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.     

Human leukocyte antigen-DR and ABO mismatch are associated with accelerated homograft valve failure in children: implications for therapeutic interventions

OBJECTIVE: This study examines the incidence and factors associated with the failure of homograft valves and identifies those factors that are modifiable. METHODS: From 1990 to 2001, 96 homograft valves were implanted in the right ventricular outflow tract of 83 children (mean age 5.1 +/- 5.6 years). Clinical and blinded serial echocardiographic follow-up was performed on all 90 valves in the 77 survivors. RESULTS: Eighteen homograft valves were replaced as the result of pulmonary insufficiency (3), stenosis (9), or both (6). Freedom from reoperation was 71% at 9 years (95% confidence interval, 58%-84%). Forty-eight valves developed progressive pulmonary insufficiency of at least 2 grades, 26 valves developed transvalvular gradients of 50 mm Hg or greater, and 14 of these valves were also insufficient. The freedom from echocardiographic failure (progressive pulmonary insufficiency >or=2 grades or >or=50 mm Hg gradient) was only 27% at 5 years (95% confidence interval, 17%-37%). In a multivariate analysis (Cox regression), use of an aortic homograft (P =.001) and short antibiotic preservation time (P =.04) were associated with reoperation. Younger age (P =.01), ABO mismatch (P =.04), and diagnosis (P =.005) were associated with echocardiographic failure. In the subanalysis of patients with human leukocyte antigen typing, age (P =.002), aortic homograft (P =.04), and human leukocyte antigen-DR mismatch (P =.03) were associated with echocardiographic valve failure. CONCLUSION: Many homografts rapidly become insufficient and require replacement. In our analysis of both reoperation and echocardiographic failure, several immunologic factors are consistently associated with homograft failure. Matching for human leukocyte antigen-DR, blood group, and avoiding short preservation times (thus minimizing antigenicity) offers the potential to extend the life of these valves.     

Twenty-year comparison of tissue and mechanical valve replacement

OBJECTIVE: We sought to compare outcomes with tissue and St Jude Medical mechanical valves over a 20-year period. METHODS: Valve-related events and overall survival were analyzed in 2533 patients 18 years of age or older undergoing initial aortic, mitral, or combined aortic and mitral (double) valve replacement with a tissue valve (Hancock, Carpentier-Edwards porcine, or Carpentier-Edwards pericardial) or a St Jude Medical mechanical valve. Total follow-up was 13,390 patient-years. There were 666 St Jude Medical aortic valve replacements, 723 tissue aortic valve replacements, 513 St Jude Medical mitral valve replacements, 402 tissue mitral valve replacements, 161 St Jude Medical double valve replacements, and 68 tissue double valve replacements. The mean age was 68 +/- 13.3 years (St Jude Medical valve, 64.5 +/- 12.9; tissue valve, 72.0 +/- 12.6). RESULTS: There were no overall differences in survival between tissue and mechanical valves. Multivariable analysis indicated that the type of valve did not affect survival. Analysis by age less than 65 years or 65 years or older and presence or absence of coronary disease revealed similar long-term survival in all subgroups. The risk of hemorrhage was lower in patients receiving tissue aortic valve replacements but was not significantly different in patients receiving mitral valve or double valve replacements. Thromboembolism rates were similar for tissue and mechanical valve recipients. However, reoperation rates were significantly higher in patients receiving both aortic and mitral tissue valves. The reoperation hazard increased progressively with time both in patients receiving aortic and in those receiving mitral tissue valves. Overall valve complications were initially higher with mechanical aortic valves but not with mechanical mitral valves. However, valve complication rates later crossed over, with higher rates in tissue valve recipients after 7 years in patients undergoing mitral valve replacement and 10 years in those undergoing aortic valve replacement. CONCLUSIONS: Tissue and mechanical valve recipients have similar survival over 20 years of follow-up. The primary tradeoff is an increased risk of hemorrhage in patients receiving mechanical aortic valve replacements and an increased risk of late reoperation in all patients receiving tissue valve replacements. The risk of tissue valve reoperation increases progressively with time.     

