Comparative analysis of mechanical and bioprosthetic valves after aortic valve replacement

Comparative long-term performance characteristics of Bj?rk-Shiley mechanical and bioprosthetic valves were analyzed for patients undergoing aortic valve replacement between 1976 and 1981. A total of 419 patients received either a standard Bj?rk-Shiley (n = 266) or bioprosthetic (porcine, n = 126, or pericardial, n = 27) aortic valve. Cumulative patient follow-up was 1,705 patient-years; the average patient follow-up was 4.1 +/- 2.7 years. Survival data were obtained for all but 11 patients (97% complete follow-up) up to 9 years after operation. Survival at 5 years was 81% +/- 4% (+/- standard error) for Bj?rk-Shiley and for bioprosthetic valve recipients. Valve failure in the Bj?rk-Shiley group was predominantly due to valve-related mortality and did not result from structural failure. Patients with bioprosthetic valves experienced valve failure as a result of prosthetic valve endocarditis and intrinsic valve degeneration. Although patients with bioprostheses experienced a lower incidence of valve-related morbidity than Bj?rk-Shiley valve recipients (p less than 0.03), no difference could be demonstrated in the incidence of valve-related mortality or valve failure at 5 years between bioprosthetic and Bj?rk-Shiley valves. Mortality rate from valve failure was higher for Bj?rk-Shiley (86%, 12/14) than bioprosthetic valves (36%, 5/14) (p less than 0.01).     

Aortic valve replacement in patients age 70 years and older: early and late results

This retrospective analysis was performed to determine the early and late outcome in patients 70 years and older undergoing aortic valve replacement (AVR). From October 1994 to May 2001, 49 patients (24 men and 25 women, age 70 to 88 years [mean 74 +/- 4.6 years]) underwent primary AVR with or without concomitant procedures. Twenty-one received mechanical valves and 28 bioprostheses. Age was different between both groups: 72 +/- 2.3 years (mechanical) and 76 +/- 5.1 years (bioprosthetic) (p = 0.0005). Aortic stenosis was present in 25 patients (51%). Follow-up was 100% complete at a mean follow-up of 2.9 years (range 0.3-6.5 years). Overall hospital mortality was 4.1% (2/49). There were no postoperative complications in 24% of patients. Postoperative hospital stay or hospital survival was 27 +/- 13 days. Survival at 3 and 5 years was 89 +/- 5% and 80 +/- 7%, respectively. Three late deaths were due to noncardiac causes and 1 each had a cardiac or valve-related cause (thromboembolism). Other valve-related complications such as anticoagulant-related hemorrhage, perivalvular leak, endocarditis, prosthetic valve failure, and reoperation were not noted in any of the 49 patients. The actuarial survival curve was similar in each group of bioprosthetic versus mechanical and septuagenarians versus octogenarians. Under the selection criteria for AVR currently applied in our hospital, geriatric patients showed a satisfactory early outcome and medium-term survival benefit.     

Carpentier-Edwards supra-annular porcine bioprosthesis. Clinical experience and implantation characteristics

The investigational Carpentier-Edwards supra-annular valve was implanted in 592 patients from November, 1981, to February, 1984 (aortic valve replacement in 286, mitral valve replacement in 259, and multiple valve replacement in 47, for a total of 638 prostheses). A previous cardiac operation had been performed in 77 patients (13%). Concomitant procedures were performed in 202 patients (34.1%), including coronary artery bypass in 163 patients. The patient evaluation was 98.6% complete. The early mortality was 7.4% (44 patients) and the late mortality was 6.2% per patient-year (41 patients). The valve-related causes of late mortality were thromboembolism (five), anticoagulant-related hemorrhage (one), and prosthetic valve endocarditis (one). The overall patient survival, including operative death, was 85% at 2 years. The linearized occurrence rate for valve-related complications was 5.6% per patient-year (37 events)--thromboembolism 2.7% per patient-year (18) anticoagulant-related hemorrhage 1.2% (eight), prosthetic valve endocarditis 0.8% (five), and periprosthetic leak 0.9% per patient-year (six). There were no cases of primary tissue failure or structural failure. At 2 years, the freedom from valve-related complications was 86.9%, from valve-related mortality, 98.7%, and from valve-related mortality and reoperation, 97.7%. This valve is fixed in glutaraldehyde at low pressure and is designed to improve durability. It has provided a low incidence of valve-related complications without structural failure. The structural design of the prosthesis does not always conform to the anatomy of bicuspid aortic valves.     

