| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 1996;62:1301-1311
© 1996 The Society of Thoracic Surgeons
Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California
 |
Abstract |
|---|
 TopFootnotes Abstract IntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
Methods. We retrospectively analyzed 2,879 patients who underwent aortic (AVR; n = 1,594) or mitral (MVR; n = 1,285) valve replacement between 1971 and 1990. Follow-up was 97% complete and extended to 20 years (total, 17,976 patient-years). Patient age ranged from 16 to 94 years; mean age in patients who underwent AVR was 60 ± 15 (± standard deviation) years; that for patients who underwent MVR was 58 ± 13 years.
Results. The operative mortality rates were 7% ± 1% (70% confidence limits) for AVR and 10% ± 1% for MVR. Actuarial estimates of freedom from structural valve deterioration at 10 and 15 years were 78% ± 2% (SE) and 49% ± 4%, respectively, for the AVR subgroup; and 69% ± 2% and 32% ± 4%, respectively, for the MVR subgroup (AVR > MVR; p< 0.05). Estimates of freedom from reoperation at 10 and 15 years were 76% ± 2% and 53% ± 4%, respectively, for the AVR subgroup and 70% ± 2% and 33% ± 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from thromboembolism at 10 and 15 years were 92% ± 1% and 87% ± 2%, respectively, for the AVR subgroup and 86% ± 1% and 77% ± 3%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from anticoagulant-related hemorrhage at 10 and 15 years were both 96% ± 1% for the AVR subgroup and 93% ± 1% and 90% ± 2%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from valve-related mortality at 10 and 15 years were 86% ± 1% and 78% ± 3%, respectively, for the AVR subgroup and 84% ± 2% and 70% ± 4%, respectively, for the MVR subgroup (p = not significant). Multivariate analysis (Cox model) showed younger age, later year of operation, and valve site (MVR > AVR) to be significant risk factors for structural valve deterioration. Younger age, later year of operation, valve site (MVR > AVR), and renal insufficiency were the significant, independent risk factors for reoperation. Multivariate analysis revealed that higher New York Heart Association functional class, longer cardiopulmonary bypass time, congestive heart failure, renal insufficiency, and longer cross-clamp time were significant risk factors for valve-related mortality. Valve manufacturer did not emerge as a factor in any analysis.
Conclusions. These long-term results with porcine bioprostheses were satisfactory, particularly in older patients and those undergoing AVR. As expected, younger age was a significant risk factor for structural valve deterioration and reoperation in both groups. Surprisingly, the durability of porcine bioprosthetic valves has not improved over time, which possibly can be attributed to more enhanced postoperative surveillance and earlier reintervention. These first-generation Hancock and Carpentier-Edwards porcine bioprostheses achieved similar long-term performance.
|
Introduction |
|---|
|
TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
For the past 25 years, porcine bioprostheses have been the most widely implanted tissue valve substitute, becoming the standard for comparison with newer types of bioprostheses [1–8]. Although mechanical valves have greater durability and are associated with lower reoperation rates, a large fraction of patients with bioprostheses do not require indefinite anticoagulation and consequently have fewer anticoagulant-related hemorrhagic complications. The main disadvantage of tissue valves, however, is their limited long-term durability as the result of fibrocalcification and fatigue-related leaflet disruption. Nonetheless, the performance of porcine bioprostheses is perceived to have improved over the years, a finding that has been attributed to better patient selection, particularly with regard to age, and to valve design [8].
Standardizing the guidelines for reporting valve-related complications has resulted in more comprehensive assessments of the long-term performance of any given prosthesis; additionally, it has permitted more meaningful comparisons of different prostheses implanted in different institutions [1–11]. In reviewing the available long-term data, Grunkemeier and Bodnar [8] found varying results in terms of valve durability, which may be the consequence of factors other than the bioprosthetic valve per se. Clearly, valve durability depends on many factors, including the age of the patient population, the completeness of follow-up, and the size of the patient sample [8]. The clinical experience reported in recent series has provided valuable information with regard to structural durability and valve-related complications of biologic and mechanical valve substitutes [1–7, 9–13]. With the distillation of these data, physicians can now counsel individual patients regarding the merits and potential hazards of different types of valves. In this study, we retrospectively evaluated the performance of two first-generation porcine bioprostheses in the aortic or mitral positions in patients who received them over a 20-year period at Stanford University Medical Center.
|
Material and Methods |
|---|
|
TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
.
|
Oral anticoagulant therapy was started postoperatively and administered for 6 weeks in patients with AVR and 3 months in patients with MVR, unless there was a contraindication to it. Anticoagulant therapy was continued indefinitely in selected patients considered at high risk for thromboembolic events, including those with left atrial thrombus noted intraoperatively, chronic atrial fibrillation (with or without previous or subsequent thromboembolic events), and postoperative paroxysmal atrial fibrillation.