Porcine versus pericardial bioprostheses: a comparison of late results in 1,593 patients

From 1976 to 1988, 1,593 patients underwent valve replacement with a porcine (878 patients) or a pericardial bioprosthesis (715 patients). There were 701 aortic, 678 mitral, and 214 multiple-valve replacements. Follow-up was obtained for 1,559 patients (98%). Early mortality was 9% (79 patients) in the porcine valve group and 5% (37 patients) among patients with a pericardial valve (p less than 0.01). Late survival after replacement with porcine valves was 80% +/- 1% and 62% +/- 3% at 5 and 10 years, respectively. With pericardial valves, 5-year survival was 79% +/- 2%. Among valve-related complications, rates of freedom from thromboembolism, endocarditis, and hemorrhage after 6 years were similar for both valve groups. Freedom from reoperation at 6 years was also similar after aortic (96% versus 91%) or multiple-valve replacement (95% versus 88%). However, for mitral valve replacement, freedom from reoperation was significantly better with porcine valves than with pericardial valves at 6 years (92% versus 68%; p less than 0.001). This difference was mainly due to the Ionescu-Shiley valve, which accounted for 83% of primary tissue failures among pericardial bioprostheses implanted in the mitral position (10/12 patients). After 6 years, freedom from primary tissue failure of mitral valves was 92% +/- 2% with porcine and 70% +/- 11% with pericardial bioprostheses (p less than 0.0001). The degree of clinical improvement among survivors was similar with both valve types. Thus, in the aortic position, pericardial valves compare with porcine valves up to 6 years, whereas in the mitral position, the durability of the former is significantly less, mainly because of the suboptimal performance of the Ionescu-Shiley pericardial bioprosthesis.     

Hypercholesterolemia is a risk factor for bioprosthetic valve calcification and explantation

OBJECTIVE: There are pathophysiologic similarities between calcification and atherosclerosis. We wished to determine whether risk factors for atherosclerosis were linked to bioprosthetic valve calcification and dysfunction. METHODS: We performed a retrospective cohort study on 144 patients at a single institution who had bioprosthetic aortic or mitral valves removed, serum cholesterol levels recorded, and valve calcification assessed on the basis of hematoxylin and eosin staining and radiography of the valve. We also performed case-control analysis of a group of 66 patients whose tissue valves were explanted and compared them with an age- and position-matched group of 66 patients with similar duration of implantation. We also compared mean serum cholesterol levels. RESULTS: In the retrospective cohort study cholesterol (P =.035), younger age at implantation (P =.014), and coronary artery disease (P =.017) were linked to calcification of the valve by means of univariate analysis. In stepwise multiple regression analysis only the mean serum cholesterol level was linked to calcification (P =.02). Sex, hypertension, smoking, diabetes, and implant position were not linked to calcification. In the case-control analysis the mean serum cholesterol level of the explanted valve group was significantly higher (189 vs 163 mg/dL, P <.0001) than that of the group whose valves did not require explantation. For those whose serum cholesterol levels were greater than 200 mg/dL, the odds ratio was 3.9 (95% confidence interval, 1.7-8.9) for valve explantation. CONCLUSIONS: Increased serum cholesterol level may be a risk factor for bioprosthetic valve calcification requiring explantation.     

Vascular matrix remodeling in patients with bicuspid aortic valve malformations: implications for aortic dilatation

BACKGROUND: Patients with bicuspid aortic valve malformations are at an increased risk of aortic dilatation, aneurysm formation, and dissection. Vascular tissues with deficient fibrillin-1 microfibrils release matrix metalloproteinases, enzymes that weaken the vessel wall by degrading elastic matrix components. In bicuspid aortic valve disease a deficiency of fibrillin-1 and increased matrix metalloproteinase matrix degradation might result in aortic degeneration and dilatation. METHODS: Samples of the pulmonary artery and aorta were obtained from surgical patients with bicuspid aortic valves (n = 21) and tricuspid aortic valves (n = 16). RESULTS: Fibrillin-1 content was reduced in bicuspid aortic valve aortas compared with that seen in tricuspid aortic valve aortas (P =.001), whereas the associated matrix components, elastin and collagen, were unchanged (P =.51 and P =.21). Reductions of aortic fibrillin-1 content were independent of valve function and patient age. Compared with tricuspid aortic valve aorta, matrix metalloproteinase 2 activity was increased more than 2-fold in bicuspid aortic valve aortas (P =.04) and correlated positively with aortic diameter (r = 0.74, P =.05). Matrix metalloproteinase 9 activity was not significantly different. Fibrillin-1 content was also reduced in the pulmonary arteries of patients with bicuspid aortic valves (P =.06), suggesting a systemic deficiency of fibrillin-1. Promatrix metalloproteinase 2 was increased (P =.04), reflecting an increased production of matrix metalloproteinase 2 in these fibrillin-1-deficient tissues, whereas active matrix metalloproteinase 2 and matrix metalloproteinase 9 species were unchanged, and correspondingly, the pulmonary arteries were not dilated. CONCLUSIONS: Deficient fibrillin-1 content in the vasculature of patients with bicuspid aortic valves might trigger matrix metalloproteinase production, leading to matrix disruption and dilatation. This process of vascular matrix remodeling in patients with bicuspid aortic valves offers novel therapeutic targets to prevent the aortic degeneration and dilatation characteristic of this disease.     

