Aspire porcine bioprosthesis: ten years' experience

BACKGROUND AND AIM OF THE STUDY: Clinical results of this multicenter study of the Aspire porcine valve were reported previously at eight years; the present report provides an update of valve performance to 10 years postoperatively. METHODS: A total of 749 patients (60% males; mean age 73+/-7 years) underwent implantation with the Aspire (Tissuemed) porcine bioprosthesis between 1991 and 2002, at three institutions. Follow up was complete for 98% of the cohort. The mean follow up period was 51.6+/-39.6 months (range: 0-181 months); total follow up was 3,159 patient-years (pt-yr). RESULTS: There were 617 aortic valve replacements (AVR), 96 mitral valve replacements (MVR) and 32 double valve replacements. There were 62 deaths (8.3%), one of which was valve-related. The late mortality rate was 9.3% per pt-yr (1.2%/pt-yr valve-related). Actuarial freedom from complications at 10 years was: thromboembolism 76+/-4% (2.6%/pt-yr); hemorrhage 73+/-4% (2.8%/pt-yr); structural valve deterioration (SVD) 96+/-2% (0.2%/pt-yr); non-structural deterioration 99+/-1% (0.1%/pt-y); prosthetic valve endocarditis 97+/-1% (0.3%/pt-yr); and reoperation 97+/-1% (0.4%/pt-yr). In patients aged >70 years, the 10-year actuarial freedom from SVD was 98+/-2% for AVR and 93+/-7% for MVR. Preoperative atrial fibrillation (AF) was a significant predictor of late mortality (p <0.001), thromboembolism (p = 0.05) and hemorrhage (p = 0.01). CONCLUSION: The Aspire porcine bioprostheses is a reliable choice for a tissue valve, for both the aortic and mitral positions, especially in patients aged >70 years. In elderly patients the presence of AF is a significant predictor of early and late mortality and morbidity.     

Five-year follow up of the ATS mechanical heart valve

BACKGROUND AND AIM OF THE STUDY: Between January 1, 1997 and December 31, 2001, a total of 342 patients underwent aortic valve replacement (AVR) or mitral valve replacement (MVR) with the ATS Medical prosthesis. The initial three-year phase of this study took place under a United States Food and Drug Administration-approved investigational device exemption study. The study aim was to determine the incidence of valve-related events in up to five years of follow up after valve implantation, and to assess patient disturbance from valve noise. METHODS: Patients were consecutively enrolled to undergo AVR or MVR with the ATS prosthesis. Follow up studies were conducted by patient questionnaire and/or telephone call. Follow up was 96% complete. AVR was conducted in 246 patients (80 with coronary bypass), and MVR in 96 patients (29 with coronary bypass). RESULTS: The overall operative mortality was 2.6% (n = 9; AVR 3.2%, n = 8; MVR 1.0%, n = 1), with two deaths being valve-related (0.6%). In 878 patient-years (pt-yr) of follow up (613 pt-yr for AVR; 265 pt-yr for MVR) there were an additional 22 deaths. Five deaths (0.6%/pt-yr) were valve-related: two were neuroembolic (both MVR), one from endocarditis (AVR), and two from bleeding events (both AVR). Late valve-related complications (>30 days) included 17 episodes of major bleeding (11 AVR, 1.8%/pt-yr; six MVR, 2.3%/pt-yr), five permanent neuroembolic events (four AVR, 0.7%/pt-yr; one MVR, 0.4%/pt-yr); 16 transient neuroembolic events (10 AVR, 1.6%/pt-yr; six MVR, 2.3%/pt-yr); three transient peripheral emboli (two AVR, 0.3%/pt-yr; one MVR, 0.4%/pt-yr); four paravalvular leaks (two AVR, 0.3%/pt-yr; two MVR, 0.8%/pt-yr); and one episode of valve thrombosis (MVR, 0.4%/pt-yr; AVR, 0%/pt-yr). Reoperation was required in two patients: one AVR (paravalvular leak, 0.2%/pt-yr) and one MVR (replacement due to thrombosis, 0.4%/pt-yr). CONCLUSION: These results indicate that intermediate-term results with the ATS mechanical prosthesis continue to be excellent, though further long-term follow up is warranted.     