Operative mortality included any death that occurred within 30 days after the operation or before hospital discharge. Valve-related events were categorized in accordance with the guidelines for reporting morbidity and mortality devised by the American Association of Thoracic Surgery and The Society of Thoracic Surgeons ad hoc committee and included structural valve deterioration (SVD), nonstructural valve dysfunction, reoperation, thromboembolism (TE), anticoagulant-related hemorrhage (ACH), prosthetic valve endocarditis, valve-related mortality (VRM) (including sudden, unexplained deaths), and all valve-related morbidity and mortality (VRM&M) [9]. Structural valve deterioration is defined as any intrinsic degenerative change causing valvular stenosis or regurgitation, excluding bioprosthetic valve failure, caused by infection, thrombosis, or perivalvular leaks. Nonstructural valve dysfunction included valvular dysfunction, such as perivalvular leak, inappropriate sizing, or clinically significant hemolytic anemia. Reoperation was defined as any subsequent procedure to repair or replace a previously placed prosthesis.
Continuous data are expressed as the mean ± 1 standard deviation and clinically important ratios as mean ± 70% confidence limits. The actuarial life-table estimates for valve-related events were calculated using the Cutler-Ederer method [14]. Actuarial estimates are presented as time-related survival or event-free rates from valve-related complications, and the variability is indicated by ± 1 standard error of the mean (SPSS, Chicago, IL). Multivariate (Cox model) proportional hazard regression analysis was used to determine the preoperative risk factors that were significant, independent predictors of valve-related complications. The factors examined included age, sex, year of operation, valve site, (AVR versus MVR), valve size, valve manufacturer (Hancock or Carpenter-Edwards), emergency operation, angina, New York Heart Association (NYHA) functional class, congestive heart failure, renal insufficiency, pulmonary disease, hepatic disease, diabetes mellitus, hyperlipidemia, hypertension, cross-clamp time, and cardiopulmonary bypass time. A two-tailed p value of less than 0.05 was considered statistically significant.
|
Results |
|---|
|
TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
. Long-term survival estimates at 5, 10, and 15 years were 77% ± 1%, 54% ± 2%, and 32% ± 3%, respectively, for the AVR subgroup; the respective rates for the MVR subgroup were 70% ± 1%, 50% ± 2%, and 32% ± 3% (Fig 1). The actuarial survival estimates subdivided according to arbitrarily defined age groups are illustrated in Figure 2.
|
|
|
|
.
|
).
|
and Figure 4 and those categorized according to operative year intervals are shown in Table 6 and Figure 5.
|
|
|
|
Reoperation
A total of 254 patients in the AVR subgroup and 272 patients in the MVR subgroup underwent reoperation for any form of valve-related complications. The operative mortality rates for reoperation were 14% ± 2% for the AVR subgroup and 13% ± 2% for the MVR subgroup. Estimates of freedom from reoperation at 5, 10, and 15 years for the AVR subgroup were 96% ± 1%, 76% ± 2%, and 53% ± 4%, respectively; the respective estimates for the MVR subgroup were 96% ± 1%, 70% ± 2%, and 33% ± 4% (p < 0.05 versus AVR subgroup at 10 and 15 years) (Fig 6).
|
and Figure 7.
|
|
). For all patients, multivariate analysis demonstrated older age and valve site (MVR) to be significant, independent risk factors for TE.
|
). For all patients, multivariate analysis revealed older age and valve site (MVR) to be the significant, independent predictors of a higher probability of ACH.
|
All Valve-Related Mortality
A total of 292 patients (149 in the AVR subgroup and 143 in the MVR subgroup) suffered VRM. Estimates of freedom from VRM (including sudden, unexplained deaths) at 5, 10, and 15 years in the AVR subgroup were 94% ± 1%, 86% ± 1%, and 78% ± 3%, respectively; these respective estimates in the MVR subgroup were 93% ± 1%, 84% ± 2%, and 70% ± 4% (p = not significant versus the AVR subgroup). For all patients, multivariate analysis showed higher NYHA functional class, longer cardiopulmonary bypass time, congestive heart failure, renal insufficiency, and longer cross-clamp time to be significant, independent predictors of VRM.