Valve replacement in the elderly. Is the mechanical valve a good alternative?

The controversy surrounding the choice of a prosthesis for valve replacement in the elderly patient prompted me to review the performance of mechanical (Medtronic Hall [Medtronic, Inc., Minneapolis, Minn.] and St. Jude Medical [St. Jude Medical, Inc., St. Paul, Minn.]) valves implanted in 213 patients 65 years and older (mean 70.4 years) from 1980 to 1985. There were 63 mitral, 131 aortic, and 19 double (aortic and mitral) valve replacements. Most patients undergoing aortic valve replacement had stenotic lesions, but half of the patients in the mitral valve replacement group had regurgitation with or without stenosis. Early mortality rates for mitral, aortic, and double valve replacement were 4.8%, 6.1%, and 21.1%, respectively (p less than 0.01). The mortality rate for patients 65 to 74 years old was 6.5% and that for those older than 75 years was 9.1%. The cumulative follow-up for the survivors was 850 patient-years. The late mortality rate was 8.1% per patient-year but was valve-related in only 1.3% per patient-year. Noncardiac causes accounted for 43.5% of the late deaths. The late mortality rate was significantly higher in patients who had regurgitant lesions than in those who had stenotic or mixed disease. It was also higher in the older patients (10.3% per patient-year) than in the younger group (7.6% per patient-year; p less than 0.05). Reoperation was required in only six patients (0.7% per patient-year). Thrombotic obstruction of the prosthesis and systemic thromboembolism occurred at linearized rates of 0.6% per patient-year and 2.5% per patient year, respectively, and significant anticoagulant-related hemorrhage at a rate of 0.6% per patient-year. With the exception of late mortality, the incidence of all late complications was similar to that of patients younger than 65 years operated on during the same period. Actuarially, global survival (58% +/- 4%) and freedom from reoperation (95% +/- 2%), from thrombotic obstruction (96% +/- 1%), from thromboembolism (92% +/- 2%), from all valve-related mortality and morbidity (82% +/- 3%), and from valve failure (93% +/- 2%) were also similar to those of the younger patients. Mechanical prostheses perform well in elderly patients. I could not confirm an increase in thromboembolic or hemorrhagic episodes, and the respective mortality and morbidity indexes were similar to those observed in younger patients.     

Early and late risk of mitral valve replacement. A 12 year concomitant comparison of the porcine bioprosthetic and prosthetic disc mitral valves

A consecutive series of 706 mitral valve replacements was performed from January, 1972, to January, 1984. The follow-up ranged from 6 to 150 months with a mean of 50 and a median of 43 months. Seven percent (50) of the patient were lost to follow-up. There were 243 men and 463 women, whose ages ranged from 17 to 86 years (mean 58). A porcine bioprosthetic valve was implanted in 528 patients (514 Hancock and 14 Carpentier-Edwards valves) and a prosthetic disc valve in 178 patients (102 standard disc Bj?rk-Shiley, 34 Beall, and 42 Harken disc valves). Seven patients were in Functional Class II, 325 in Class III, and 374 in Class IV. A concomitant operative procedure was performed in 253 of the 706 patients (36%). Mitral regurgitation was the primary hemodynamic lesion in 363 and mitral stenosis in 343. Operative mortality figures were as follows: 77 of 706 (11%) for the overall group, 34 of 453 (7.5%) for isolated mitral valve replacement, 30 of 169 (17.5%, p = 0.001) for mitral replacement plus coronary bypass, 49 of 528 (9%) for the bioprosthetic valve group, and 28 of 178 (16%) for the prosthetic disc valve group (p = 0.01). After the operation, 262 patients were in Functional Class I, 99 in Class II, and 18 in Class III. The long-term survival rate was significantly lower in patients who had an associated procedure (45% +/- 6%), who had mitral regurgitation rather than mitral stenosis (53% +/- 5% versus 67% +/- 4%) (p = 0.002), who were in Functional Class IV rather than Classes I to III (51% +/- 4% versus 70% +/- 4%) (p = 0.001), and who received a prosthetic disc valve rather than a bioprosthesis (40% +/- 6% versus 67% +/- 4%) (p = 0.001). Thromboembolic rates were significantly higher with prosthetic valves than with bioprosthetic valves (4.6% +/- 0.22% versus 2.4% +/- 0.5% per patient-year of follow-up), and the incidence of anticoagulant-related hemorrhage was significantly higher in the prosthetic valve group (1.65% versus 0.43% per patient-year). Primary valve dysfunction was significantly more common in the bioprostheses (1.23% versus 0.40% per patient-year).(ABSTRACT TRUNCATED AT 400 WORDS)     

