Mid-term follow-up in patients with Biocor porcine bioprostheses.
BACKGROUND
Prosthetic cardiac valves have increased life expectancy of patients (pts) with valvular heart disease. Bioprosthetic complications required devices replacements within 10 years of implantation; structural valve deterioration (SVD) has emerged as the major cause of reoperation. We reviewed survival and prosthetic complications of Biocor porcine bioprostheses implanted in mitral, aortic and mitro-aortic position.


METHODS
Between January 1991 and January 2001 446 pts (192 males; 254 females; mean age 73.4+/-6.7 year, range 40-91) received 258 aortic, 138 mitral and 50 mitro-aortic Biocor porcine valves; of these 83 pts have previous different types of prosthetic devices (15 aortic, 53 mitral and 15 double). Concomitant cardiac procedures, namely myocardial revascularization, were performed in 91/446 pts (20.5%). All explanted bioprostheses (BPS) were available for pathologic investigation. Follow-up included 1319 pt.-years and was 98% complete with a median time of 36 pt.-months.


RESULTS
Perioperative mortality was 6.8% (30/446 pts; 12 aortic, 17 mitral and 1 double) and was mostly related to reoperations. At the end of follow-up 18.5% of pts died (77/416), 12 deaths were valve-related with freedom from valve related mortality of 94% at 9 years. Survival was 54% at 9 years. It was 63%, 41% and 62% for aortic, mitral and double valve replacement, respectively. At follow-up 87% of pts. were in NYHA I-II class and 13% were in III-IV class; 55% were in sinus rhythm, 36% in atrial fibrillation and 9% had a pace-maker. Eighty-five percent of pts were anticoagulated. There were 6 thromboembolic and 5 anticoagulant-related haemorrhagic episodes with no significant difference between aortic and mitral position (p=0.7). The event freedom was respectively 92% and 98.5% at 9 years. Prosthetic valve endocarditis (PVE) and non-SVD freedom were 96% and 93% at 9 years. SVD due to tissue degeneration, calcification and cusp's tears affected 2 pts with 94% freedom at 9 years. Overall freedom from all valve-related complications was 80% at 9 years and freedom from reoperation was 92% at 9 years.


CONCLUSIONS
(1) Our intermediate-term follow-up of the Biocor porcine valve (BPS) showed excellent durability in all positions. (2) The aortic patients and especially the oldest group had better results than the mitral patients (41% vs. 63% 9 years survival, p=0.0004). (3) Higher mitral risk was related to higher prevalence of reoperations. (4) The incidence of anticoagulation-related complications is low in both aortic and mitral position without significant difference (p=0.7). 4) A longer follow-up is required to get more information about SVD timing.
Bottio
Tomaso
T
Department of Cardiovascular Surgery, University of Padua Medical School, Padua, Italy. tbottio@hotmail.com
Rizzoli
Giulio
G
Gerosa
Gino
G
Thiene
Gaetano
G
Casarotto
Dino
D
D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000601:surgery; D001705:Bioprosthesis / Q000009:adverse effects*; D005260:Female; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome