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PubMed2003

Prosthesis size and long-term survival after aortic valve replacement.

OBJECTIVE: This study was undertaken to quantify the relationship between prosthesis size adjusted for patient size (prosthesis-patient size) and long-term survival after aortic valve replacement. METHODS: Data from nine representative sources on 13,258 aortic valve replacements provided 69,780 patient-years of follow-up (mean 5.3 +/- 4.7 years), with reliable survival estimates to 15 years. Prostheses included 5757 stented porcine xenografts, 3198 stented bovine pericardial xenografts, 3583 mechanical valves, and 720 allografts. Manufacturers' labeled prosthesis size was 19 mm or smaller in 1109 patients. Expressions of prosthesis-patient size assessed were indexed internal prosthesis orifice area (in centimeters squared per square meter of body surface area) and standardized internal prosthesis orifice size (Z, the number of SDs from mean normal native aortic valve size). Multivariable hazard domain analysis with balancing score and risk factor adjustment quantified the association of prosthesis-patient size with survival. RESULTS: Prosthesis-patient size down to at least 1.1 cm(2)/m(2) or -3 Z did not adversely affect intermediate- or long-term survival (P >.2). However, 30-day mortality increased 1% to 2% when indexed orifice area fell below 1.2 cm(2)/m(2) (P =.002) or standardized orifice size fell below -2.5 Z (P =.0003). The increased early risk affected fewer than 1% of patients receiving bioprostheses but about 25% of those receiving mechanical devices. CONCLUSIONS: Aortic prosthesis-patient size down to 1.1 cm(2)/m(2) or -3 Z did not reduce intermediate- or long-term survival after aortic valve replacement. However, patient-prosthesis size under 1.2 cm(2)/m(2) or -2.5 Z was associated with a 1% to 2% increase in 30-day mortality. Prosthesis-patient sizes this small or smaller were rarely implanted in patients receiving bioprostheses.

Aged↗
PubMed1999

Influence of aortic valve replacement, prosthesis type, and size on functional outcome and ventricular mass in patients with aortic stenosis.

OBJECTIVES: Two years after surgery for severe aortic stenosis, we prospectively evaluated the influence of aortic valve replacement, as well as valve type (mechanical or stented biologic) and size, on functional status, left ventricular function, and regression of mass. METHODS: Patients who received either a mechanical (n = 95) or a biologic valve (n = 42) were studied by echocardiography before the operation and after 2 years. RESULTS: The percentage of patients with severe dyspnea decreased from 53% to 13% (P =.001). The cardiac index increased from mean 2.6 L/min per square meter (95% CI: 2.48-2. 72 L/min per square meter) to 3.1 L/min per square meter (95% CI: 2. 94-3.26 L/min per square meter; P =.001). The percentage of the patients with mild-to-moderate diastolic dysfunction decreased from 43% to 18% (P =.001). The left ventricular mass index was reduced by 42.4 g (95% CI: 35-50 g; P =.001). In comparison with biologic valves of the same size, mechanical valves produced a more pronounced reduction in mass index (overall difference 21.7 g; 95% CI: 37.1-6.4 g; P =.007) and a lower mean Doppler gradient (overall difference 4 mm Hg; 95% CI: 2-6 mm Hg; P =.0002). CONCLUSIONS: Patients undergoing aortic valve replacement had an improvement in functional status, as well as systolic and diastolic left ventricular function, and a reduction in left ventricular mass index, irrespective of prosthesis size and type. Mechanical valves are somewhat less obstructive than stented bioprosthetic valves of the same size. They are also associated with a concomitantly more pronounced reduction of left ventricular mass.

Aged↗
PubMed2000

Preliminary experience with Silzone-coated St. Jude medical valves in acute infective endocarditis.