Early mechanical failures of the Hancock pericardial xenograft

From August 1981 to July 1984, a total of 97 Hancock pericardial xenografts were implanted in 84 patients, whose ages ranged from 13 to 75 years (mean 55.7 +/- 13). Mitral value replacement was performed in 17, aortic valve replacement in 54, and mitral-aortic valve replacement in 13. Operative survivors were reevaluated from July to September 1985. Cumulative duration of follow-up is 167 patient-years (range 0.5 to 4.1 years), and follow-up is 99% complete. The overall late mortality (at 4 years) is 3.6% +/- 1.4% per patient year, and the actuarial survival rate is 95.4% +/- 3% for aortic valve replacement, 74.7% +/- 16.5% for mitral valve replacement, and 67.1% +/- 20.7% for mitral-aortic valve replacement. One patient sustained a thromboembolic event after mitral valve replacement, but no such complications occurred after aortic or mitral-aortic valve replacement. Actuarial freedom from embolism at 4 years is 100% for aortic and mitral-aortic valve replacement and 93.3% +/- 6.4% for mitral valve replacement. Reoperation for Hancock pericardial xenograft dysfunction was performed in seven patients (five aortic and two mitral-aortic). In the aortic valve replacement group the causes were endocarditis in one, paravalvular leak in one, and primary tissue failure in three; all survived reoperation. The two patients with mitral-aortic valve replacement required reoperation because of primary tissue failure of both Hancock pericardial xenografts, and one died. All values explanted because of primary tissue failure showed commissural tears causing severe prosthetic regurgitation. Calcium deposits were severe in one and mild but unrelated to the cusp rupture in another. Collagen disarray was seen only at the site of the tears, whereas the collagen structure was well preserved in the intact parts of the cusps. Four patients with aortic valve replacement and one with mitral valve replacement show evidence of Hancock pericardial xenograft failure and are awaiting reoperation. The actuarial freedom from primary tissue failure at 4 years is 74.3% +/- 9.8% for aortic and 78.9% +/- 13.2% for mitral Hancock pericardial xenografts. At medium-term follow-up, the Hancock pericardial xenograft has shown poor durability and an extremely high rate of early mechanical failure, especially in the aortic position. These observations suggest the need for a close follow-up of Hancock pericardial xenograft recipients and possibly elective reoperation in asymptomatic patients with clinical evidence of prosthetic failure. These results have led us to discontinue the clinical use of this pericardial xenograft.     

Ten-year echocardiographic and clinical follow-up of aortic Carpentier-Edwards pericardial and supraannular prosthesis: a case-match study

BACKGROUND: There are little comparative data on Carpentier-Edwards supraannular and pericardial second-generation bioprostheses. The aim of this work was to compare their hemodynamic and clinical outcomes in patients with aortic stenosis. METHODS: We conducted a retrospective study including 150 patients operated on for aortic stenosis between 1989 and 1993. Patients undergoing aortic valve replacement with either a Carpentier-Edwards supraannular or pericardial prosthesis were matched for sex (49% male), age (72 +/- 8 years), body surface area, valve size, associated procedures, and left ventricular ejection fraction. RESULTS: Mean follow-up was 6.5 +/- 3.3 years, giving a total follow-up of 983 patient-years. Thirty-day mortality and 10-year actuarial survival were, respectively, 8% and 51% in the supraannular group and 6.7% and 43.4% in the pericardial group. At 10 years, freedom from thromboembolism, structural failure, and all valve-related events were, respectively, 88.7%, 88.9%, and 68.7% in the supraannular group and 85%, 100%, and 82.2% in the pericardial group. There were four (5.3%) structural failures, and four (5.3%) reoperations for degeneration (n = 3) and endocarditis (n = 1) in the supraannular group. Freedom from structural dysfunction or reoperation was 87.3% in the supraannular group and 100% (p < 0.05) in the pericardial group. Echocardiographic review of 62 of 76 survivors (81.5%) demonstrated a trend toward a better hemodynamic profile of pericardial valves at the end of follow-up. CONCLUSIONS: Ten years after aortic valve replacement for aortic stenosis, Carpentier-Edwards pericardial prostheses give comparable and probably better results than Carpentier-Edwards supraannular prostheses.     