All Valve-Related Morbidity and Mortality
A total of 1,008 patients (493 in the AVR subgroup and 515 in the MVR subgroup) constituted this composite category, which included all morbid and fatal events that were clearly or possibly valve related. Estimates of freedom from all VRM&M in the AVR subgroup at 5, 10, and 15 years were 84% ± 1%, 59% ± 2%, and 31% ± 3%, respectively; these respective figures in the MVR subgroup were 80% ± 1%, 48% ± 2%, and 18% ± 2% (p = not significant versus the AVR subgroup). For all patients, multivariate analysis revealed that younger age, larger valve size, no history of angina, congestive heart failure, renal insufficiency, and hypertension were the significant, independent risk factors for all VRM&M.
|
Comment |
|---|
|
TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
At Stanford University the use of bioprostheses has decreased in the past decade, and the use of mechanical valve substitutes has progressively increased, from less than 2% in 1983 to approximately 30% in 1991 in both the aortic and mitral positions. Over the past 5 years, the use of mechanical valves has increased, so that they constituted half of all valves implanted in 1995; this is due in part to the fact that more patients with Marfan syndrome have undergone composite valve grafting since 1991. A similar trend is evident for patients undergoing MVR, with mechanical valve replacement constituting less than a third of all valve procedures performed in the early part of this decade but constituting approximately half of all valve procedures performed in 1995 (a bioprosthesis was used in a quarter of patients, and the remaining 25% underwent mitral valve repair).
In general, the operative mortality rates for patients undergoing valve replacement has been acceptable. In this study, the early mortality rates were 7% ± 1% for the AVR subgroup and 10% ± 1% for the MVR subgroup. These rates compare with the rates cited for other series, in which the overall operative mortality rates were 4% to 12% for patients undergoing AVR and 5% to 9% for patients undergoing MVR [1, 4, 5, 7, 13, 16]. In a relatively lower risk subset, such as those undergoing isolated first-time operations, the hospital mortality rates were 6% ± 1% for AVR and 8% ± 1% for MVR; others have also shown lower rates for isolated valve replacement in the range of 1.9% to 3.4% for AVR and 4.1% to 6% for MVR [4, 16]. Jones and associates [16] reported an operative mortality rate of 8% for patients undergoing AVR with CABG (versus 3.4% for AVR alone); the early mortality rate was 14% for those undergoing combined MVR and CABG. In our experience, the operative mortality rate for patients undergoing AVR with CABG has been similar at 8% ± 1%; however, MVR with CABG was associated with a higher operative mortality rate of 19% ± 2% in this series, which goes back to 1971. Not surprisingly, age at time of operation influenced operative survival [12, 16, 17]. We found that in patients 61 to 70 years of age, the operative mortality rates were 8% ± 1% for those undergoing AVR and 12% ± 1% for those undergoing MVR; older patients (those greater than 70 years of age) had higher operative mortality rates of 11% ± 2% for AVR and 20% ± 3% for MVR. Pupello and colleagues [17] reported operative mortality rates of 8% for AVR and 14% for MVR in patients 70 years of age and older.
