Aortic valve selection in the elderly patient

To determine the influence of valve selection on valve-related morbidity and mortality and patient survival, comparative long-term performance characteristics of mechanical (N = 68) and bioprosthetic (N = 73) heart valves were analyzed for 141 patients more than 70 years old who underwent isolated aortic valve replacement between 1970 and 1985. Cumulative patient follow-up was 491 patient-years (average, 4.3 years per patient). Hospital mortality was 18% and 19% for patients with mechanical valves and bioprosthetic valves, respectively. Survival at 5 years was 61 +/- 7% (+/- the standard error) and 67 +/- 10% for recipients of mechanical valves and bioprosthetic valves, respectively. Male sex (p = 0.014) and urgency of operation (p = 0.006) were independent risk factors for hospital mortality. Atrial fibrillation increased valve-related mortality (p = 0.01). No patient required reoperation or experienced structural valve failure. While anticoagulant-related hemorrhage was increased in recipients of mechanical valves (9.2 +/- 2.1%/patient-year) compared with recipients of bioprosthetic valves (2.3 +/- 1.1%/patient-year), it did not result in a death or lead to permanent disability. There was no difference in freedom from any valve-related complication at 5 years. However, when all morbid events are considered, recipients of bioprosthetic valves experienced fewer valve-related complications than patients receiving mechanical valves (10.7 +/- 2.3%/patient-year versus 17.6 +/- 2.5%/patient-year, respectively; p less than 0.05). The reduced incidence of anticoagulant-related hemorrhage and the infrequent need for warfarin sodium anticoagulation favor selection of a bioprosthetic heart valve in patients older than 70 years.     

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.     

Comparison of outcomes after mitral valve replacement with a mechanical versus a bioprosthetic valve in patients between forty and sixty years of age

Background  The American College of Cardiology/American Heart Association (ACC/AHA), guidelines for choice of prosthetic valve based on patients’ age are difficult to apply to the developing world because of a lower life expectancy and difficulty in maintaining correct levels of anticoagulation for a variety of reasons. While there is general agreement on the choice of prosthetic valves for patients below 40 years of age (mechanical) and above 60 years of age (biologic), the 40 to 60 age group remains a grey zone. The goal of our study was to compare outcomes after mitral valve replacement with a mechanical versus a bioprosthetic valve in patients between forty and sixty years of age. Methods  From Jan 2003 to July 2008, 250 patients between the ages of 40 and 60, undergoing mitral valve replacement at our institution were randomized to receive either a mechanical or a bioprosthetic valve. Outcomes in the form of incidence of valve thrombosis and thromboembolism, bleeding complications, incidence of prosthetic valve endocarditis and survival were compared in the two groups. Results  Out of 250 patients, 135 patients received mechanical valve and 115 patients were implanted with a bioprosthetic valve. Patients were followed up for a mean period of 3 years (range 6 months to 4.8 years). The incidence of valve thrombosis was higher in mechanical valve as compared to bioprosthetic valve (6% vs. 0.9%, p= 0.04). Similarly there was a higher incidence of thromboembolism in mechanical valves as compared to bioprosthetic valves (4.5% vs. 0%, p=0.03). Bleeding complications occurred more frequently in mechanical than bioprosthetic valve (6% vs. 0.9%, p=0.04). There was no significant difference in the incidence of prosthetic valve endocarditis (2.2% vs. 2.7%, p >0.05) or survival at three years (96.2% vs. 97.2%, p > 0.05) in the two groups. Conclusions  Patients in the age group of 40 to 60 years undergoing mitral valve replacement with a mechanical valve have a higher incidence of thrombotic and bleeding complications as compared to bioprosthetic valve, even though short term survival is similar. This favours implantation of a bioprosthetic valve in this age group.     