Impact of small prosthetic valve size on operative mortality in elderly patients after aortic valve replacement for aortic stenosis: does gender matter?

OBJECTIVE: Ideal management of the elderly patient with a small aortic root remains controversial. This retrospective analysis was performed to determine whether small prosthetic valve size is related to outcome in patients 70 years of age or older undergoing aortic valve replacement for aortic stenosis. METHODS: Between December 1991 and July 1998, 366 patients 70 years of age or older (median age 77 years, range 73-81 years, 49% male) underwent isolated aortic valve replacement or aortic valve replacement with coronary bypass grafting with standard Carpentier-Edwards bovine pericardial valves (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) (n = 277; 76%) or St Jude Medical mechanical valves (St Jude Medical, Inc, St Paul, Minn) (n = 89; 24%). Propensity scoring and multivariable regression models were used to evaluate the risks associated with implantation of 19-mm valves. RESULTS: Operative mortality was 16.7% (17/102) in patients who received 19-mm valves and 3% (8/264) among those receiving >/=21-mm valves (P /=21-mm valves was 6.4 (95% CI 2.7, 15.4; P 相似文献   

A morphologic study of Carpentier-Edwards pericardial xenografts in the mitral position exhibiting primary tissue failure in adults in comparison with Ionescu-Shiley pericardial xenografts

OBJECTIVE: We sought to investigate the durability and mechanism of the Carpentier-Edwards pericardial xenograft in the mitral position in comparison with that of the Ionescu-Shiley pericardial xenograft. METHODS: A total of 284 patients who received the Ionescu-Shiley pericardial xenograft in the mitral position between 1980 and 1984 and 84 patients who received the Carpentier-Edwards pericardial xenograft in the mitral position between 1984 and 1999 were included in the study. The freedom from reoperation rates for both graft types were determined. For morphologic study, the pathologic findings of 23 valves of 123 explanted Ionescu-Shiley pericardial xenografts with structural valve deterioration, nonstructural valve deterioration, or both were determined and compared with those of 20 explanted Carpentier-Edwards pericardial xenografts with structural valve deterioration, nonstructural valve deterioration, or both. Each pathologic finding was graded and assigned a score. Both types were matched for age at reoperation (50-75 years) and duration of valve function (8-11 years). RESULTS: Freedom from reoperation caused by structural valve deterioration, nonstructural valve deterioration, or both was significantly better for Carpentier-Edwards pericardial xenografts than for Ionescu-Shiley pericardial xenografts at 8 years after the operation (Carpentier-Edwards pericardial xenografts: 91.3% vs Ionescu-Shiley pericardial xenografts: 71.9%, P =.0061), but it was similar for both types at 12 years (Carpentier-Edwards pericardial xenografts: 43.6% vs Ionescu-Shiley pericardial xenografts: 43.6%, P =.2865). No severe leaflet tears were seen among Carpentier-Edwards pericardial xenografts. The mean area percentage of tissue overgrowth was 15.3% in Carpentier-Edwards pericardial xenografts and 3.4% in Ionescu-Shiley pericardial xenografts (P =.0001). The mean calcification area percentage was 13.6% in Carpentier-Edwards pericardial xenografts and 31.5% in Ionescu-Shiley pericardial xenografts (P =.0001). CONCLUSIONS: Tissue overgrowth on the atrial surface, ventricular surface, or both was the cause of structural valve deterioration, nonstructural valve deterioration, or both of Carpentier-Edwards pericardial xenografts in adults. This was different from Ionescu-Shiley pericardial xenograft failure, which resulted from severe calcification and leaflet tears. Organized thrombi on cusps, in addition to valve design, may have contributed to such tissue overgrowth on Carpentier-Edwards pericardial xenografts.     

