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Results for “HEART VALVE PROSTHESIS”

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PubMed2003

Three-dimensional flow analysis of a mechanical bileaflet mitral prosthesis.

The Jyros (JR) and the Advancing The Standard (ATS) valves were compared with the St. Jude Medical (SJM) valve in the mitral position to study the effects of design differences, installed valve orientation to the flow, and closing sounds using particle tracking velocimetry and particle image velocimetry methods utilizing a high-speed video flow visualization technique to map the velocity field. Sound measurements were made to confirm the claims of the manufacturers. Based on the experimental data, the following general conclusions can be made: On the vertical measuring plane which passes through the centers of the aortic and the mitral valves, the SJM valve shows a distinct circulatory flow pattern when the valve is installed in the antianatomical orientation; the SJM valve maintains the flow through the central orifice quite well; the newer curved leaflet JR valve and the ATS valve, which does not fully open during the peak flow phase, generates a higher but divergent flow close to the valve location when the valve was installed anatomically. The antianatomically installed JR valve showed diverse and less distinctive flow patterns and slower velocity on the central measuring plane than the SJM valve did, with noticeably lower valve closing noise. On the velocity field directly below the mitral valve that is normal to the previous measuring plane, the three valves show symmetrical twin circulations due to the divergent nature of the flow generated by the two inclined half discs; the SJM valve with centrally downward circulation is contrasted by the two other valves with peripherally downward circulation. These differences may have an important role in generation of the valve closing sound.

Equipment Design↗

PubMed1999

Lack of durability of the Mitroflow valve does not affect survival.

BACKGROUND AND AIM OF THE STUDY: The aim of the study was to compare the durability and risk of reoperation in patients undergoing isolated aortic valve replacement with either a porcine standard Carpentier Edwards or a Mitroflow pericardial valve. METHODS: Follow up evaluation was performed in 118 patients receiving a Mitroflow valve (M) and 94 patients receiving a standard Carpentier Edwards porcine valve (CE) between 1980 and 1987. The two groups were identical in terms of clinical characteristics; only prosthesis size differed, with small-sized valves used more frequently among the Mitroflow group. RESULTS: The risk of structural valve deterioration (SVD) was 2.3% per patient-year (pt-yr) in CE valves, and 5.4 per pt-yr in M valves. Freedom from SVD was 100%, 87 +/- 4% and 63 +/- 8% at 5, 10 and 15 years for CE valves, and 96 +/- 2%, 56 +/- 7% and 5 +/- 4% for M valves. Freedom of reoperation was 98 +/- 1%, 83 +/- 5% and 76 +/- 7% at 5, 10 and 15 years respectively for CE valves, and 94 +/- 2%, 55 +/- 7% and 11 +/- 9% for M valves. Despite the high number of valve-related reoperations, survival at 5, 10 and 15 years was not affected in M valve patients. Multivariate analysis (Cox model) showed that age and valve type were the two main risk factors for SVD and reoperation, though the latter factor had no impact on survival. CONCLUSIONS: In younger patients (aged < 75 years), the CE valves offer superior results to the M counterpart in valve replacement. However, in patients aged > 75 years, pericardial and porcine bioprostheses demonstrate equivalent durability, despite post-implantation tissue changes in the former material.

Age Factors↗

PubMed2003

Initial clinical and hemodynamic experience with Edwards MIRA mechanical bileaflet valve.