Valvuloplasty for rheumatic mitral valve disease. A surgical challenge

From January 1981 through February 1985, 241 patients with rheumatic mitral valve disease (mean age 21.5 +/- 11.8 years) were subjected to comprehensive mitral valvuloplasty. One hundred seven patients (44.4%) were 15 years or younger and 63 (26.1%) were 12 years or younger. One hundred seventy five patients had pure or predominant regurgitation (mean age 19.3 +/- 10.7 years) and 40 (16.6%) had active rheumatic carditis at the time of the operation. Almost all patients (229) were in New York Heart Association Functional Class III or IV. The techniques used included shortening of anterior leaflet chordae tendineae (136 patients), resection of secondary, tertiary, and basal posterior leaflet chordae (156 patients), commissurotomy (113 patients), and implantation of a Carpentier ring (164 patients). Current operative mortality is 1.9%. The survivors were followed up for 576 patient-years (mean 2.64 +/- 1.32 years). Late mortality was 2.60% per patient-year and was valve related in 1.04% per patient-year. Reoperation was required in 25 patients (4.34% per patient-year), mostly (72%) in the first year. There were only two cases (0.35% per patient-year) of thromboembolism and three cases (0.52% per patient-year) of infective endocarditis. Hence valve failure occurred at a linearized rate of 6.08% per patient-year but was fatal in only 22% of the patients. There was no relationship between valve failure and the type of lesion or procedure performed, but reoperation was required more frequently in patients aged 12 years or less (7.33% per patient-year) than in those older than 12 years (3.29% per patient-year) (p less than 0.05). Actuarial survival rate at 41/2 years was 90%, and 82% of the patients were free from valve-related complications. Valve function after valvuloplasty was assessed clinically. Eighty-four percent of the patients had a good immediate result, but this figure dropped to 69% at the end of the follow-up period (p less than 0.05). The remainder had moderate valve dysfunction. However, 85% of the patients remain in New York Heart Association Functional Class I. Mitral valvuloplasty is an excellent alternative to valve replacement in young patients with rheumatic mitral valve disease. Persistent or reactivated rheumatic carditis may be a significant factor of valve failure, and penicillin prophylaxis is mandatory after operation.     

Intrinsic failure of Hancock mitral bioprostheses: 10- to 15-year experience

Hancock porcine bioprostheses have been implanted in the mitral position at the National Institutes of Health since July, 1970. Eight models (330, 330A, 330B, 330C, 332, 340, 341, and 342) were used during a 54-month period ending December, 1974, and 100 consecutive surviving patients were evaluated for subsequent bioprosthetic valve failure and prosthesis-related complications by annual clinic examinations and serial hemodynamic studies. Actuarial patient survival was 76 +/- 4%, 51 +/- 5%, and 30 +/- 6% after 5, 10, and 15 years, respectively. Intrinsic valve failure, defined as structural degeneration of bioprosthetic tissue or stent geometry alteration or both, in the absence of prior infection, occurred in 23 patients. The linear occurrence rate of bioprosthetic valve failure was 0.2%, 5%, and 15% per patient-year, and it affected 1 patient, 14 patients, and 8 patients at sequential 5-year milestones. The actuarial freedom from valve failure was 99 +/- 1%, 75 +/- 6%, 58 +/- 8%, and 40 +/- 12% after 5, 10, 12, and 14 years, respectively. The valve durability of early Hancock bioprostheses (models 330 through 341; N = 39) was not appreciably different from that of the current model 342 valves (N = 61). However, an increased incidence of intrinsic valve failure was observed for the first polypropylene-stented valve type (model 330) compared with the currently available model 342 valve (8/16, 50%, versus 12/61, 20%; p = 0.034). The yearly occurrence rate of prosthesis-related complications remained constant, but the rate of intrinsic valve failure increased in a progressive, nonlinear fashion. The high intrinsic failure rate of the Hancock porcine bioprosthesis after 10 to 12 years has moderated our initial enthusiasm for this valve in the mitral position, and has resulted in more frequent implantations of mechanical valve substitutes at this institution.     

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.     

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.     

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.     

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.     

An eight-year experience with porcine bioprosthetic cardiac valves

A total of 589 porcine bioprostheses were implanted in 509 patients from January, 1976, through December, 1983. Of the valves implanted, 390 were Hancock and 199 were Carpentier-Edwards. A total of 1,633 patient-years was accrued, with a mean follow-up of 38 months per patient. Two hundred eight patients had aortic valve replacement, 209 had mitral valve replacement, and 79 had multiple valve replacements, of which 46 were aortic and mitral replacements. The mortality for isolated aortic valve replacement was 5.8%; for isolated mitral replacement, 8.6%, and for all patients, 10.9%. Late mortality was 3.9% per patient-year. The actuarial survival rate at 5 years was 79% for aortic, 68% for mitral, and 76% for aortic-mitral valve replacement. There were 12 thromboembolic events (0.73% per patient-year). Two episodes occurred in patients with an aortic bioprosthesis, nine in patients with a porcine mitral valve, and one in a patient with mitral and tricuspid bioprosthetic valves. The probability of remaining free of thromboembolism at 5 years was 99% for the group having aortic valve replacement, 93% for those having mitral replacement, and 100% for the group having aortic-mitral valve replacements. Thirteen episodes of endocarditis occurred (0.8% per patient-year). Seven of the 13 patients died as a direct result of endocarditis. The probability of remaining free of prosthetic endocarditis at 5 years was 97% for the aortic valve replacement group, 95% for the mitral group, and 97% for the aortic-mitral group. There were 20 instances of xenograft failure (1.2% per patient-year). The probability of remaining free of valve failure at 5 years was 96% for the aortic valve replacement group, 93% for the mitral group, and 93% for the aortic-mitral replacement group. Primary tissue failure of a prosthesis occurred in seven patients, all with Hancock valves (0.43% per patient-year). As yet there has been no primary tissue failure of the Carpentier-Edwards prosthesis. There also appears to be a lower incidence of thromboembolism (Edwards, 0.3% per patient-year; Hancock, 0.8% per patient-year) and endocarditis (Edwards, 0.6% per patient-year; Hancock, 1.0% per patient-year). The low incidence of complications with the porcine bioprosthetic valve, especially the Carpentier-Edwards, encourages us to recommend its continued use, especially in situations in which anticoagulation is contraindicated.     

