Long-term outcomes of valve replacement with modern prostheses in young adults.

OBJECTIVES: To examine the multiple impacts of valve replacement on the lives of young adults. METHODS: Patients (N=500) between age 18 and 50 who had aortic valve replacement (AVR) and/or mitral valve replacement (MVR) with contemporary prostheses were followed annually. Events, functional status, and quality of life were examined with regression models. RESULTS: Median follow-up was 7.1+/-5.3 years (maximum 26.7 years). Five, 10, and 15-year survival was 92.7+/-1.7, 88.3+/-2.4 and 80.1+/-4.7% after AVR, and 93.1+/-2.3, 79.5+/-4.3 and 71.5+/-5.4% after MVR, respectively. Survival decreased with concomitant coronary disease (hazard ratio (HR): 4.5) and preoperative LV grade (HR: 2.0/grade increase) in AVR patients, and with atrial fibrillation (HR: 5.5), coronary disease (HR: 5.7), preoperative left atrial diameter (HR: 3.0/cm increase) and NYHA class (HR: 2.1/class increase) in MVR patients. Despite reoperation, late survival was equivalent between bioprostheses and mechanical valves in both implant positions. The ten-year cumulative incidence of embolic stroke was 6.3+/-2.4% for mechanical AVR patients, 6.4+/-2.9% for bioprosthetic AVR patients, 12.7+/-3.9% for mechanical MVR patients, and 3.1+/-3.1% for bioprosthetic MVR patients. Atrial fibrillation (HR: 2.8) and smoking (HR: 4.0) were risk factors for stroke in MVR patients. In AVR patients, SF-12 physical scores, freedom from recurrent heart failure, and freedom from disability were significantly higher in bioprosthetic than mechanical valve patients. Career or income limitations were more often subjectively linked to a mechanical prosthesis in both implant positions. CONCLUSIONS: Late outcomes of modern prosthetic valves in young adults remain suboptimal. Bioprostheses deserve consideration in the aortic position, as mechanical valves are associated with lower physical capacity, a higher prevalence of disability, and poorer disease perception. Early surgical referral and atrial fibrillation surgery may improve survival after MVR.     

Late incidence and determinants of reoperation in patients with prosthetic heart valves.

OBJECTIVES: Reoperation is a relatively common event in patients with prosthetic heart valves, but its actual occurrence can vary widely from one patient to another. With a focus on bioprosthetic valves, this study examines risk factors for reoperation in a large patient cohort. METHODS: Patients (N=3233) who underwent a total of 3633 operations for aortic (AVR) or mitral valve replacement (MVR) between 1970 and 2002 were prospectively followed (total 21,179 patient-years; mean 6.6+/-5.0 years; maximum 32.4 years). The incidence of prosthetic valve reoperation and the impact of patient- and valve-related variables were determined with actual and actuarial methods. RESULTS: Fifteen-year actual freedom from all-cause reoperation was 94.1% for aortic mechanical valves, 61.4% for aortic bioprosthetic valves, 94.8% for mitral mechanical valves, and 63.3% for mitral bioprosthetic valves. In both aortic and mitral positions, current bioprosthesis models had significantly better durability than discontinued bioprostheses (15-year reoperation odds-ratio 0.11+/-0.04; P<0.01 for aortic, and 0.42+/-0.14; P=0.009 for mitral). Current bioprostheses were significantly more durable in the aortic position than in the mitral position (14.3+/-6.8% more freedom from 15-year reoperation; (P=0.018)). Older age was protective, but smoking was an independent risk factor for reoperation after bioprosthetic AVR and MVR (hazard ratio for smoking 2.58 and 1.78, respectively). In patients with aortic bioprostheses, persistent left ventricular hypertrophy at follow-up and smaller prosthesis size predicted an increased incidence of reoperation, while this was not observed in patients with mitral bioprostheses. CONCLUSIONS: These analyses indicate that current bioprostheses have significantly better durability than discontinued bioprostheses, reveal a detrimental impact for smoking after AVR and MVR, and indicate an increased reoperation risk in patients with a small aortic bioprosthesis or with persistent left ventricular hypertrophy after AVR.     

