Long-term clinical results with the Ionescu-Shiley pericardial xenograft

From 1977 to 1987, 829 Ionescu-Shiley pericardial valves (Shiley, Inc., Irvine, Calif.) were implanted in 766 patients at the University of Ottawa Heart Institute. There were 476 patients who had aortic valve replacement, 234 who had mitral valve replacement, and 44 who had double valve replacement. The standard-profile design was used in 508 patients and the low-profile design in 321 patients. Follow-up was obtained for 97% of patients, with calculation of event-free probabilities. At 10 years the overall probability of freedom from structural failure was 48% +/- 7% after aortic valve replacement, 44% +/- 15% after mitral valve replacement, and 79% +/- 11% after double valve replacement. Although at 5 years the probability of failure was statistically lower with the low-profile design, this favorability was lost by 6 years. Freedom from structural failure was only 47% +/- 7% for the standard-profile valve at 10 years. Thus the probability of freedom from reoperation was only 46% +/- 7% after aortic valve replacement, 39% +/- 6% after mitral valve replacement, and 65% +/- 20% after double valve replacement at 10 years. Thromboembolism occurred in 69 patients, for a predicted freedom from this complication at 10 years of 79% +/- 3% after aortic, 73% +/- 7% after mitral, and 96% +/- 4% after double valve replacement. There were 31 cases of endocarditis. The 10-year predicted freedom from endocarditis, therefore, was 86% +/- 3% after aortic, 98% +/- 1% after mitral, and 97% +/- 1% after double valve replacement. A total of 221 operative and late deaths were recorded in this series. Prosthetic valve failure accounted for 27% of late deaths. The 10-year survival rates were estimated to be 56% +/- 5% (aortic valve replacement), 54% +/- 6% (mitral valve replacement), and 51% +/- 8% (double valve replacement). We concluded that the Ionescu-Shiley pericardial xenograft provides less than optimal clinical performance and its use has been discontinued.     

Long-term durability of the Hancock porcine bioprosthesis following combined mitral and aortic valve replacement: an 11-year experience

Long-term evaluation of patients undergoing combined mitral and aortic valve replacement (MVR + AVR) with a porcine bioprosthesis provides the opportunity for a direct comparison of the durability of the mitral versus the aortic porcine bioprosthesis in the same patient. From 1970 to 1983, 71 patients underwent MVR + AVR with Hancock porcine bioprostheses. There were 46 men an 25 women ranging in age from 21 to 64 years (mean, 47.5 +/- 5 years). Sixteen patients (22.5%) died at operation. The survivors were followed from 0.2 to 11.5 years (mean, 5.7 +/- 3 years). Duration of follow-up was 313 patient-years and was 100% complete. Overall late mortality was 6.7 +/- 1.4% per patient-year (linearized incidence), and actuarial survival was 54.2 +/- 8% at 11 years. Endocarditis occurred in 4 patients (linearized incidence of 1.3 +/- 0.6% per patient-year); thromboembolic events were sustained by 4 patients (linearized incidence of 1.3 +/- 0.6% per patient-year); the event was fatal in 1 patient. Actuarial freedom from thromboembolism was 90 +/- 4.8% at 11 years. Reoperation for primary tissue failure was performed in 11 patients (linearized incidence of 3.5 +/- 1% per patient-year) with no deaths; in 7 patients both bioprostheses were explanted, and in 4, only the mitral bioprosthesis was replaced. The durability of explanted aortic and mitral porcine bioprostheses was not significantly different, and the evaluation of seven pairs of explanted aortic and mitral bioprostheses showed similar amounts of calcification. Actuarial freedom from reoperation because of primary tissue failure was 44.6 +/- 13.7% at 11 years.(ABSTRACT TRUNCATED AT 250 WORDS)     

More than ten years' follow-up of the Hancock porcine bioprosthesis in Japan.

