Incidence and Risk Factors of Pannus after Mechanical Aortic Valve Replacement

Abstract

Background This study was conducted to evaluate the occurrence rate and risk factors of subaortic pannus (SAP) after bileaflet mechanical aortic valve (AV) replacement.

Methods Between 1990 and 2014, 862 patients underwent primary AV replacement with bileaflet mechanical prosthesis. SAP was defined as (1) gradual increase in mean pressure gradient through mechanical AV without any evidence of motion limitation of the leaflets on echocardiography and (2) AV mean pressure gradient >40 mm Hg or AV peak velocity >4 m/s on echocardiography, and (3) any visible subaortic tissue ingrowth beneath the mechanical AV on echocardiography or computed tomography. Clinical and echocardiographic follow-up durations were 13.8 ± 8.0 and 10.7 ± 7.9 years, respectively.

Results Mean age was 51.1 ± 12.1 years and concomitant surgeries were performed in 503 patients (58.4%). Overall survival at 10 and 20 years was 84.2 and 67.1%, respectively. SAP occurred in 33 patients, and in only 2 patients during the first 10 years after surgery. The cumulative incidence of SAP formation at 10, 20, and 25 years were 0.3, 5.0, and 9.9%, respectively. The Fine and Gray model demonstrated that small prosthetic valve size (hazard ratio [HR] [95% confidence interval, CI] = 0.738 [0.575–0.946]), young age (HR [95% CI] = 0.944 [0.909–0.981]), and concomitant mitral valve replacement (MVR) (HR [95% CI] = 3.863 [1.358–10.988]) were significant risk factors for the SAP formation.

Conclusions SAP occurred gradually over time with 10- and 20-year cumulative incidence of 0.3 and 5.0%, respectively. Young age, small prosthetic valve size, and concomitant MVR were risk factors for SAP formation. Therefore, we recommend efforts to select large prostheses for young patients requiring concomitant MVR.

Keywords

aortic valve and root - heart valve surgery - outcomes

Publikationsverlauf

Eingereicht: 03. November 2020

Angenommen: 23. Februar 2021

Artikel online veröffentlicht:
03. Mai 2021

• References

• 1 Aoyagi S, Nishimi M, Tayama E. et al. Obstruction of St Jude medical valves in the aortic position: a consideration for pathogenic mechanism of prosthetic valve obstruction. Cardiovasc Surg 2002; 10 (04) 339-344
• 2 Park PW, Park B, Jeong DS. et al. Clinical outcomes of repeat aortic valve replacement for subaortic pannus in mechanical aortic valve. Circ J 2018; 82 (10) 2535-2541
• 3 Oh SJ, Park S, Kim JS, Kim KH, Kim KB, Ahn H. Reoperation for non-structural valvular dysfunction caused by pannus ingrowth in aortic valve prosthesis. J Heart Valve Dis 2013; 22 (04) 591-598
• 4 Teshima H, Hayashida N, Yano H. et al. Obstruction of St Jude Medical valves in the aortic position: histology and immunohistochemistry of pannus. J Thorac Cardiovasc Surg 2003; 126 (02) 401-407
• 5 Vitale N, Renzulli A, Agozzino L. et al. Obstruction of mechanical mitral prostheses: analysis of pathologic findings. Ann Thorac Surg 1997; 63 (04) 1101-1106
• 6 Gray RJ. A class of K-sample tests for comparing the cumulative incidence of a competing risk. Ann Stat 1988; 16 (03) 1141-1154
• 7 Fine JP, Gray RJ. A proportional hazards model for the subdistribution of a competing risk. J Am Stat Assoc 1999; 94 (446) 496-509
• 8 Altman DG, Lausen B, Sauerbrei W, Schumacher M. Dangers of using “optimal” cutpoints in the evaluation of prognostic factors. J Natl Cancer Inst 1994; 86 (11) 829-835
• 9 Rizzoli G, Guglielmi C, Toscano G. et al. Reoperations for acute prosthetic thrombosis and pannus: an assessment of rates, relationship and risk. Eur J Cardiothorac Surg 1999; 16 (01) 74-80
• 10 Sakamoto Y, Hashimoto K, Okuyama H, Ishii S, Shingo T, Kagawa H. Prevalence of pannus formation after aortic valve replacement: clinical aspects and surgical management. J Artif Organs 2006; 9 (03) 199-202
• 11 Kuniyoshi Y, Koja K, Miyagi K. et al. Pannus formation in aortic valve prostheses in the late postoperative period. J Artif Organs 2003; 6 (03) 179-182
• 12 Han K, Yang DH, Shin SY. et al. Subprosthetic pannus after aortic valve replacement surgery: cardiac CT findings and clinical features. Radiology 2015; 276 (03) 724-731
• 13 Lee S, Lee SP, Park EA. et al. Real-time 3D TEE for diagnosis of subvalvular pannus formation in mechanical aortic valves: comparison with multidetector CT and surgical findings. JACC Cardiovasc Imaging 2015; 8 (12) 1461-1464
• 14 Roudaut R, Roques X, Lafitte S. et al. Surgery for prosthetic valve obstruction. A single center study of 136 patients. Eur J Cardiothorac Surg 2003; 24 (06) 868-872
• 15 Teshima H, Fukunaga S, Takaseya T, Tomoeda H, Akashi H, Aoyagi S. Obstruction of St. Jude medical valves in the aortic position: plasma transforming growth factor type beta 1 in patients with pannus overgrowth. Artif Organs 2010; 34 (03) 210-215
• 16 Cho YH, Jeong DS, Park PW. et al. Serial changes of hemodynamic performance with Medtronic Hall valve in aortic position. Ann Thorac Surg 2011; 91 (02) 424-431
• 17 Jeong DS, Park PW, Sung K. et al. Long-term hemodynamic performance of bileaflet prostheses versus tilting-disc prostheses in the aortic position. Int J Cardiol 2013; 166 (03) 681-687