Ten-year experience with the porcine bioprosthetic valve: interrelationship of valve survival and patient survival in 1,050 valve replacements

The porcine bioprosthetic valve was used in 440 patients having isolated mitral valve replacement (MVR), 522 patients having isolated aortic valve replacement (AVR), and 88 patients having MVR + AVR between 1974 and 1981. Patients with associated surgical procedures were excluded. Mean follow-up was 8.3 years. At 10 years, there was no difference in patient survival between those having AVR and those having MVR. Reoperations were performed on 192 patients. Endocarditis was the reason for reoperation in 3.7% of patients who had MVR and 10.6% of those who had AVR. Structural valve degeneration was the reason for reoperation in 89.7% of MVR patients and 78.8% of AVR patients (p = 0.04). Hospital mortality among patients having valve reoperations was 4.7%. At 10 years, the freedom from valve reoperation for all causes and from structural valve degeneration was significantly better for the AVR group than the MVR group (74% +/- 3% versus 61% +/- 4%, p = 0.004; and 79% +/- 3% versus 63% +/- 4%, p = 0.0006, respectively). For patients in their 60s, the 10-year freedom from reoperation was 92% +/- 2% for AVR and 80% +/- 6% for MVR (p = not significant). At 10 years, freedom from cardiac-related death and valve reoperation was best for both MVR and AVR patients in their 60s. Patients 70 years old or older rarely had reoperation but died before valve failure occurred. The 10-year freedom from all major valve-related events (cardiac-related death, reoperation, thromboembolism, endocarditis, and anticoagulant-related bleeding) was practically the same for both MVR and AVR patients (48% +/- 3% versus 49% +/- 3%, respectively). The porcine bioprosthetic valve is the valve of choice only for patients 60 years old or older. Patients in their 70s have an extremely low rate of reoperation but a high rate of cardiac-related death and do not outlive the prostheses.     

Elderly valve replacement with bioprostheses and mechanical prostheses. Comparison by composites of complications

AIM: The goal of aortic valve replacement (AVR) surgery in the elderly (= or >75 years) is to extend survival and minimize valve-related morbidity, mortality and reoperation. As the elderly population lives longer, those with implanted valves are at risk of suffering valve related complications. We hypothesize that bioprostheses are appropriate for the elderly. METHODS: The follow-up evaluation of 966 patients with valves (AVR, 666; mitral valve replacements [MVR], 226; multiple valve replacements [MR], 74) implanted between 1975 and 1999 was examined. There were 879 bioprotheses (BP) and 87 mechanical prostheses (MP). The mean age was 78.9+/-3.3 years (range 75-94.6 years). Concomitant coronary artery bypass was performed in AVR in 51.7%, MVR in 50.4% and MR in 28.4%. Valve type, valve lesion, coronary artery bypass (previous/concomitant), age and gender were considered as independent predictors of composites and survival. The total follow-up was 3905 patient-years. RESULTS: Early mortality was for AVR 9.6% (64), MVR 15.0% (34) and MR 25.7% (19). The late mortality was for AVR 8.8%, MVR 10.4% and MR 8.8%/patient-year. The only independent predictor of survival and valve-related mortality, morbidity and reoperation was age for survival in those with AVR, hazard ratio 1.15 [CL 1.03-1.27] p=0.0094). The BP reoperative rate was 0.5%/patient-year (reoperation was fatal in 6/15) of total, MP reoperative rate was 0% [reasons for reoperation structural valve deterioration (4), non-structural dysfunction (6), prosthetic valve endocarditis (5), reoperation fatality due to non-structural dysfunction (2), prosthetic valve endocarditis (4)]. Overall patient survival at 10 and 15 years, respectively, was 30.5+/-2.4% and 3.6+/-2.2% irrespective of valve position and type. Overall actual and actuarial freedom from valve-related morbidity at 15 years was 96.8+/-0.9% and 93.7+/-2.3%, respectively. Actual and actuarial overall freedom from valve-related mortality at 15 years was 84.3+/-2.4% and 58.4+/-0.9%, respectively. Overall actual and actuarial freedom from valve related reoperation at 15 years was 95.8+/-1.6% and 74.8+/-16.9%, respectively. CONCLUSIONS: BP valves are further confirmed to be a good option for AVR in patients = or >75 years of age.     