Nine-year follow up of the omnicarbon prosthesis in the aortic position

BACKGROUND AND AIM OF THE STUDY: Clinical experience with the Omnicarbon mechanical valve implanted in the aortic position is reported in this retrospective survey. METHODS: A total of 110 patients (mean age 56 years) undergoing isolated aortic valve replacement with Omnicarbon mechanical prostheses at the authors' institution between November 1991 and October 2000 was included. Follow was available in 94.5% of patients (mean follow up 4 years per patient; total follow up was 415 patient-years (pt-yr)). RESULTS: Hospital mortality was 3.6%. There were no instances of valve thrombosis or structural failure. The incidence of valve-related complications (linearized rates in events per 100 pt-yr/actuarial freedom at 9 years, in %) was: valve-related mortality 2.4+/-0.7 / 80.3+/-8.0; non-structural failure 0.7+/-0.4 / 93.8+/-4.2; thromboembolism 0.2+/-0.2 / 99.0+/-1.0; anticoagulant-related hemorrhage 0.9+/-0.5 / 93.7+/-3.3; prosthetic valve endocarditis 0.2+/-0.2 / 99.0+/-1.0; and reoperation 0.7+/-0.4 / 93.8+/-4.2. CONCLUSION: In the authors' experience the Omnicarbon mechanical prosthesis provides a good clinical performance for up to nine years in the aortic position.     

Seventeen-year clinical results of 1,037 Mitroflow pericardial heart valve prostheses in the aortic position

BACKGROUND AND AIM OF THE STUDY: It is generally believed that the pericardial tissue valve is associated with a greater propensity to early structural failure and subsequent valve-related complications. However, a modified valve design during recent years has considerably improved the clinical durability of this bioprosthesis. METHODS: Between April 1986 and December 2003, single Mitroflow pericardial valve prostheses were inserted in the aortic position in 1,037 patients (mean age 72.4 +/- 8.4 years). Coronary artery bypass grafting (CABG) was performed in 373 patients (36%). Preoperative echocardiographic findings of structural valve deterioration (SVD) were confirmed at reoperation. Total follow up was 5,022 patient-years (pt-yr) (mean 4.85 +/- 4.7 years) and was 99.7% complete (three patients lost). RESULTS: Early (30-day) mortality was 2.9% for elective surgery; 434 patients (41.9%) died during the follow up period. Actuarial survival at 17 years was 23.2 +/- 2%. Actuarial freedom from valve-related mortality at 17 years was 92.0 +/- 2.2%, whereas the linearized mortality rate was 0.4%/pt-yr. Linearized valve-related complications occurred at a rate of 3.6%/pt-yr (n = 122). SVD of Mitroflow bioprostheses occurred at a rate of 1.0%/pt-yr, and caused stenosis (36.7%), insufficiency (20.4%) and combined stenosis and insufficiency (42.9%). Actual freedom from SVD at 17 years was 95.3 +/- 0.7% for all patients, 96.2 +/- 0.6% for those aged > 60 years, and 99.0 +/- 0.4% for those aged > 70 years. CONCLUSION: The Mitroflow pericardial bioprosthesis, in the aortic position, provides an excellent clinical performance and a low rate of valve-related morbidity, mortality and reoperation for up to 17 years. The prosthesis also demonstrates satisfactory hemodynamic performance, and is therefore recommended for patients aged > or = 70 years and for those aged 60-69 years with comorbidities.     

Structural durability in Carpentier Edwards Standard bioprosthesis in the mitral position: a 20-year experience

BACKGROUND AND AIM OF THE STUDY: Few long-term data are available on the Carpentier-Edwards Standard bioprosthesis in the mitral position. As for other bioprostheses, patient age at the time of implant is the main risk factor for structural deterioration, but no published report has analyzed the life-span of these bioprostheses with respect to this parameter. METHODS: A series of 139 patients who underwent mitral valve replacement with the Carpentier-Edwards Standard bioprosthesis between 1978 and 1987 was reviewed. Mean age at implant was 59.6+/-14.7 years (range: 17-79 years). Follow up was 98.4% complete; total follow up was 1,078.7 patient-years (pt-yr) (mean 8.4+/-4.1 years). Mean follow up in the subgroup of patients alive at the time of the survey was 10.4+/-3.4 years. RESULTS: Structural valve deterioration (SVD) occurred in 30 patients, with mean time to onset of deterioration 9.0+/-2.7 years (median 8.7 years). This time was independent of age at the time of implantation. Analysis by age group (< or =35, 36-50, 51-60, 61-65, 66-70, >70 years) showed deterioration to be more frequent in younger subjects (linear rates 7.9, 6.0, 3.3, 2.4, 0.6 and 0.4% pt-yr, respectively). Over the age of 65 years, the risk of SVD no longer varied with age, and was a rare complication. CONCLUSION: The mean time to onset of SVD was independent of patient age at the time of implant. After 65 years, the risk of SVD was low, without any significant variation. The Carpentier-Edwards Standard bioprosthesis may be used in the mitral position in subjects aged over 65 years, and with a low risk of deterioration.     

