Role of multimodality imaging in the assessment of mechanical prosthetic heart valve dysfunction

Abstract

In patients with suspected mechanical prosthetic heart valve (PHV) dysfunction, transthoracic and transesophageal echocardiography are considered as the first-line imaging, but may provide unsatisfactory results related to reverberations and acoustic shadowing. This study assessed the value of ECG-gated multidetector computed tomography (MDCT) as a complementary imaging modality in suspected prosthetic dysfunction. Patients with suspected mechanical PHV dysfunction were prospectively recruited between 2018 and 2020 in the cardiology department of Ariana hospital. All patients underwent transthoracic/transesophageal echocardiography and additional MDCT imaging. We compared the diagnosis based on echocardiography and on MDCT information. Our study enrolled 32 patients (median age was 53.7 years: 26–76). 16 patients had an aortic prosthetic valve (50%), 8 patients had a mitral prosthetic valve (25%), 8 patients had mitro-aortic prosthetic valves (25%). An obstructive dysfonction was noticed in 23 patients (72%): a thrombus in 12 cases, a pannus in 4 cases, a mismatch in 2 cases and a reduction in a leaflet motion in 4 cases, a vegetation in one case. A regurgitation was noticed in 4 patients: two paraprosthetic regurgitation and two paraprosthetic aneurysm. Ultrasound imaging and MDCT found same results for mismatach. Echocardiogram was more performant in the diagnosis of thrombosis ( P = 0,02). The addition of MDCT showed incremental value in detecting pannus ( P = 0,02), leaflet restriction and paraprosthetic aneurysm.The leaflet restriction diagnosed by CT in significantly associated with thrombus ( P = 0,03) ( Fig. 1 ). Mechanical PHV dysfunction is rare but life-threatening. A multimodality imaging assessment (ultrasound and CT) is necessary to precise mechanism and indicate the appropriate treatment. MDCT imaging is superior for detecting pannus and leaflet motion restriction.