Susceptibility to acidification of groundwater-dependent wetlands affected by water level declines, and potential risk to an early-breeding amphibian species.

Eggs of the Western spadefoot toad (Pelobates cultripes) reached a 100% mortality in all 29 clutches deposited at a pH below 5.0 in a temporary pond of the Doñana National Park (SW Spain) throughout the wet season of 2006-2007. A similar trend was detected in a neighbouring pond. The proximity of these two ponds to a groundwater pumping area (<1.5km), prompted us to elucidate the possible links between the reduction in pond hydroperiod over past decades (1989-2008) and the decrease of groundwater pH-buffering capacity. The average hydroperiod had decreased by 4months since 1998-99 in the pond where the extensive egg mortality had occurred. The total alkalinity, and the Mg(2+)concentration had also significantly declined in the shallow water-table since 1998-99, from an average of 8.56 to 0.32meql(-1), and of 3.57 to 1.15meql(-1), respectively. This decline of the shallow groundwater buffering capacity could turn this pond more susceptible to the inorganic acidity associated with pyrite oxidation as the sediment S content was often above 0.03%. The initial ratio of S/Ca+Mg in the summer dry sediment was a good predictor of pore-water pH on re-wetting after desiccation (r(2)=0.802, p<0.01). Therefore, this ratio can give some anticipation to mitigate the impact of acidity on toad hatching before these temporary ponds are reflooded on the next wet season. Our results suggest that the long-term damage to pond water levels can trigger a potential risk of soil acidification in the presence of iron-sulphide minerals.

Fifteen-year experience with the mitral Carpentier-Edwards PERIMOUNT pericardial bioprosthesis.

BACKGROUND: This multicenter study concerning the mitral PERIMOUNT valve previously reported clinical results at 12 years; this report updates the performance to 15 years postoperatively. METHODS: The 435 patients (mean age 60.7+/-11.6 years; 41.1% male) underwent implantation with the PERIMOUNT valve between 1984 and 1989 at seven institutions. Follow-up was complete for 96.1% of the cohort. The mean follow-up was 8.1+/-4.4 years (range 0 to 15.4 years) for a total of 3492 patient-years. RESULTS: There were 34 (7.8%) operative deaths, one (0.2%) valve related. The late mortality rate was 5.3%/patient-year (2.2%/patient-year valve related). At 14 years, the overall actuarial survival rate was 37.1%+/-3.3% (63.1%+/-4.4% valve related). Actuarial freedom from complications at 14 years was as follows: thromboembolism, 83.8%+/-3.2% (1.1%/patient-year); hemorrhage, 86.6%+/-3.2% (1.1%/patient-year); and explant due to structural valve deterioration (SVD), 68.8%+/-4.7%. Actual freedom from explant due to SVD was 83.4%+/-2.3%. Rates of structural failure decreased with increasing age at implant. CONCLUSIONS: The Carpentier-Edwards PERIMOUNT Pericardial Bioprosthesis is a reliable choice for a tissue valve in the mitral position, especially in patients more than 60 years of age.

Short-term hemodynamic performance of the mitral Carpentier-Edwards PERIMOUNT pericardial valve. Carpentier-Edwards PERIMOUNT Investigators.

BACKGROUND: Although long-term durability data exist, little data are available concerning the hemodynamic performance of the Carpentier-Edwards PERIMOUNT pericardial valve in the mitral position. METHODS: Sixty-nine patients who were implanted with mitral PERIMOUNT valves at seven international centers between January 1996 and February 1997 consented to participate in a short-term echocardiography follow-up. Echocardiographs were collected at a mean of 600+/-133 days after implantation (range, 110 to 889 days); all underwent blinded core lab analysis. RESULTS: At follow-up, peak gradients were 9.09+/-3.43 mm Hg (mean, 4.36+/-1.79 mm Hg) and varied inversely with valve size (p < 0.05). The effective orifice areas were 2.5+/-0.6 cm2 and tended to increase with valve size (p = 0.08). Trace mitral regurgitation (MR) was common (n = 48), 9 patients had mild MR, 1 had moderate MR, none had severe MR. All MR was central (n = 55) or indeterminate (n = 3). No paravalvular leaks were observed. Mitral regurgitation flow areas were 3.4+/-2.8 cm2 and were without significant volumes. CONCLUSIONS: In this multicenter study, these mitral valves are associated with trace, although physiologically insignificant, central MR. Despite known echocardiographic limitations, the PERIMOUNT mitral valves exhibit similar hemodynamics to other prosthetic valves.

Structural valve deterioration in mitral replacement surgery: comparison of Carpentier-Edwards supra-annular porcine and perimount pericardial bioprostheses.

BACKGROUND: Bioprostheses preserved with glutaraldehyde, both porcine and pericardial, have been available as second-generation prostheses for valve replacement surgery. The performance with regard to structural valve deterioration with the Carpentier-Edwards supra-annular (CE-SAV) porcine bioprosthesis and the Carpentier-Edwards Perimount (CE-P) pericardial bioprosthesis (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) was evaluated to determine whether there was a difference in mitral valve replacement. METHODS: The CE-SAV bioprosthesis was implanted in 1266 overall mitral valve replacements (isolated mitral, 1066; mitral in multiple, 200) and the CE-P bioprosthesis in 429 overall mitral valve replacements (isolated mitral, 328; mitral in multiple, 101). The mean age of the CE-SAV population was 64.2 +/- 12.2 years and that of the CE-P population, 60.7 +/- 11.7 years (P =.0001). For the study, structural valve deterioration was diagnosed at reoperation for explantation. RESULTS: The freedom from structural valve deterioration was evaluated to 10 years, and the freedom rates reported are at 10 years. For the overall mitral valve replacement groups, the actuarial freedom from deterioration was significant (P =.0001): CE-P > CE-SAV for 40 years or younger, 80% versus 60%; 41 to 50 years, 91% versus 61%; 51 to 60 years, 84% versus 69%; 61 to 70 years, 95% versus 75%. The older than 70-year group was 100% versus 92% (no significant difference). The actual freedom from structural valve deterioration also demonstrated the same pattern at 10 years: 40 years or younger, CE-P 82% versus CE-SAV 68%; 41 to 50 years, 92% versus 70%; 51 to 60 years, 90% versus 80%; 61 to 70 years, 97% versus 88%; and older than 70 years, 100% versus 97%. The independent risk factors of structural valve deterioration for the overall mitral valve replacement group were age and age groups and prosthesis type (CE-SAV > CE-P). The prosthesis type either in isolated replacement or in multiple replacement was not predictive of structural valve deterioration. The pathology of structural valve deterioration was different: 70% of CE-P failures were due to calcification and 57% of CE-SAV failures were due to combined calcification and leaflet tear. CONCLUSION: The actuarial and actual freedom from structural valve deterioration, diagnosed at reoperation, is greater at 10 years for CE-P than for CE-SAV bioprostheses. The mode of failure is different, and the cause remains obscure. Long-term evaluation is recommended, because the different modes of failure may alter the clinical performance by 15 and 20 years.

Twelve-year experience with the 19 mm Carpentier-Edwards pericardial aortic valve.

BACKGROUND AND AIMS OF THE STUDY: In patients with small aortic annuli, the choice of prosthesis should be based on hemodynamics and valve durability. The Carpentier-Edwards pericardial valve offers good hemodynamic performance and long-term valve durability. We reviewed our 12-year experience with 121 patients who received a 19 mm prosthesis. METHODS: A total of 121 patients (97 females, 24 males; mean age 73.2 +/- 9.4 years) underwent isolated aortic valve replacement with a 19 mm Carpentier-Edwards pericardial bioprosthesis in our institution between July 1984 and December 1995. Patients were followed up for an average of 4.84 years after surgery; total follow up was 581 patient-years (pt-yr). RESULTS: The operative mortality rate was 3.3% (4/121). At the present time, 77 patients (86%) are in NYHA class I or II with a mean gradient of 18.0 +/- 6.9 mmHg and mean effective orifice area 1.1 +/- 0.23 cm2. There were 25 late deaths. After 12 years the actuarial survival rate was 42 +/- 26%. Eight patients died of valve-related cause (one endocarditis, one structural failure, two thromboembolisms, one anticoagulant-related hemorrhage, three sudden deaths). At 12 years, the actuarial rate of freedom from valve-related death was 61 +/- 37% and from non-sudden valve-related death 88 +/- 11%. Valve-related complications included six thromboembolic episodes (1.0%/pt-yr), one endocarditis (0.17%/pt-yr), two reoperations (0.34%/pt-yr) and two structural valve failures (0.34%/pt-yr). After 12 years, freedom from reoperation was 89 +/- 11%, from valve failure 92 +/- 8%, from thromboembolic episodes 82 +/- 16% and from endocarditis 99 +/- 1%. CONCLUSION: With a low rate of structural valve failure at 12 years and a good clinical performance, the Carpentier-Edwards prosthesis is a reliable alternative for small aortic annuli.

Carpentier-Edwards pericardial bioprosthesis in aortic or mitral position: a 12-year experience.

