606 Formation of Coronary Artery Fistula After Mitral Valve Repair

Abstract

We report a case of a 72-year-old male, who was incidentally found to have developed a coronary artery fistula (CAF) following cardiac surgery. The patient had undergone mitral valve (MV) repair, left atrial appendage excision and AF ablation for management of mitral regurgitation secondary to bileaflet MV prolapse 3 years prior. He reported intermittent exertional dyspnoea and underwent coronary angiography following an abnormal exercise stress test. At coronary angiography, a CAF between the right atrial branch artery of the right coronary artery (RCA) and the right atrium was demonstrated. No CAF was present on angiography preoperatively. As there was no echographic evidence of haemodynamic significance, the CAF was managed conservatively. The cause of CAF formation at this specific site is hypothesised to be due to injury to the right atrial branch artery by cannulation of the right atrium for cardiopulmonary bypass, a rarely described occurrence in the literature [[1]Lee R.M. Colucci G. W Coronary artery fistula after mitral valve surgery.American Heart Journal. 1988; 115: 1128-1130Crossref PubMed Scopus (17) Google Scholar]. Coronary artery fistulae are anomalous connections between the coronary arteries and other vessels or cardiac chambers (coronary-cameral fistula). The population incidence is estimated at 0.2% and is most often due to a congenital malformation. Invasive procedures including coronary angiography and cardiac surgery are known to cause CAF. The incidence of CAF in the post cardiac surgery population has been reported in case series of up to 2.3% post coronary artery bypass grafting (CABG) and 8.9% following CABG and valve surgery [[2]Young A, Cheng R, Wei J, Esmailian F, Currier J, Azarbal B. Prevalence of coronary artery fistulae after cardiac surgery. Comparison between coronary artery bypass grafting, valve surgery, and orthotopic heart transplantation. Herz 2015;40 Suppl 1:51-5.Google Scholar]. Importantly, this case highlights that CAF can occur, following cardiac surgery, at a site distant to the operative region.