From February 1975 through October 1981, 256 Hancock porcine bioprostheses (Johnson & Johnson Cardiovascular, King of Prussia, Pa.) (60 aortic, 169 mitral, and 27 pulmonary/tricuspid position) were implanted in 220 patients (104 male and 116 female, aged 9 to 67 years; mean 43.3) at Kyushu University Hospital in Japan. The procedures include 41 aortic valve replacements, 121 mitral valve replacements, 4 pulmonary valve replacements, 6 tricuspid valve replacements, and 48 combined valve replacements (31 aortic plus mitral, 13 mitral plus tricuspid, and 4 aortic plus mitral plus tricuspid). Hospital mortality was 6.4%. Follow-up was 98% during 8 to 14 (mean 10.5) years. Cumulative follow-up was 1836 patient-years and 2078 valve-years. At 10 years the overall actuarial survival rate, including hospital morality, was 70% +/- 3%, and freedom from valve-related mortality with sudden death was 87% +/- 3%. More than half of the current survivors required no anticoagulant therapy. Freedom from thromboembolism or anticoagulant-related hemorrhage (or both) and prosthetic valve endocarditis was common. Freedom from structural valve failure and reoperation declined more than 9 years after replacement of left-sided heart valves but not after replacement of right-sided heart valves. Sixty-seven patients underwent 68 repeat operations, and there were four deaths (5.9%). The rate of freedom from overall valve-related complications at 10 years was 62% +/- 8% for aortic valve replacement, 53% +/- 5% for mitral valve replacement, 80% +/- 13% for pulmonary/tricuspid valve replacement, and 42% +/- 9% for combined valve replacement. There was a significant difference between pulmonary/tricuspid valve replacement and combined valve replacement (p less than 0.05). The Hancock bioprosthesis is suitable for the replacement of valves in the right side of the heart but not for combined valve replacement.     

Results of reoperation for primary tissue failure of porcine bioprostheses

Results of reoperation for primary tissue failure of porcine bioprostheses were evaluated in 574 patients discharged from the hospital from 1970 to 1981. A total of 413 had undergone isolated mitral valve replacement and 161 isolated aortic valve replacement. Through March, 1984, 88 patients (15%) had required reoperation: 59 had undergone mitral and 29, aortic valve replacement. Primary tissue failure was the main cause of bioprosthetic dysfunction; it occurred in 64 patients (46 mitral and 18 aortic) at a mean postoperative interval of 93 +/- 4 months (range 34 to 158). During the same period, 11 patients required reoperation for bioprosthetic endocarditis, 11 for paravalvular leak, and two for thrombosis. These patients are not included in this review. Reoperation for primary tissue failure was performed after a mean interval of 72 +/- 6 months (range 38 to 158) for patients with aortic bioprostheses and after 101 +/- 5 months (range 34 to 153) for those with mitral bioprostheses (p less than 0.05). Overall mortality at reoperation was 12.5%: 11% for the mitral group and 16% for the aortic group. In 62 patients (45 mitral and 17 aortic) primary tissue failure was caused by calcification of the cusps, associated with severe fibrous tissue overgrowth in seven. Bioprosthetic failure was caused by an intracuspal hematoma in one patient with mitral valve replacement and by lipid infiltration of the cusps in one patient with aortic valve replacement. Actuarial freedom from bioprosthetic primary tissue failure at 12 years is 61% +/- 5% for the mitral group and 69% +/- 7% for the aortic group. On the basis of our long-term follow-up of patients after mitral or aortic replacement with a porcine bioprosthesis, we conclude: primary tissue failure is the most frequent indication for reoperation in patients with a porcine bioprosthesis; calcification of the cusp tissue is the leading cause of primary tissue failure; reoperation for primary tissue failure may be a major concern, although mortality for elective cases is low; and the limited durability of porcine bioprostheses suggests their use be restricted to selected patients.     

Valve-related complications with the Hancock I porcine bioprosthesis. A twelve- to fourteen-year follow-up study

Valve-related morbidity and mortality after heart valve replacement with the Hancock I porcine bioprosthesis has been retrospectively analyzed. From June 1974 through December 1976, 253 Hancock I bioprostheses (150 mitral and 103 aortic) were inserted in 220 selected patients who survived the operation and had follow-up until June 1989 (mean follow-up 13.5 years, with an accumulative follow-up of 2956.4 patient-years). One hundred seventeen patients had mitral valve replacement, 70 had aortic valve replacement, and 33 had combined mitral and aortic valve replacement. There were 27 thromboembolic events. The probability of being free from thromboembolism at 14 years was 81.0% +/- 7.4% for the mitral valve replacement group, 85.4% +/- 6.7% for the aortic group, and 67.1% +/- 18.4% for the mitral-aortic group. Fifteen episodes of prosthetic valve endocarditis occurred. There were 10 instances of nonstructural dysfunction (paravalvular leaks) in seven mitral valves (4.6%) and in three aortic valves (2.9%). One hundred twenty-two bioprostheses in 106 patients resulted in structural deterioration. The probability of freedom from structural deterioration at 14 years was 37.2% +/- 3.9% for the mitral group, 43.9% +/- 7.1% for the aortic group, and 30.1% +/- 8.9% for the mitral-aortic group. The logistic regression analysis between age at the time of operation and bioprosthetic life (structural deterioration-free period) demonstrates a linear regression curve (r = 0.53). There were 56 late deaths (27 patients died at reoperation). The actuarial survival rate (including hospital mortality) at 14 years was 57.2% +/- 5.4% for the entire series, with no statistically significant difference between groups. The probability of remaining free from valve-related morbidity and mortality at 14 years was 16.7% +/- 4.8% for the mitral group, 20.8% +/- 6.2% for the aortic group, and 14.0% +/- 7.0% for the mitral-aortic group. The long-term results of this series show that the clinical performance of the Hancock I porcine valve appears satisfactory during the first 6 years. The behavior of this bioprosthesis at 14 years' follow-up changes drastically, because only a minor group of patients is free from valve-related complications, justifying the restriction of its use for selected patients.     