AIM: An enhanced bileaflet valve, the Edwards MIRA feminine Mechanical Valve became available in 1998. Favorable hydrodynamic features and a redesigned sewing ring encouraged us to implant this device in indicated patients. Hemodynamics and clinical performance parameters were evaluated. METHODS: Between February 1998 and October 1999, 338 patients (171 males, 167 females) underwent native valve replacement with a MIRA prosthesis. Mean age 56.6+/-13.6 years, 320 patients were in NYHA class III/IV. Sixty-seven patients had echocardiographic examinations. Standard cardiopulmonary bypass was employed utilizing institutionally accepted implantation techniques. Aortic valve replacement was performed in 163 patients, mitral valve replacement in 134 patients, 35* double valve replacements and 1 triple valve replacement. RESULTS: Follow-up is 98% complete. Mean follow-up is 6.9+/-3.3 months (178.2 patient years). There were no operative deaths. Four early deaths were seen (1.18%). Late deaths reported in 12 patients. Linearized rate of late mortality was 6.7% per patient year (ppy). Overall actuarial survival at 13 months is 92.2%. Mean gradients and Effective Orifice Areas (EOA's) are comparable to other bileaflet valves. Linearized rates for valve-related complications was 4.49% ppy. Only 5 transient thromboembolic events (TE = 2.81% ppy) and 3 non-structural valve dysfunction events (NSVD = 1.68%) were seen. No reports of bleeding events, prosthetic endocarditis, valve thrombosis or structural valve deterioration. One patient required mitral valve reoperation for perivalvular leak. CONCLUSIONS: Short-term hemodynamic and clinical results are comparable to other bileaflet valves. The sewing ring is non-obstructive, compliant with smoother needle penetration. Early clinical results are encouraging, follow-up should be continued.

Adolescent↗

PubMed2006

Forces at single point attached commissures (SPAC) in pericardial aortic valve prosthesis.

OBJECTIVE: New pericardial aortic bioprostheses (3F Therapeutics and temporarily stented autologous pericardial valve prosthesis) were developed recently. These valves are designed with commissures connected to the aortic wall at only three single points (single point attached commissures (SPAC)). The aim of this study was to investigate the forces acting on SPAC during varying pressure load. METHODS: Aortic roots with diameters 19, 25, and 29 mm were made using silicone polymer. A bovine pericardial SPAC aortic valve prosthesis was constructed using a 3D-mold and was implanted in the silicone aortic root. The base of the valve was sutured onto the aortic annulus with 4-0 polypropylene running suture and each commissure was sutured to a miniaturized force transducer with only one 3-0 polypropylene U-stitch. Three silicon aortic roots of each size were pressurized up to 200 mmHg and forces on SPAC were measured. RESULTS: All valves remained competent at a pressure of 200 mmHg. Recordings showed a linear correlation between applied pressure and forces measured at SPAC. At a pressure of 80 mmHg (equivalent to diastolic pressure), the forces were 0.44+/-0.22N, 1.15+/-0.18N, and 2.00+/-0.35N in annular diameters 19 mm, 25 mm, and 29 mm, respectively. It was observed, that the main forces were acting along the axial direction and not along the radial direction. CONCLUSIONS: Forces on "single point attached commissures" in pericardial aortic valves were measured. These forces were acting mainly in axial direction and not in radial direction. This knowledge is important for the implantation technique of SPAC pericardial aortic valves.

Animals↗

PubMed2005

Impact of valve prosthesis-patient mismatch on pulmonary arterial pressure after mitral valve replacement.

OBJECTIVES: We sought to determine the impact of valve prosthesis-patient mismatch (PPM) on pulmonary arterial (PA) pressure after mitral valve replacement (MVR). BACKGROUND: Pulmonary arterial hypertension is a serious complication of mitral valve disease, and it is a major risk factor for poor outcome after MVR. We hypothesized that valve PPM might be a determinant of PA hypertension after MVR. METHODS: Systolic PA pressure was measured by Doppler echocardiography in 56 patients with normally functioning mitral prosthetic valves. Mitral valve effective orifice area (EOA) was determined by the continuity equation and indexed for body surface area. RESULTS: Thirty patients (54%) had PA hypertension defined as systolic PA pressure >40 mm Hg, whereas 40 patients (71%) had PPM defined as an indexed EOA < or =1.2 cm(2)/m(2). There was a significant correlation (r = 0.64) between systolic PA pressure and indexed EOA. The average systolic PA pressure and prevalence of PA hypertension were 34 +/- 8 mm Hg and 19% in patients with no PPM versus 46 +/- 8 mm Hg and 68% in patients with PPM (p < 0.001). In multivariate analysis, the indexed EOA was by far the strongest predictor of systolic PA pressure. CONCLUSIONS: Persistent PA hypertension is frequent after MVR and strongly associated with the presence of PPM. The clinical implications of these findings are important given that PPM can largely be avoided by using a simple prospective strategy at the time of operation.