BACKGROUND: The first generation of pericardial valves was withdrawn from the market for a high rate of premature failure. With an original design, Carpentier-Edwards pericardial valves promised improved results. METHODS: Seven hundred eighty-seven patients who underwent isolated aortic valve replacement and 182 patients who underwent isolated mitral valve replacement between July 1984 and December 1995 with Carpentier-Edwards pericardial bioprostheses in our institution were followed up. The patients' mean age was 68.3 (aortic valve replacement, AVR) and 63.9 (mitral valve replacement, MVR) years. All but five AVR patients were followed up for an average of 4.7 years after operation, with a total follow-up of 3,624 patient-years. All patients with MVR were followed up for an average of 5.3 years after operation, with a total follow-up of 969 patient-years. RESULTS: After 12 years, actuarial survival rate is 53% for AVR and 54% for MVR. Freedom from valve-related complications for aortic versus mitral valve replacement is, respectively, 68% and 55%, freedom from valve-related death is 84% and 85%, freedom from thromboembolism 87% and 94%, and freedom from endocarditis 97% and 94%. The behavior of the aortic valve is better than that of the mitral valve: freedom from reoperation is 92% and 76%, respectively; freedom from valve failure is 94% and 78%. Age is an important factor, especially in the mitral position: freedom from valve failure is 52% in patients younger than 60 years and 100% in patients older than 60 years. CONCLUSIONS: With a low rate of valve-related events at 12 years and a low rate of structural deterioration, this prosthesis is a reliable choice for AVR and in patients over 60 years for MVR. A more durable mitral bioprosthesis is needed for patients younger than 60 years.

Carpentier-Edwards pericardial valves in the mitral position: ten-year follow-up.

OBJECTIVE: The first generation of pericardial valves was withdrawn from the market because of a high rate of premature failure. With an original design, Carpentier-Edwards pericardial valves promised improved results. METHODS: One hundred fifty patients who underwent isolated mitral valve replacement, between July 1984 and December 1993, with Carpentier-Edwards pericardial bioprostheses in our institution were followed up. Patient mean age was 62.9 +/- 11.9 years. Operative mortality was 3.3%. All but three patients were followed up for an average of 4.7 years after operation, and total follow-up was 710 patients-years. RESULTS: At the time this article was written, over 80% of patients were in New York Heart Association class I or II. After 10 years, actuarial survival rate was 71% (confidence limit 61% to 81%). Valve-related complications included the following: six valve-related deaths (0.8% patient-year), five thromboembolic episodes (0.7% patient-year), three cases of endocarditis (0.4% patient-year), four reoperations (0.5% patient-year), and four structural valve failures with calcification and stenosis (0.5% patient-year). After 10 years, freedom from valve-related complications was 66% (confidence limit 46% to 86%), from valve-related death 94% (confidence limit 89% to 99%), from reoperation 90% (confidence limit 82% to 98%), and from valve failure 76% (confidence limit 62% to 90%). CONCLUSIONS: With a low rate of valve-related events at 10 years and a low rate of structural deterioration with no leaflet tear, this prosthesis is a reliable choice for patients over 60 years of age.

The Carbomedics prosthetic heart valve: four year follow-up in 100 patients.

From December 1988 to December 1991, 100 patients underwent valve replacement with a Carbomedics bileaflet valve in our institution (55 aortic valve replacements, 28 mitral valve replacements, and 17 double valve replacements). Fifty-nine percent were males. Mean age was 55.7+/-12.3 years. Fifty eight percent of patients were in NYHA Clinical status III or IV. Operative mortality was 3% (3/100). All patients but one were followed up for an average of 2.8 years after their operation and total follow-up was 280 patient years. At the time of the study, more than 80% of patients were in NYHA class I or II, 34% were in atrial fibrillation and 100% of patients received anticoagulation treatment. There were 3 late deaths. After 4 years, the actuarial survival rate was 94%+/-5%. No patients died of valve-related causes. Valve-related complications included 2 thromboembolic episodes (0.7%-patient-year), 8 anticoagulant-related complications (2% patient-year), and one reoperation (0.3% patient-year). After 4 years, freedom from thromboembolic complication was 96%+/-4%, from endocarditis was 100%, from reoperation was 99%+/-1%, and from anticoagulant-related complications was 93%+/-5%. We conclude that the 4-year results compare with other bileaflet valves. More follow-up and larger studies are mandated to give definite conclusions.

Double valve replacement with the Carpentier-Edwards pericardial valve: 10-year results.

