Case report: Coronary artery fistula in a patient with a heart transplant

Abstract

Coronary artery fistula (CAF) is a direct communication of the epicardial coronary artery with one of the four cardiac chambers. It comprises 0.8% of all coronary anomalies. 90% of cases are congenital. Its incidence is only 0.002% in the general population and 0.1% in all patients with cardiac catheterization. In patients with heart transplantation, up to 12.5% ​​of acquired CAF incidence is reported with probable iatrogenic etiology after endomyocardial biopsy (EMB).

CASE PRESENTATION: A 52-year-old male patient presented for his first angiography for surveillance of coronary allograft vasculopathy one year after undergoing an orthotopic heart transplant. His history included myocardial revascularization surgery, with subsequent progression to advanced heart failure and severe pulmonary hypertension requiring a heart transplant. Seven routine EMBs were performed as part of cell rejection surveillance. He was asymptomatic and had a normal physical examination. The EMBs were performed from an anterior access to the right internal jugular vein, with an average of 3 to 4 samples per EMB from areas such as the apex, anterior wall of the right ventricle and interventricular septum. It was noteworthy that the first sample showed adipose tissue in 3 of 4 samples, suggesting non-endomyocardial tissue. No significant obstructive lesions were observed in the surveillance coronary angiography. However, in the middle third of the anterior descending artery, marked ectasia was seen with a moderate-sized fistula towards the right ventricle. An echocardiogram was subsequently performed, showing a flow projected on the apex of the right ventricle consistent with the angiography, and a coronary artery fistula was diagnosed.

In heart transplant patients, the development of FAC may be asymptomatic, so protocolized follow-up with angiography for the diagnosis of allograft vasculopathy is mandatory.