The Stentless Cryo-Life O'Brien porcine aortic valve at 10 years

BACKGROUND AND AIM OF THE STUDY: If stentless devices--with their physiological advantages--are to remain attractive, their long-term durability must equate with that of reference stented valves. METHODS: Between August 1991 and August 2001, 650 patients (mean age 72.0+/-4.2 years) received a Cryo-Life O'Brien Stentless aortic porcine bioprosthesis. The mean follow up was 4.6 years; total follow up was 2,644 patient-years (pt-yr). Among patients, 79% were in NYHA classes III-IV. Calcific aortic stenosis accounted for 93% of patients, who were predominantly female (75%), with associated coronary surgery in 19% and mitral surgery in 10.3%. Follow up was based on serial echocardiography, referring cardiologists' reports, and direct home telephone calls. Data were gathered over a six-month period. RESULTS: Operative mortality was 8.1% (n = 51). Of these deaths, 2.7% were in isolated cases (mean age 72.0+/-4.2 years) and 14% with associated procedures (mean age 77.0+/-5.3 years). There were 103 late deaths (3.9% per pt-yr). Valve-related complications included 14 deaths (linearized rate 0.52% per pt-yr), reoperation in 22 (0.8% per pt-yr), eight operated valvular endocarditis (0.3% per pt-yr), two valve thrombosis (0.07% per pt-yr), 11 embolic events (0.3% per pt-yr), and 14 anticoagulant-related bleeding (0.52% per pt-yr). Actuarial survival was 76+/-6% at 10 years, with a freedom from structural deterioration of 99.75% in patients aged > or =65 years (mean age 76+/-8 years), and 86% in patients aged <65 years (mean age 44+/-15 years). The gradients remained low, and the echocardiographic aspect was close to that of a normal valve. CONCLUSION: At 10 years, the Cryo-Life O'Brien Stentless provided excellent results in terms of durability associated with all the stentless advantages relating to physiology--gradients, orifice areas, and mass regression--that translate into an appropriately adapted left ventricular exertion profile.     

Four years' experience with the Edwards-Tekna bileaflet valve prosthesis

BACKGROUND AND AIM OF THE STUDY: Although over 20,000 Edwards-Duromedics valves were implanted worldwide between 1982 and May 1988, use of the valve was voluntarily suspended by the manufacturer in May 1988 on the basis of reported leaflet escapes. In 1990, a modified version was introduced to the market, the Edwards-Tekna. The study aim was to evaluate the short-term outcome with this revised valve. METHODS: Between 1994 and 1998, 137 patients (67 males, 70 females; mean age 36.3+/-9.1 years) underwent heart valve replacement with the Edwards-Tekna prosthesis. Among these patients, 72 had isolated mitral valve replacement, 59 isolated aortic valve replacement, and six double-valve replacement. RESULTS: Early hospital mortality was 0.72% (n = 1). Follow up was 95% complete (129/136 patients discharged from hospital). Mean follow up was 24.9+/-10.5 months (range: 2 to 48 months); total follow up was 282.9 patient-years (pt-yr). Actuarial freedom from complications at two-year follow up and linearized incidence (%/pt-yr) of these events were: late mortality 87.8+/-8.5% (1.77%/pt-yr); thromboembolism 89.8+/-4.9% (2.12%/pt-yr); anticoagulation-related bleeding 97.8+/-1.5% (0.71%/pt-yr); prosthetic valve endocarditis 99.1+/-0.9% (0.35%/pt-yr); valve-related mortality 98.2+/-1.2% (0.71%/pt-yr); and valve-related morbidity and mortality 85.0+/-5.0% (4.24%/pt-yr). There was no structural valve failure such as leaflet escape in this series. Clinically significant hemolysis was not encountered (mean postoperative plasma LDH level 345+/-124 IU/l). Preoperatively, 69% of patients were in NYHA classes III/IV; at two years postoperatively 90% of survivors were in classes I/II. CONCLUSION: The Edwards-Tekna mechanical valve prosthesis has shown excellent overall clinical performance in the short term, though long-term data are needed to confirm its durability.     

Single-center experience with the On-X prosthetic heart valve between 1996 and 2005