Stentless porcine and pericardial valve in aortic position.

Fifty-seven patients underwent aortic valve replacement with a stentless glutaraldehyde-fixed bioprosthesis; 27 received a porcine aortic valve and 30 had a bovine pericardial valve. Two groups of 30 patients each who had aortic valve replacement with a tilting-disc mechanical valve or a stented porcine bioprosthesis served as controls. There were no differences in sex, body surface area, valve lesion, and valve size among the four groups. Results were assessed on a Doppler-based determination of maximum velocity across the valve, aortic valve area, and degree of valve regurgitation. Velocity across the valve was significantly less with stentless pericardial valves than with stentless porcine valves, stented bioprostheses, and mechanical valves. Stentless valves had a significantly larger aortic valve area when compared with stented valves. Mild central aortic insufficiency was detected more often with stentless pericardial than with stentless porcine bioprostheses (p = 0.04). Stentless valves showed a higher incidence of complete atrioventricular block when compared with stented valves (p = 0.04). Long-term studies are now warranted to assess the durability of both types of stentless valves.     

The Hancock II porcine bioprosthesis. A preliminary report

From May 1983 to July 1987 a total of 153 Hancock II porcine bioprostheses have been implanted in 130 patients with a mean age of 59 +/- 8 years (range 29 to 76 years). Mitral valve replacement was performed in 72 patients, aortic valve replacement in 35, and mitral-aortic valve replacement in 23. Cumulative follow-up of 121 survivors is 223 patient-years and 100% complete (range 0.4 to 4.5 years). The actuarial survival rate at 4 years is 88% +/- 8% for mitral, 86% +/- 7.8% for aortic, and 84% +/- 8% for mitral-aortic valve replacement. Minor thomboembolism occurred in two patients (0.9% +/- 0.6%/pt-yr) with an actuarial freedom from emboli at 4 years of 100% for mitral, 96% +/- 3.7% for aortic, and 91% +/- 8.6% for mitral-aortic valve replacement. Anticoagulant-related hemorrhage occurred in 10 patients (4.4% +/- 1.4%/pt-yr) with an actuarial freedom at 4 years of 90% +/- 4.8% for mitral, 89% +/- 5.8% for aortic, and 84% +/- 10.6% for mitral-aortic valve replacement. Failure of the porcine bioprosthesis was observed in three patients with an actuarial freedom at 4 years of 96% +/- 3.6% for aortic, 91% +/- 8% for mitral, and 91% +/- 8.6% for mitral-aortic valve replacement. Actuarial freedom from all porcine bioprosthesis-related complications at 4 years is 85.7% +/- 6.6% for aortic, 79% +/- 9% for mitral, and 70% +/- 13% for mitral-aortic valve replacement. No instances of primary tissue failure occurred.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ionescu-Shiley pericardial xenografts: follow-up of up to 6 years

The results of valve replacement with the Ionescu-Shiley pericardial xenograft compare favorably with results obtained with other bioprostheses. From March, 1977, to July, 1983, 497 Ionescu-Shiley pericardial valves were implanted in 463 patients at the University of Ottawa Heart Institute. There were 292 patients who had aortic valve replacement (AVR), 140 with mitral valve replacement (MVR), 28 with double valve replacement, and 3 with triple valve replacement. The survivors were followed regularly. Actuarial analysis of late results indicates an expected survival of 71% at 6 years for patients who underwent AVR and 72% at 3 years for patients who had MVR. The only valve-related deaths were due to endocarditis, which occurred at a rate of 3.9% per patient-year for aortic valves and 0.6% per patient-year for mitral valves. Despite a low usage of formal anticoagulation, embolic complications occurred at a rate of 1.4% per patient-year for aortic valves and 4.0% per patient-year for mitral valves. Five valves were removed for intrinsic failure after 36 to 72 months of follow-up. New York Heart Association Functional Class improved an average of 1.28 classes per patient.     

