Sequential moderate coronary artery fistula and moderate coronary artery stenosis causing ischemia demonstrated by fractional flow reserve and relieved following percutaneous coronary intervention

The functional impact on donor vessel following transcatheter closure of coronary artery fistulas-a retrospective study using QFR analysis

Background

The impact of transcatheter closure of coronary artery fistula (CAF) and residual shunt after occlusion on improving blood flow in the donor vessel remains uncertain.

Objectives

To evaluate the functional impact on the donor vessel following CAFs closure using QFR (Quantitative Flow Ratio) analysis.

Methods

A total of 46 patients with 48 CAFs who underwent transcatheter closure at Shanghai Chest Hospital and Shuguang Hospital between March 2015 and August 2023 were included in the review. The clinical, angiographic details, and QFR data were subjected to analysis. The size of the fistulae was defined according to the ratio between the diameters of the fistulae and the largest diameter of the coronary vessel not feeding the coronary fistula.

Results

Among 48 CAFs, the average diameter of the fistulae ostium was 3.19 ± 1.04 mm, while the mean diameter of the donor vessel segment following fistulae was 3.45 ± 1.01 mm. The mean QFR value of the donor vessels with medium CAFs was found to be significantly lower than those with small CAFs (0.93 ± 0.10 vs. 0.98 ± 0.03; p < 0.05). Furthermore, the mean QFR value of donor vessels with medium CAFs was observed to be significantly improved after occlusion (0.99 ± 0.01 vs. 0.93 ± 0.10; p = 0.01). However, there was no statistical difference in the mean QFR value of donor vessels with small CAFs before and after occlusion (0.98 ± 0.03 vs. 0.98 ± 0.02; p > 0.05). Moreover, the changes in QFR were more pronounced in donor vessels with medium CAFs compared to those with small CAFs after occlusion (0.06 ± 0.10 vs. 0.005 ± 0.012; p = 0.01). There is no statistical difference in the mean QFR variation and QFR variation rate between donor vessels with CAFs that occurred residual shunt and those without residual shunt after occlusion (p > 0.05).

Conclusions

The presence of medium CAFs has a significant impact on the blood flow of the donor vessel, as compared to small CAFs, and may benefit from occlusion. A small residual shunt has no significant impact on the effectiveness of CAFs occlusion in enhancing donor blood flow.

Transcatheter Occlusion of Coronary-Pulmonary Fistula With a Liquid Embolic Agent After Evaluation by FFR

A 58-year-old man was admitted for stable angina. The coronary angiogram revealed a coronary-pulmonary fistula with a nonsignificant atheroma. We decided to perform percutaneous embolization of the fistula in view of the symptoms and the hemodynamic assessment findings. Embolization was performed using a liquid embolic agent with no residual flow. (Level of Difficulty: Intermediate.)

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

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.

Is Fractional Flow Reserve Useful in Assessing Coronary Artery Fistula: A Case-Based Discussion and Review

We present two cases where fractional flow reserve (FFR) was utilised to guide management of coronary artery fistula (CAF), an approach advocated in recent case studies. CAF is a coronary anomaly that may present with a variety of syndromes though is frequently asymptomatic. When to exclude the fistula (surgically or percutaneously) is not always clear. A way to quantify if the fistula is physiologically meaningful would be advantageous. Our findings suggest FFR may only be assessing the concomitant epicardial coronary artery disease (CAD) rather than the degree of coronary steal and its routine use in this setting is not supported.

Functional assessment of sequential coronary artery fistula and coronary artery stenosis with fractional flow reserve and stress adenosine myocardial perfusion imaging

Coronary artery fistula is an abnormal connection between one coronary artery to another coronary artery or cardiac chambers. The coronary artery fistula may cause significant shunting of blood and cause “pseudo-stenosis” or “steal phenomenon”. This will also accentuate pre-existing mild-moderate de novo coronary lesions with resultant greater pressure gradient difference across the lesions. Thus, fractional flow reserve can be a useful tool to guide intervention decision on the coronary artery fistula. There are very few published reports regarding the use of FFR to assess coronary artery fistula. In fact, there is no outcome data regarding the deferment of coronary artery fistula intervention when the FFR is not physiologically significant. This case highlighted the use of FFR to evaluate the functional significance of coronary fistula in the setting of ischemia evaluation and it was proven to be safe to defer intervention with good 3 year clinical outcome. Stress adenosine myocardial perfusion imaging correlated with the FFR result.

Unilateral and multilateral congenital coronary-pulmonary fistulas in adults: clinical presentation, diagnostic modalities, and management with a brief review of the literature

BACKGROUND

Congenital coronary-pulmonary fistulas (CPFs) are commonly unilateral, but bilateral and multilateral fistulas may occur. In multilateral CPFs, the value of a multidetector computed tomography (MDCT) imaging technique as an adjuvant to coronary angiography (CAG) is eminent. The purpose of this study was to describe the clinical presentation, diagnostic modalities, and management of coincidentally detected congenital CPFs.

HYPOTHESIS

Unilateral and multilateral coronary-pulmonary fistulas are increasingly detected due to the wide speard application of multidetector computed tomography which might be a supplementary or replacing to conventional coronary angiography.

METHODS

We evaluated 14 adult patients with congenital coronary artery fistulas (CAFs) who were identified from several Dutch cardiology departments.

RESULTS

Fourteen adult patients (5 female and 9 male), with a mean age of 57.5 years (range, 24-80 years) had the following abnormal findings: audible systolic cardiac murmur (n = 4), chronic atrial fibrillation (n = 2), nonsustained ventricular tachycardia (n = 1), and cardiomegaly on chest x-ray (n = 2). Echocardiography revealed normal findings with trivial valvular abnormalities (n = 9), depressed left ventricle systolic function (n = 3), and severe mitral regurgitation and atrial dilatation (n = 2). The findings in the rest of the patients were unremarkable. CAG and MDCT were used as a diagnostic imaging techniques either alone (CAG, n = 6; MDCT, n = 1) or in combination (n = 7). Single modality and multimodality diagnostic methods revealed 22 fistulas including CPFs (n = 15), coronary cameral fistulas terminating into the right (n = 2) and the left atrium (n = 1), and systemic-pulmonary fistulas (n = 4). Of all of the fistulas, 10 were unilateral, 6 were bilateral, and 6 was hexalateral. (13) N-ammonia positron emission tomography-computed tomography was performed in 3 patients revealing decreased myocardial perfusion reserve.

CONCLUSIONS

CAG remains the gold standard for detection of CPFs. An adjuvant technique using MDCT provides full anatomical details of the fistulas.