Aged↗

PubMedDate not supplied

Percutaneous transcatheter one-step mechanical aortic disc valve prosthesis implantation: a preliminary feasibility study in swine.

PURPOSE: To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. METHODS: The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. RESULTS: MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. CONCLUSION: The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.

Animals↗

PubMed2005

Hemodynamic performance and clinical consequences of aortic valve replacement with 21-mm sized pericardial bioprostheses.

BACKGROUND: Aortic valve replacement (AVR) with a 21-mm sized bioprothesis is still discussed controversially. Since better results have been reported for pericardial valves, the aim of the current study was to analyze the hemodynamic performance as well as clinical parameters in our patients and to compare pericardial and standard porcine valves in particular. METHODS: 342 patients underwent AVR with a bioprosthesis between 1987 and 2000. A 21 mm prosthesis was used in 39 patients (group S), while 303 patients received at least a 23-mm sized valve (group L). Group S was further divided into 19 patients with a pericardial valve (group S1) and 20 patients with a standard porcine valve (group S2). The hemodynamic and clinical parameters were studied in all three groups. RESULTS: The peak and mean transprosthetic gradients were significantly lower in the pericardial group than in the porcine group, particularly between patients with 21 mm valves (peak/mean: S1: 24 +/- 9/20.8 +/- 6.5 mm Hg vs. S2: 38 +/- 15/33 +/- 9 mm Hg, p < 0.05) at discharge. We could also observe that the peak transprosthetic gradient 7 days postoperatively was not significantly higher in patients with a 21 mm pericardial valve compared to group L patients. Comparing clinical parameters, we found significantly more cerebral ischemic events, a prolonged mechanical ventilation, a higher mortality and a longer stay in hospital in the group S2 compared to the group S1. CONCLUSION: The current study shows that pericardial valves perform well, particularly in patients with small aortic roots. Postoperative hemodynamics and clinical results were better than for comparable standard porcine valves. As the outcome of patients with a 21 mm pericardial valve was no worse than that in patients with bigger valves, enlarging procedures for the aortic root are not necessary in the majority of these patients.

Animals↗

PubMed2005

[Early and long term results of mechanical aortic valve replacement at the Instituto Nacional del Torax in Chile].

BACKGROUND: Mechanical aortic valve replacement (AVR) results have been published extensively in industrialized countries. AIM: To assess our immediate and late results in patients subjected to AVR. PATIENTS AND METHODS: We retrospectively studied 194 patients subjected to isolated AVR between 1995 and 2003. Mean age was 57 +/- 13 years and 119 (61%) were male. One hundred thirty nine (73%) were in functional class III-IV, 20 (10%) had a previous cardiac operation and 25 (13%) were operated as an emergency. Surgical indication was stenosis in 110 (58%), regurgitation in 49 (26%) and stenosis/regurgitation in 31 (16%). Etiology was bicuspid valve 56 (29%), degenerative lesions 55 (28%), rheumatic valve disease 38 (20%) and endocarditis 27 (14%). Medtronic Hall was the most common prosthesis used in 157 patients (81%). Mean cardiopulmonary bypass time 97 +/- 29 min and mean cross clamp time was 69 +/- 21 min. RESULTS: Operative mortality was 4.6% (3% in elective surgery, 16% in emergency surgery and 0% in reoperations). Follow-up was complete in 100% of cases, totalizing 636 patients-year. Survival was 91 +/- 2%, 80 +/- 4% and 73 +/- 6%, at 1, 5 and 7 years, respectively. Multivariate risk analysis identified renal failure and endocarditis as predictors of early and late mortality. During follow up, the linear incidence rate for hemorrhage was 3.29% /patients-year, thromboembolism 2.04% patients-year and endocarditis 1.1% patients-year. CONCLUSIONS: AVR has low overall and elective mortality. Midterm survival is good but linear event rates related to anticoagulant treatment are higher than those previously published in industrialized countries. Renal failure and endocarditis were risk factors for early and late death.

Aged↗

PubMed2006

Prosthesis-patient mismatch is not clinically relevant in aortic valve replacement using the Carpentier-Edwards Perimount valve.