BACKGROUND AND AIM OF THE STUDY: Herein are presented long-term results for the On-X mechanical heart valve. All On-X heart valve recipients since the first implantation worldwide at the University of Bochum in September 1996 were followed retrospectively; the present authors' single-center experience over a period of almost 10 years is reported. METHODS: A total of 428 patients (255 males, 173 females; mean age 62.7 years) underwent either aortic valve replacement (AVR; n = 264) or mitral valve replacement (MVR; n = 164) using the On-X prosthesis. Preoperatively, 329 patients (76.8%) were in NYHA class III or IV. Approximately 5% of AVR and 23% of MVR patients had undergone previous cardiac surgery. Concomitant surgery was performed in 189 patients (44.2%). The mean follow up was 3.9 years, and cumulative follow up 1,625 patient-years (pt-yr); the overall follow up rate was 98.7%. RESULTS: Early mortality (< or = 30 days) was 3.7% after AVR and 14.0% after MVR, with valve-related mortality rates of 0.4% and 1.2%, respectively. At autopsy (n = 12) all implants were intact. Freedom from valve-related death at nine years was 85.0 +/- 3.9% after AVR and 87.6 +/- 3.2% after MVR. The overall survival rate was 67.9 +/- 4.3% after AVR and 52.7 +/- 8.1% after MVR. The linearized rate of thromboembolism for AVR and MVR was 1.49%/pt-yr and 1.61%/pt-yr; of thrombosis 0%/pt-yr and 0.35%/pt-yr; of hemorrhage 0.93%/pt-yr and 1.43%/pt-yr; of endocarditis 0.37%/pt-yr and 0.17%/pt-yr; of non-structural failure 0.18%/pt-yr and 1.43%/pt-yr; and of reoperation 0.28%/pt-yr and 0.53%/pt-yr. There were no cases of structural valve failure. CONCLUSION: After almost one decade of clinical experience in a single center, the On-X heart valve continues to be reliable and effective.     

Does the Ross operation fulfil the objective performance criteria established for new prosthetic heart valves?

BACKGROUND AND AIM OF THE STUDY: Objective Performance Criteria (OPC) were established to compare a new heart valve prosthesis with fixed standards of linearized complication rates for morbid events: thromboembolism, thrombosis, hemorrhage, leakage and endocarditis. Although the pulmonary autograft operation provides optimal hemodynamic performances, the morbidity of both the autograft and homograft remain topics of controversy. METHODS: Valve-related morbid events and echocardiography in 109 patients who have undergone the Ross operation since 1991 were evaluated at annual follow up examination (mean 2.8 years; range: 1 month to 8 years). Linearized rates (number of events per 100 years patient exposure) were calculated to establish the safety and efficacy of this operation (288.7 years cumulative patient-years). RESULTS: Three patients died perioperatively (2.8%); two patients were reoperated due to autograft incompetence (1.8%, both valve repairs). No patient is currently on anticoagulation therapy, and no events of thromboembolism, valve thrombosis or bleeding were observed during follow up. Two patients had homograft endocarditis but were asymptomatic with moderate incompetence at the last follow up examination. There was no significant increase in aortic incompetence (AI) or pulmonary incompetence (PI) between discharge and follow up (AI, 0.4 +/- 0.5 versus 0.6 +/- 0.6; PI, 0.2 +/- 0.4 versus 0.4 +/- 0.6). In comparing the OPC (events per patient-year) for the Ross operation with those for tissue and mechanical valves, the results were: thromboembolism 0% (tissue 2.5%, mechanical 3%), valve thrombosis 0% (0.2% and 0.8%), all bleeding 0% (1.4% and 3.5%), major bleeding 0% (0.9% and 1.5%), all leakage 0.7% (1.2% and 1.2%), major leakage 0.7% (1.2% and 1.2%) and endocarditis 0.7% (1.2% and 1.2%). CONCLUSION: The pulmonary autograft procedure provides optimal hemodynamics and echocardiographic performance, and low valve-related complication rates; thus, the OPC for tissue and mechanical heart valve prostheses can be fulfilled by this technically demanding operation. These results confirm that the autograft is an ideal aortic valve replacement device.     

Single-center outcome analysis of 1,161 patients with St. Jude medical and ATS open pivot mechanical heart valves

BACKGROUND AND AIM OF THE STUDY: The clinical performance of mechanical heart valves and valve-related complications are important safety endpoints in patients after heart valve replacement. In this retrospective analysis, the mid- to long-term clinical outcomes of two similar bileaflet heart valves, routinely implanted at the authors' institution over an 11-year period, were compared. METHODS: Between January 1993 and December 2003, a total of 1,161 patients (758 males, 403 females) received either a St. Jude Medical (SJM) or ATS mechanical heart valve. Follow up was obtained via an in-house Quality Management Database, ascertained by telephone questionnaire of the patients and/or family physicians. Follow up was 98.9% complete; the median follow up was 4.6 years; total follow up was 5,624 patient-years (pt-yr). RESULTS: A total of 604 SJM and 601 ATS prostheses was implanted as isolated (n = 669) or combined (n = 492) procedures. The overall 30-day mortality for SJM and ATS was 4.1% and 3.4%, respectively (p = 0.45). Cumulative survival and freedom from valve-related mortality at 10 years for SJM and ATS valves were 66 +/- 3% versus 68 +/- 5% (p = 0.84) and 96 +/- 1% versus 97 +/- 1% (p = 0.36), respectively. No structural valve failure was encountered for both valve types. Freedom from overall valve-related complications at 10 years was 79 +/- 4% for SJM and 66 +/- 6% for ATS (p = 0.08). The linearized rates for valve-related adverse events for SJM and ATS valves, respectively, were: thromboembolism 0.9 and 1.1%/pt-yr; major bleeding requiring transfusion 0.3 and 0.5%/pt-yr; prosthetic endocarditis 0.03 and 0.1%/pt-yr; paravalvular leak 0.1 and 0.6%/pt-yr. CONCLUSION: On the basis of an 11-year experience, both bileaflet valves showed very good clinical results, with low incidences of adverse events during the mid-term outcome. Gender and/or concomitant coronary artery disease were not predictors for reduced life expectancy.     