Late incidence and determinants of reoperation in patients with prosthetic heart valves.

OBJECTIVES: Reoperation is a relatively common event in patients with prosthetic heart valves, but its actual occurrence can vary widely from one patient to another. With a focus on bioprosthetic valves, this study examines risk factors for reoperation in a large patient cohort. METHODS: Patients (N=3233) who underwent a total of 3633 operations for aortic (AVR) or mitral valve replacement (MVR) between 1970 and 2002 were prospectively followed (total 21,179 patient-years; mean 6.6+/-5.0 years; maximum 32.4 years). The incidence of prosthetic valve reoperation and the impact of patient- and valve-related variables were determined with actual and actuarial methods. RESULTS: Fifteen-year actual freedom from all-cause reoperation was 94.1% for aortic mechanical valves, 61.4% for aortic bioprosthetic valves, 94.8% for mitral mechanical valves, and 63.3% for mitral bioprosthetic valves. In both aortic and mitral positions, current bioprosthesis models had significantly better durability than discontinued bioprostheses (15-year reoperation odds-ratio 0.11+/-0.04; P<0.01 for aortic, and 0.42+/-0.14; P=0.009 for mitral). Current bioprostheses were significantly more durable in the aortic position than in the mitral position (14.3+/-6.8% more freedom from 15-year reoperation; (P=0.018)). Older age was protective, but smoking was an independent risk factor for reoperation after bioprosthetic AVR and MVR (hazard ratio for smoking 2.58 and 1.78, respectively). In patients with aortic bioprostheses, persistent left ventricular hypertrophy at follow-up and smaller prosthesis size predicted an increased incidence of reoperation, while this was not observed in patients with mitral bioprostheses. CONCLUSIONS: These analyses indicate that current bioprostheses have significantly better durability than discontinued bioprostheses, reveal a detrimental impact for smoking after AVR and MVR, and indicate an increased reoperation risk in patients with a small aortic bioprosthesis or with persistent left ventricular hypertrophy after AVR.     

Carpentier-Edwards standard porcine bioprosthesis: primary tissue failure (structural valve deterioration) by age groups

Primary tissue failure (structural valve deterioration) has been documented as the most prominent complication of porcine bioprostheses. The influence of age on primary tissue failure has received limited consideration. From 1975 to 1986, 1,301 Carpentier-Edwards standard porcine bioprostheses were implanted in 1,183 patients in 1,201 operations. Of the total number of prostheses, 97.7% were implanted prior to 1983. The mean follow-up was 5.6 years and was 97.5% complete. Primary tissue failure was identified in 96 patients (98 operations) at reoperation (95) or autopsy (3). One hundred four (104) prostheses were involved. Thirty-one failed after aortic valve replacement (AVR), 49 after mitral valve replacement (MVR), and 24 after multiple-valve replacement (18 patients). There were 47 male and 49 female patients. The mean age at implantation was 47 years (range, 8 to 72 years). The mean implantation time was 74.0 months. The freedom from primary tissue failure at 10 years is 77.0 +/- 2.9% overall; for AVR, 83.1 +/- 3.7%; for MVR, 72.1 +/- 4.9%; and for multiple-valve replacement, 65.5 +/- 7.8%. The freedom from deterioration for patients less than 20 years of age is significantly less than that for other age groups. The freedom from deterioration increased by decades; the greatest freedom was noted in patients 70 to 80 years old and 80 years old or older. The freedom from deterioration at 10 years for patients less than 30 years of age is 26.8 +/- 17.2%; 30 to 59 years, 77.4 +/- 3.0%; and 60 years and older, 83.1 +/- 4.2%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac valve replacement in patients on dialysis: influence of prosthesis on survival

BACKGROUND: Mechanical valves have been recommended for patients on dialysis because of purported accelerated bioprosthesis degeneration. This study was undertaken to determine time-related outcomes in dialysis patients requiring cardiac valve replacement. METHODS: From 1986 to 1998, 42 patients on chronic preoperative dialysis underwent valve replacement; 17 received mechanical valves and 25 received bioprostheses. Age was similar in both groups: 54+/-18.5 years (mechanical) and 59+/-15.5 years (bioprosthetic, p = 0.4). Sites of valve replacement were aortic (27), mitral (11), and aortic and mitral (4). Follow-up was 100% complete. RESULTS: Survival at 3 and 5 years was 50% and 33% after mechanical valve replacement, and 36% and 27% after bioprosthetic valve replacement (p = 0.3). Four patients with bioprostheses required reoperation: 3 for allograft endocarditis and 1 at 10 months for mitral bioprosthesis degeneration. One patient who received a mechanical valve required reoperation. CONCLUSIONS: Prosthetic valve-related complications in patients on dialysis were similar for both mechanical and bioprosthetic valves. Because of the limited life expectancy of patients on dialysis, bioprosthesis degeneration will be uncommon. Therefore, surgeons should not hesitate to implant bioprosthetic valves in these patients.     

