Feasibility of Coronary Computed Tomography Angiography Assessment of Explanted Donor Hearts

Abstract

In the United Kingdom, coronary angiography is rarely performed of donation after brain death donors. Currently up to 30% of potential donor hearts are not utilised due to potential but unconfirmed coronary disease. For Donation After Circulatory death donors, coronary angiography is prohibited, as are all antemortem interventions. We believe that ex situ coronary CT angiography (CTA) will be logistically more feasible than in situ donor coronary angiography or ex situ coronary angiography allowing greater yield of donor hearts. Organ retrieval is performed by direct procurement and perfusion. The aorta of the donor heart is cannulated to allow retrograde perfusion of the heart via the coronary arteries in the setting of a competent aortic valve. Electrocardiographic (ECG) monitoring is performed. The donor heart is paced epicardially to a rate between 70-90 beats per minute as required. Coronary CTA is performed after direct administration of contrast media (iomeron 350) and nitroglycerin administration. Coronary CTA post processing facilitated segmental analysis of all of the coronary arteries with detailed assessment of atherosclerotic plaque burden, plaque morphology and luminal stenosis. Coronary CTA findings are directly compared to histological correlation of plaque burden. Two human cardiac allografts (donation after brain death) were assessed using coronary CTA during ex-vivo perfusion on a local centre ex-vivo perfusion device. Images were reconstructed using Siemens SyngoVia software. In both patients eccentric atherosclerotic plaque burden was quantified using conventional techniques and luminal calibre assessed. Assessment of ex-vivo coronary arteries is feasible using coronary CTA during ex-vivo perfusion of donor hearts. Atherosclerotic plaque and luminal stenosis of ex-vivo coronary arteries can be diagnosed using coronary CTA.