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.     

Mid-term results of valve replacement with the ATS valve: a seven-year follow up

BACKGROUND AND AIM of the study: The ATS open pivot bileaflet valve has been the prosthesis of choice at the authors' hospital since 1997. Herein is presented a retrospective analysis of the mid-term results of valve replacement with the ATS valve prosthesis. METHODS: Between 1997 and 2005, a total of 280 patients (mean age 58.3 years) underwent valve replacement with the ATS valve; these included 133 aortic valve replacements (AVR), 115 mitral valve replacements (MVR), and 32 double (aortic plus mitral) valve replacements (DVR). Preoperatively, 162 patients (57.9%) were in NYHA functional class II, 97 (34.6%) in class III, 19 (6.8%) in class IV, and two (0.7%) in class V. Atrial fibrillation was detected in 105 patients (37.5%), and significant coronary artery disease was found concomitantly in 13 (4.6%). Postoperative anticoagulant therapy consisting of warfarin and an antiplatelet drug was usually instituted on the first postoperative day, and the International Normalized Ratio maintained between 1.6 and 2.5. RESULTS: Overall hospital mortality was 3.6% (n = 10). Hospital survivors were followed for a mean period of 4.2 years (maximum 10 years); the total follow up was 1,127.9 patient-years (pt-yr). Follow up was complete for 267 patients (98.9%). Actuarial survival at seven years was 87.1% for AVR, 79.8% for MVR, and 90.1% for DVR. The probability of freedom from valve-related death at seven years was 96.7% for AVR, 94.4% for MVR, and 100% for DVR. The linearized rates for postoperative complications were thromboembolism 1.2%/pt-yr, major bleeding 0.7%/pt-yr, prosthetic valve endocarditis 0.2%/pt-yr, non-structural dysfunction 0.7%/pt-yr, and reoperation 0.5%/pt-yr. Structural valve failure was not encountered. CONCLUSION: This clinical experience with the ATS open pivot heart valve demonstrated low rates of adverse events and valve-related complications.     

Simultaneous aortic and mitral valve replacement: predictors of adverse outcome

BACKGROUND AND AIM OF THE STUDY: Uncertainties remain regarding the influence of several preoperative and intraoperative factors on outcome after double (simultaneous aortic and mitral) valve replacement (DVR). METHODS: Between 1981 and 1999, 132 patients (58 males, 74 females; mean age 53.8 years) underwent DVR with either aortic and mitral bileaflet mechanical valves in 81 patients, aortic tilting disk valve and mitral bileaflet valve in 36, and aortic tilting disk and mitral biological valve in 15. The mean duration of follow up was 7.6 years; cumulative follow up was 860 patient-years (pt-yr). RESULTS: Early mortality was 9.9% (n = 13). Late death occurred in 21 patients (linearized rate 2.4%/pt-yr; freedom rate at 10 years 77.6 +/- 5.4%) including cardiac-related death in 16 patients (linearized rate 1.9%/pt-yr; freedom rate at 10 years 86.9 +/- 4.5%) and valve-related death in 11 (linearized rate 1.3%/pt-yr; freedom rate at 10 years 87.7 +/- 4.3%). Late morbidity included 30 cases of thromboembolism (linearized rate 3.5%/pt-yr; freedom rate at 10 years 70.2 +/- 6.1%), seven bleeding (linearized rate 0.8%/pt-yr; freedom rate at 10 years 95.6 +/- 2.2%), 22 reoperations (linearized rate 2.6%/pt-yr; freedom rate at 10 years 79.4 +/- 5.1%), three prosthetic valve endocarditis, 13 structural valve deterioration, and two paravalvular leakage. Independent determinants of early and late mortality and morbidity, except for valve reoperation, were preoperative patient-related factors of NYHA class IV, left ventricular ejection fraction < or = 40%, mean right atrial pressure > or = 15 mmHg, and mean pulmonary artery wedge pressure > or = 25 mmHg. However, late valve reoperation and all valve-related complications were influenced by a valve-related factor, namely mitral bioprosthesis. CONCLUSION: Earlier surgical management before the development of severe heart failure, myocardial dysfunction and hemodynamic deterioration would improve the results of DVR. Mitral bioprosthesis combined with a mechanical aortic valve should be avoided as it increases the risk of reoperation.     