BACKGROUND AND AIM OF THE STUDY: The rate of recurrent postoperative endocarditis after valve replacement in early-stage acute infective endocarditis is extremely high. Metallic silver coating of the sewing ring may improve the short- and long-term outcome after valve implantation. This report details our experience with the St. Jude Medical Silzone prosthesis in early surgical treatment of acute infective endocarditis. METHODS: Ten patients (mean age 66.4 years) referred for native valve or prosthetic valve endocarditis were operated on between April 1998 and June 1999. The microorganisms responsible for the acute infection were Staphylococcus (n = 1), Streptococcus (n = 1) and Pseudomonas aeruginosa (n = 1); blood cultures remained negative in two cases. The indication for surgical treatment was related to hemodynamic condition (n = 5), a major cerebral event (stroke; n = 1), annulus abscess (n = 1), and echocardiographic evidence of large cuspal vegetations (n = 3). All patients had received preoperative intravenous antibiotics (mean 7.8 days). Four mitral, five aortic valve replacements, and one double mitral-aortic valve replacement, were performed after extensive debridement of the infected and necrotic tissues. Mean duration of postoperative antibiotic treatment was 32.3 days. Postoperative follow up (mean 6 months; range: 2-14.2 months) was 100% complete, and included prospective repeated transthoracic echocardiography at one week, and one, six and 12 months postoperatively. RESULTS: One patient died early in the immediate postoperative period from pneumonia and major hypoxemia. All other patients are symptom-free, without evidence of recurrent infection and perivalvular leak. CONCLUSION: Although these early results with the St. Jude Medical Silzone prosthesis require confirmation by more extensive studies, they infer that silver coating of the sewing ring may dramatically improve management of patients with active endocarditis.

Aged↗
PubMed2006

Stented bioprosthetic valve hemodynamics: is the supra-annular implant better than the intra-annular?

BACKGROUND AND AIM OF THE STUDY: The use of stented bioprostheses for aortic valve replacement (AVR) in elderly patients with a small aortic annulus may result in unsatisfactory hemodynamic performance of the prosthesis. To overcome this limitation, new bioprostheses have been designed for complete supra-annular implantation, but the actual hemodynamic advantage of the supra-annular implant over the intra-annular has not been fully investigated. Accordingly, the hemodynamic performance of the same stented bioprosthesis (except for sewing ring design) implanted in the supra-annular and conventional intra-annular seating was compared. METHODS: Twenty-two patients received an intra-annular implant, and 38 a supra-annular implant. Age (74 +/- 5 versus 76 +/- 5 years, p = 0.54), gender (55% versus 50% males, p = 0.79) and body surface area (1.74 +/- 0.2 versus 1.81 +/- 0.2 m2, p = 0.13) were similar in both subgroups, who underwent echocardiography at 8 +/- 2 and 6 +/- 2 months after surgery, respectively (p = 0.09). RESULTS: The two patient subgroups had similar preoperative left ventricular outflow tract diameters (2.06 +/- 0.2 and 2.1 +/- 0.2 cm; p = 0.62), average size of implanted prosthesis (21.0 and 21.3 mm; p = 0.44) and mean transprosthetic flow rate (246 +/- 70 and 218 +/- 58 ml/s; p = 0.12). Mean (8 +/- 3 and 19 +/- 8 mmHg, p < 0.0001), and peak (17 +/- 6 and 40 +/- 13 mmHg; p < 0.0001) transprosthetic gradients were lower, and mean effective orifice area (EOA) (1.78 +/- 0.4 and 1.45 +/- 0.5 cm2, p = 0.006) was higher in patients with supra-annular implants than in those with intraannular. The incidence of patient-prosthesis mismatch (EOA index < 0.85 cm2/m2) decreased from 50% to 34% (p < 0.0001), with no case of severe mismatch using the supra-annular implant. During follow up, a left ventricular mass reduction occurred in patients with supra-annular implants (from 225 +/- 110 to 173 +/- 59 g/m2; p < 0.03), but not in patients with intra-annular implants (173 +/- 62 and 186 +/- 64 g/m2; p = 0.87) CONCLUSION: The study results showed that, compared to intra-annular implantation, supra-annular implantation of bioprosthetic stented valves in the aortic position was associated with a significantly better hemodynamic performance of the prosthesis and significant regression of left ventricular hypertrophy.