BACKGROUND AND AIMS OF THE STUDY: The first generation of pericardial valves was withdrawn from the market because of an excessive rate of premature failure. With an original design, the Carpentier-Edwards pericardial valve promised improved results. MATERIALS AND METHODS: From July 1984 to December 1993, 71 patients underwent double mitral and aortic valve replacement with the Carpentier-Edwards pericardial valve. Mean age was 63.4 years. 58% were male, mean clinical status was 2.9 with 71% of patients in NYHA class III or IV, 55% were in atrial fibrillation. All patients were followed for an average of 4.17 years after their operation, and total follow up was 296 patients years. RESULTS: Operative mortality was 7% (5/71). At this point of the study, 70% of patients are in clinical NYHA class I or II, 42% of patients are in atrial fibrillation and 66% receive anticoagulation treatment. We observed 19 late deaths with an actuarial survival of 58% +/- 14% at ten years. Valve-related complications include four endocarditis, four reoperations, seven anticoagulant-related hemorrhages, two structural failures, one thromboembolic episode, and one sudden death. Two patients died of valve-related causes. After 10 years, freedom from valve related death is 97% +/- 3%, from endocarditis 90% +/- 8%, from reoperation 87% +/- 10%, from thromboembolic complications 98% +/- 2%, from valve failure 93% +/- 7%, and freedom from all complications is 58% +/- 18%. No failure in patients older than 60 years was noted and no leaflet tear was observed. CONCLUSIONS: The 10-year results of this pericardial bioprosthesis make this valve an outstanding choice when a bioprosthesis is required and in patients over 60 years old.

The last generation of pericardial valves in the aortic position: ten-year follow-up in 589 patients.

BACKGROUND: The first generation of pericardial valves has been withdrawn from the market because of excessively high rates of premature failure. With its original design, the Carpentier-Edwards pericardial valve has promised improved results. METHODS: In our institution, 589 patients underwent an isolated aortic valve replacement with a Carpentier-Edwards pericardial bioprosthesis between July 1984 and December 1993. The patients' mean age was 67.5 +/- 11.2 years, and 49% of the patients were in New York Heart Association clinical class III or IV. The operative mortality rate was 2.3% (14 of 595). All patients but 4 were followed up for an average of 4.1 years after their operation, and total follow-up was 2,408 patient-years. RESULTS: At the time of the study, more than 85% of the patients were in New York Heart Association class I or II. There were 79 late deaths. After 10 years, the actuarial survival rate was 71% +/- 7%. Nineteen patients died of valve-related causes (3 endocarditis, 7 thromboembolic complications, 1 structural failure, and 8 sudden deaths). The actuarial rate of freedom from valve-related death was 94% +/- 3% at 10 years. Valve-related complications included 23 thromboembolic episodes (0.9% per patient-year), 14 endocarditis (0.5% per patient-year), 9 reoperations (0.4% per patient-year), and 4 structural valve failures with calcification and stenosis (0.2% per patient-year). After 10 years, freedom from valve-related complications was 84% +/- 6%, from reoperation 97% +/- 2%, and from valve failure 96% +/- 4%. CONCLUSIONS: Because of its low rate of valve-related events at 10 years and low rate of structural deterioration with no leaflet tears, this prosthesis is an outstanding choice for patients who need tissue valves and for patients aged 60 years or older.

The influence of age on valve related events with Carpentier-Edwards pericardial valves.

From July 1984 to December 1991, 641 Carpentier-Edwards pericardial valves were used in 585 consecutive patients. There were 420 aortic valve replacements, 121 mitral valve replacements, and 50 double valve replacements. Mean age was 65.5 +/- 12 years. All patients but 10 were followed up at 3 months periods with a total follow-up of 2074 patients years and a mean follow-up of 3.7 years. Patients were subdivided in 4 groups: Group I: < 50 years, Group II: 50 < age < 65, Group III: 65 < age < 75, Group IV: > 75 years. Actuarial survival rates were 100% in group I, 80 +/- 9% in group II, 68 +/- 11% in group III, and 64 +/- 13% in group IV. Valve related complications included 54 patients and valve related deaths 17. Valve related death rates were 100%, 96 +/- 3%, 95 +/- 4%, 89 +/- 10% respectively (NS). We observed 4 structural failure of the values with respective rates of freedom from valve deterioration of: 92 +/- 6%, 98 +/- 2%, 100%, 100% (NS). No leaflet tears were observed. No difference was found between the 4 age groups in terms of valve related events except for thromboembolic accidents which were more frequent in patients older than 75 years. The absence of difference at 8 years and the absence of leaflet tears indicate the superiority of the Carpentier-Edwards pericardial over previous bioprostheses and the better stress behaviour of this valve. The coming years will allow us to determine the precise place of this pericardial device, especially in young patients and in the mitral position.