Hyun Jung Koo1, Hojin Ha2, Joon-Won Kang1, Jeong A Kim3, Jae-Kwan Song4, Hwa Jung Kim5, Tae-Hwan Lim1, Dong Hyun Yang6,7. 1. Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Olympic-ro 388-1, Seoul, 05505, Republic of Korea. 2. Department of Mechanical and Biomedical Engineering, Kangwon National University, Chuncheon, Kangwon, 24341, Republic of Korea. 3. Department of Radiology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, 411-706, Republic of Korea. 4. Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Olympic-ro 388-1, Seoul, 05505, Republic of Korea. 5. Department of Clinical Epidemiology and Biostatistics, Cancer Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. 6. Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Olympic-ro 388-1, Seoul, 05505, Republic of Korea. donghyun.yang@gmail.com. 7. Department of Radiology and Research Institute of Radiology, Cardiac Imaging Center, Asan Medical Center, University of Ulsan College of Medicine, Olympic-ro 388-1, Seoul, 05505, Republic of Korea. donghyun.yang@gmail.com.
Abstract
BACKGROUND: Although pannus is an important cause of prosthetic valve dysfunction, the minimum pannus size that can induce hemodynamic dysfunction has not yet been determined. This study investigated the correlation between the limitation of motion (LOM) of the prosthetic valve and pannus extent and determined the pannus extent that could induce severe aortic stenosis. METHODS: This study included 49 patients who underwent mechanical aortic valve replacement (AVR) and showed pannus on cardiac computed tomography (CT). Pannus width, ratio of pannus width to valve diameter, pannus area, effective orifice area, encroachment ratio by pannus, pannus involvement angle and percent LOM of mechanical valves were evaluated on CT. Transvalvular peak velocity (TPV) and transvalvular pressure gradient (TPG) were measured by transesophageal echocardiography to determine the degree of aortic stenosis. The relationship between percent LOM of the prosthetic valve and pannus extent and the cut-off of pannus extent required to induce severe aortic stenosis were evaluated. RESULTS: The mean interval between AVR and pannus formation was 11 years and was longer in patients with than without severe aortic stenosis (14.0 vs. 7.3 years). On CT, the percent LOM of the prosthetic valve was significantly associated with the extent of pannus only in patients with pannus involvement angle > 180° (r = 0.55-0.68, P < 0.01). Pannus width, effective orifice area, and encroachment ratio were significantly associated with increased TPV and TPG (r = 0.51-0.62, P < 0.01). Pannus width > 3.5 mm, pannus width/valve inner diameter > 0.15, and encroachment ratio > 0.14 were significantly associated with severe aortic stenosis (TPV > 4 m/s; mean TPG ≥ 35 mmHg), with c-indices of 0.74-079 (P < 0.005). CONCLUSION: CT-derived pannus extent parameters are good indicators of significant hemodynamic changes with increased TPV and mean TPG.
BACKGROUND: Although pannus is an important cause of prosthetic valve dysfunction, the minimum pannus size that can induce hemodynamic dysfunction has not yet been determined. This study investigated the correlation between the limitation of motion (LOM) of the prosthetic valve and pannus extent and determined the pannus extent that could induce severe aortic stenosis. METHODS: This study included 49 patients who underwent mechanical aortic valve replacement (AVR) and showed pannus on cardiac computed tomography (CT). Pannus width, ratio of pannus width to valve diameter, pannus area, effective orifice area, encroachment ratio by pannus, pannus involvement angle and percent LOM of mechanical valves were evaluated on CT. Transvalvular peak velocity (TPV) and transvalvular pressure gradient (TPG) were measured by transesophageal echocardiography to determine the degree of aortic stenosis. The relationship between percent LOM of the prosthetic valve and pannus extent and the cut-off of pannus extent required to induce severe aortic stenosis were evaluated. RESULTS: The mean interval between AVR and pannus formation was 11 years and was longer in patients with than without severe aortic stenosis (14.0 vs. 7.3 years). On CT, the percent LOM of the prosthetic valve was significantly associated with the extent of pannus only in patients with pannus involvement angle > 180° (r = 0.55-0.68, P < 0.01). Pannus width, effective orifice area, and encroachment ratio were significantly associated with increased TPV and TPG (r = 0.51-0.62, P < 0.01). Pannus width > 3.5 mm, pannus width/valve inner diameter > 0.15, and encroachment ratio > 0.14 were significantly associated with severe aortic stenosis (TPV > 4 m/s; mean TPG ≥ 35 mmHg), with c-indices of 0.74-079 (P < 0.005). CONCLUSION: CT-derived pannus extent parameters are good indicators of significant hemodynamic changes with increased TPV and mean TPG.
Authors: Troy M LaBounty; Prachi P Agarwal; Aamer Chughtai; David S Bach; Eric Wizauer; Ella A Kazerooni Journal: AJR Am J Roentgenol Date: 2009-11 Impact factor: 3.959
Authors: Young Joo Suh; Young Jin Kim; Yoo Jin Hong; Hye-Jeong Lee; Jin Hur; Dong Jin Im; Yun Jung Kim; Byoung Wook Choi Journal: Korean J Radiol Date: 2015-08-21 Impact factor: 3.500