Aged↗
PubMed2003

Intraoperative assessment of mitral valve and peri-operative results of surgical treatment of mitral valve disease in patients who previously underwent closed surgical and percutaneous transluminal mitral commissurotomy.

BACKGROUND: Surgical open or closed mitral commisurotomy and percutaneous transluminal mitral commissurotomy (PTMC) are the well-established therapies in patients with mitral valve stenosis. However, due to various factors the long-term effects may not be optimal in some patients, so they should undergo surgical mitral valve replacement. AIM: The intra-operative assessment of the morphology of mitral valve and the evaluation of the peri-operative results of surgical treatment in patients with mitral valve disease who previously underwent closed surgical commissurotomy followed by PTMC. METHODS: Twenty one patients (20 males, mean age 49 years) who underwent surgery due to mitral valve disease after closed mitral commissurotomy and PTMC, are presented. The time from closed mitral commissurotomy to PTMC was 3-42 years, and the time from PTMC to mitral valve replacement - 9 days to almost 9 years. RESULTS: One patient died on the second day after the operation because of left ventricular failure. The outcome of the remaining patients was good. Advanced changes of the mitral valve and subvalvular apparatus were present in the majority of patients. CONCLUSIONS: The results of the implantation of mitral valve prosthesis in patients who previously underwent closed surgical mitral commissurotomy and PTMC are good. In some patients with a history of closed surgical mitral commissurotomy, PTMC delays surgical replacement of the mitral valve. Advanced changes in the mitral valve leaflets and subvalvular apparatus are the causes of PTMC failure.

Adult↗
PubMed1998

Early calcific stenosis of the aortic sorin pericarbon valve implanted in the elderly.

BACKGROUND: We reviewed our experience with the Sorin Pericarbon (Sorin, Saluggia, Italy) valve implanted in the aortic position. METHODS: From January 1990 to January 1996, 143 consecutive patients had a Pericarbon valve implanted in the aortic position. The mean age was 75+/-5 years. Seventy-eight patients (55%) were in New York Heart Association (NYHA) class III or IV. Sixty patients (42%) had one or more concomitant procedures (51 coronary artery bypass grafting [CABG], 7 carotid endarterectomies, 9 others). RESULTS: The hospital mortality rate was 12% (17 of 143 patients). The follow-up was 100% complete and the median time was 42 months (range, 2 to 79 months). There were 36 late deaths, 20 being cardiac-related: 5 non-valve-related, 11 valve-related, and 4 sudden unexpected deaths. The 5-year actuarial survival was 57%+/-5%. There were 6 early valve failures related to a calcific stenosis at a median time of 36 months (range, 5 to 66 months). Three patients had to undergo another operation and one of these patients died. One patient died the day before the planned reoperation and 2 patients are followed with a symptomatic aortic stenosis but refuse reoperation. Freedom from structural deterioration was 93%+/-3% at 4 years. Echocardiographic examination was obtained in 73 patients at a median time of 42 months (range, 4 to 79 months). Four additional asymptomatic patients were found to have calcifications of their prosthesis. The 5-year freedom from thromboembolic events and from endocarditis were, respectively, 87%+/-5% and 92%+/-3%. CONCLUSION: The surprisingly high rate of early failure due to calcific stenosis and of thromboembolic events of the Pericarbon valve implanted in the aortic position in the elderly made us discontinue its use in our institution.

Actuarial Analysis↗
PubMed2003

Predictors of prosthesis survival, growth, and functional status following mechanical mitral valve replacement in children aged <5 years, a multi-institutional study.