The leading cause of bioprosthetic valve dysfunction is SVD, the incidence of which begins to increase 5 to 6 years after implantation [1, 2, 4–7]. In this series, the respective estimates of freedom from SVD at 10 and 15 years were 78% ± 2% and 49% ± 4% for AVR patients and 69% ± 2% and 32% ± 4% for MVR patients; the event-free estimates were higher for the AVR subgroup, a finding previously reported [1, 2, 4, 5]. Others have reported similar estimates at 10 years of 76% to 91% for AVR and 63% to 78% for MVR; at 14 to 15 years, the event-free estimates have been reported to be 37% to 58% for AVR and 21% to 45% for MVR [1, 2, 4–7, 13]. Although SVD is of particular concern in patients with bioprostheses, this rising incidence over time should be favorably offset by the limited survival of older patients, leading to the premise that the durability of the valve may be sufficient for most elderly patients. For a combined series of AVR and MVR subgroups at various age intervals, Burr and associates [18] reported 10- and 15-year survival rates of 53% and 25%, respectively, for patients who are 65 to 69 years old; 38% and 13% for those 70 to 74 years of age; and 30% and 9% for those 75 to 79 years of age. Similarly, we found that the 10- and 15-year survival rates for patients 61 to 70 years of age who underwent AVR were 50% ± 3% and 28% ± 5%, respectively; for patients more than 70 years of age, the respective rates were 34% ± 3% and 11% ± 4%. In the MVR subgroup, the 10- and 15-year survival rates were 41% ± 3% and 21% ± 4% for patients 61 to 70 years of age; in those over 70 years of age, the estimated survival rates were lower at 26% ± 4% and 12% ± 5%, respectively. Additionally, on the basis of the decreased long-term survival of certain subsets (eg, patients with coronary artery disease), Jones and colleagues [16] suggested that bioprostheses are preferable to mechanical prostheses in two groups of patients: those greater than 60 years of age who are undergoing MVR and CABG and those older than 70 years of age without coronary artery disease. They reasoned that a mechanical prosthesis may be more appropriate in patients younger than 70 years of age without coronary artery disease because of the excellent long-term survival after isolated valve replacement [16].
Because younger age at operation was found to be a predictor of SVD for both the AVR and MVR subsets in this and other reports [1, 4–6, 19–21], the estimates of freedom from SVD were examined with attention paid to selected age groups. As shown in Figure 4
, event-free estimates at 5 years were comparable in all age groups, ranging from 95% to 100%; however, freedom from SVD at 10 and 15 years for the AVR and MVR subgroups combined was superior in the older patients and higher for AVR than for MVR: For patients between 16 and 30 years of age, the respective event-free estimates were 50% ± 8% and 29% ± 10% for AVR and 63% ± 11% and 17% ± 14% for MVR. Others have also reported lower figures for younger patients; for those under 40 to 44 years of age, the estimates of freedom from SVD at 10 years have ranged from 58% to 70% for AVR and 48% to 68% for MVR [5, 7, 21]. In contrast, the respective event-free estimates at 10 and 15 years for patients older than 70 years of age were 91% ± 3% and 89% ± 3% for AVR and 77% ± 7% and 34% ± 20% for MVR, which were similar to those in the 61- to 70-year group in our study. For this older patient population, others have shown event-free estimates at 10 years of between 94% to 100% for AVR and 84% to 100% for MVR [2, 5, 7, 17, 18]. Interestingly, in older patients, particularly those undergoing AVR, there appeared to be no abrupt change in the incidence of SVD at the end of 10 years, and this seemed to plateau at 15 years after implantation.
One important issue that should also be considered is that the actuarial analysis used to assess valve prosthesis performance in this study is limited, in that it was originally devised to describe freedom from death and not nonfatal complications [22]. Grunkemeier and associates [22] pointed to the problems of this method because the risk described for nonfatal events (eg, valve failure) is that which a patient would experience provided he or she were immortal. A more accurate estimate of actual failure is the percentage of patients whose valve will actually fail or who will suffer an event before they die. The difference between the actual and actuarial estimates increases with the patient's age, because older patients have a lower risk of tissue failure and a higher risk of death than younger patients. Because of the high incidence of bioprosthetic valve failure, a mechanical prosthesis is well suited for younger patients, unless there exists a specific contraindication to its use. In contrast, the longer durability of the bioprosthesis and the shorter patient life expectancy favor the use of a bioprosthetic valve in patients older than 70 years.