Fifteen-year clinical experience with the biocor porcine bioprostheses in the mitral position

BACKGROUND: Bioprosthetic valve use represents a crucial improvement in surgical treatment of mitral valve disease. The aim of this study is to determine the long-term durability of the Biocor porcine bioprosthetic mitral valve. METHODS: Between 1985 and 1989, a total of 158 Biocor porcine bioprosthetic valves were placed in the mitral position, and long-term results of these patients were investigated retrospectively in 1999. RESULTS: Thirty-day mortality was 4.4% (7 patients). Total follow-up was 1,499 patient-years. Actuarial survival was 83.66% +/- 3% at 5 years, 77.78% +/- 3.36% at 13 years (1.8% patient-year). Multivariate analysis demonstrated younger age, duration of implantation, congestive heart failure, and functional class to be significant predictors of late mortality. Actuarial freedom from valve-related mortality was 98.58% +/- 1% at 15 years (0.13% patient-year). Actuarial freedom from structural valve deterioration was 95.49% +/- 1.8% at 5 years, 70.2% +/- 4.12% at 10 years, and 64.82% +/- 5.34% at 13 years (2.6% patient-year). Actuarial freedom from structural valve deterioration-related reoperation was 98.43% +/- 1.1% at 5 years, 89.15% +/- 2.85% at 10 years, and 76.82% +/- 7.91% at 14 years. Multivariate analysis showed younger age and duration of implantation to be significant predictors of structural valve deterioration and its related reoperation. CONCLUSIONS: By studying a 15-year time period, it is seen that this new generation porcine bioprosthetic valve should be considered an alternative for mechanical valves in selected patients.     

Ten-year analysis of the Bj?rk-Shiley standard aortic valve

Long-term performance characteristics of the Bj?rk-Shiley standard aortic valve were determined by analyzing the follow-up of 514 patients undergoing operation between 1971 and 1981. Cumulative follow-up was 2,601 patient-years (average, 5.3 +/- 3.8 years); 53% (238/452) of hospital survivors have been followed more than 5 years. Valve-related complications expressed as both actuarial event-free percents (+/- standard error at 10 years) and first-event linearized determinations (percent per patient-year) occurred at the following rates: thromboembolism, 82 +/- 3 and 2.3 +/- 0.3, respectively; anticoagulant-related hemorrhage, 60 +/- 4 and 5.6 +/- 0.5; prosthetic valve endocarditis, 94 +/- 2 and 0.8 +/- 0.2; valve thrombosis, 97 +/- 1 and 0.4 +/- 0.1; reoperation, 94 +/- 2 and 0.6 +/- 0.2; valve failure, 82 +/- 4 and 1.6 +/- 0.2; and composite valve-related morbidity and mortality, 46 +/- 4 and 8.8 +/- 0.2. Overall survival was 72 +/- 2% at 5 years and 55 +/- 3% at 10 years; valve-related complications accounted for 22% of the late deaths. Although no instance of structural valve failure could be identified, 25% of valve-related complications resulted from valve failure, of which 67% were fatal. By 10 years, 54% of patients had experienced at least one form of major valve-related complication, 16% of which proved fatal. The Bj?rk-Shiley standard aortic valve has late valve-related complications similar to other existing mechanical prostheses that have been subjected to long-term analysis.     

Cardiac valve replacement in the elderly: clinical performance of biological prostheses