The Carpentier-Edwards supraannular porcine bioprosthesis. A new generation tissue valve with excellent intermediate clinical performance

The Carpentier-Edwards supraannular porcine bioprosthesis, an investigational valve, was implanted in 1167 patients (1174 operations, 1274 valves) between November 1981 and December 1985 (age range 13 to 85 years, mean 61 years). The early mortality rate was 7.2% (with concomitant procedures 10.9%, without 4.8%; with previous operation 10.5%, without 6.6%). The late mortality rate was 4.5% per patient-year (aortic valve replacement, 4.0%; mitral valve replacement, 4.8%; multiple valve replacement, 5.6%). Total cumulative follow-up was 2272.3 years. The prevalence of thromboembolism was 2.6% per patient-year (fatal 0.4% per patient-year, major 1.4%, minor 1.2%); hemorrhage related to antithromboembolic therapy, 0.7% (fatal 0.1%); prosthetic valve endocarditis, 0.4% (fatal 0.2%); periprosthetic leak, 0.4% (fatal 0%); structural valve deterioration (primary tissue failure/structural failure), 0.1% per patient-year; and clinical valve dysfunction, 0.4%. The reoperation rate was 0.8% per patient-year (thromboembolism, 0.1%; clinical valve dysfunction, 0.1%; prosthetic valve endocarditis, 0.1%; periprosthetic leak, 0.4%; structural valve deterioration, 0.1%). Thromboembolism occurred throughout the observation period but with decreasing frequency, hemorrhage throughout the period in no predictable fashion, prosthetic valve endocarditis within 2 years, periprosthetic leak within 2 years, and structural valve deterioration occurred during the fourth year of assessment. The overall survival rate was 79.8% +/- 1.7% (4 years). Freedom (at 4 years) from thromboembolism was 92.2% +/- 1.2%; from structural valve deterioration, 98.8% +/- 0.8%; and from reoperation, 95.8% +/- 1.3%. Freedom from all complications (4 years) was 85.9% +/- 1.7%; from complication mortality, 98.4% +/- 0.4%; and from valve failure (mortality and reoperation), 94.3% +/- 1.3%. This investigational Carpentier-Edwards supraannular porcine bioprosthetic valve has provided excellent clinical performance and remains our overall prosthesis of choice.     

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).     

Case-matched comparison of mitral valve replacement and repair

Carpentier's techniques of prosthetic ring mitral valve repair for mitral regurgitation offer the potential for immediate and long-term improvement in valve function without the necessity of replacing the native valve with a prosthesis. A consecutive, case-matched series of 65 patients with prosthetic ring mitral valve repair was compared with 65 patients undergoing mitral valve replacement for mitral regurgitation. The aortic cross-clamp time was 57 +/- 33 minutes in the repair operations and 41 +/- 25 minutes in the replacement operations (p = 0.003). The cardiopulmonary bypass time was 154 +/- 44 minutes in the repair operations and 113 +/- 41 minutes in the replacement operations (p = 0.0001). There were no myocardial infarctions in the hospital in either group. Hospital death was noted in 1.5% of repairs and 4.6% of replacements (p = not significant). Survival at 4 years was 0.84 for repairs and 0.82 for replacements (p = not significant). Freedom from reoperation to replace the mitral valve at 4 years was 62 of 65 patients in the repair group and 64 of 65 patients in the replacement group (p = not significant). In-hospital and midterm results in a closely matched population show that mitral valve repair yields results comparable with those of replacement despite a more difficult procedure. The benefits of maintaining the native valve with chordal and papillary muscle structure intact and avoidance of prosthetic valve implantation may then become apparent with longer follow-up.     