Structural valve deterioration in mitral replacement surgery: comparison of Carpentier-Edwards supra-annular porcine and perimount pericardial bioprostheses.

BACKGROUND: Bioprostheses preserved with glutaraldehyde, both porcine and pericardial, have been available as second-generation prostheses for valve replacement surgery. The performance with regard to structural valve deterioration with the Carpentier-Edwards supra-annular (CE-SAV) porcine bioprosthesis and the Carpentier-Edwards Perimount (CE-P) pericardial bioprosthesis (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) was evaluated to determine whether there was a difference in mitral valve replacement. METHODS: The CE-SAV bioprosthesis was implanted in 1266 overall mitral valve replacements (isolated mitral, 1066; mitral in multiple, 200) and the CE-P bioprosthesis in 429 overall mitral valve replacements (isolated mitral, 328; mitral in multiple, 101). The mean age of the CE-SAV population was 64.2 +/- 12.2 years and that of the CE-P population, 60.7 +/- 11.7 years (P =.0001). For the study, structural valve deterioration was diagnosed at reoperation for explantation. RESULTS: The freedom from structural valve deterioration was evaluated to 10 years, and the freedom rates reported are at 10 years. For the overall mitral valve replacement groups, the actuarial freedom from deterioration was significant (P =.0001): CE-P > CE-SAV for 40 years or younger, 80% versus 60%; 41 to 50 years, 91% versus 61%; 51 to 60 years, 84% versus 69%; 61 to 70 years, 95% versus 75%. The older than 70-year group was 100% versus 92% (no significant difference). The actual freedom from structural valve deterioration also demonstrated the same pattern at 10 years: 40 years or younger, CE-P 82% versus CE-SAV 68%; 41 to 50 years, 92% versus 70%; 51 to 60 years, 90% versus 80%; 61 to 70 years, 97% versus 88%; and older than 70 years, 100% versus 97%. The independent risk factors of structural valve deterioration for the overall mitral valve replacement group were age and age groups and prosthesis type (CE-SAV > CE-P). The prosthesis type either in isolated replacement or in multiple replacement was not predictive of structural valve deterioration. The pathology of structural valve deterioration was different: 70% of CE-P failures were due to calcification and 57% of CE-SAV failures were due to combined calcification and leaflet tear. CONCLUSION: The actuarial and actual freedom from structural valve deterioration, diagnosed at reoperation, is greater at 10 years for CE-P than for CE-SAV bioprostheses. The mode of failure is different, and the cause remains obscure. Long-term evaluation is recommended, because the different modes of failure may alter the clinical performance by 15 and 20 years.     

Long-term performance of the Hancock porcine bioprosthesis in the tricuspid position. A review of forty-five patients with fourteen-year follow-up

Because little information is available regarding the clinical performance of the Hancock porcine bioprosthesis (Johnson & Johnson Cardiovascular, King of Prussia, Pa.) implanted in the tricuspid position, we reviewed the long-term follow-up of patients who had tricuspid valve replacement with this device. From March 1970 to December 1983, 45 patients had tricuspid valve replacement, either isolated (seven patients) or combined with replacement of other valves (38 patients) by means of a standard, glutaraldehyde-preserved Hancock porcine bioprosthesis. Follow-up ranged from 0.2 to 14.7 years (mean, 7.6 +/- 3.6 years) and was complete. The late mortality rate was 6.6% +/- 1.6%/pt-yr and the actuarial survival rate at 14 years was 23% +/- 9%. Reoperation because of structural deterioration of the tricuspid, the mitral, or both bioprostheses was performed in nine patients (3.7% +/- 1.2%/pt-yr) from 40 to 177 months (mean, 112 +/- 43 months) and resulted in no deaths. Actuarial freedom from structural deterioration of a Hancock tricuspid porcine bioprosthesis at 14 years is 68% +/- 13%. Morphologic examination of explanted porcine bioprostheses showed that those implanted in the tricuspid position had lower degrees of calcification and less severe structural changes than those simultaneously explanted from the mitral position. We conclude that the Hancock porcine bioprosthesis has an acceptable long-term durability and satisfactory performance after tricuspid valve replacement, and we continue to favor its use in the tricuspid position even in association with mechanical prostheses in the left side of the heart.     