BACKGROUND: Prosthesis survival, growth, and functional status after initial mechanical mitral valve replacement (MVR) in children <5 years of age are poorly defined. METHODS AND RESULTS: The experience of the Pediatric Cardiac Care Consortium (45 centers, 1982 to 1999), which included 102 survivors after initial MVR, was analyzed. Median follow-up: 6.0 years (interquartile range: 3.0 to 10.6 years; 96% complete). Twenty-nine survivors had undergone a second MVR at an interval of 4.8+/-3.8 years after initial MVR. Reasons for second MVR were prosthetic valve stenosis 24 (83%), thrombosis 4 (14%), and endocarditis 1 (3%). For those who had second MVR, prosthesis sizes were: first MVR 19+/-2 mm and second MVR 22+/-3 mm, and their body weight increased from 7.4+/-2.8 kg to 16.8+/-10.5 kg. To identify risk factors for having a second MVR, the 29 second MVR survivors were compared with the 73 who did not have a second MVR on first-MVR demographic and perioperative variables. By univariate analysis, patients with shorter prosthesis survival were younger, weighed less, had smaller prostheses, greater ratio of prosthesis size:body weight, were less likely to have a St. Jude prosthesis and more likely to have Shone's syndrome. By multivariate analysis prosthesis survival was predicted only by first MVR age: odds ratio (OR) 7.7 (95% confidence interval [CI] 2.6-22.7) and prosthesis size: OR 6.8 (95% CI 2.6-18.2). High risk patients (age <2 years and prosthesis <20 mm at first MVR) had an OR=46.3 compared with low-risk patients (age >or=2 years and prosthesis >or=20 mm at first MVR) over similar follow-up intervals. Using first-MVR weight-matched controls, body weight increased similarly for patients <2 years old who had a second MVR versus those who did not. Prosthesis size, however, differed significantly, with second MVR patients having smaller prostheses at first MVR (18.7+/-0.8 mm versus 22.4+/-3.6 mm, P=0.017). An estimate of current New York Heart Association (NYHA) functional status was class 1 in 76%, class 2 in 22%, and classes 3 or 4 in 2%. CONCLUSIONS: Prosthesis survival can be predicted based on first MVR age and prosthesis size. Somatic growth is comparable regardless of the need for second MVR. There is an increment in prosthesis size at second MVR, suggesting continued annular growth. Significant limitation of function after MVR is uncommon. MVR may be an appropriate strategy for children <5 years old despite the risk of second MVR in the youngest patients in whom the smallest prostheses are used.

Age Distribution↗
PubMed2005

Mitral valve replacement in a severely calcified posterior annulus: a novel technique.

We describe a technique for insertion of a mitral valve prosthesis in the presence of severe posterior annular calcification by plicating the left atrial tissue over the sewing ring. Extensive calcification often creates the technical difficulty of seating the prosthetic valve resulting in peri prosthetic leakage. Extensive decalcification may weaken the annulus and result in prosthetic valve dehiscence and atrioventricular dissociation.

Aged↗
PubMed2004

Indications for reoperation for valvular prosthesis dysfunction in urgent and elective patients.