Durability and outcome of aortic valve replacement with mitral valve repair versus double valve replacement

BACKGROUND: The purpose of this study was to evaluate morbidity and mortality after double valve replacement (DVR) and aortic valve replacement with mitral valve repair (AVR + MVP). METHODS: From 1977 to 2000, 379 patients underwent DVR (n = 299) or AVR + MVP (n = 80). Actuarial survival and freedom from reoperation were determined by the Kaplan-Meier method. Potential predictors of mortality and reoperation were entered into a Cox multiple regression model. Propensity score was introduced for the multivariable regression modeling for adjustment of a selection bias. RESULTS: Survival 15 years after surgery was similar between the groups (DVR, 81% +/- 3%; AVR + MVP, 79% +/- 7%; p = 0.44). Freedom from thromboembolic event at 15 years was similar between the groups (p = 0.25). Freedom from mitral valve reoperation at 15 years was significantly better for the DVR group (54% +/- 5%) as compared with the AVR + MVP group (15% +/- 6%; p = 0.0006), primarily due to progression of mitral valve pathology and early structural deterioration of bioprosthetic aortic valve used for patients with AVR + MVP. After AVR + MVP, freedom from mitral reoperation at 15 years was 63% +/- 16% for nonrheumatic heart diseases, and 5% +/- 5% for rheumatic disease (p = 0.04). CONCLUSIONS: Although both DVR and AVR + MVP provided excellent survival, DVR with mechanical valves should be the procedure of choice for the majority of patients because of lower incidence of valve failure and similar rate of thromboembolic complications compared with AVR + MVP. MVP should not be performed in patients with rheumatic disease because of higher incidence of late failure.     

Failure of Hancock pericardial xenografts: is prophylactic bioprosthetic replacement justified?

The incidence of major valve-related complications was evaluated in a series of patients in whom the Hancock pericardial xenograft was used for aortic (AVR; n = 84), mitral (MVR; n = 17) and mitral-aortic (MAVR; n = 13) valve replacement. At 7 years actuarial survival is 66% +/- 8% after AVR, 64% +/- 13% after MVR, and 41% +/- 15% after MAVR, whereas actuarial freedom from valve-related death is 79% +/- 7% after AVR, 78% +/- 13% after MVR, and 81% +/- 12% after MAVR. Actuarial freedom from thromboemboli and anticoagulant-related hemorrhage at 7 years is 93% +/- 4% and 98% +/- 2% after AVR and 83% +/- 10% and 88% +/- 11% after MVR; no such complications occurred after MAVR. Structural valve deterioration determined at reoperation, at autopsy, or by clinical investigation was observed in 34 patients with AVR (10.0 +/- 0.2%/patient-year), in 10 with MVR (10.6 +/- 3.3%/patient-year), and in 9 with MAVR (16.6 +/- 5.5%/patient-year). After AVR, 19 patients underwent reoperation and 2 died before reoperation; 4 patients with MVR underwent reoperation, and 7 patients with MAVR underwent reoperation and 1 died before reoperation. Seventy-eight percent of the current survivors (13 patients with AVR, 7 with MVR, and 1 with MAVR) have clinical evidence of valve failure. At 7 years actuarial freedom from structural deterioration of the Hancock pericardial xenograft is 25% +/- 7% after AVR, 29% +/- 14% after MVR, and 0% after MAVR.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiac valve replacement in patients on dialysis: influence of prosthesis on survival

BACKGROUND: Mechanical valves have been recommended for patients on dialysis because of purported accelerated bioprosthesis degeneration. This study was undertaken to determine time-related outcomes in dialysis patients requiring cardiac valve replacement. METHODS: From 1986 to 1998, 42 patients on chronic preoperative dialysis underwent valve replacement; 17 received mechanical valves and 25 received bioprostheses. Age was similar in both groups: 54+/-18.5 years (mechanical) and 59+/-15.5 years (bioprosthetic, p = 0.4). Sites of valve replacement were aortic (27), mitral (11), and aortic and mitral (4). Follow-up was 100% complete. RESULTS: Survival at 3 and 5 years was 50% and 33% after mechanical valve replacement, and 36% and 27% after bioprosthetic valve replacement (p = 0.3). Four patients with bioprostheses required reoperation: 3 for allograft endocarditis and 1 at 10 months for mitral bioprosthesis degeneration. One patient who received a mechanical valve required reoperation. CONCLUSIONS: Prosthetic valve-related complications in patients on dialysis were similar for both mechanical and bioprosthetic valves. Because of the limited life expectancy of patients on dialysis, bioprosthesis degeneration will be uncommon. Therefore, surgeons should not hesitate to implant bioprosthetic valves in these patients.     