Clinical experience of 473 patients with the omnicarbon prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: The long-term clinical experience of patients receiving Omnicarbon heart valve prostheses between January 1985 and December 1996 was investigated. METHODS: In total, 473 patients (255 males, 218 females; mean age 57.5 +/- 10.1 years (range: 20n-73 years) received 523 prostheses. These included 253 mitral (MVR), 170 atrial (AVR) and 50 double (DVR) valve replacements. RESULTS: The 30-day mortality rate was 4.7% (n = 22); in addition eight patients died more than 30 days after surgery, but during the same hospital stay. Mean follow up was 3.9 years (maximum 11 years and 7 months). Cumulative follow up was 1,750.1 patient-years (pt-yr); follow up was 97.5% complete. Among 39 late deaths, 20 were valve-related (seven cerebral infarction, seven cerebral bleeding, six endocarditis) and four cardiac-related. The overall five-year cumulative survival rate (excluding early mortality) was 90.2 +/- 11.7% (MVR 88.0 +/- 2.5%, AVR 93.1 +/- 2.3%, DVR 93.7 +/- 4.8%). At 10 years, the overall survival rate was 76.4 +/- 7.7%. Valve-related complications included thromboembolism (n = 13, 0.7%/pt-yr), anticoagulation-related hemorrhage (n = 12, 0.7%/pt-yr) and endocarditis (n = 7, 0.4%/pt-yr). Neither mechanical failure nor clinical hemolysis was observed. The overall valve-related event-free rate after five years was 89.3 +/- 2.0% (MVR 89.8 +/- 2.4%, AVR 93.5 +/- 2.6%, DVR 89.4 +/- 5.7%) and after 10 years it was 87.6 +/- 2.6% (MVR 85.4 +/- 3.7%, AVR 93.5 +/- 2.6%, DVR 82.5 +/-10.1%). CONCLUSIONS: These long-term results with the Omnicarbon valve are excellent; especially satisfactory results were achieved in terms of the low rate of thromboembolic complication.     

The Mosaic bioprosthesis in the aortic position: seven years' results

BACKGROUND AND AIM OF THE STUDY: The Mosaic bioprosthesis is a stented porcine aortic valve, which combines glutaraldehyde fixation with zero-pressure and root-pressure techniques and anti-mineralization treatment with amino-oleic acid for improved hemodynamics and tissue durability. The study aim was to collect intermediate-term data of the Mosaic bioprosthesis in the aortic position, the first device having been implanted in February 1994 at the authors' institution. METHODS: A total of 100 patients (49 females, 51 males) underwent aortic valve replacement with the Mosaic bioprosthesis between February 1994 and May 1999. Mean age at implant was 73.4 +/- 7.3 years. Concomitant procedures were performed in 40.0% of cases. Patients were followed up within 30 days postoperatively, after six months, and at annual intervals thereafter. Mean follow up was 3.8 years (range: 0.1-7.1 years); total follow up was 383.1 patient-years (pt-yr) and 100% complete. RESULTS: Early mortality (< or = 30 days) was 3.0%; late mortality was 4.6%/pt-yr, including a valve-related mortality of 0.6%/pt-yr. Freedom from event at seven years was 96.8 +/- 1.8% for thromboembolic events, 97.2 +/- 2.0% for thrombosed bioprosthesis, 96.6 +/- 2.6% for structural valve deterioration, 98.2 +/- 1.8% for nonstructural dysfunction, 95.9 +/- 2.0% for anti-thromboembolic hemorrhage, 98.9 +/- 1.1% for endocarditis, and 93.9 +/- 3.2% for reoperation/explant. After one year, the mean systolic pressure gradient was 15.3 +/- 6.7, 14.5 +/- 5.7, 12.7 +/- 4.1 and 12.9 +/- 4.8 mmHg for 21, 23, 25 and 27 mm valves respectively; the effective orifice area (EOA) was 1.4 +/- 0.4, 1.7 +/- 0.4, 1.8 +/- 0.4 and 2.6 +/- 0.4 cm2 for 21, 23, 25 and 27 mm valves respectively; and the EOA index was 0.8 +/- 0.3, 0.9 +/- 0.2, 0.9 +/- 0.2 and 1.3 +/- 0.1 cm2/m2 respectively. The mean left ventricular mass index was decreased significantly, from 159.7 +/- 56.8 g/m2 to 137.3 +/- 40.8 g/m2, for all valve sizes after one year. CONCLUSION: Clinical and hemodynamic performance of the Mosaic bioprosthesis was highly satisfactory during the first seven years after clinical introduction.     