BACKGROUND: Previous studies have shown that prosthesis-patient mismatch (PPM) results in higher early and late mortality after bioprosthetic aortic valve replacement. Careful selection of stented bioprostheses was recommended to avoid inadequate effective orifice area. We studied the incidence of PPM and its potential effects on clinical outcome in patients undergoing aortic valve replacement using the Carpentier-Edwards Perimount bioprosthesis. METHODS: Independent predictors of early and late mortality and hospital readmission for cardiac reasons were defined in 506 patients (mean age, 73 years; range, 57 to 87 years) by multivariate analysis. Mean follow-up was 6.1 +/- 4.8 years; maximum follow-up was 18.6 years. RESULTS: The incidence of severe PPM (effective orifice area index < 0.65 cm2/m2) was 0.2% and of moderate PPM (effective orifice area index > 0.65 and < 0.85) was 20%. Multivariate analysis revealed that moderate PPM was not an independent predictor of early mortality, late mortality, or hospital readmission for cardiac reasons. Reduction of septal hypertrophy was similar in patients with and without moderate PPM. CONCLUSIONS: The incidence of severe PPM is virtually nonexistent after aortic valve replacement using the Carpentier-Edwards Perimount valve. Moderate PPM is found in 20% of cases and is clinically irrelevant in this population.

Aged↗

PubMed1999

Long-term outcome after biologic versus mechanical aortic valve replacement in 841 patients.

OBJECTIVE: The purpose of this study was to optimize selection criteria of biologic versus mechanical valve prostheses for aortic valve replacement. METHODS: Retrospective analysis was performed for 841 patients undergoing isolated, first-time aortic valve replacement with Carpentier-Edwards (n = 429) or St Jude Medical (n = 412) prostheses. RESULTS: Patients with Carpentier-Edwards and St Jude Medical valves had similar characteristics. Ten-year survival was similar in each group (Carpentier-Edwards 54% 3% versus St Jude Medical 50% 6%; P =.4). Independent predictors of worse survival were older age, renal or lung disease, ejection fraction less than 40%, diabetes, and coronary disease. Carpentier-Edwards versus St Jude Medical prostheses did not affect survival (P =.4). Independent predictors of aortic valve reoperation were younger age and Carpentier-Edwards prosthesis. The linearized rates of thromboembolism were similar, but the linearized rate of hemorrhage was lower with Carpentier-Edwards prostheses (P <.01). Perivalvular leak within 6 months of operation was more likely with St Jude Medical than with Carpentier-Edwards prostheses (P =.02). Estimated 10-year survival free from valve-related morbidity was better for the St Jude Medical valve in patients aged less than 65 years and was better for the Carpentier-Edwards valve in patients aged more than 65 years. Patients with renal disease, lung disease (in patients more than age 60 years), ejection fraction less than 40%, or coronary disease had a life expectancy of less than 10 years. CONCLUSIONS: For first-time, isolated aortic valve replacement, mechanical prostheses should be considered in patients under age 65 years with a life expectancy of at least 10 years. Bioprostheses should be considered in patients over age 65 years or with lung disease (in patients over age 60 years), renal disease, coronary disease, ejection fraction less than 40%, or a life expectancy less than 10 years.

Adolescent↗

PubMed2004

Comparison of outcomes after aortic valve replacement with a mechanical valve or a bioprosthesis using microsimulation.

BACKGROUND: Mechanical valves and bioprostheses are widely used for aortic valve replacement. Though previous randomised studies indicate that there is no important difference in outcome after implantation with either type of valve, knowledge of outcomes after aortic valve replacement is incomplete. OBJECTIVE: To predict age and sex specific outcomes of patients after aortic valve replacement with bileaflet mechanical valves and stented porcine bioprostheses, and to provide evidence based support for the choice of prosthesis. METHODS: Meta-analysis of published results of primary aortic valve replacement with bileaflet mechanical prostheses (nine reports, 4274 patients, and 25,726 patient-years) and stented porcine bioprostheses (13 reports, 9007 patients, and 54,151 patient-years) was used to estimate the annual risks of postoperative valve related events and their outcomes. These estimates were entered into a microsimulation model, which was employed to calculate age and sex specific outcomes after aortic valve replacement. RESULTS: Life expectancy (LE) and event-free life expectancy (EFLE) for a 65 year old man after implantation with a mechanical valve or a bioprosthesis were 10.4 and 10.7 years and 7.7 and 8.4 years, respectively. The lifetime risk of at least one valve related event for a mechanical valve was 48%, and for a bioprosthesis, 44%. For LE and EFLE, the age crossover point between the two valve types was 59 and 60 years, respectively. CONCLUSIONS: Meta-analysis based microsimulation provides insight into the long term outcome after aortic valve replacement and suggests that the currently recommended age threshold for implanting a bioprosthesis could be lowered further.