Porcine cardiac bioprostheses: evaluation of long-term results in 990 patients

Clinical results with porcine bioprostheses were reviewed for 990 patients who underwent heart valve replacement from January, 1974, to December, 1980. Eight hundred and seventy-four Hancock, 283 Carpentier-Edwards, and 10 Liotta bioprostheses were used. In 23 patients, 26 mechanical prostheses were implanted as well. Overall operative mortality was 60 out of 990 (6.06%): 30 out of 506 (5.9%) for mitral valve replacement (MVR), 13 out of 287 (4.5%) for aortic valve replacement (AVR), 1 out of 4 (25%) for tricuspid valve replacement, 0 out of 2 for pulmonary valve replacement, and 16 out of 191 (8.4%) for multiple valve replacement. Cumulative follow-up covered 1,793 patient-years. (Actuarial survival at 7 years was 76.6 +/- 3% for MVR. At 6 years, it was 83.2 +/- 2.8% for AVR and 55 +/- 13.5% for multiple valve replacement.) Prosthesis-related survival at 7 years was 91.7 +/- 1.9% for MVR, and at 6 years, it was 96.6 +/- 1.5% for AVR and 95.1 +/- 2.2% for multiple valve replacement. Bioprosthesis survival, considering deaths or complications that led to reoperation as final events, was 84.2 +/- 3.7% at 7 years for mitral valves and 87.7 +/- 3.8% at 6 years for aortic valves. Emboli per 100 patient-years numbered 3.2 for MVR, 0.5 for AVR, and 1.6 for multiple valve replacement. Twenty-seven patients underwent reoperation, 12 for perivalvular leak, 5 for endocarditis, 6 for valve thrombosis, and 4 for primary tissue failure (linearized rates of 0.7, 0.3, 0.3, and 0.2% per patient-year, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Prosthetic valve replacement in children

Between 1975 and 1998, 27 patients aged 3 months to 14 years underwent replacement of the aortic, mitral, tricuspid, and pulmonary valves. Five different types of prosthetic valves were used; three were mechanical valves and two were bioprosthetic valves. There were 3 hospital deaths. Among the 24 survivors there were 4 late deaths. Arrhythmia requiring pacemaker implantation occurred in 2 cases after AVR and TVR. Thromboembolic events occurred in 3 patients, all with mechanical valves in pulmonary position. Infective endocarditis occurred in 1 patient after PVR with a mechanical valve. No bleeding complication occurred among the patients on a regimen of Coumadin and Dipyridamole. Two patients, both with Hancock bioprosthesis, required a second valve replacement on account of severely calcified changes. Mechanical valves in left side heart had a satisfactory long-term performance. One patient who had undergone MVR for congenital parachute mitral valve received reoperation for growth. A larger sized prosthetic valve should be used at the first replacement, and special procedures including supra-annular positioning or annular augmentation are recommended for MVR or AVR respectively.     

Long-term clinical results after aortic valve replacement with mechanical heart valves and mitral valve replacement with porcine valves]

Long-term clinical results of aortic valve replacement (AVR) with mechanical heart valves and mitral valve replacement (MVR) with porcine valves were analysed. Sixty-three patients received isolated AVR and 48 received isolated MVR. Sixty-eight patients with MVR including double or triple valve replacement were also added in order to evaluate the primary tissue failure (PTF). The patients with operative deaths were excluded. Survival rate at 11 years in AVR was 68 +/- 10% and 67 +/- 15% in MVR without statistical difference. At 11 years, 76 +/- 8% of the patients in AVR were free from valve-related complications in contrast with the poor result of 34 +/- 31% in MVR (p less than 0.01). Main cause of this poor result in MVR was PTF as indicated in following event free rates; 83 +/- 9% at 7 years, 61 +/- 25% at 10 years and 49 +/- 31% at 13 years. There was no statistical difference between patients of above 50 years and below 49 years in PTF. Valve-related death event free was 93 +/- 5% in AVR and 86 +/- 11% in MVR at 11 years (not significant), however, there was statistical difference in re-operation event free rate as 94 +/- 5% in AVR and 76 +/- 11% in MVR at 11 years (p less than 0.001). These results suggest that the use of porcine valves in mitral position is confined to the selected patients.     