North American multicenter experience with the On-X prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: This ongoing, longitudinal, multi-center, North American study was designed to evaluate the safety and effectiveness of the On-X valve. METHODS: The On-X valve was implanted in isolated aortic (AVR) and mitral (MVR) valve replacement patients at nine North American centers. Follow up was 98.6% complete. Anticoagulation compliance was evaluated by collection of international normalized ratio (INR) results in all patients throughout their postoperative follow up. Adverse events were recorded according to the AATS/STS guidance criteria. Hematologic studies were conducted postoperatively to evaluate hemodynamics and hemolysis. RESULTS: In total, 142 AVR and 142 MVR implants were performed; the mean follow up was 4.5 years; total follow up was 1,273 patient-years (pt-yr). At implant, the mean patient age was 59.2 years (range: 28 to 85 years); 71.8% of patients who underwent AVR and 33.1% who underwent MVR were males. Preoperatively, 89.4% of AVR patients and 56.3% of MVR patients were in sinus rhythm. The cardiac disease etiology was primarily stenotic, calcific degeneration in AVR and rheumatic or degenerative regurgitation in MVR. Hemolysis represented by postoperative elevation of serum lactate dehydrogenase was very low (median 217 IU after AVR and 251 IU after MVR at one year (82% AVR and 98% MVR of upper normal). Late adverse event rates were low, most notably thromboembolism (0.9%/pt-yr after AVR; 1.6%/pt-yr after MVR) and thrombosis. Kaplan-Meier event-free rates at five years were correspondingly high. Anticoagulation compliance analysis showed only about 40% of INR readings to be within target ranges postoperatively; thus, the control range achieved was much greater than the desired target, as might generally be expected for clinic-controlled INR. CONCLUSION: The On-X valve performed well in this study, confirming the original design intent of minimal hemolysis and low adverse event rates.     

Mid-term results with 1,503 CarboMedics mechanical valve implants

BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was introduced in 1986, and first implanted by the authors in March 1991. The aim of this study was to analyze the authors' clinical experience with this valve. METHODS: Between March 1991 and October 1998, 1,503 valves were implanted in 1,350 patients (758 males, 592 female; mean age 62 +/- 13 years). Follow up was 99% complete and totaled 4,342 patient-years (pt-yr). Results: The hospital mortality rate was 4.3% (59/1,350). Preoperative NYHA class (p = 0.012), emergency surgery (p = 0.03) and cardiopulmonary bypass time (p = 0.01) were significantly associated with increased risk of operative death (multiple logistic regression). Mean (+/- SEM) survival rates at one and five years were 92.0 +/- 0.7% (n = 1,109) and 80.0 +/- 1.3% (n = 335). Freedom from valve-related complications (linearized rate 5.6%/pt-yr) at one and five years was 89.5 +/- 0.8% (n = 1,031) and 76.3 +/- 1.4% (n = 284). Linearized rates for bleeding events were 2.19%/pt-yr, thromboembolic events 2%/pt-yr, operated valvular endocarditis 0.18%/pt-yr, valve thrombosis 0.14%/pt-yr and non-structural dysfunction 1.22%/pt-yr. Freedom from reoperation at one and five years was 98.5 +/- 0.3% (n = 1,107) and 97.3 +/- 0.5% (n = 334). CONCLUSION: Mid-term results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.     

CarboMedics and Monostrut valves: clinical and hemodynamic outcomes in a randomized study

BACKGROUND AND AIM OF THE STUDY: Our aim was to compare the CarboMedics (CM) and Monostrut (M) mechanical heart valve prostheses in the aortic position. These prostheses have been studied extensively in the past, both have well-defined characteristics, and have not been modified for many years. METHODS: This randomized, prospective study included 200 consecutive patients; 100 received the CM prosthesis and 100 the M prosthesis. Both groups were statistically similar in terms of age, aortic valve lesion, and preoperative clinical and surgical characteristics. Mean follow up was 5.58 years (range: 2 months to 11 years); total follow up was 1095 patient-years (pt-yr) (CM 5.33 years, 528 pt-yr; M 5.85 years, 567 pt-yr). RESULTS: Early mortality rates were 1% in the CM group and 3% in the M group. Late mortality rates were 7% and 9%, respectively. Mean (+/- SD) survival rates at 11 years were 80.51 +/- 7.36% for the CM group and 79.62 +/- 5.59% for the M group. There were no cases of mechanical valve failure in either group. The linearized rates of major thromboembolism were 1.03% and 0.20% per pt-yr for the CM and M groups, respectively; the rates of major bleeding-events were 0.71% and 0.61% per pt-yr, respectively. The rate of paravalvular leak was 0.35% and 0% per pt-yr in the CM and M groups, respectively. Postoperative NYHA class was I-II in 95.83% of CM patients, and in 94.37% of M patients. CONCLUSION: Clinical results with CarboMedics and Monostrut prostheses are highly satisfactory, but no superiority of one valve over the other can be identified.     