OBJECTIVES: Comparison analysis of indications for operation, early clinical outcomes and hospital mortality between patients reoperated for valvular prosthesis dysfunction urgently and electively. MATERIAL AND METHODS: Retrospective data analysis of 94 patients (pts) reoperated for valve prosthesis dysfunction at Department of Cardiovascular Surgery and Transplantology in Kraków, Poland between January 1999 and December 2002. RESULTS: Valvular reoperation was elective procedure in 69 pts (73.4%)--group A: 46 males (M), 23 females (F), age 23-71 (av. 51.31 +/- 10.2). Urgent operation was performed in 25 pts--group B: 17 M, 8 F, age 29-77 years (av. 5.41 +/- 13.26). In group B: 9 patients underwent reoperation for dysfunction of aortic valve (2 allogenic, 7 mechanical), 13 pts for mitral valve dysfunction and 3 pts for both aortic and mitral valve dysfunction. In group A: 24 pts for mitral valve dysfunction, 37 pts for aortic valve dysfunction (25 allogenic, 12 mechanical) and 8 pts for both aortic and mitral valve dysfunction. In group B: 16 pts (64%) were operated in NYHA class IV; 8 in cardiogenic shock; on which 8 pts with active endocarditis, 3 pts with sepsis and 1 patient in septic shock. Average operative risk calculated as Euroscore was 30.86 in group B and 13.15 in group A (p<0.05). Overall hospital mortality was 12.6% (12 pts). In group B: 7 pts died (28%), 3 pts due to multiorgan failure, 1 patient due to sepsis, 2 pts due to aorta rupture and 1 due to left ventricle rupture during cardiopulmonary rescuscitation. In group B 5 pts died (7.2%). CONCLUSION: Patients reoperated urgently for valve prosthesis dysfunction were in worse preoperative state, had significantly higher preoperative risk and in hospital mortality than patients reoperated electively.

Adult↗
PubMedDate not supplied

Continuous-suture technique in aortic valve replacement.

From April 2000 to April 2003 total 103 patients underwent aortic valve replacement and some concomitant cardiac procedures including mitral valve replacement in our hospital. According to the suture technique used in aortic valve replacement, the patients were divided into two groups: group A, 42 patients, the continuous suture technique with some modifications was used; group B, 61 patients, the conventional interrupted suture technique was used. There were no statistical differences between the two groups in age, sex, bodyweight, valve lesion, concomitant cardiac procedure and early mortality. But there were significant differences ([<0.001 approximately 0.012) in aortic cross-clamp time (AOCT) and cardiopulmonary bypass time (CPBT) between the two groups with less time for the group A patients. During a follow-up from 1 to 35 months, in group B, one patient developed perivalvular leak. The incidence of perivalvular leak was 1.7% (1/59). Three patients developed prosthetic bacterial endocarditis, the incidence of which was 5.0% (3/59). All the patients in group A recovered satisfactorily without suture technique or prosthesis associated complications. The modified technique was introduced and illustrated with diagrams, and the reasons for the advantages of the technique over the conventional interrupted suture technique were discussed.

Adult↗
PubMed2004

Dysfunction of primary aortic valve prosthesis--allogenic versus mechanical--preoperative differences.

OBJECTIVES: Comparison of preoperative characteristics between patients reoperated for allogenic and mechanical aortic valve prosthesis dysfunction. METHODS: Retrospective data analysis of 47 patients reoperated for aortic valve prosthesis dysfunction at Department of Cardiovascular Surgery and Transplantology in Kraków, Poland between January 1999 and December 2002. RESULTS: In analyzed group 27 patients were operated for dysfunction of allogenic valve (Gr. A), 20 pts for mechanical valve (Gr. B). Group A: 21 males (M), 6 females (F), age 23-68 years old (av. 47.10 +/- 11.71); Group B: 18 M, 2 F, age 38-77 (av. 54.73 +/- 11.03), p<0.05. Time between operations in group A was 69-258 months (av. 164.34 +/- 66.02) months and in group B 0.5-348 months (av. 77.27 +/- 98.29) p<0.01. In group A, 5 pts and in group B, 7 pts were in NYHA group IV preoperatively. Echocardiography revealed that diastolic left ventricular dimension (LVDD) was larger in group A: av. 6.7 cm and 5.36 cm in group B, p<0.05. 2 pts from group A and 7 pts from group B were operated urgently (p<0.05), including 3 pts with aortic dissection. Definite infective endocarditis was diagnosed in 6 pts from group A and 11 pts from group B, p<0.05. In group A, 1 patient was urgently operated for infective endocarditis with vegetations, he died due to multiorgan failure. In group B, 6 pts died including all 3 with aortic dissection. CONCLUSIONS: Patients reoperated for allogenic aortic valve prosthesis dysfunction are: younger, reoperated after a much longer period of time with slower valve dysfunction progress (larger LVDD), most frequently reoperated electively, less frequently with endocarditis as the cause of valve dysfunction than in patients reoperated for mechanical aortic valve dysfunction.