From 1975 to 1987, 1,127 elderly patients underwent 1,223 valve replacements with the Carpentier-Edwards standard or supraannular porcine bioprostheses in 1,147 operations. Of the total patient population seen during these years, 33.5% receiving a standard porcine bioprosthesis and 48.6% receiving a supraannular bioprosthesis were 65 years of age or older. Of this elderly patient population, 465 patients were between 65 and 69 years old; 618 patients, 70 and 79 years old; and 52 patients, 80 years old and older. Aortic valve replacement was performed in 635 patients, mitral valve replacement in 417 patients, tricuspid valve replacement in 2 patients, and multiple-valve replacement in 80 patients. The cumulative follow-up was 3,957 patient-years. Early mortality was 9.5%: 7.3% for the 65- to 69-year-old group, 10.7% for the 70- to 79-year-old group, and 15.4% for the group 80 years old and older. Late mortality was 5.5% per patient-year: 4.2% per patient-year for the 65- to 69-year-old group, 6.3% per patient-year for the 70- to 79-year-old group, and 14.1% per patient-year for the group 80 years old and older. Valve-related causes contributed to 7 early deaths and 33 late deaths. The overall patient survival, including operative deaths, was 70.7% +/- 1.6% at 5 years and 47.8% +/- 3.7% at 10 and 12 years. The freedom from all valve-related complications was 52.1% +/- 6.1% at 10 and 12 years. The overall rate of valve-related complications was 5.0% per patient-year (fatal complications, 1.13% per patient-year). The overall rate of thromboembolism was 2.3% per patient-year and the freedom from thromboembolism, 69.6% +/- 5.2% at 10 and 12 years. The freedom from structural valve deterioration was 80.8% +/- 8.1% at 10 and 12 years: 71.7% +/- 11.0% at 10 and 12 years for the 65- to 69-year-old group, 97.9% +/- 1.2% at 10 years for the 70- to 79-year-old group, and 100% at 12 years for the group 80 years old and older. At 10 and 12 years, the freedom from valve-related death was 83.7% +/- 4.3% and the freedom from reoperation, 73.3% +/- 8.6%. The freedom from valve-related death, residual morbidity from thromboembolism and anticoagulant-related hemorrhage, and reoperation was 61.7% +/- 7.0% at 10 and 12 years. The clinical performance of porcine bioprostheses in the elderly patient population has been excellent. The early mortality increases in patients 70 years old or older.(ABSTRACT TRUNCATED AT 400 WORDS)     

Twenty years' experience with the Model 6120 Starr-Edwards valve in the mitral position

A total of 549 nonconsecutive patients underwent isolated mitral valve replacement with a Starr-Edwards valve prosthesis (Model 6120) at the University of Louvain (Belgium) from 1965 to 1985. Ninety-seven percent of the patients could be traced and only 17 patients were lost to follow-up. Cumulative follow-up totalled 3,130 patient-years. Actuarial and linearized statistical techniques were used to describe the survival and the incidence of valve-related complications (according to stringent criteria). Long-term overall survival rate including early deaths was 79% +/- 0.02% at 5 years, 65% +/- 0.03% at 10 years, and 54% +/- 0.04% at 19 years, with a linearized incidence of late deaths of 3.9% +/- 0.5% per patient-year. The incidence of late valve-related deaths was 1.25% per patient-year. Valve-related complications occurred at the following rates: thromboembolism 3.1% per patient-year, anticoagulant-related hemorrhage 1.08% per patient-year, endocarditis 0.26% per patient-year, reoperation and periprosthetic leak 0.45% per patient-year, and structural failure 0% per patient-year. All valve-related mortality and morbidity were calculated at 4.9% per patient-year and the rate of valve failure (deaths and reoperations) at 1.4% per patient-year. Among 376 survivors, 352 clinical functions could be obtained: 95% of patients belong to Class I or II of the New York Heart Association after operation versus 24% before operation. The study shows the structural durability of the Starr-Edwards mitral valve with a follow-up over 20 years. The Model 6120 valve may be considered a faithful standard.     

Elderly valve replacement with bioprostheses and mechanical prostheses. Comparison by composites of complications

AIM: The goal of aortic valve replacement (AVR) surgery in the elderly (= or >75 years) is to extend survival and minimize valve-related morbidity, mortality and reoperation. As the elderly population lives longer, those with implanted valves are at risk of suffering valve related complications. We hypothesize that bioprostheses are appropriate for the elderly. METHODS: The follow-up evaluation of 966 patients with valves (AVR, 666; mitral valve replacements [MVR], 226; multiple valve replacements [MR], 74) implanted between 1975 and 1999 was examined. There were 879 bioprotheses (BP) and 87 mechanical prostheses (MP). The mean age was 78.9+/-3.3 years (range 75-94.6 years). Concomitant coronary artery bypass was performed in AVR in 51.7%, MVR in 50.4% and MR in 28.4%. Valve type, valve lesion, coronary artery bypass (previous/concomitant), age and gender were considered as independent predictors of composites and survival. The total follow-up was 3905 patient-years. RESULTS: Early mortality was for AVR 9.6% (64), MVR 15.0% (34) and MR 25.7% (19). The late mortality was for AVR 8.8%, MVR 10.4% and MR 8.8%/patient-year. The only independent predictor of survival and valve-related mortality, morbidity and reoperation was age for survival in those with AVR, hazard ratio 1.15 [CL 1.03-1.27] p=0.0094). The BP reoperative rate was 0.5%/patient-year (reoperation was fatal in 6/15) of total, MP reoperative rate was 0% [reasons for reoperation structural valve deterioration (4), non-structural dysfunction (6), prosthetic valve endocarditis (5), reoperation fatality due to non-structural dysfunction (2), prosthetic valve endocarditis (4)]. Overall patient survival at 10 and 15 years, respectively, was 30.5+/-2.4% and 3.6+/-2.2% irrespective of valve position and type. Overall actual and actuarial freedom from valve-related morbidity at 15 years was 96.8+/-0.9% and 93.7+/-2.3%, respectively. Actual and actuarial overall freedom from valve-related mortality at 15 years was 84.3+/-2.4% and 58.4+/-0.9%, respectively. Overall actual and actuarial freedom from valve related reoperation at 15 years was 95.8+/-1.6% and 74.8+/-16.9%, respectively. CONCLUSIONS: BP valves are further confirmed to be a good option for AVR in patients = or >75 years of age.     