The porcine bioprosthetic valve. Twelve years later

The porcine bioprosthetic heart valve has been commercially available since 1970 and has been the prosthetic heart valve of choice in our institution since 1971. Since that time 817 patients with 951 porcine valves have been discharged from the hospital and were available for long-term follow-up. Patient survival rates, with operative mortality excluded, were 80% +/- 1.7% (standard error) at 5 years and 68% +/- 2.7% at 10 years. Survival rates for patients with aortic valve prostheses were 78% +/- 2.8% at 5 years and 57% +/- 5.4% at 10 years; for patients with mitral valve prostheses, survival rates were 80% +/- 2.2% at 5 years and 69% +/- 3.2% at 10 years. Freedom from thromboembolism for aortic valves was 93% +/- 1.4% at 5 years and 88% +/- 2.6% at 10 years; for mitral valves the freedom from degeneration or primary tissue failure for aortic valves was 97% +/- 1.3% at 5 years and 71% +/- 7.6% at 10 years; for mitral valves these figures were 96% +/- 1.2% at 5 years and 71% +/- 4.1% at 10 years. Valves in patients 35 years of age and below had a significantly greater rate of degeneration (p less than 0.001). After 12 years' experience the porcine bioprosthetic valve has performed well with regard to patient survival and low rate of thromboembolism. For patients older than 35 years the freedom from primary tissue failure is 80% at 10 years.     

Durability and outcome of aortic valve replacement with mitral valve repair versus double valve replacement

BACKGROUND: The purpose of this study was to evaluate morbidity and mortality after double valve replacement (DVR) and aortic valve replacement with mitral valve repair (AVR + MVP). METHODS: From 1977 to 2000, 379 patients underwent DVR (n = 299) or AVR + MVP (n = 80). Actuarial survival and freedom from reoperation were determined by the Kaplan-Meier method. Potential predictors of mortality and reoperation were entered into a Cox multiple regression model. Propensity score was introduced for the multivariable regression modeling for adjustment of a selection bias. RESULTS: Survival 15 years after surgery was similar between the groups (DVR, 81% +/- 3%; AVR + MVP, 79% +/- 7%; p = 0.44). Freedom from thromboembolic event at 15 years was similar between the groups (p = 0.25). Freedom from mitral valve reoperation at 15 years was significantly better for the DVR group (54% +/- 5%) as compared with the AVR + MVP group (15% +/- 6%; p = 0.0006), primarily due to progression of mitral valve pathology and early structural deterioration of bioprosthetic aortic valve used for patients with AVR + MVP. After AVR + MVP, freedom from mitral reoperation at 15 years was 63% +/- 16% for nonrheumatic heart diseases, and 5% +/- 5% for rheumatic disease (p = 0.04). CONCLUSIONS: Although both DVR and AVR + MVP provided excellent survival, DVR with mechanical valves should be the procedure of choice for the majority of patients because of lower incidence of valve failure and similar rate of thromboembolic complications compared with AVR + MVP. MVP should not be performed in patients with rheumatic disease because of higher incidence of late failure.     

Incidence and risk factors of prosthetic valve endocarditis

To study the incidence and risk factors of prosthetic valve endocarditis (PVE) we followed 99.5% of 912 patients who had valve replacements from 1 January 1981 to 31 December 1985 for 1-6 (mean 3) years. PVE occurred in 27 patients (2.96% or 0.98% per patient-year). The incidence of PVE in the aortic position (3.9%) was significantly higher than in the mitral position (1.5%): chi-square = 6.1, P less than 0.025. PVE developed in 19 of 329 patients with bioprostheses (5.8%), and in 8 of 583 patients with mechanical valves (1.4%): chi-square = 14.48, P less than 0.005). Actuarially at 5-year follow-up, 90.7% +/- 2.16% of the bioprosthetic group and 98.4% +/- 0.56% of the mechanical valve group was free of PVE (P less than 0.001). Antecedent endocarditis increased both the incidence and relative risk of PVE 7-fold compared to patients without antecedent endocarditis (chi-square = 32.0, P less than 0.0001). Bioprosthetic valve replacement in infective endocarditis increased the risk of PVE 12-fold compared to valve replacement by mechanical prostheses. In conclusion: in the order of importance, antecedent endocarditis, bioprostheses and aortic position are risk factors in the development of PVE. Bioprostheses implanted in patients with antecedent endocarditis further enhance the risk of PVE.     

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.     