Adult↗
PubMed2002

Clinical evaluation of the carbomedics prosthesis: experience at providence health system in Portland.

BACKGROUND AND AIMS OF THE STUDY: This study details the authors' experience with the CarboMedics bileaflet mechanical prosthesis, and assesses the valve's efficacy in terms of early mortality and long-term morbidity. METHODS: Between July 1994 and December 2000, a total of 696 CarboMedics valves was implanted in 616 patients. Aortic valve replacement (AVR) was performed in 350 (57%) patients, mitral valve replacement (MVR) in 161 (26%), double (aortic + mitral) valve replacement (DVR) in 79 (13%), and other procedures in 26 (4%). RESULTS: There were 32 operative deaths. Operative mortality was 4.3% for AVR, 6.8% for MVR, and 7.6% for DVR. Linearized rates for late death were 3.4%/patient-year (pt-yr), 5.5%/pt-yr and 7.7%/pt-yr for AVR, MVR and DVR, respectively. Survival at five years was 80.1% for AVR, 73.0% for MVR, and 64.6% for DVR (p = 0.004). Freedom from reoperation at five years was 97.6% for AVR, 98.1% for MVR, and 94.1% for DVR (p = 0.718); freedom from thromboembolism at five years was 96.3% for AVR, 98.6% for MVR, and 88.3% for DVR (p = 0.04). Linearized rates of late thromboembolism were 0.7%/pt-yr, 0.4%/pt-yr and 2.3%/pt-yr, respectively. Freedom from PVE at five years was 98.4% for AVR, 97.0% for MVR, and 89.7% for the DVR group (p = 0.172). Linearized rates of PVE were 0.5%/pt-yr, 0.9%/pt-yr and 1.8%/pt-yr, respectively. Freedom from anticoagulant-related bleeding at five years was 98.0% in the AVR group, 97.8% in the MVR group, and 88.3% in the DVR group (p <0.001); linearized rates of this event were 0.4%/pt-yr, 0.6%/pt-yr and 3.2%/pt-yr, respectively. One valve thrombosis was found after MVR, and another in the mitral position after DVR. CONCLUSION: Early and intermediate-term follow up of the CarboMedics prosthesis indicates that the clinical performance of this valve is satisfactory, and results are comparable with those obtained for other mechanical valves.

Adolescent↗
PubMed2001

Long term results of mechanical prostheses for treatment of active infective endocarditis.

OBJECTIVE: To analyse the long term results of mechanical prostheses for treating active infective endocarditis. DESIGN: Prospective cohort study of a consecutive series of patients diagnosed with infective endocarditis and operated on in the active phase of the infection for insertion of a mechanical prosthesis. SETTING: Tertiary referral centre in a metropolitan area. RESULTS: Between 1975 and 1997, 637 cases of infective endocarditis were diagnosed in the centre. Of these, 436 were left sided (with overall mortality of 20.3%). Surgical treatment in the active phase of the infection was needed in 141 patients (72% native, 28% prosthetic infective endocarditis). Mechanical prostheses were used in 131 patients. Operative mortality was 30.5% (40 patients). Ninety one survivors were followed up prospectively for (mean (SD)) 5.4 (4.5) years. Thirteen patients developed prosthetic valve dysfunction. Nine patients suffered reinfection: four of these (4%) were early and five were late. The median time from surgery for late reinfection was 1.4 years. During follow up, 12 patients died. Excluding operative mortality, actuarial survival was 86.6% at five years and 83.7% at 10 years; actuarial survival free from death, reoperation, and reinfection was 73.1% at five years and 59.8% at 10 years. CONCLUSIONS: In patients surviving acute infective endocarditis and receiving mechanical prostheses, the rate of early reinfection compares well with reported results of homografts. In addition, prosthesis dysfunction rate is low and long term survival is good. These data should prove useful for comparison with long term studies, when available, using other types of valve surgery in active infective endocarditis.