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.     

Late results after left-sided cardiac valve replacement in children

Selection of types of cardiac valve substitutes for children remains controversial. Between 1976 and 1984, 166 children, 15 years of age or younger, underwent aortic (N = 53) or mitral valve replacement (N = 90) or both (N = 23). Biological prostheses were used in 84 patients and mechanical prostheses in 71; both a mitral bioprosthesis and an aortic mechanical valve were used in 11 patients. The overall early mortality was 9%. Mean follow-up intervals were 4.1 years for the bioprosthesis group, 3.3 years for the mechanical valve group, and 3.5 years for the group receiving both. The 7 year survival rates (+/- standard error) were 63% +/- 6% in the bioprosthesis group and 70% +/- 7% in the mechanical valve group (p = NS). After aortic valve replacement the 7 year survival rates were 66% +/- 14% (bioprosthesis group) and 77% +/- 9% (mechanical valve group) (p = NS); after mitral valve replacement the rates were 65% +/- 7% (bioprosthesis group) and 54% +/- 17% (mechanical valve group) (p = NS). The incidence of thromboembolic events was 0.6% +/- 0.4% per patient-year in the bioprosthesis group (none after aortic valve replacement, 0.8% +/- 0.6% per patient-year after mitral valve replacement) and 1.4% +/- 0.8% per patient-year in the mechanical valve group (0.7% +/- 0.7% per patient-year after aortic valve replacement, 4.0% +/- 2.8% per patient-year after mitral valve replacement) (p = NS). The linearized rates of reoperation were 10.4% +/- 1.8% per patient-year (bioprosthesis group) and 2.3% +/- 1.0% per patient-year (mechanical valve group) (p less than 0.001). The 7 year probability rates of freedom from all valve-related complications were 43% +/- 6% in the bioprosthesis group and 86% +/- 4% in the mechanical valve group (p less than 0.001). In the aortic position, a mechanical adult-sized prosthesis can always be implanted, and satisfactory long-term results can be anticipated. In the systemic atrioventricular position, the results are less than satisfactory with either type of prosthesis; every effort should be made to preserve the natural valve of the child.     

Long-term results of porcine bioprosthetic heterograft; a 13-years' experience

One hundred and ninety-four patients underwent valve replacements with the glutaraldehyde-preserved porcine bioprostheses (133 Hancock valves, 39 Angell-Shiley valves, 22 Carpentier-Edwards valves and 3 other valves) from 1974 through 1979. There were 105 women and 89 men, whose age ranged 18 to 62 (mean 38.8) years. One hundred and eighty-two patients had mitral bioprosthetic valve replacement (BVR)s, of which 52 had combined aortic mechanical valve replacements, 8 had aortic BVR's, 3 had tricuspid BVR's and 3 had multi-BVR's. Operative mortality was 10.8%. Only one patient was lost to follow-up. Cumulative duration of follow-up is 1421 patient-years. Linearized rate of anticoagulant related hemorrhage, thromboembolism (TE), prosthetic valve endocarditis (PVE), primary tissue failure (PTF) and valve dysfunction (VD) were 0.07, 1.62, 0.49, 2.74 and 3.66% per patient-year. Actuarial freedom from TE, PVE, PTF and VD were 87.0 +/- 2.7%, 95.6 +/- 1.5%, 65.2 +/- 4.9% and 56.9 +/- 5.6% at 13 years. Actuarial survival rate was 67.4 +/- 4.0% at 13 years. Long term follow-up after valve replacement with porcine bioprosthetic valve confirms low thrombogenicity. But primary tissue failure was the chief cause of valve dysfunction and represent a major problem. At this time, we are going to use porcine bioprosthetic valve in the selected patients, that is in the situations in which anticoagulation is contraindicated.     