Aged↗

PubMed1999

[Long-term results of valve replacement using the Cobomedics prosthesis].

The Carbomedics valve prosthesis is a second generation mechanical prosthesis with a double hemi-disc. This study analysed long-term morbidity and mortality associated with this prosthesis. Between 1987 and 1996, 397 prostheses were implanted, 306 aortic, 42 mitral and 26 double replacements (3 combining a Carbomedics aortic prothesis with a mitral valve from another type) in 370 patients with a mean age of 62 (range 4 to 88 years). The global operative mortality was 7.4%. A questionnaire sent to treating cardiologists, general practitioners and patients updated the prospective data base of the cardiac surgical department. The follow-up was 99%, representing a total of 1244 patient-years with an average of 41 months (range 1.1 month to 9.9 years). The 1, 3, 5 and 7 year survival (operative mortality included) was 88%, 80%, 76% and 69.6% respectively. Haemorrhagic complications were the most common (17 cases, 1.36% per patient-year) and 11 thromboembolic episodes were observed (0.88% per patient-year) with a higher incidence (p < 10-4) in mitral valve replacement (3.8% in patient-year). The other complications observed were: 5 aseptic paravalvular leaks (0.4% per patient-year) and 5 prosthetic valve infections; no structural alterations were observed. In all, ten reoperations (0.8% per patient-year) were required for prosthetic valve complications. This study shows the reliability of Carbomedics valve prostheses with a low complication rate comparable to that of other modern mechanical valve prostheses.

Aortic Valve Insufficiency↗

PubMed2006

Clinical and echocardiographic assessment of the Medtronic Advantage aortic valve prosthesis: the Scandinavian multicentre, prospective study.

OBJECTIVE: The aim of this report is the prospective, multicentre evaluation of clinical results and haemodynamic performance of the Medtronic Advantage aortic valve prosthesis. METHODS: From April 2001 to June 2003, 166 patients (male:female 125:41; mean (SD) age 61.8 (11.8) years) received an aortic advantage valve prosthesis. Complete cumulative follow-up was 242.7 patient-years (maximum 3.2; mean 1.6 years). Postoperatively, patients underwent early (within 30 days) and 1 year transthoracic echocardiography. RESULTS: 30 day mortality was 2.4% (n = 4). Kaplan-Meier estimates of freedom from complications and linearised rates were as follows: 96.9 (1.6)% survival; 94.7 (1.3)% (2.06 patients/year) thrombo-embolism; 99.4 (0.6)% (0.4 patients/year) bleeding; 98.8 (0.9)% (0.8 patients/year) non-structural valve dysfunction; 98.8 (0.9)% (0.8 patients/year) reoperation. Valvular mean pressure gradients ranged from 16 (3) mm Hg for size 19 to 7 (2) mm Hg for size 27 and the corresponding effective orifice areas ranged from 1.2 (0.25) to 3.2 (0.66) cm(2). In all, left ventricular mass significantly decreased (p<0.001) and fractional shortening increased (p<0.001) from postoperative to 1 year echocardiography. CONCLUSIONS: Haemodynamic performance and early clinical results of Medtronic advantage in the aortic position were satisfactory and comparable with those of other bileaflet valves in current clinical use.

Aortic Valve Insufficiency↗

PubMed2003

Ten year experience with Aspire (Tissuemed) porcine bioprosthesis: single centre experience.