Intermediate-term outcomes of aortic valve replacement with bioprosthetic or mechanical valves in patients on hemodialysis

ObjectiveTo investigate the influence of choice of prosthesis (bioprosthetic valves or mechanical valves) on intermediate-term outcomes in patients on hemodialysis undergoing aortic valve replacement (AVR).MethodsA multi-institutional retrospective cohort study was conducted in 18 Japanese centers. All adult patients on chronic hemodialysis who underwent AVR from 2008 and 2015 were included (n = 491). The early and late results were compared between groups. The hazard ratios were calculated using Cox regression and Fine–Gray models with adjustment for propensity score based on 41 confounders. The mean follow-up period was 2.5 ± 2.1 years (up to 8.3 years) with 98% completeness.ResultsThere were 323 patients who received a bioprosthetic valve (group B), and 168 patients who received a mechanical valve (group M). There was no significant difference for in-hospital death rate between groups (group B: 12.1%; group M: 8.9%; P = .29). The overall survival rate at 5 years after surgery was 39.3% in group B and 50.4% in group M (P = .42). Freedom from reoperation at 5 years was 97.1% in group B and 97.8% in group M (P = .88). On propensity-score adjusted analyses, there were no significant differences in overall survival between groups.ConclusionsThere were no significant differences in overall survival between bioprosthetic valves and mechanical valves in patients on hemodialysis undergoing AVR.     

Aortic valve selection in the elderly patient

To determine the influence of valve selection on valve-related morbidity and mortality and patient survival, comparative long-term performance characteristics of mechanical (N = 68) and bioprosthetic (N = 73) heart valves were analyzed for 141 patients more than 70 years old who underwent isolated aortic valve replacement between 1970 and 1985. Cumulative patient follow-up was 491 patient-years (average, 4.3 years per patient). Hospital mortality was 18% and 19% for patients with mechanical valves and bioprosthetic valves, respectively. Survival at 5 years was 61 +/- 7% (+/- the standard error) and 67 +/- 10% for recipients of mechanical valves and bioprosthetic valves, respectively. Male sex (p = 0.014) and urgency of operation (p = 0.006) were independent risk factors for hospital mortality. Atrial fibrillation increased valve-related mortality (p = 0.01). No patient required reoperation or experienced structural valve failure. While anticoagulant-related hemorrhage was increased in recipients of mechanical valves (9.2 +/- 2.1%/patient-year) compared with recipients of bioprosthetic valves (2.3 +/- 1.1%/patient-year), it did not result in a death or lead to permanent disability. There was no difference in freedom from any valve-related complication at 5 years. However, when all morbid events are considered, recipients of bioprosthetic valves experienced fewer valve-related complications than patients receiving mechanical valves (10.7 +/- 2.3%/patient-year versus 17.6 +/- 2.5%/patient-year, respectively; p less than 0.05). The reduced incidence of anticoagulant-related hemorrhage and the infrequent need for warfarin sodium anticoagulation favor selection of a bioprosthetic heart valve in patients older than 70 years.     