Eight years' experience with the Medtronic-Hall valve prosthesis

During the period January 1981 to September 1986, 444 Medtronic-Hall heart valve prostheses were implanted in 351 patients (mean age, 45 +/- 10 years) mainly for rheumatic valve disease (63.2%). Most of the patients were in New York Heart Association functional class III. Concomitant surgical procedures, mainly conservative tricuspid or mitral procedures or coronary artery bypass grafting, were performed in 101 patients (28.7%). Single-valve replacement was performed in 262 patients (74.6%) (aortic in 117 patients, mitral in 143, and tricuspid in 2), double-valve replacement in 85 (24.2%) (mitral and aortic in 83 and mitral and tricuspid in 2), and triple-valve replacement in 4 (1.1%). Hospital mortality was 6.2%. Follow-up was 97.7% complete. The overall actuarial 8-year survival rate was 77.2%. The linearized incidence of valve-related complications was as follows: thromboembolism, 1.5%/patient-year; reoperation, 1.5%/patient-year; endocarditis, 1.25%/patient-year; hemolysis, 0.52%/patient-year; anticoagulant-related hemorrhage, 0.39%/patient-year; and noninfection-related paraprosthetic leak, 0.33%/patient-year. There were no instances of structural failure. We conclude that after 8 years of follow-up, the Medtronic-Hall valve prosthesis has an excellent clinical performance and a low range of valve-related complications.     

Mitral Valve Replacement with the Hancock Bioprosthesis: Five- to Ten-Year Follow-up

One hundred eleven patients undergoing mitral valve replacement, either alone (56) or in conjunction with another type of prosthetic valve, prior to 1975 were evaluated. Hospital mortality was 9.9%. Cumulative follow-up is 505 patient-years (mean, 5.4 years). Seventy patients have been followed between 5 and 10 years. Late mortality for mitral valve replacement alone is 4.3 ± 1.3% per patient-year; actuarial survival is 82 ± 6% at 5 years and 65 ± 11% at 10 years. The incidence of emboli was 3.3 ± 0.9% per patient-year for all patients with bioprostheses (62) and 4.2 ± 1.7% per patient-year for bioprostheses and concomitant mechanical aortic valves (32). In patients with only bioprostheses, two of twelve emboli occurred within the first 6 postoperative months and there were three fatal cerebral emboli (0.8 + 0.5% per patient-year). The incidence of hemorrhagic complications is 4.9 ± 1.9% for anticoagulated patients with bioprostheses and mechanical aortic valves; one hemorrhage was fatal (0.7 ± 0.7% per patient-year). Intrinsic mitral bioprosthesis failure occurred in 10 patients; 2 died. Five patients had valve failure secondary to perivalvular regurgitation (3) or endocarditis (2). Actuarial late survival free from intrinsic mitral bioprosthetic failure was 99 ± 1% at 5 years, 92 ± 4% at 7 years, 70 ± 12% at 9 years, and 61 ± 13% at 10 years.It is unknown at the present time whether the long-term risk of late intrinsic valve failure and reoperation will outweigh the low incidence of emboli and avoidance of anticoagulant-related hemorrhage. Until further information becomes available, the Hancock bioprosthesis is used for mitral valve replacement only in patients older than 60 years or in patients with contraindications for anticoagulant therapy.     

Bioprostheses for cardiac valve replacement

Biologic tissue has been used successfully for cardiac valve substitutes since the introduction of glutaraldehyde preservation in 1969. Assessment of the clinical performance of prosthetic valves requires consideration of thromboembolism, anticoagulant-related hemorrhage, prosthetic valve endocarditis, periprosthetic leak and prosthesis failure. Two methods of assessment of valve performance, linearized occurrence rates and multiple decrement analysis of valve-related complications, are illustrated in evaluation of previous and new-generation Carpentier-Edwards porcine bioprostheses. The standard valve has a valve-related complication rate of 2.9% per patient-year over 5 years, while the rate for the new-generation supra-annular prosthesis is 4.3% per patient-year in the 2-year interval. Thromboembolism has been 1.6% and 1.7% per patient-year, respectively, for the previous and new-generation prostheses. Primary tissue failure has occurred only in the standard prosthesis, 0.6% per patient-year. The freedom from all valve-related complications is 93.1% at 2 years and 87.5% at 6 years with the standard valve and 95.1% at 2 years with the new-generation prosthesis. Standardized assessment of prosthetic performance should provide physicians and surgeons with the knowledge to optimize patient management. The new-generation biologic prostheses with improved preservation should reduce calcification and fatigue lesions. Tissue valves have afforded patients an excellent quality of life with a low incidence of valve-related complications.     