Excellent durability of the Hancock porcine bioprosthesis in the tricuspid position. A sixteen-year follow-up study.

From February 1975 to August 1981, 23 consecutive patients underwent tricuspid valve replacement, which was either isolated (six patients) or combined with the replacement of other valves (17) by means of a standard, glutaraldehyde-preserved Hancock porcine bioprostheses. Patients' ages ranged from 9 to 53 (mean 36.2) years. The follow-up period ranged from 0.2 to 16.5 years (mean 9.1) and was complete in 100% of all cases. Structural valve failure of the tricuspid Hancock valve was noticed in two patients, a 9-year-old boy and a 13-year-old girl 3.4 and 16.5 years after implantation, respectively. The actuarial freedom rate from structural valve failure at 10 years was 94 +/- 6%. There were six tricuspid prosthesis-related events: structural valve failure in two and valve thrombosis, anticoagulant-related bleeding, prosthetic valve endocarditis, and periprosthetic leak in one each, respectively. The actuarial freedom from these events at 10 years was 78 +/- 10%. Five pairs of aortic/mitral-tricuspid Hancock valves were explanted simultaneously from the same patients after 8.1 to 13.9 (mean 11.4) years postoperatively. A gross examination showed no valve dysfunction in the explants from the tricuspid position, but degenerative changes with valve dysfunction in those from the mitral and aortic position were observed (none of five versus five of seven; p < 0.03). We concluded that the selection of a Hancock bioprosthesis in the tricuspid position is acceptable because of the low incidence of prosthesis-related complications and the excellent durability of more than 10 years.     

Use of the Carpentier-Edwards porcine bioprosthesis: assessment of a patient selection policy.

The Carpentier-Edwards bioprosthesis was implanted in 369 patients (414 valves) between May 1977 and December 1987 (age 67.2 +/- 0.5 years); 242 had aortic valve replacement, 80 had mitral valve replacement, 44 had multiple valve replacement, of which 41 were aortic and mitral valve replacement, 2 had isolated tricuspid valve replacement, and 1 had a pulmonary valve replacement. The selection criteria were the following: shorter life expectancy (253 patients) or contraindications to anticoagulants for organic (113 patients) or psychologic (38 patients) reasons, or both. The early mortality rate was 11.1% (aortic valve replacement, 9.1%; mitral valve replacement, 12.4%; aortic and mitral valve replacement, 23.1%). Total cumulative follow-up was 1456 pt-yr (mean 4.4 years, range 1 to 148 months), and the patient evaluation was 99.5% complete. Late mortality was 4.9%/pt-yr. Five-year survival was 70.4% +/- 2.7% overall, 74.3% +/- 3.2% after aortic valve replacement, 60.9% +/- 6.2% after mitral valve replacement (p < 0.03), and 60.7% +/- 8.1% after aortic and mitral valve replacement. Eight patients were reoperated on for primary tissue failure, and freedom from reoperation for structural valve deterioration was 97.5% +/- 1.2% at 5 years and 95.6% +/- 1.8% at 8 years. Failing aortic bioprostheses were explanted in four patients (0.4%/pt-yr) and mitral bioprostheses in seven (1.6%/pt-yr). No patient whose valve was inserted after the age of 70 had to be reoperated on for structural valve dysfunction. The probability of freedom from thromboembolism after 5 and 8 years of follow-up was 93.1% +/- 1.6% and 92.2% +/- 1.8%, respectively. The prevalence of anticoagulant-related hemorrhage was 0.8%/pt-yr (major 0.6%, minor 0.2%). Anticoagulants had to be maintained in 16.3% of the patients: 5.9% after aortic valve replacement, 35.7% after mitral valve replacement, and 45.8% after aortic and mitral valve replacement, while 80.0% were on a regimen of antiplatelet drug therapy. Prosthetic valve endocarditis happened in five patients (0.3%/pt-yr). Freedom from all valve-related morbidity and mortality, including hospital deaths, was 71.0% +/- 2.7% at 5 years and 58.6% +/- 4.6% at 8 years and was significantly better in the aortic valve replacement group (61.3% +/- 6.6% at 8 years) compared with the mitral valve replacement group (54.4% +/- 7.7% at 8 years; p = 0.04). This study confirms the satisfactory performance of the Carpentier-Edwards valve after aortic valve replacement in elderly patients.(ABSTRACT TRUNCATED AT 400 WORDS)     

Long-term results of bioprosthetic mitral valve replacement: the pericardial perspective