Consistent with previous findings [1, 4, 5, 23, 24], the overall performance of porcine bioprostheses in the aortic position has been better than that in the mitral position in the patients in our series. This is evident in all age groups, except for the very old (>70 years of age) and the very young (<40 years of age) [5]. Akins and colleagues [4] demonstrated in patients receiving Carpentier-Edwards bioprosthetic valves that estimates of freedom from SVD, reoperation, ACH, VRM, and VRM&M were better for patients with valves in the aortic position. Similarly, in the present analysis, estimates of freedom from SVD, reoperation, and ACH were statistically better for the AVR subgroup, but long-term results with respect to VRM and VRM&M were comparable for the AVR and MVR subgroups. The reason for the MVR subgroup being at higher risk for valve deterioration than the AVR subgroup is unknown, but it may be the result of differences in valve sizes or transvalvular hemodynamics [6, 23–25]. Valve size, however, did not emerge as a risk factor for SVD or reoperation in our analysis, although larger size was a risk factor for VRM&M.
The method of fabrication of the first-generation porcine prostheses has not changed tremendously since their introduction. One can argue that improved quality control over the years and more refined patient selection criteria (especially with regard to age) should have contributed to higher estimates of freedom from SVD [8]. We found the opposite: Later year of operation was a risk factor for SVD and reoperation in both the AVR and MVR subgroups. When assessed on the basis of arbitrary time intervals, there was a worse trend in terms of the incidence of SVD and reoperation for the 1981-to-1985 interval (see Fig 5). The extent of follow-up for the most recent period (1986 to 1990) is still insufficient at this time to provide any useful information. Also, the mean age of patients in the more recent time interval did not differ from that of patients in earlier time periods; thus, this finding cannot be attributed to differences in age. Although the cause is not evident, it is possible that the higher incidence of SVD may be due to enhanced patient surveillance and earlier detection of SVD (eg, using transesophageal echocardiography), with resultant earlier reintervention before cardiac decompensation has occurred.
With regard to reoperation, the operative mortality rates were slightly higher at 14% ± 2% for the AVR subgroup and 13% ± 2% for the MVR subgroup than they were for the initial procedure. Others have reported similar early mortality rates for reoperation of 10% to 11% for AVR and 8% to 15% for MVR [1, 2, 6, 26]. In an analysis conducted by Piehler and colleagues [27], risk factors for operative death after reoperation included older age, lower weight, higher number of previous heart operations, higher NYHA functional class, poorer hemodynamic status, tricuspid incompetence, prosthetic valve infection, renal failure, and numerous surgical variables (eg, aortic and mitral valve replacement, concomitant aortic graft technique, CABG, left ventricular aneurysmectomy, and reoperation before 1970). The urgency of the reintervention has also been shown to be a risk factor for operative death [6]. The risk of reoperation is influenced by the higher risk associated with certain subsets, such as patients with prosthetic valve endocarditis, which in this series was associated with a reoperative mortality rate of 30% ± 7% for AVR and 25% ± 10% for MVR. Estimates of freedom from reoperation at 10 and 15 years were 76% ± 2% and 53% ± 4% for AVR, respectively; for MVR, these rates were 70% ± 2% and 33% ± 4%. Similarly, the estimates of freedom from reoperation at 10 and 15 years for AVR in other series have ranged from 74% to 91% and 55% to 57%, respectively; for MVR the respective estimates at 10 and 15 years have ranged from 57% to 79% and 20% to 41% [4, 5, 7, 23, 28, 29]. In general, actuarial and hazard function curves for reoperation have paralleled those for SVD, since the latter is the most common indication for reoperation (up to 81%), with perivalvular leak and infection accounting for smaller fractions [1, 21, 23].
Similar to SVD, younger age emerged as a significant predictor of reoperation for patients in the AVR and MVR groups in both this and other series [1, 5, 21, 23]. Based on age at time of operation, the respective estimates of freedom from reoperation at 10 and 15 years for patients greater than 70 years of age were 93% ± 2% and 93% ± 2% for the AVR group; these event-free estimates were 84% ± 6% and 47% ± 25% for the MVR subgroup. The respective estimates at 10 and 15 years for patients between 61 and 70 years of age were 89% ± 2% and 74% ± 5% for the AVR subgroup and 76% ± 4% and 57% ± 7% for the MVR subgroup at the same time periods. At the other end of the spectrum, the respective event-free estimates at 10 and 15 years for patients less than 30 years of age were 44% ± 8% and 26% ± 9% for the AVR subgroup and 58% ± 10% and 14% ± 11% for the MVR subgroup. Jones and colleagues [5] found that the estimates of freedom from reoperation at 9 to 10 years for patients 70 years of age or greater were 100% for AVR and 100% for MVR; at 92% for AVR and 80% for MVR, these figures were lower for patients 60 to 69 years of age. Conversely, the event-free estimates at 10 years for younger patients (less than 40 years of age) were much lower at 46% for AVR and 47% for MVR [5]. In an analysis conducted by Glower and associates [23], age less that 60 years reduced freedom from reoperation at 10 years from 90% to 65% for AVR; age less than 60 years decreased freedom from REOP from 75% to 48% for MVR. The decreasing incidence of reoperation with increasing age strongly argues for the preferential placement of tissue valves in older patients.
