Incidental congenital coronary artery vascular fistulas in adults: Evaluation with adenosine-13N-ammonia PET-CT

Abstract

Aim: To assess the functionality of congenital coronary artery fistulas (CAFs) using adenosine stress ¹³N-ammonia positron emission tomography computed tomography (PET-CT).

Methods: Congenital CAFs were incidentally detected during coronary angiography (CAG) procedures in 11 adult patients (six males and five females) with a mean age of 64.3 years (range 41-81). Patients were collected from three institutes in the Netherlands. The characteristics of the fistulas (origin, pathway and termination), multiplicity of the origins and pathways of the fistulous vessels were assessed by CAG. Five patients underwent adenosine pharmacologic stress ¹³N-ammonia PET-CT to assess myocardial perfusion and the functional behavior of the fistula.

Results: Eleven patients with 12 CAFs, 10 unilateral and one bilateral, originating from the left anterior descending coronary artery (n = 8), right coronary artery (n = 2) and circumflex (n = 2). All fistulas were of the vascular type, terminating into either the pulmonary artery (n = 11) or coronary sinus (n = 1). The CAG delineated the characteristics of the fistula (origin, pathway and termination). Multiplicity of the origins and pathways of the fistulous vessels were common in most fistulas (8/12, 67% and 9/12, 75%, respectively). Multiplicity was common among the different fistula components (23/36, 64%). Adenosine pharmacologic stress ¹³N-ammonia PET-CT revealed normal myocardial perfusion and ejection fraction in all but one patient, who showed a reduced ejection fraction.

Conclusion: PET-CT may be helpful for assessing the functional status of congenital CAFs in selected patients regarding clinical decision-making. Studies with a larger patient series are warranted.

Keywords: Adenosine ammonia positron emission tomography computed tomography; Congenital coronary artery fistulas; Coronary angiography; Coronary vascular fistulas; Coronary-pulmonary artery fistulas.

Figure 1

Flowchart of the study patients who were collected from 3 different non-academic Dutch institutes.

Figure 2

^99mTc-sestamibi single-photon emission computed tomography scintigraphy, demonstrating normal myocardial perfusion and a normal left ventricular ejection fraction.

Figure 3

Bilateral fistulas. A: Balateral fistulas from the left anterior descending coronary artery to the pulmonary artery with single origin, multiple pathway and single termination (arrow); B: Balateral fistulas from the right coronary artery to the PA with multiple origin, pathway and termination (arrowheads).

Figure 4

Fistula from the proximal left anterior descending coronary artery to pulmonary artery with multiple origin, pathway and termination associated with large aneurysmal formation (arrow).

Figure 5

Fistula from the proximal left circumflex artery ending into the pulmonary artery characterized with single origin, pathway and termination emptying with double jets (arrowheads) ending into the pulmonary artery.

Figure 6

Unilateral fistula and computed tomography coronary angiography. A: Unilateral fistula originating from the right coronary artery (RCA) terminating into the coronary sinus (CS) with single origin, pathway and termination with dilated RCA and enlarged CS; B: Computed tomography coronary angiography: Coronary artery fistula originating from the distal segment of RCA (arrow) and terminating into the coronary sinus. Volume-rendered three-dimensional image reconstruction demonstrating fistulous vessel located posterior connected with the CS (arrowhead). RAC: Right coronary artery; CS: Coronary sinus.

Figure 7

A fistulous connection between the left anterior descending coronary artery and pulmonary artery with single origin, pathway and termination with a single jet ending into the pulmonary artery (arrow).

Figure 8

Right anterior oblique view shows the fistulous vessel between the left anterior descending coronary artery and the pulmonary artery with multiple origin, pathway and termination with small aneurysmal formation (arrow).

Figure 9

Left lateral frame demonstrating a fistula with multiple origin (arrow) and pathway from the proximal left anterior descending coronary artery ending to the pulmonary artery with a single termination. O: Origin; P: Pathway; T: Termination.

Figure 10

Left anterior oblique view shows a fistula between proximal left circumflex coronary artery (arrow) with multiple origin, pathway and termination with outflow to the pulmonary artery.

Figure 11

Positron emission tomography computed tomography scanning demonstrating normal findings on the rest ¹³N-ammonia polar map (left panel) and normal perfusion on adenosine ¹³N-ammonia polar map (right panel). Myocardial perfusion was assessed at rest and during vasodilator pharmacological stress induced by adenosine, using 400 MBq of ¹³N-ammonia as the perfusion radiotracer.