BACKGROUND: Aspire (Tissuemed) bioprosthesis is a third generation porcine bioprosthesis. 10-year outcome of this bioprosthesis is unknown. METHODS: We report our experience of 139 consecutive prosthesis implanted between 1990-1998. The clinical outcome was reviewed retrospectively. RESULTS: 126 patients (67 males and 59 females), mean age 68.4+/-8.4 years underwent 139 valve replacements. Sites of valve implantation included the aortic in 77 patients (61%); mitral in 35 patients (27%); aortic+mitral in 13 patients (10%) and tricuspid in 1 patient (0.8%). 32/126 patients (25%) also underwent concomitant coronary artery bypass grafting (CABG). 30-day mortality for the whole group was 8.7% (11/126) with no valve related deaths. Follow up was 98.4% complete with a mean follow up of 6.1+/-3.3 years (766 patient-years, range 0-10.2 years). Overall 10-year actuarial survival was 41+/-7% (AVR 49+/-10%, MVR 29+/-11%) and this was influenced by pre-operative poor left ventricular function (EF<30%) (p=0.007) and pre-operative NYHA class III/IV (p=0.001). Overall estimated 10-year actuarial freedom from valve related events (Kaplan-Meier) and valve related events expressed as linearised rates (%/patient-year) were: freedom from structural valve failure 97+/-2% (0.26%/patient-year); non-structural dysfunction 98+/-1% (0.13%/patient-year); freedom from prosthetic valve endocarditis 94+/-3% (0.39%/patient-year); freedom from significant haemorrhagic event 82+/-6% (1.33%/patient-year); freedom from thrombo-embolism 90+/-3% (0.91%/patient-year) and freedom from re-operation was 93+/-3% (0.52%/patient-year). CONCLUSION: In our experience Aspire (Tissuemed) porcine bioprosthesis functions satisfactorily at 10-years with low valve related complications. Further follow-up will determine its long-term durability.

Adult↗

PubMed2006

Effect of the increase in valve area after aortic valve replacement with a 19-mm aortic valve prosthesis on left ventricular mass regression in patients with pure aortic stenosis.

OBJECTIVES: Although patients with aortic stenosis, who receive 19-mm valves, are at high risk for prosthesis-patient mismatch, most of them show a significant left ventricular mass (LVM) regression postoperatively. The aim of this study was to identify factors predicting postoperative relative LVM regression in this subgroup of patients. METHODS: A population of 44 patients operated on for pure aortic stenosis and receiving a 19-mm valve was studied by echocardiography at 1.4 +/- 0.5 years postoperatively. RESULTS: The mean relative LVM regression was -19.3 +/- 18.9%, the mean gradient drop was -31.6 +/- 13.3 mmHg, and the mean Delta increase in aortic area index (postoperative aortic area index minus preoperative aortic area index) was 0.30 +/- 0.14 cm/m. Thirty-two patients had an indexed effective orifice area of less than 0.8 cm/m. At multivariate analysis (r = 0.63; r = 40%; P < 0.0001) preoperative LVM (P = 0.006), hypertension (P = 0.018) and Delta aortic area index (P = 0.049) were independent predictors of relative LVM regression. CONCLUSIONS: Our study shows that, at least 1 year postoperatively, in patients receiving a 19-mm valve, LVM regression is influenced by several parameters, in particular preoperative LVM, hypertension and the magnitude of the increase in aortic area.

Aged↗

PubMed2006

What prosthesis should be used at valve re-replacement after structural valve deterioration of a bioprosthesis?