Thromboembolism and ACH were infrequent complications, consistent with the main advantage of implanting bioprosthetic valves; however, when TE and ACH did occur, they were both associated with relatively high fatality rates (14% ± 4% and 23% ± 4% for TE and 17% ± 6% and 49% ± 6% for ACH in the AVR and MVR subgroups, respectively). Actuarial estimates of freedom from TE at 10 and 15 years were 92% ± 1% and 87% ± 2%, respectively, for the AVR subgroup and 86% ± 1% and 77% ± 3%, respectively, for the MVR subgroup. These results are comparable to those previously reported for other series, in which the event-free estimates for AVR ranged from 86% to 93% at 10 years and from 68% to 87% at 15 to 17 years; the respective estimates for MVR were 81% to 96% and 70% to 89% [1, 2, 4, 5, 7, 28]. Even less frequent were ACH complications, as reported previously: For AVR, the estimates were 95% to 98% at 10 years and 97% at 15 years; for MVR, the estimates were 87% to 96% at 10 years and 94% at 15 years [4, 5, 7, 29]. Not surprisingly, older age and the mitral position were significant risk factors for both TE and ACH.
The overall clinical performance of a particular valve substitute can be summarized using estimates of freedom from VRM and VRM&M. Valve-related mortality is the likelihood of a patient dying of any valve-related complication, including sudden, unexplained early and late deaths. Although this index of clinical valve performance represents the clinical "bottom line," it is an overestimate of the true prevalence of VRM because it includes sudden, unexpected deaths. The respective estimates of freedom from VRM at 10 and 15 years were 86% ± 1% and 78% ± 3% for the AVR subgroup and 84% ± 2% and 70% ± 4% for the MVR subgroup, with no difference between the AVR and MVR subgroups. In previous reports, the event-free estimates for AVR patients were 78% to 94% at 10 years and 69% to 86% at 15 to 17 years; the estimates for MVR patients were 71% to 90% at 10 years and 63% to 79% at 15 to 17 years [1, 2, 4, 7, 13, 28]. Factors portending a higher risk of VRM included higher NYHA functional classification, congestive heart failure, and renal insufficiency, emphasizing the fact that patients who are more debilitated are at greater risk of late mortality, although not all these late deaths were directly valve related. The category of VRM&M includes all morbid and fatal events that were clearly or possibly valve related. The 10- and 15-year actuarial estimates of freedom from VRM&M were low at 59% ± 2% and 31% ± 3% for the AVR subgroup and 48% ± 2% and 18% ± 2% for the MVR subgroup, respectively. Similar statistics have been reported previously: The event-free estimates for AVR patients were 48% to 69% at 10 years and 34% at 15 years; these estimates for MVR patients were 40% to 81% at 10 years and 20% to 66% at 15 years [1, 4, 5, 13, 29]. Significant predictors of VRM&M included higher NYHA functional classification, increased cardiopulmonary bypass time, congestive heart failure, renal insufficiency, and increased cross-clamp time. With regard to the different types or models of bioprostheses, no appreciable differences in long-term valve performance up to 15 years have been noted in this or other analyses [11, 24, 28, 30].