Tricuspid valve replacement: bioprostheses are preferable

BACKGROUND AND AIM OF THE STUDY: Tricuspid valve replacement (TVR) is rarely undertaken, most surgeons preferring to use conservative tricuspid valve procedures. Thus, limited data are available in patients following TVR. The purpose of this study was to analyze the early and late results in 87 patients (52 tissue valves, 35 mechanical prostheses) who underwent TVR between January 1973 and September 1996. METHODS: The patient group comprised 74 (85%) females and 13 (15%) males; mean (+/- SD) age was 59.4 +/- 12.8 years; range: 15 to 81 years). Forty-four patients (51%) had undergone at least one previous cardiac operation. There were 19 (23%) isolated TVRs, 43 (49%) triple valve replacements, and 25 (29%) double valve replacements. Total cumulative follow up was 707 patient-years (pt-yr) (tissue valves 393 pt-yr, mechanical valves 314 pt-yr); mean follow up was 8.1 years (range: 0 to 23.6 years). RESULTS: The early (30-day) mortality rate was 10.3% (n = 9; tissue 7, mechanical 2, p = 0.28). Logistic regression identified prolonged cardiopulmonary bypass time (p <0.03) and advanced NYHA functional class (p <0.007) as risk factors for operative death. No risk factors were significant on multiple logistic regression analysis. Mean (+/- SEM) survival rate was 68 +/-5.3% (n = 50) at 5 years, 52 +/- 5.9% (n = 36) at 10 years, 35 +/- 6% (n = 20) at 15 years, and 16 +/- 5.3% (n = 7) at 20 years. Freedom from tricuspid valve reoperation at 5, 10 and 15 years was 93 +/- 3.3% (n = 46), 83 +/- 5.8% (n = 33) and 71 +/- 2.8% (n = 17) respectively. Eleven patients required tricuspid valve reoperation: six mechanical valves (five for prosthetic valve thrombosis and one for mechanical failure secondary to pannus ingrowth), and five tissue valves (two for prosthetic valve endocarditis and three for prosthetic valve degeneration). Freedom from reoperation at 5, 10 and 15 years for tissue prostheses was 97 +/- 2.5%, 89 +/- 6.3% and it was 70 +/- 12%, and 86 +/- 7.4%, 74 +/- 9.9% and 68 +/-11% for mechanical prostheses. The mechanical prostheses required reoperation earlier after the initial surgery. CONCLUSIONS: We recommend the use of a bioprosthesis in the tricuspid position because of its initial durability and low reoperation rate.     

Fourteen years' experience with the CarboMedics valve in young adults with aortic valve disease

BACKGROUND AND AIM OF THE STUDY: Homografts and the Ross procedure are recommended by many surgeons for aortic valve replacement (AVR) in young adults. The study aim was to monitor patient outcome over a 14-year period after implanting mechanical CarboMedics prosthetic heart valves in young adults with aortic valve disease. METHODS: Between November 1987 and December 2000, 55 patients (42 males, 13 females; median age 33 years; range 15-40 years) each received a CarboMedics valve in the aortic position. All patients were included on a consecutive and non-selected basis. Concomitant surgery was performed in five patients. Anticoagulation was commenced on postoperative day 1. After discharge, patients were followed up by their cardiologist or general practitioner using questionnaires and telephone calls. Actuarial estimates of survival and freedom from morbid events were calculated using the Kaplan-Meier method. RESULTS: No patient died during surgery. Complete follow up data were available for all patients; total follow up was 404 patient-years (pt-yr). The 30-day mortality rate was zero. Actuarial survival at 14 years was 90 +/- 4.9%, and actuarial freedom from all valve-related events 92 +/- 3.7%. No valve thrombosis or major bleeding events were identified. Linearized rates per 100 pt-yr were: embolism 0.25; paravalvular leakage 0.25; prosthetic endocarditis 0.25; and reoperation 0.50. There was no hemolysis, prosthetic valve dysfunction, or structural deterioration. CONCLUSION: Over a 14-year period, implantation of the CarboMedics prosthetic heart valve has proven to be an excellent solution for AVR in young adults with aortic valve disease.