Pericardial valve bioprostheses were introduced in early 1970s and were widely used in the 1980s. The longterm results with the Ionescu-Shiley valve, the first commercially available pericardial valve, were disappointing because of high rate cusp tears during the first decade after implantation. The enthusiasm for this type of bioprosthetic valve was further hampered by the premature failure of the Hancock pericardial valve. The long-term results of aortic valve replacement with the Carpentier-Edwards pericardial valve, which was introduced in 1981, indicated that that valve was durable and the issue of cusp tears had been resolved by an appropriate design. This knowledge prompted surgeons to revisit the merits of pericardial valves for mitral valve replacement and several other pericardial valves are now commercially available. The largest data on long-term results are with the Carpentier-Edwards pericardial mitral valve. The reported freedom from structure valve failure ranged from 69% to 85% at 10 years in patient population with mean age of 60 to 70 years. Young age is a major determinant of valve failure, which is largely due to calcification. There are also long-term data, albeit more limited on the Sorin Pericarbon and Mitroflow valves used for mitral valve replacement. This paper review the published experience with various pericardial bioprosthetic valves used for mitral valve replacement during the past 3 decades.     

The Hancock pericardial xenograft: incidence of early mechanical failures at a medium-term follow-up

The Hancock pericardial xenograft has been used in our Institution since August 1981 as an alternative to porcine bioprostheses. Up to July 1984, 97 Hancock pericardial xenografts have been implanted in 84 patients; of 76 operative survivors with a mean age of 55.2±13 years (range 13–75 years), 50 had undergone aortic valve replacement, 16 mitral valve replacement and 10 mitral-aortic valve replacement. Follow-up ranged from 0.5 to 5.2 years with a cumulative duration of 239 patient/years and is 99% complete. Actuarial survival is 92%±4% for patients with aortic valve replacement and 84%±10% for patients with mitral valve replacement at 5 years, and 77%±14% for those with mitral-aortic valve replacement at 4 years. Thromboembolic episodes occurred in 2 patients (1 after aortic and 1 after mitral valve replacement). The actuarial freedom from emboli is 100% for patients with mitral-aortic valve replacement at 4 years, and 96%±3% for patients with aortic and 93%±6% for patients with mitral valve replacement at 5 years. Reoperation was performed in 13 patients (9 aortic, 2 mitral and 2 mitral-aortic valve replacements), because of endocarditis in 3 (2 aortic and 1 mitral valve replacement), paravalvular leak in 1 (aortic valve replacement), and primary tissue failure in 9 (6 aortic, 1 mitral and 2 mitral-aortic valve replacements). Actuarial freedom from primary tissue failure is 72%±9% for aortic and 83%±8% for mitral Hancock pericardial xenografts at 5 years. Eleven xenografts explanted because of primary tissue failure were studied pathologically. All showed commissural tears with gross regurgitation; calcium deposits were severe in 2, mild but unrelated to the tears in 2 and absent in 7. Collagen disarray was observed at the site of cusp rupture while the collagen was well preserved in the intact areas of the leaflets. Our results show that: 1) Hancock pericardial xenografts have a high rate of early primary tissue failure, 2) primary tissue failure is caused by cusp rupture at the commissures and can be considered fatigue-induced, 3) tissue calcification does not influence the durability of pericardial xenografts which do not represent a valid alternative to porcine bioprostheses.     

Durability of porcine valves at fifteen years in a representative North American patient population.

Isolated aortic (n = 857) or mitral (n = 793) valve replacement with a porcine bioprosthesis was performed in 1650 patients between 1971 and 1980. Follow-up (total = 12,012 patient-years) extended to more than 15 years and was 96% complete. Patient age ranged from 16 to 87 years; mean age was 59 +/- 11 years (+/- 1 standard deviation) for the aortic valve replacement cohort and 56 +/- 12 years for the mitral valve replacement cohort. The operative mortality rates were 5% +/- 1% (+/- 70% confidence limits) and 8% +/- 1%, respectively, for the aortic and mitral subgroups. Estimated freedom from structural valve deterioration (+/- 1 standard error of the mean) after 10 and 15 years was significantly higher for the aortic than for the mitral valve replacement subgroup (85% +/- 0.4% and 63% +/- 3% versus 78% +/- 2% and 45% +/- 3%, respectively, p = 0.001). Reoperation-free actuarial estimates were also significantly greater for the aortic valve replacement cohort: 83% +/- 2% and 57% +/- 3% versus 78% +/- 2% and 43% +/- 3% for mitral valve replacement at 10 and 15 years, respectively. The mortality rate for reoperative aortic valve replacement was 11% +/- 1%; it was 8% +/- 1% for reoperative mitral valve replacement. Importantly, the estimates of freedom from valve-related death (including sudden, unexplained deaths) were relatively high at 10 and 15 years: 78% +/- 2% and 69% +/- 3% in the aortic cohort and 74% +/- 2% and 63% +/- 3% in the mitral cohort (p = not significant). Excluding sudden, unexplained deaths, these estimates were 81% +/- 3% (aortic) and 73% +/- 4% (mitral) at 15 years. Thromboembolism-free rates were 84% +/- 3% (aortic) and 78% +/- 6% (mitral) at 15 years, and freedom from anticoagulant-related hemorrhage was 96% +/- 1% and 89% +/- 2%, respectively. At the time of current follow-up, 13% of patients having aortic valve replacement and 50% of patients having mitral valve replacement were receiving warfarin sodium. The hazard functions for thromboembolism and prosthetic valve endocarditis were constant and remained less than 1%/pt-yr over the entire follow-up period.(ABSTRACT TRUNCATED AT 400 WORDS)     