Tricuspid valve replacement: an analysis of 25 years of experience at a single center

BACKGROUND: Tricuspid valve replacement is seldom used in clinical practice, but the choice between mechanical and biologic prostheses remains controversial. METHODS: Between 1977 and 2002, 97 patients underwent tricuspid valve replacement and were followed at the Montreal Heart Institute Valve Clinic. Patients underwent replacement with bioprostheses (n = 82) and mechanical valves (n = 15). RESULTS: Patients with bioprosthetic tricuspid replacements averaged 53 +/- 13 years of age compared with 48 +/- 11 years in those with tricuspid mechanical valve replacements (p = 0.2). Isolated tricuspid valve replacement was performed in 11 patients (73%) in the mechanical valve group compared with 31 patients (38%. p = 0.01) in the bioprosthetic replacement group. In patients undergoing bioprosthetic tricuspid replacement, 51 (62%) underwent multiple associated valve replacements. The 5-year survival after tricuspid replacement averaged 60% +/- 13% in the mechanical valve group and 56% +/- 6% in the biologic replacement group (p = 0.8). The 5-year freedom rate from tricuspid valve reoperation averaged 91% +/- 9% in patients with mechanical valves and 97% +/- 3% in those with biologic valves (p = 0.2). CONCLUSIONS; Patient survival after tricuspid valve replacement is suboptimal but related to the clinical condition at operation. The use of biologic prostheses for tricuspid valve replacement remains a good option in young patients because of limited life expectancy unrelated to the type of tricuspid prostheses at long-term follow-up.     

Hematological complications with the St. Jude valve and reduced-dose Coumadin

We examined hematological complications in 415 patients having valve replacement with the St. Jude mechanical prosthesis (212, aortic valve replacement [AVR]; 159, mitral valve replacement [MVR]; and 44, AVR + MVR). There were 164 men and 251 women with a mean age of 59 years (range, 20 to 88 years). Preoperatively 386 patients were in New York Heart Association functional classes III and IV. There were 154 associated procedures (37%), the most common being myocardial revascularization. Overall hospital mortality was 7.5% (31/415), 7% after AVR, 8% after MVR, and 7% after AVR + MVR. All operative survivors were anticoagulated with Coumadin (crystalline warfarin sodium) to maintain the prothrombin time at 1.5 times control. During a mean follow-up of 21 months (range, 6 to 60 months), there were 29 late deaths (7.6%) and 5 patients (1.3%) lost to follow-up. No patient experienced structural valve degeneration. At 48 months, actuarial freedom from thromboembolism was 87% +/- 3% after AVR and 91% +/- 9% after MVR; from anticoagulation-related hemorrhage, 97% +/- 3% after AVR and 91% +/- 3% after MVR; and from hemolysis, 100% after AVR and 98% +/- 2% after MVR. Freedom from all valve-related morbidity at 4 years was 82% +/- 5% after AVR and 75% +/- 10% after MVR. Actuarial survival at 48 months was 80% +/- 4% after AVR and 65% +/- 7% after MVR.     

Mitral valve replacement with mechanical prostheses in children: improved operative risk and survival.

OBJECTIVE: The purpose of this study was to assess the early and late outcome following mitral valve replacement (MVR) with mechanical prostheses in children. PATIENTS AND METHODS: Between 1981 and 2000, 44 consecutive children (mean age 6.8+/-4.7 years, 2 months--16 years) underwent mechanical MVR in Southampton. Twenty-three children were less than 5-years-old and nine were infants. Disease aetiology was congenital in 37, rheumatic in four, infective in two and Marfan's syndrome in one. Mitral regurgitation was present in 36 and mitral stenosis in eight. Concomitant procedures were performed in 13, including aortic valve replacement (AVR) in seven. Follow-up was complete (mean 6.4+/-4.8 years, 1 month--18.1 years). RESULTS: The overall operative mortality was 14% (six patients). Before and after 1990 operative mortality was 31 vs 3.6% (P=0.02). From 1990, operative mortality for infants was zero out of six, for children less than 5-years-old was one out of 16 (one death after emergency AVR and MVR) and for older children it was 0/12. Seven children experienced valve or anticoagulation treatment-related events and eight had a mitral valve re-operation. Ten-year freedom from thromboembolism, prosthetic valve infection, bleeding, paravalvular leak and a mitral valve re-operation was 92.8+/-5.2, 97.3+/-2.7, 97.7+/-2.3, 97.2+/-2.7 and 75+/-9.7%, respectively. Overall 10-year survival was 78+/-7% (four late deaths); for children under vs over 5 years it was 61+/-11 vs 95.2+/-4.6% (P=0.02), for atrio-ventricular septal defect (AVSD) vs other pathology 55+/-15 vs 89+/-6.1% (P=0.05) and for those operated before 1990 vs after 1990 it was 63+/-8.1 vs 86+/-8.2% (P=0.04). CONCLUSIONS: Mechanical MVR, in the current era, carries a low operative risk across the spectrum of paediatric age. Late survival is better for older children and those having no-AVSD pathology but it has improved substantially during the 1990s irrespective of age and disease aetiology.     