BACKGROUND: The fate of bioprostheses (BP) and mechanical prostheses (MP) after valve re-replacement for bioprostheses is not well-documented. This research compares the late fate of these two valve types after valve re-replacement for structural valve deterioration (SVD) of a bioprosthesis. METHODS: Between 1975 and 2000, 298 patients had successful aortic valve re-replacements (AVRR) (BP n = 149, average age = 67.1 +/- 12.3 years; MP 149, 58.9 +/- 10.9) and 442 patients had successful mitral valve re-replacements (MVRR) (BP 155, 65.8 +/- 14.1; MP 287, 60.8 +/- 11.7) after SVD of a previous BP. Follow-up was five years in all groups. RESULTS: (1) Aortic position (AVRR): Survival favored MP over BP overall, at 10 years (70.3 +/- 5.4% vs 56.7 +/- 5.7%, p = 0.0220). This survival advantage was seen to be significant only in patients less than 60 years of age (at 10 years, 85.3 +/- 4.9% vs 59.2 +/- 9.8%, p = 0.038). No significant difference in survival between the two valve types was observed in patient age groups greater than 60 years of age. Freedoms from valve-specific complications, including reoperation for SVD-thrombosis, major thromboembolism and hemorrhage, and valve-related mortality were not significantly different between the two groups overall. (2) Mitral position (MVRR): Survival favored MP over BP overall (58.6 +/- 4.2% vs 42.1 +/- 5.2%, p = 0.0011), and in patients greater than 70 years of age (32.8 +/- 8.9% vs 16.7 +/- 7.1%, p = 0.008). Freedoms from valve-specific complications and valve-related mortality favored MP over BP. CONCLUSIONS: There was no clinical performance difference between mechanical and bioprosthetic valves in patients greater than 60 years of age upon AVRR. Mechanical valves generally outperformed bioprosthetic valves in all age groups in MVRR.

Age Factors↗

PubMed2006

[Avoidance of patient-prosthesis mismatch].

To minimize the incidence of patient-prosthesis mismatch (PPM), we have routinely adopted aortic root enlargement to avoid PPM for patients with small aortic annulus. The aim of this study was to review our strategy of avoiding PPM. The Carpentier-Edwards Perimount (CEP) valves were implanted in 53 patients who were mostly aged over 65 and the St. Jude Medical (SJM) mechanical valves were used in 128 patients aged under 65. A standard 21-mm SJM valve was used in only 3 patients and no 19-mm valves were employed. However, 19-mm CEP valves were used in 12 patients with a small body surface area (1.43 +/- 0.14 m2). Of these, 26 patients (14.4%) who had a small aortic annulus and 24 patients aged under 65 underwent aortic root enlargement. No patient receiving an SJM valve had an projected indexed effective orifice area (EOAI) < or = 0.85 cm2/m2 because of performing aortic valve replacement (AVR) with annular enlargement and only 2 (3.8%) out of 53 patients receiving CEP valves developed PPM. Consequently, the prevalence of PPM was 1.1% in this series. The prevalence of PPM was low in patients over 65 years old with a relatively small body size who received bioprosthetic valves. A pericardial bioprosthesis was considered to be an appropriate valve in older population with regard to avoiding PPM. In patients under 65 years old with a small annulus, the first choice for avoiding PPM is aortic annular enlargement, which may be avoided by high performance mechanical valves with larger EOA.

Adult↗

PubMed2003

Impact of valve prosthesis-patient mismatch on short-term mortality after aortic valve replacement.

BACKGROUND: The prosthesis used for aortic valve replacement (AVR) can be too small in relation to body size, thus causing valve prosthesis-patient mismatch (PPM) and abnormally high transvalvular pressure gradients. This study examined if there is a relation between PPM and short-term mortality after operation. METHODS AND RESULTS: The indexed valve effective orifice area (EOA) was estimated for each type and size of prosthesis being implanted in 1266 consecutive patients and used to define PPM as not clinically significant if >0.85 cm2/m2, as moderate if >0.65 cm2/m2 and 120 minutes (P=0.001), and PPM (P=0.003). Relative risk of mortality was increased 2.1-fold (95% confidence interval, 1.2 to 3.7) in patients with moderate PPM and 11.4-fold (4.4 to 29.5) in those with severe PPM. Moreover, risk of mortality for every category of PPM was higher in patients with a left ventricular ejection fraction <40% as compared with >or=40% (nonsignificant PPM, 2.7 versus 1.0; moderate PPM, 7.1 versus 1.8; severe PPM, 77.1 versus 11.3). CONCLUSIONS: PPM is a strong and independent predictor of short-term mortality among patients undergoing AVR, and its impact is related both to its degree of severity and the status of left ventricular function. In contrast to other risk factors, moderate-severe PPM can be largely avoided with the use of a prospective strategy at the time of operation.

Aged↗