Primary failure of pericardial valvular heterografts

From July 1981 to October 1984, 79 Hancock pericardial valves were implanted in 74 patients surviving the hospital period and with a mean age of 64.2 years. Fifty-two patients underwent aortic valve replacement, 16 had mitral valve replacement, 5 bad a double replacement and 19 associated procedures were performed. The mean survival is 48 months. Until 1st June 1987, 11 primary failures have required reoperation (14.9%), 4 in the mitral position (4.6% patient-years), 7 in the aortic position (3.01% patient-years). The time to reoperation was 48.4 months for the aortic orifice and 36.5 months for the mitral orifice. The lesions most frequently encountered were tears (7 cases), calcifications (5 cases) and stretching of valvular tissue (2 cases); two patients died during the postoperative phase of this operation. Despite the small number of patients followed, this series demonstrates of high incidence of dysfunction due to primary tissue degeneration as, after the 5th year, the actuarial rate of absence of primary lesion is 85.3 +/- 8% with no significant difference between the aortic and the mitral orifices, although dysfunction appears to occur more rapidly in mitral prostheses. These results are much less favourable than those obtained with Ionescu bioprostheses in the aortic position of those obtained with porcine bioprostheses in either position. This justifies very regular clinical and echocardiographic follow-up of patients with Hancock pericardial valvular heterografts.     

Long-term durability of the Hancock II porcine bioprosthesis

BACKGROUND: Survival and prosthetic complications of patients receiving the Hancock II second-generation bioprosthesis (Medtronic, Inc, Minneapolis, Minn) in the aortic, mitral, mitral-aortic, and tricuspid positions were analyzed at 15 years' follow-up. METHODS: Between May 1983 and December 1993, 212 patients (104 men and 108 women; mean age, 63 +/- 9 years; age range, 29-81 years) received 66 aortic, 114 mitral, 26 mitral-aortic, and 6 tricuspid Hancock II valves. Thirty-one percent of patients had previous valve operations, 15% had concomitant cardiac procedures, and 87% were in New York Heart Association class III or IV. Follow-up included 1704 patient-years and was 98% complete, with a median of 9 patient-years (range, 0.013-17.4 years). Forty-six patients were at risk at 14 to 15 years, and 30 were at risk after 15 years. RESULTS: One hundred twenty-two (57%) of 212 patients died, 20 of them perioperatively. Fifteen-year actuarial Kaplan-Meier survival was 35.2% +/- 3.8%, and freedom from valve-related mortality was 84% +/- 3.5%, with no difference on the basis of position or age (<65 or >or=65 years). Percentages for freedom from thromboembolism, anticoagulant-related hemorrhage, endocarditis, and paravalvular leak were, respectively, 78.2% +/- 4%, 83.5% +/- 3.6%, 95.7% +/- 2%, and 97.3% +/- 1.4%, with no significant difference between the aortic and mitral positions. Freedom from structural valve deterioration was 71.8% +/- 5.6%: 88.9% +/- 6.2% in the aortic position versus 59.5% +/- 3.9% in the mitral position (P =.01) and 64.3% +/- 3% in the mitral-aortic position. In patients younger than 65 years, actual freedom from structural valve deterioration was less than that seen in older patients (84.5% +/- 3.5% vs 95% +/- 3.0%) and was better in the aortic versus the mitral position (92% +/- 4.5% vs 82% +/- 4.2%). CONCLUSION: The Hancock II porcine valve showed excellent 15-year durability. We recommend its use in patients 65 years of age, as well as in younger patients undergoing aortic replacement.