In summary, the long-term performance of first-generation porcine bioprosthesis is satisfactory in older patients and those undergoing AVR. However, younger patients remain at substantial risk for SVD and reoperation. Interestingly, bioprosthetic valve durability has not appeared to improve over time. The different types of valves (Hancock and Carpentier-Edwards) showed similar long-term clinical performance in both the aortic and mitral positions. The increased incidence of SVD with time is offset by the limited survival of older patients, which is the rationale for our belief that the durability of bioprostheses may be sufficient for a large majority of patients. The actuarial analysis used in assessing the performance of valve prostheses has limitations; actual probabilities calculated using parametric methods may be more accurate, because they reflect the percentage of patients whose valve will actually fail or suffer a valve-related event before they die.
|
Acknowledgments |
|---|
|
TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
|
Footnotes |
|---|
|
TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
Address reprint requests to Dr Miller, Department of Cardiothoracic Surgery, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94305-5247.
|
References |
|---|
|
TopFootnotesAbstractIntroductionMaterial and MethodsResultsCommentAcknowledgmentsReferences |
|---|
Related Article
This article has been cited by other articles:
|
|
 |
|
  W. B. Eichinger, I. M. Hettich, D. J. Ruzicka, K. Holper, C. Schricker, S. Bleiziffer, and R. Lange Twenty-year experience with the st. Jude medical biocor bioprosthesis in the aortic position. Ann. Thorac. Surg., October 1, 2008; 86(4): 1204 - 1210. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Hickey, S. M. Langley, O. Allemby-Smith, S. A. Livesey, and J. L. Monro Subcoronary Allograft Aortic Valve Replacement: Parametric Risk-Hazard Outcome Analysis to a Minimum of 20 Years Ann. Thorac. Surg., November 1, 2007; 84(5): 1564 - 1570. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. W.A. van Geldorp, W.R. E. Jamieson, A. P. Kappetein, J. P.A. Puvimanasinghe, M. J.C. Eijkemans, G. L. Grunkemeier, J. J.M. Takkenberg, and A. J.J.C. Bogers Usefulness of microsimulation to translate valve performance into patient outcome: Patient prognosis after aortic valve replacement with the Carpentier Edwards supra-annular valve J. Thorac. Cardiovasc. Surg., September 1, 2007; 134(3): 702 - 709. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Lehmann, T. Walther, J. Kempfert, S. Leontjev, A. Rastan, V. Falk, and F. W. Mohr Stentless Versus Conventional Xenograft Aortic Valve Replacement: Midterm Results of a Prospectively Randomized Trial Ann. Thorac. Surg., August 1, 2007; 84(2): 467 - 472. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Yadav, A. J. Hodge, A. D. Hilless, and P. D. Skillington Outcomes with Toronto stentless porcine aortic valve: the Australian experience Interactive CardioVascular and Thoracic Surgery, December 1, 2006; 5(6): 709 - 715. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Valfre, G. Rizzoli, C. Zussa, P. Ius, E. Polesel, S. Mirone, T. Bottio, and G. Gerosa Clinical results of Hancock II versus Hancock Standard at long-term follow-up. J. Thorac. Cardiovasc. Surg., September 1, 2006; 132(3): 595 - 601.e2. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. R. Moon, M. K. Pasque, N. A. Munfakh, S. J. Melby, J. S. Lawton, N. Moazami, J. E. Codd, T. D. Crabtree, H. B. Barner, and R. J. Damiano Jr Prosthesis-Patient Mismatch After Aortic Valve Replacement: Impact of Age and Body Size on Late Survival Ann. Thorac. Surg., February 1, 2006; 81(2): 481 - 489. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Totaro, N. Degno, A. Zaidi, A. Youhana, and V. Argano Carpentier-Edwards PERIMOUNT Magna bioprosthesis: A stented valve with stentless performance? J. Thorac. Cardiovasc. Surg., December 1, 2005; 130(6): 1668 - 1674. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. P.A. Puvimanasinghe, J. J.M. Takkenberg, M. J.C. Eijkemans, E. W. Steyerberg, L. A. van Herwerden, G. L. Grunkemeier, J. D. F. Habbema, and A. J.J.C. Bogers Prognosis After Aortic Valve Replacement With the Carpentier-Edwards Pericardial Valve: Use of Microsimulation Ann. Thorac. Surg., September 1, 2005; 80(3): 825 - 831. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Martinovic, I. Farah, M. Everlien, S. Lindemann, I. Knez, T. Wittlinger, H. Greve, and P. Vogt Eight-year results after aortic valve replacement with the CryoLife-O'Brien Stentless Aortic Porcine Bioprosthesis J. Thorac. Cardiovasc. Surg., September 1, 2005; 130(3): 777 - 777. [Abstract] [Full Text] [PDF]
|