Long-term experience with the St. Jude Medical valve prosthesis.

BACKGROUND: All patients undergoing St. Jude Medical valve replacement at the Medical University of South Carolina since January 1979 have been followed prospectively at 12-month intervals. METHODS: This report describes long-term experience in 710 adult patients undergoing isolated aortic (AVR) (418) or mitral valve replacements (MVR) (292) with this prosthesis from January 1979 to December 1996. RESULTS: Ages ranged from 19 to 84 years (54.8 +/- 15.1 AVR, 51.8 +/- 12.9 MVR; mean +/- SD). Male gender predominated in the AVR group (70%) and female gender in the MVR group (62%). One hundred and fifty-seven patients (22%) had associated coronary artery bypass grafting (AVR 27%, MVR 15%). Thirty-day operative mortality was 5.3% (22/418) in the AVR group and 5.1% (15/292) in the MVR group. Follow-up is 96.9% complete and ranges from 1 month to 16.9 years (AVR, 2,376 patient-years, mean 5.7 +/- 4.5 years; MVR, 1,868 patient-years, mean 6.4 +/- 4.8 years). In the AVR group, 120 late deaths have occurred and actuarial survival was 78.0 +/- 2.3%, 58.0 +/- 3.2%, and 36.8 +/- 4.8%; at 5, 10, and 15 years, respectively. Forty-six patients have sustained 55 thromboembolic (TE) events (2.3%/patient-year). Fifty-one patients had anticoagulant-related bleeding complications (2.7%/patient-year). The mean improvement in New York Heart Association (NYHA) functional class from preoperative to postoperative was 3.0 +/- 0.8 to 1.7 +/- 0.1 (p < 0.05). In the MVR group, there have been 84 late deaths, and the actuarial survival was 79.3 +/- 2.5%, 60.1 +/- 3.5%, and 49.3 +/- 4.1% at 5, 10, and 15 years, respectively. Fifty-two patients have had 64 TE events (3.5%/patient-year). Twenty-three patients had anticoagulant-related bleeding complications (1.6%/patient-year). The mean improvement in NYHA functional class was from 3.3 +/- 0.6 to 1.8 +/- 0.1. There were no mechanical failures in either group. CONCLUSIONS: With a follow-up now extending to 17 years, the St. Jude Medical valve continues to be a reliable mechanical prosthesis with low and stable rates of valve-related complications.     

Survival and valve failure after aortic valve replacement.

A prospective evaluation of 412 consecutive patients undergoing isolated aortic valve replacement between January 1982 and December 1985 was performed in an attempt to identify the determinants of survival and valve failure. A variety of valves were inserted to permit a prospective evaluation of alternative valves including: Bj?rk-Shiley mechanical (n = 37), Ionescu-Shiley pericardial (n = 261), Hancock pericardial (n = 78), and Carpentier-Edwards porcine (n = 36). Thirteen patients died in the hospital (3.2%) and 47 patients died in the follow-up period producing an actuarial survival of 81% +/- 3% at 48 months. Survival was independently predicted by advancing age, preoperative New York Heart Association functional class, and the presence of endocarditis (p less than 0.05 by Cox regression analysis). The majority of patients were symptomatically improved (New York Heart Association class I or II: 21% preoperative, 88% postoperative). Freedom from structural valve dysfunction, prosthetic valve endocarditis, and reoperation for valve-related complications were 95% +/- 2%, 95% +/- 2%, and 92% +/- 2% at 48 months, respectively. These valve-related complications occurred more frequently in younger patients and in those with a Hancock pericardial valve (freedom from structural valve dysfunction, 89% +/- 5%; prosthetic valve endocarditis, 84% +/- 9%; reoperation, 78% +/- 10%; p less than 0.05 by Cox regression). Freedom from thromboembolism was 88% +/- 2% at 48 months; it was significantly lower in patients with a preoperative thromboembolic event and was not influenced by the type of prosthesis inserted. Freedom from anticoagulant-related hemorrhage was 85% +/- 8% at 48 months and was not influenced by any preoperative factors.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bivalvular mechanical mitral-aortic valve replacement in 254 patients: long-term results--a 22-year follow-up