Acute Disease↗
PubMedDate not supplied

Aortic valve replacement with stentless porcine bioprostheses.

The implantation of stentless porcine valves (SPVs) is technically more demanding than implantation of stented bioprosthetic valves. Implantation of the Toronto SPV bioprosthesis requires an,understanding of the relationships between the leaflets and the aortic annulus and sinotubular junction. In addition to proper alignment of the three commissures within the aortic root, the diameter of sinotubular junction should not exceed the external diameter of the porcine aortic valve after completion of the operation. The Medtronic Freestyle porcine aortic root bioprosthesis can be used for subcoronary implantation as well as for aortic root replacement. Degenerative calcification of a tricuspid aortic valve is the most common cause of aortic valve disease in older patients. Implantation of stentless valves in the subcoronary position is usually feasible because the geometry of the aortic root is well maintained in these patients. The bicuspid aortic valve is the second most common cause of aortic valve disease in older patients and the most common in younger patients. These patients frequently have dilated aortic root, and the Medtronic Freestyle bioprosthesis is ideal for implantation using the root inclusion technique. Stentless porcine bioprostheses are minimally obstructive and associated with low mean systolic gradients. In addition, they have better hemodynamic performance during exercise than stented bioprostheses. For these reasons, patient-prosthesis mismatch has not been described with stentless valves. Left ventricular function after aortic valve replacement appears to be better with stentless than with stented bioprostheses. Comparative, nonrandomized studies of aortic valve replacement with stented and stentless valves suggest that the risk of cardiac death is reduced with stentless valves and the rates of valve-related complications also appear to be lower. What remains unknown is whether stentless valves are more durable than stented ones.

Aortic Valve↗
PubMed2006

Indexed effective orifice area after mechanical aortic valve replacement does not affect left ventricular mass regression in elderly.

OBJECTIVE: After aortic valve replacement, the effects of a small functional prosthesis on the extent and pattern of regression of left ventricular hypertrophy and on clinical outcomes may be less significant in older patients with low cardiac output requirements. The objective of this study was therefore to determine whether patient-prosthesis mismatch affects left ventricular mass regression in the elderly. METHODS: The population studied was made up of 88 patients over 65 years of age with pure aortic stenosis who underwent mechanical aortic valve replacement. The effective orifice area index was calculated for each patient on the basis of the projected prosthesis in vivo effective orifice area. It was considered a continuous variable and influence of its entire range of values on the extent of left ventricular mass regression was analyzed in a multivariate prediction model. RESULTS: Even though, in the group with prosthesis-patient mismatch there was a trend for lower postoperative left ventricular mass index (115+/-24 g/m(2) vs 102+/-27 g/m(2), p=0.24) and postoperative peak trans-prosthetic gradients (32+/-9.8 mmHg vs 28.9+/-7.79 mmHg, p=0.35) these differences were not statistically significant. The prevalence of residual left ventricular hypertrophy at follow-up was 50% in the group with patient-prosthesis mismatch and 50% in the group without patient-prosthesis mismatch (p=0.83). In multivariate analysis the only factors associated with indexed left ventricular mass were the follow-up time (p=0.015, r(2)=0.22) and preoperative indexed left ventricular mass (p=0.0012, r(2)=0.11). CONCLUSIONS: The major finding of our study is that patient-prosthesis mismatch does not affect left ventricular mass regression in patients older than 65 with pure aortic stenosis who underwent mechanical aortic valve replacement. In older patients with low cardiac output requirements, even a small change in the valve effective orifice area after aortic valve replacement with modern efficient mechanical prosthesis, will result in a marked reduction of pressure gradient and this will be associated with a significant regression of left ventricular mass.

