Abstract 6108: Cardiac 64-slice Multidetector Computerized Tomography in the Management of Prosthetic Heart Valve Obstruction

Differentiation of pannus (P) and thrombus (THR) in prosthetic heart valve obstruction (PHVO) is still a confusive state at the present cardiological practise. Transesophageal echocardiography (TEE) is not fully capable method in this condition. We considered that cardiac 64-slice multidetector computerized tomography (MDCT) may have a value in the management of PHVO. Thirtytwo of 37 pts (22 male, mean age 47±11 years, 17 with atrial fibrillation) with PHVO (35 mitral, 2 tricuspid) were detected with TEE and also with MDCT before and after thrombolytic therapy (TT). Five pts having monoleaflet valves were excluded due to excessive artifacts. Pre-TT MDCT revealed at least 1 culprit mass (CM) which was considered to be the cause of PHVO and the Hounsfield unit (HU) values of CM’s were measured. All pts underwent TT under the guidance of serial TEE. The study consisted of 2 groups up to response of CM’s to TT demonstrated by post-TT MDCT. Group I: Successfully lysed CM’s, Group II: Nonresponder CM’s. TEE disclosed THR in 26 pts, however the cause of PHVO in 6 pts remained undefined. Pre-TT MDCT disclosed 45 distinct CM’s on 32 valves. Post-TT MDCT disclosed the number of CM’s for groups I and II: 26 and 19, respectively. Significant difference between mean HU values of groups was found [87 (range 11–180), 331 (range 168–510), respectively, p<0.001]. A cut-off value of HU>200 predicted nonresponder CM’s (sensitivity 94%, specificity 96%, p<0.001). CM’s of 6 pts with undefined TEE findings were all in group II and pure P was demonstrated surgically. In group I, 17 of 26 (%65) CM’s were completely and the remaining partially lysed which was confirmed by TEE. A cut-off value of HU<100 predicted complete lysis (sensitivity 100%, specificity %95, p<0.001). Subgroup analysis of CM’s with HU=100–200 revealed 10% completely and 80% partially lysis and 10% remained unresponded as confirmed by TEE. MDCT can be a useful technique for evaluation of PHVO caused by THR or P formation. Higher HU values denote P whereas the lower values THR. MDCT can also predict the response to TT. The higher the HU value the less the successful outcome. The CM’s with HU>200 are almost always resistant to TT.