Mitral valve repair and replacement for rheumatic disease

OBJECTIVES: Mitral valve repair may be technically feasible in patients with suitable anatomy, but the appropriateness of repair for rheumatic disease remains controversial. We evaluated our late outcomes after mitral repair and replacement for rheumatic disease. METHODS: Five hundred seventy-three patients underwent mitral valve surgery for rheumatic disease at our institution from 1978-1995. Follow-up was 98% complete (mean, 68 +/- 46 months). Survival and morbidity were evaluated by Kaplan-Meier analysis and Cox regression, including propensity score analysis. RESULTS: Mean age was 54 +/- 14 years, 55% of patients had congestive heart failure, 22% were undergoing redo mitral valve surgery, and 9% also underwent coronary bypass. Mitral stenosis was present in 53%, regurgitation in 15%, and both in 32%. Valve repair was performed in 25%, bioprosthetic replacement was performed in 28%, and a mechanical valve was placed in 47%. Patients undergoing repair were younger and less likely to be undergoing reoperation or to have atrial fibrillation than those undergoing replacement (P =.001). The operative mortality rate was 4. 2%. Better late cardiac survival was independently predicted by valve repair rather than replacement (P =.04) after adjustment for baseline differences between patients. Freedom from reoperation was greatest (P =.005) but that from thromboembolic complications was worst (P <.0001) after mechanical valve replacement. Twenty-three patients underwent reoperation after initial repair, with no operative deaths. CONCLUSIONS: Mechanical valves minimize reoperation but limit survival and increase thromboembolic complications. Patients undergoing valve repair had improved late cardiac survival independent of their preoperative characteristics. Rheumatic mitral valves should be repaired when technically feasible, accepting a risk of reoperation, to maximize survival and reduce morbidity.     

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)     

Midterm results of aortic valve repair with the pericardial cusp extension technique in rheumatic valve disease

BACKGROUND: The encouraging results of valve repair in the atrioventricular valves have influenced a decision about aortic valve (AV) reconstruction. We report our experience with pericardial cusp extension to repair rheumatic AV disease. METHODS: From 1993 to 1998, 46 patients (25 women, 21 men) with a mean age of 31.5 +/- 12.2 years (range, 15 to 58 years) underwent AV repair. Twenty-two (47.8%) patients had moderate and 24 (52.2%) had severe aortic insufficiency (AI). Severe cusp retraction was repaired with glutaraldehyde-treated autologous pericardium. Twenty-one patients had more than one maneuver (mean, 1.8) to attain competence besides augmentation, which consisted of the release of stenotic commissures (in 11 cases), thinning of the AV cusps (in 10 cases), and resuspension of the cusps (in 17 cases). Simultaneous mitral valve repair was performed on 17 patients. Eight patients received triple valve reconstruction. RESULTS: There was no early mortality. Thirty patients no longer had AI with any significant transvalvular gradients. Five patients were followed with mild residual AI, and 2 patients with moderate AI not requiring reoperation. Nine patients developing severe AI required AV replacement with a reoperation rate 19.6% (4.26%/patient-year). The mean interval between repair and reoperation was 28.2 +/- 18.3 months (range, 3 to 58 months). The mean observation time was 4.6 +/- 3 years (211.6 patient-years). Late mortality rate was 2.2% with 1 patient. The significant negative predictors of aortic reoperation determined by univariate analysis were preoperative New York Heart Association class (p = 0.002) and postoperative severe AI (p < 0.001). Cox hazard studies identified that all risk factors were insignificant for aortic reoperation. The actuarial rate of freedom from aortic reoperation was 76.1% +/- 7% at 7.5 years. CONCLUSIONS: Although AV repair by extension with pericardium is worth considering with an acceptable solution to achieve a good geometry from unequal cusps, especially in young rheumatic patients for preservation of the native AV, the patients should be followed periodically for reoperation risk.     

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).     

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.     

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.     

Bicuspid aortic valve disease and pulmonary autograft root dilatation after the Ross procedure: a clinicopathologic study.