Aged↗
PubMed2005

Performance at 10 years of the CarboMedics "Top-Hat" valve. Postclamping time is a predictor of mortality.

OBJECTIVE: The CarboMedics "Top-Hat" supraannular prosthesis was designed to permit the implantation of a larger prosthesis. We evaluated the outcome at 10 years in patients with this prosthesis. METHODS: Between June 1993 and May 2001, 269 patients (average age, 63.9 years) received a CarboMedics "Top-Hat" supraannular aortic prosthesis. Primary valve replacement was performed on 203 patients (75.5%) and repeat valve replacement on 66 (24.5%). The duration of myocardial ischemia was 70.2+/-31.4 min, cardiopulmonary bypass 96.1+/-48.3 min, and postclamping time (time between release of aortic clamp and the end of extracorporeal circulation) 22.1+/-41.3 min. The mean follow-up was 82.3+/-17.8 months. Follow-up was 97.6% complete. RESULTS: The hospital mortality was 5.9%. It was 1% when the duration of postclamping time was <15 min, 2.8% between 15 and 29 min, 13.2% between 30 and 44 min, and 26.9% >44 min. In the multivariate analysis, postclamping time, urgent surgery, and body mass index were statistically significant risk factors for hospital mortality. The late mortality was 17.1%. Cardiac-related mortality showed a linearized rate of 18.1% per 1000 patients-year. The Kaplan-Meier estimates for cardiac-related mortality was 75.0% at 10 years. Postclamping time, aortic valve gradient, age over 70 years, and BMI were statistically significant risk factors for cardiac-related late mortality. The incidence of paravalvular leak in the "Top-Hat" aortic prosthesis was 1.7% per 1000 patients-year. CONCLUSIONS: Using the CarboMedics supraannular prosthesis allows implantation of a larger prosthesis without increasing valve-related complications. Postclamping time appears as a strong predictor of both hospital mortality and late cardiac-related death.

Adult↗
PubMed2000

The CarboMedics 'Top-Hat' aortic valve prosthesis: short-term results.

BACKGROUND AND AIM OF THE STUDY: The CarboMedics 'Top-Hat' aortic valve prosthesis has been specifically designed for supra-annular implantation. The aim of this study was to assess the safety of implantation of this prosthesis by reporting the short-term results of follow up. METHODS: Between May 1993 and May 1998, 128 patients (mean age 62.5 +/- 9.8 years; range: 22-76 years) received a CarboMedics 'Top-Hat' prosthesis at our institution. Among patients, 55% were in NYHA functional classes III or IV, and 54.7% had an isolated aortic valve replacement. Associated procedures were: coronary artery bypass grafting (25.7%), double valve replacement (17.1%), treatment of ascending aortic aneurysm (4.7%) and miscellaneous (5.5%). Follow up was 100% complete; total cumulative follow up was 265 patient-years (pt-yr) (range: 2-60 months). RESULTS: The overall mortality rate was 1.5% (two deaths). The operative mortality rate was 0.8% (one death); this patient died from neurological complications after operation for aortic dissection. The other patient died on postoperative day 40 from a massive cerebral hemorrhage. Four patients presented thromboembolic events; in all cases these were reversible ischemic neurologic deficits. One patient had a nonstructural deterioration (endocarditis) and required reoperation. Freedom from mortality was 98.3% at five years (linearized rate of 0.75%/pt-yr). Freedom from thromboembolism was 63.1% at five years (linearized rate 1.5%/pt-yr). CONCLUSION: Short-term results with the CarboMedics 'Top-Hat' prosthesis were satisfactory, with low rates of morbidity and mortality. As this prosthesis has demonstrated a good reliability to date, we have continued its implantation in our institution, and long-term follow up will be necessary to confirm these good early results.

Adult↗