104: Comparison of multidetector row computed tomography to echocardiography for evaluation of patients with mechanical and biological prosthetic valves

Abstract

Our objective was to evaluate whether ECG gated multidetector-row computed tomographic (MDCT) imaging could detect the abnormalities of prosthetic heart valves. We reviewed the image sequences of 35 patients who underwent a MDCT and a echocardiography (TTE) with a total of 46 prosthetic valves (PV) in different position: 27 bileaflet PV, 2 tilting disc, 2 caged ball PV, and 15 biological PV. According to TTE data, 21 were abnormal and 25 normal. MDCT data were retrospectively reconstructed and analyzed using reformatting in anatomically adapted planes. The abnormalities on CT were following: 12 obstructions, 14 dehiscences and 1 vegetation. MDCT identified obstruction with a sensitivity of 100% and specificity of 84%. The causes for obstruction were subprosthetic tissue (pannus) (n=3), thrombus (n=2), leaflets calcifications (n=4), periprostetic and annulus calcifications (n=6). A good correlation was found between the mean prosthetic gradient on TTE and difference of angles for bileaflet PV on MDCT (r=0,7, p=0,0005). 4 patients with PV obstruction were re-operated and the MDCT imaging was confirmed by surgery. MDCT identified dehiscence of PV with a sensitivity of 100% and specificity of 84%. MDCT detect the false aneurysms (n=4) and sequels of ancient abscess (n=6). 5 patients were re-operated and the MDCT imaging of dehiscence was confirmed by surgery. In 6 cases, MDCT showed abnormalities that were not seen during TTE: 3 dehiscences of PV and 3 opening dysfunction of PV without significant obstruction (1 pannus, 1 calcification of prosthetic annulus and 1 asymmetry of opening. The Bjork PV cannot be exanimated on MDCT because of numerous artifacts. This experience demonstrates that MDCT have additional value because it can show perivalvular structures as well as cardiac and mediastinal abnormalities and can identify causes of PV dysfunction that constitute indications for surgery, but could be are missed at TTE.