Aortic valve replacement in patients age 70 years and older: early and late results

This retrospective analysis was performed to determine the early and late outcome in patients 70 years and older undergoing aortic valve replacement (AVR). From October 1994 to May 2001, 49 patients (24 men and 25 women, age 70 to 88 years [mean 74 +/- 4.6 years]) underwent primary AVR with or without concomitant procedures. Twenty-one received mechanical valves and 28 bioprostheses. Age was different between both groups: 72 +/- 2.3 years (mechanical) and 76 +/- 5.1 years (bioprosthetic) (p = 0.0005). Aortic stenosis was present in 25 patients (51%). Follow-up was 100% complete at a mean follow-up of 2.9 years (range 0.3-6.5 years). Overall hospital mortality was 4.1% (2/49). There were no postoperative complications in 24% of patients. Postoperative hospital stay or hospital survival was 27 +/- 13 days. Survival at 3 and 5 years was 89 +/- 5% and 80 +/- 7%, respectively. Three late deaths were due to noncardiac causes and 1 each had a cardiac or valve-related cause (thromboembolism). Other valve-related complications such as anticoagulant-related hemorrhage, perivalvular leak, endocarditis, prosthetic valve failure, and reoperation were not noted in any of the 49 patients. The actuarial survival curve was similar in each group of bioprosthetic versus mechanical and septuagenarians versus octogenarians. Under the selection criteria for AVR currently applied in our hospital, geriatric patients showed a satisfactory early outcome and medium-term survival benefit.     

Early clinical experience with the On-X prosthetic heart valve

The study aimed to assess the performance of the On-X valve (Medical Carbon Research Institute, Austin, TX). Between December 2000 and January 2003 On-X valves were implanted in 400 patients aged 19-85 years (mean: 55.6+/-16), 290 males and 210 females. There were 120 cases of aortic valve replacement (AVR), 258 mitral valve replacement (MVR) and 22 combined aortic and mitral valve replacement (DVR). Additional procedures were performed in 144 patients. Patients were followed up prospectively at 3- to 6-month intervals. Mean follow-up was 38.4+/-11.8 months (maximum 55.6 months). Overall hospital mortality was 3.5%. Freedom from adverse events at 4 years in the study were as follows: thromboembolism, 99.1% for AVR, 98.3% for MVR and 94.7% for DVR patients; thrombosis, 100% for AVR, 99.2% for MVR and 94.7% for DVR; bleeding events, 99.1% for AVR, 99.2% for MVR and 88.8% for DVR; prosthetic endocarditis, 98.2% for AVR, 99.2% for MVR and 94.7% for DVR. Overall survival at 4 years was 92+/-1%. At echocardiographical examination within 1 year of the AVR, the mean aortic valve gradient was 12.8+/-6, 10.3+/-3, 9.0+/-4, 8.3+/-3, and 6.2+/-3 mmHg for 19, 21, 23, 25, 27/29 mm valve sizes, respectively. MVR mean gradient was 4.9+/-2, 4.5+/-1.2 and 4.0+/-0.8 mmHg for 25, 27/29, 31/33 mm valve sizes, respectively. On-X valve is a highly effective mechanical valve substitute with low morbidity and mortality and good functional results.     

Are older patients with mechanical heart valves at increased risk?

Background. Controversy exists regarding the use of mechanical valves in older patients. Many authorities believe that the use of anticoagulants in the elderly is associated with an increased risk of warfarin-related complications. Therefore, we compared the results with mechanical valves in older patients to a cohort of younger patients.

Methods. Aortic (AVR) or mitral valve replacement (MVR) with a mechanical valve was performed in 1,245 consecutive patients who were followed prospectively. They were grouped by age (group 1, ≤ 65 years; group 2, > 65 years). The study groups consisted of AVR (group 1, 459 patients; group 2, 323 patients) MVR (group 1, 313 patients; group 2, 150 patients).