Mitral valve replacement in the first 5 years of life

Between 1976 and 1986, 19 children aged 1 month to 5 years underwent replacement of the mitral (systemic atrioventricular) valve. Indications for valve replacement included isolated congenital mitral stenosis (n = 2), valve dysfunction associated with a more complex procedure (n = 15), and failed valvuloplasty (n = 2). Seven different valve types were used; nine were mechanical valves and ten were bioprosthetic valves. There were 6 hospital deaths (32%; 70% confidence limits, 20% to 47%). Among the 13 survivors there were 3 late deaths at a mean of 14 months after operation. The late deaths were unrelated to valve malfunction. Thromboembolic events occurred in 2 patients, both with mechanical valves. One minor bleeding complication occurred among 10 patients on a regimen of Coumadin (crystalline warfarin sodium). Five patients, all with bioprostheses, required a second valve replacement. Indications for reoperation included prosthetic valve regurgitation (n = 1) and calcific stenosis (n = 4). No early or late deaths occurred after second valve replacement. Survival was 51% +/- 12% (standard error) at 112 months after valve replacement. Analysis failed to identify age, weight, sex, previous operation, underlying cardiac lesion, or prosthesis size and type as significant risk factors for mortality. Mechanical valves had a lower reoperation rate compared with bioprostheses. These data suggest that although mitral valve replacement within the first 5 years of life is associated with a high operative and late mortality, satisfactory long-term palliation for many patients can be achieved. Mechanical valves are superior to bioprosthetic valves, and offer the best long-term results.     

Treatment of endocarditis with valve replacement: the question of tissue versus mechanical prosthesis

BACKGROUND: It remains unknown whether there is any important clinical advantage to the use of either a bioprosthetic or mechanical valve for patients with native or prosthetic valve endocarditis. METHODS: Between 1964 and 1995, 306 patients underwent valve replacement for left-sided native (209 patients) or prosthetic (97 patients) valve endocarditis. Mechanical valves were implanted in 65 patients, bioprostheses in 221 patients, and homografts in 20 patients. RESULTS: Operative mortality was 18+/-2% and was independent of replacement valve type (p > 0.74). Long-term survival was superior for patients with native valve endocarditis (44+/-5% at 20 years) compared with those with prosthetic valve endocarditis (16+/-7% at 20 years) (p < 0.003). Survival was independent of valve type (p > 0.27). The long-term freedom from reoperation for patients who received a biologic valve who were younger than 60 years of age was low (51+/-5% at 10 years, 19+/-6% at 15 years). For patients older than 60 years, however, freedom from reoperation with a biological valve (84+/-7% at 15 years) was similar to that for all patients with mechanical valves (74+/-9% at 15 years) (p > 0.64). CONCLUSIONS: Mechanical valves are most suitable for younger patients with native valve endocarditis; however, tissue valves are acceptable for patients greater than 60 years of age with native or prosthetic valve infections and for selected younger patients with prosthetic valve infections because of their limited life expectancy.     

Mitral valvuloplasty, a better alternative. Comparative study between valve reconstruction and replacement for rheumatic mitral valve disease

Valvuloplasty is now a well accepted alternative method of surgical treatment of mitral valve disease. To analyse its relative performance in rheumatic valvulopathies, three groups of patients who had mitral valvuloplasty (1980-1984; 241 patients) or mitral valve replacement with mechanical (1980-1984; 386 patients) or biological prostheses (1976-1980; 289 patients) were reviewed. The early mortality was 3.3% for valvuloplasty, 7.8% for mechanical valve replacement and 6.6% for bioprostheses (P less than 0.05). Late mortality occurred at the rate of 2.6% per patient year (15 patients) for valvuloplasty, 5.7% per patient year (70 patients) for mechanical valves and 7.4% per patient year (41 patients) for bioprostheses (P less than 0.01), but valve-related mortality was 1.0% per patient year, 2.5% per patient year and 4.2% per patient year, respectively (P less than 0.01). Reoperation was more frequent after valve replacement with bioprostheses (6.7% per patient year) than after valvuloplasty (4.3% per patient year) and after mechanical valve replacement (1.5% per patient year; P less than 0.02), and was necessitated mainly by residual or recurrent valve dysfunction after valvuloplasty, bland or infected periprosthetic leaks in mechanical valves and degradation of bioprostheses. Valve failure occurred at the rate of 6.1% per patient year for valvuloplasty, 5.7% per patient year for mechanical valves and 11.1% per patient year for bioprostheses (P less than 0.05). In actuarial terms, global survival and survival free from valve related complications were 90% +/- 4% and 70% +/- 6% for patients who had valvuloplasty, 76% +/- 3% and 71% +/- 5% for the mechanical prosthetic replacement group and 62% +/- 7% and 30% +/- 7% for bioprosthetic valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)