BACKGROUND: We have retrospectively studied 254 patients who underwent a bivalvular mechanical mitral-aortic replacement in the cardiovascular and thoracic surgery unit of Nantes from 1979 to 1989. The follow-up was 22 years (1979 to 2001). The last patient was operated on 12 years before the end of the follow-up. METHODS: All mitral prostheses were St. Jude Medical (SJM) bileaflet valves, and the aortic prostheses were 124 monodisc Bj?rk-Shiley valves, 3 Sorin prostheses, and 127 St. Jude Medical bileaflet prostheses. The mean age was 56.8 +/- 8.5 years with a sex ratio equal to 1. Rheumatism as the etiology predominated with 79.5%. Ninety-seven percent of the patients were followed for a total of 2,779 patient-years and a mean of 11.7 years. RESULTS: Operative mortality was 7.08%. Freedom from overall mortality and valve-related mortality at 22 years were 45.7% +/- 3.6% and 73.1% +/- 3%, respectively. The linearized rates of thromboembolic and hemorrhagic events were 1.07% and 0.9% per patient-year, respectively. Multivariate analysis showed age (p < 0.002), sex (p < 0.01), and degenerative etiology (p = 0.04) as independent factors of late mortality, and age, sex, degenerative disease, and tricuspid pathology were related to valve-related mortality. CONCLUSIONS: This study shows good results after mechanical mitral-aortic replacement in terms of survival rate and quality of life in surviving patients, and outlines the factors influencing long-term results as compared with isolated mitral valve replacement.     

The Carpentier-Edwards Supra-Annular Porcine Bioprosthesis: New Generation Low Pressure Glutaraldehyde Fixed Prosthesis

The Carpentier-Edwards supra-annular porcine bioprosthesis was implanted in 1,576 operations (1,536 patients with 1,704 valves) between 1981 and 1987. The mean age of the patients was 61.9 years (range 13 to 87 years). During the years 1981 and 1987, approximately 90% of the total valvular surgery population received the prosthesis. The early mortality was 7.0% (included patients with concomitant procedures including coronary artery bypass and ascending aortic aneurysm resection). Late mortality was 4.0% per patient-year. The total cumulative follow-up was 4,237 years. Thromboembolism (TE) was 2.4% per patient-year (fatal 0.4% per patient-year) (minor 1.2%; major 1.3%); antithromboembolic therapy-related hemorrhage (ATH) 0.5% (fatal 0.07%); prosthetic valve endocarditis (PVE) 0.5% (fatal 0.2%); periprosthetic leak (PPL) 0.3% (fatal 0%); clinical valve dysfunction (CVD) 0.3% (fatal 0.02%); and structural valve deterioration/primary tissue failure (SVD) 0.2%/patient-year (fatal 0%). Thromboembolism and structural valve deterioration were the significant complications, SVD occurring primarily between the fourth and fifth year of evaluation. The overall patient survival was 77.1% +/- 1.4% at five years. The patients were classified as 89.6% NYHA functional Class III and IV preoperatively and 96.1% Class I and II postoperatively. The freedom at five years from TE was 90.6% +/- 1.0%; SVD 98.9% +/- 0.5%; and reoperation 95.9% +/- 0.9%. Freedom from all valve-related complications at five years was 84.1% +/- 1.3%; valve-related mortality 96.8% +/- 0.7%; mortality and reoperation (valve failure) 92.9% +/- 1.1%; mortality and residual morbidity (treatment failure) 93.7% +/- 0.9%; and mortality, residual morbidity, and reoperation (valve failure and dysfunction) 90.0% +/- 1.2%. There were 28 valve-related deaths of a total 280 deaths (early 4, late 24) (TE 17; ATH 3; CVD 1; PVE 7; PPL 0; and SVD 0). Valve-related reoperations were performed in 32 patients (TE 2; CVD 4; PVE 7; PPL 11; and SVD 8). The supra-annular Carpentier-Edwards porcine bioprosthesis has provided very satisfactory clinical performance and afforded patients an excellent quality of life. The long-term durability of this low pressure glutaraldehyde fixed prosthesis will be determined by observation over the next five to seven years.