According to its definition, prosthesis-patient mismatch is present when the cardiac output of the patient is too large for the opening of a prosthetic valve. This causes symptoms similar to native... Show moreAccording to its definition, prosthesis-patient mismatch is present when the cardiac output of the patient is too large for the opening of a prosthetic valve. This causes symptoms similar to native aortic stenosis, which can lead to heart failure and mortality. To classify patients with PPM, a cut-off value of indexed effective orifice area is used in clinical practice.This thesis evaluates the underlying assumptions of using indexed effective orifice area as a parameter of valve performance. As these assumptions are inaccurate, the current definition of prosthesis-patient mismatch is unsuitable to diagnose patients with too small prosthetic valves after aortic valve replacement. Show less
Objective Little is known about the prevalence and degree of deformation of surgically implanted aortic biological valve prostheses (bio-sAVRs). We assessed bio-sAVR deformation using multidetector... Show moreObjective Little is known about the prevalence and degree of deformation of surgically implanted aortic biological valve prostheses (bio-sAVRs). We assessed bio-sAVR deformation using multidetector-row computed tomography (MDCT). Methods Three imaging databases were searched for patients with MDCT performed after bio-sAVR implantation. Minimal and maximal valve ring diameters were obtained in systole and/or diastole, depending on the acquired cardiac phase(s). The eccentricity index (EI) was calculated as a measure of deformation as (1 - (minimal diameter/maximal diameter)) x 100%. EI of < 5% was considered none or trivial deformation, 5-10% mild deformation, and > 10% non-circular. Indications for MDCT and implanted valve type were retrieved. Results One hundred fifty-two scans of bio-sAVRs were included. One hundred seventeen measurements were performed in systole and 35 in diastole. None or trivial deformation (EI < 5%) was seen in 67/152 (44%) of patients. Mild deformation (EI 5-10%) was seen in 59/152 (39%) and non-circularity was found in 26/152 (17%) of cases. Overall, median EI was 5.5% (IQR 3.4-7.8). In 77 patients, both systolic and diastolic measurements were performed from the same scan. For these scans, the median EI was 6.5% (IQR 3.4-10.2) in systole and 5.1% (IQR3.1-7.6) in diastole, with a significant difference between both groups (p = 0.006). Conclusions Surgically implanted aortic biological valve prostheses show mild deformation in 39% of cases and were considered non-circular in 17% of studied valves. Show less