Results. The average age for the groups was: AVR (group 1, 51 years; group 2, 70 years; p = 0.03) and MVR (group 1, 53 years; group 2, 70 years; p = 0.03). For AVR the incidence of thromboembolism was 0.050 (group 1) and 0.038 (group 2) (p = 0.37) and the actuarial freedom from thromboembolism was 83.0% ± 3.0% and 86.5% ± 1.0%, respectively (p = 0.13). The incidence of bleeding after AVR was 0.021 for group 1 and 0.028 for group 2 (p = 0.49). For MVR the incidence of thromboembolism was 0.059 for group 1 and 0.051 for group 2 (p = 0.75) and the actuarial freedom from thromboembolism was 78.8% ± 3.0% and 75.4% ± 8.7%, respectively (p = 0.71). The incidence of bleeding after MVR was 0.020 for group 1 and 0.027 for group 2 (p = 0.62).

Conclusions. Mechanical valves perform well in selected older patients with no increased risk of bleeding or thromboembolism.     

Treatment of endocarditis with valve replacement: the question of tissue versus mechanical prosthesis

BACKGROUND: It remains unknown whether there is any important clinical advantage to the use of either a bioprosthetic or mechanical valve for patients with native or prosthetic valve endocarditis. METHODS: Between 1964 and 1995, 306 patients underwent valve replacement for left-sided native (209 patients) or prosthetic (97 patients) valve endocarditis. Mechanical valves were implanted in 65 patients, bioprostheses in 221 patients, and homografts in 20 patients. RESULTS: Operative mortality was 18+/-2% and was independent of replacement valve type (p > 0.74). Long-term survival was superior for patients with native valve endocarditis (44+/-5% at 20 years) compared with those with prosthetic valve endocarditis (16+/-7% at 20 years) (p < 0.003). Survival was independent of valve type (p > 0.27). The long-term freedom from reoperation for patients who received a biologic valve who were younger than 60 years of age was low (51+/-5% at 10 years, 19+/-6% at 15 years). For patients older than 60 years, however, freedom from reoperation with a biological valve (84+/-7% at 15 years) was similar to that for all patients with mechanical valves (74+/-9% at 15 years) (p > 0.64). CONCLUSIONS: Mechanical valves are most suitable for younger patients with native valve endocarditis; however, tissue valves are acceptable for patients greater than 60 years of age with native or prosthetic valve infections and for selected younger patients with prosthetic valve infections because of their limited life expectancy.     

Clinical performance of the Duromedics bileaflet pyrolite mechanical prosthesis.

The Duromedics (Baxter Healthcare Corp., Edwards CVS Div., Irvine, Calif.) mechanical cardiac valvular prosthesis was implanted in 480 patients between 1984 and 1987 at the Montreal Heart Institute, the Hospital Clinic of Barcelona and the teaching hospitals of the University of British Columbia. The mean age of the patients was 52 years. The early mortality was 7.9% and the late mortality was 4.1% per patient-year. The overall survival at 4 years for aortic valve replacement (AVR) was 87.0% +/- 3.7% and for mitral valve replacement (MVR) was 81.9% +/- 2.9%. There were 16 valve-related reoperations in 14 patients--for prosthetic valve endocarditis in 9 patients, for thromboembolism in 1 patient and for nonstructural dysfunction in 4 patients. The freedom from thromboembolism at 3 and 4 years was 94.3% +/- 3.1% for AVR and 95.1% +/- 1.8% for MVR. The freedom from prosthetic valve endocarditis at 3 and 4 years was 95.3% +/- 2.2% for AVR and 96.2% +/- 1.6% for MVR. The freedom from structural valve deterioration for all positions was 100%. The freedom from reoperation at 4 years was 95.3% +/- 2.1% for AVR and 92.3% +/- 4.3% for MVR and from valve-related death was 98.7% +/- 1.3% for AVR and 96.2% +/- 1.6% for MVR. The freedom from all valve-related complications at 4 years was 87.7% +/- 3.8% for AVR and 85.7% +/- 2.9% for MVR. Long-term evaluation of the Duromedics prosthesis is required to determine the influence of documented structural valve deterioration.