Title
Post Heart Transplantation Coronary Artery Fistulaand Coronary Artery Aneurysm Successfully Managed with the Implantation of Covered Stents
Introduction
Coronary arteries fistulae to cardiac chambers are more prevalent in heart transplant recipients than in the general population. Nevertheless, there is lack of data upon predisposing factors, natural history and optimal management of this condition. In this context, repeated surveillance endomyocardial biopsies, routinely performed within the first few years post-heart transplant, potentially increase the risk of coronary-to-cardiac chambers development. Herein, we describe a case of a heart transplant recipient who developed a large left anterior descending coronary artery (LAD) fistula to the right ventricle and a coronary artery aneurysm that were successfully managed with percutaneous implantation of covered coronary stents.
Clinical Case
A 62 year-old female patient with refractory exercise intolerance was diagnosed with a large coronary-to-cardiac chamber fistula and coronary aneurysm developed within the first year post-heart transplantation. Within the first year post-heart transplant, 11 surveillance endomyocardial biopsies were performed, as per institutional standard of practice, and despite the absence of high-grade allograft rejection episodes, progressive exercise intolerance of unclear etiology occurred. At one-year post-transplant surveillance coronary angiography, a large fistula between the LAD and the right ventricle, and a 10 x 9 mm mid-LAD aneurysm were noticed. There were no hemodynamic features of constrictive physiology or significant intracardiac shunts. By right radial arterial access, the left coronary artery was engaged with a 4.0 Extra Back-Up (Medtronic, Minneapolis, USA) 6-Fr guide-catheter, and a 0.014” Whisper ES guide wire (Abbott, Santa Clara, USA) was placed at distal LAD. Under intravascular ultrasound (IVUS) guidance, a 2.5 x 15 mm polyurethane membrane-covered stent (PK Papyrus, Biotronik, Berlin, Germany) was implanted at mid-LAD segment with significant reduction of blood flow through the fistula and remarkable distal LAD flow improvement. After stent post-dilatation with a 3.5 x 9 mm noncompliant balloon (Sprinter, Medtronic, Minneapolis, USA), immediate restoration of blood flow through the coronary fistula was noticed, presumably related to stent longitudinal foreshortening. A 2.5 x 20 mm polyurethanecovered stent (PK Papyrus, Biotronik, Berlin, Germany) was then implanted in overlap with the previously implanted stent. After post-dilatation with a 3.5 x 12 mm noncompliant balloon (Sprinter, Medtronic, Minneapolis, USA), optimal stent expansion, aneurysm exclusion and closure of the LAD fistula to the right ventricle were achieved, as evidenced by angiographic and IVUS assessments. Mean right atrium pressure decreased by 30% (pre, 12 mmHg; post, 8 mmHg), after percutaneous coronary intervention. At six-month surveillance coronary angiography, sustained fistula closure and aneurysm exclusion were observed.
Discussion
Coronary-to-cardiac chambers fistulae and coronary aneurysms are potential complications after heart transplantation,presumably related to the occurrence of myocardium microperforations and direct vascular injury at surveillance endomyocardial biopsies. In the setting of exercise intolerance and large fistulae at major coronary vessels, the possibility of jeopardized myocardial perfusion should be considered.
The use of covered stents may provide an effective interventional strategy in this scenario.