OBJECTIVE: Bicuspid aortic valve disease has been associated with histologic abnormalities of the aortic root. Recent reports have suggested similar alterations may exist in the pulmonary artery of patients with bicuspid aortic valve. The present study was undertaken to define the histologic condition of the aortic and pulmonary artery root in bicuspid aortic valve disease and the relationship with pulmonary autograft root dilatation after the Ross procedure. METHODS: In 17 patients undergoing aortic root replacement with the pulmonary autograft, biopsy specimens of the aortic root and pulmonary artery trunk were collected. Clinical and histologic findings of patients with bicuspid aortic valves were compared with those with tricuspid aortic valves. RESULTS: There were 9 patients (8 male, 1 female) with bicuspid aortic valve (group 1) and 8 (all male) with tricuspid aortic valve (group 2). Mean age was comparable (24.4 +/- 9.8 vs 23.6 +/- 10.8 years, P =.9). Aortic insufficiency as an indication for operation was more common in group 1 (9/9 vs 5/8, P =.007), whereas preoperative aortic root dilatation was equally prevalent (4/9 vs 1/8, P =.1). Prior aortic valve repair had been performed in 2 patients (1/9 vs 1/8, P =.9). Prevalence of cystic medionecrosis of the aortic wall was similar in the 2 groups (4/9 vs 3/8, P =.6). Cystic medionecrosis of the pulmonary artery trunk was found only in 1 patient with tricuspid aortic valve (0/9 vs 1/8, P =.3). During a mean follow-up of 26.5 +/- 12.2 months (32.1 +/- 12.7 vs 20.1 +/- 7.4 months, P =.04), prevalence of pulmonary autograft root dilatation (greater than 4.0 cm) was equally represented in patients with native bicuspid or tricuspid aortic valve (3/9 vs 2/8, P =.6). CONCLUSIONS: Histologic abnormalities of the pulmonary artery root are rare and equally prevalent in young patients with bicuspid and tricuspid aortic valves. On the contrary, root dilatation is relatively common late after autograft root replacement but appears unrelated to bicuspid aortic valve disease or to pre-existing degenerative changes of the pulmonary artery root.     

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.     

Aortic valve replacement with pericardial valves in patients with small aortic roots. Clinical results in a consecutive series of patients receiving 19 and 21 mm prostheses

OBJECTIVE: To determine how second generation pericardial valves perform in patients with small aortic roots. DESIGN: Ninety patients who underwent isolated aortic valve replacement (AVR) with 19 or 21 mm Mitroflow or Carpentier-Edwards (Perimount) valves between 1989 and 1996 were studied. Mean age was 78 years. Concomitant coronary bypass surgery was performed in 41%. RESULTS: Thirty-day mortality was 5.6%. Ninety-seven percent had acceptable transprosthetic mean pressure gradients (25 mmHg or less) 1 week after surgery. Follow-up was 100% complete and 76% of the patients were alive after a mean of 5 years. There was no structural valve failure or valve thrombosis. One patient required reoperation for perivalvular leak. Four patients had transient ischemic attacks and seven had strokes. These figures are, however, within the expected range for the age. CONCLUSION: Second generation pericardial valves perform well in elderly patients with small aortic roots. Postoperative hemodynamics are acceptable, valve durability of up to 8 years adequate, and the clinical results good, considering the age of the patients.     

Acute type A aortic dissection complicated by aortic regurgitation: composite valve graft versus separate valve graft versus conservative valve repair

OBJECTIVE: To clarify the merits of various surgical approaches, we studied the outcome after composite valve graft versus separate valve and graft replacement versus conservative valve treatment with replacement of the ascending aorta in patients with acute type A aortic dissection complicated by aortic regurgitation. METHODS: Between 1967 and 1999, 123 patients (mean age 56 +/- 15 years) underwent composite valve graft replacement (n = 21), separate valve and graft replacement (n = 20), or conservative valve treatment (n = 82 [commissural resuspension in 46]); follow-up averaged 6.5 years (95% complete). RESULTS: The 30-day, 1-year, and 6-year survival estimates of 85% +/- 4%, 79% +/- 5%, and 69% +/- 5% (+/-1 standard error of mean), respectively, after conservative valve treatment were similar to 86% +/- 8%, 81% +/- 9%, and 65% +/- 16%, respectively, with composite valve graft replacement and better (but insignificantly so) than 70% +/- 10%, 70% +/- 10%, and 45% +/- 11%, respectively, with separate valve and graft replacement. The 6-year freedom from proximal reoperation was 95% +/- 3%, 89% +/- 10%, and 100% in conservative valve graft, separate valve and graft, and composite valve graft subgroups, respectively (P = not significant). Cox regression multivariable analysis identified that previous sternotomy (hazard ratio [or e(beta)] 95% confidence interval 1.4-10.9, P =.006), hypertension (0.99-2.9, P =.05), cardiac tamponade (1.1-4.0, P =.03), and stroke (1.7-7.0, P =.001) increased the hazard of death. No factors predicting a higher likelihood of late proximal reoperation were identified. CONCLUSIONS: In patients with acute type A aortic dissection and aortic regurgitation, there was no significant difference in overall survival or reoperation rates among these surgical approaches. We try to save the valve whenever possible unless the aortic root is pathologically dilated (eg, Marfan syndrome or annuloaortic ectasia) or destroyed by the dissection process, when composite valve graft or valve-sparing aortic root replacement is indicated.