which may reveal a continuous precordial murmur, ECG, and various imaging studies. Most CAFs are detected incidentally on coronary angiography.

      Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation 2019;139:e833-e834.

      Once detected, distinguishing and understanding the anatomic details of the CAF can be an elaborate, complex, and time-consuming process.
      • Malik M.I.K.
      Non-ST elevation myocardial infarction (NSTEMI) and complex coronary artery fistula in a fit 57-year-old man and its management.
      A CT angiogram, transthoracic echocardiogram and TEE can further characterize the size, shape, and degree of shunting of the fistula. Due to their high risk of morbidity and mortality, the closure of large fistulas is indicated, regardless of symptom presence.

      Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation 2019;139:e833-e834.

      Other indications for closure include hemodynamically significant left-to-right shunt, and any signs of myocardial ischemia or heart failure. Smaller fistulas typically go unnoticed and are normally benign. They are typically diagnosed later in life and are often incidental findings. Nonetheless, if a fistula is discovered in a symptomatic patient, consideration for vessel closure is warranted. If not promptly identified and treated, CAFs can result in catastrophic outcomes like congestive heart failure and sudden cardiac arrest, as seen in our patient.
      Symptomatology can be deceptively benign, highlighting the need for proper assessment of coronary arteries should there be suspicions for CAD or anomalous coronary artery pathways. As CAFs are rare pathologies, clear treatment protocols have yet to be defined. There is a need for rapid diagnosis and therapeutic intervention for patients with these anomalies. Assessment of coronary arteries should be done if there is a pretest suspicion for CAD, while keeping anomalous coronary artery pathways on the differential diagnosis.
      • Battisha A.
      • Madoukh B.
      • Sheikh O.
      • et al.
      Coronary Fistula Between Left Anterior Descending Artery (LAD) and Pulmonary Artery (PA) Leading to Sudden Cardiac Death: Case Report with Literature Review.
      In any case, the presence of CAFs requires a review by an experienced team of cardiologists and surgeons to determine the need for closure of the vessel which can be done in two ways. Percutaneous closure with catheterization of the vessel, or via surgical ligation, as seen in our patient.

      Supplementary material

      References

      1. Stout KK, Daniels CJ, Aboulhosn JA, et al. 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation 2019;139:e833-e834.

        • El-Sabawi B.
        • Al-Hijji M.A.
        • Eleid M.F.
        • et al.
        Transcatheter closure of coronary artery fistula: A 21-year experience.
        Catheter Cardiovasc Interv. 2020; 96: 311-319
        • Battisha A.
        • Madoukh B.
        • Sheikh O.
        • et al.
        Coronary Fistula Between Left Anterior Descending Artery (LAD) and Pulmonary Artery (PA) Leading to Sudden Cardiac Death: Case Report with Literature Review.
        Curr Cardiol Rev. 2020; 16: 98-102
        • Härle T.
        • Kronberg K.
        • Elsässer A.
        Coronary artery fistula with myocardial infarction due to steal syndrome.
        Clin Res Cardiol. 2012; 101: 313-315
        • Malik M.I.K.
        Non-ST elevation myocardial infarction (NSTEMI) and complex coronary artery fistula in a fit 57-year-old man and its management.
        BMJ Case Rep. 2021; 14e237321