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

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

Twenty-year comparison of tissue and mechanical valve replacement

OBJECTIVE: We sought to compare outcomes with tissue and St Jude Medical mechanical valves over a 20-year period. METHODS: Valve-related events and overall survival were analyzed in 2533 patients 18 years of age or older undergoing initial aortic, mitral, or combined aortic and mitral (double) valve replacement with a tissue valve (Hancock, Carpentier-Edwards porcine, or Carpentier-Edwards pericardial) or a St Jude Medical mechanical valve. Total follow-up was 13,390 patient-years. There were 666 St Jude Medical aortic valve replacements, 723 tissue aortic valve replacements, 513 St Jude Medical mitral valve replacements, 402 tissue mitral valve replacements, 161 St Jude Medical double valve replacements, and 68 tissue double valve replacements. The mean age was 68 +/- 13.3 years (St Jude Medical valve, 64.5 +/- 12.9; tissue valve, 72.0 +/- 12.6). RESULTS: There were no overall differences in survival between tissue and mechanical valves. Multivariable analysis indicated that the type of valve did not affect survival. Analysis by age less than 65 years or 65 years or older and presence or absence of coronary disease revealed similar long-term survival in all subgroups. The risk of hemorrhage was lower in patients receiving tissue aortic valve replacements but was not significantly different in patients receiving mitral valve or double valve replacements. Thromboembolism rates were similar for tissue and mechanical valve recipients. However, reoperation rates were significantly higher in patients receiving both aortic and mitral tissue valves. The reoperation hazard increased progressively with time both in patients receiving aortic and in those receiving mitral tissue valves. Overall valve complications were initially higher with mechanical aortic valves but not with mechanical mitral valves. However, valve complication rates later crossed over, with higher rates in tissue valve recipients after 7 years in patients undergoing mitral valve replacement and 10 years in those undergoing aortic valve replacement. CONCLUSIONS: Tissue and mechanical valve recipients have similar survival over 20 years of follow-up. The primary tradeoff is an increased risk of hemorrhage in patients receiving mechanical aortic valve replacements and an increased risk of late reoperation in all patients receiving tissue valve replacements. The risk of tissue valve reoperation increases progressively with time.     

Mitral and mitro-aortic valve replacement with Sorin Bicarbon valves compared with St. Jude Medical valves

OBJECTIVE: We assessed the clinical results of two bileaflet mechanical valves: the St. Jude Medical (SJM) and the Sorin Bicarbon (Sorin Bicarbon) used either in single mitral valve replacement (MVR) or in double, aortic and mitral, valve replacement (DVR). METHODS: Between September 1990 and November 1995, 217 patients received either a St. Jude Medical (n=134) or a Sorin Bicarbon (n=86): 136 mitral valve replacement with 83 St. Jude Medical and 53 Sorin Bicarbon and 84 double valve replacement with 51 St. Jude Medical and 33 Sorin Bicarbon. There was no difference between both St. Jude Medical and Sorin Bicarbon cohorts in respect of mitral valve physiopathology, etiology of valve disease, associated lesions, echocardiographic and hemodynamic data. The only significant preoperative difference was the age of patients within the double valve replacement group and the size of implanted valves within the mitral valve replacement group. Follow-up was 100% complete with a mean of 39+/-18 months, ranging between 6 and 68 months. The total follow-up was 657 patient-years (pt-y): 396 pt-y in the mitral valve replacement group and 274 pt-y in the double valve replacement group. RESULTS: Hospital mortality (St. Jude Medical: 2.2%; Sorin Bicarbon: 6.9%) and late mortality (St. Jude Medical: 8.4%; Sorin Bicarbon: 6.3%) were not significantly different. Ten deaths were considered valve-related (St. Jude Medical 6, Sorin Bicarbon 4). The estimated 4-yr overall survival, including hospital mortality, was for St. Jude Medical--mitral valve replacement: 89+/-4% and St. Jude Medical--double valve replacement: 93+/-4%, and for Sorin Bicarbon--mitral valve replacement: 87+/-5% and Sorin Bicarbon--double valve replacement: 91+/-5%. The linearized incidence (% per pt-y) of valve-related complications was 6.39 in the St. Jude Medical cohort and 9.2 in the Sorin Bicarbon cohort. The linearized incidence (% pt-y) of the prevalent complication, valve thromboembolism and bleeding, was for St. Jude Medical-mitral valve replacement: 3.41, St. Jude Medical--double valve replacement: 3.16 and for Sorin Bicarbon--mitral valve replacement: 2.17 and Sorin Bicarbon--double valve replacement: 3.67. The differences between each group of an estimated 4-yr freedom from combined thromboembolism and bleeding were not significant (St. Jude Medical--mitral valve replacement: 90+/-4%, St. Jude Medical--double valve replacement: 84+/-6%, and for Sorin Bicarbon--mitral valve replacement: 94+/-3% and Sorin Bicarbon--double valve replacement: 75+/-17%). CONCLUSIONS: In this clinical non-randomized study, there was no evidence of any significant difference between St. Jude Medical and Sorin Bicarbon valves over a 4-yr follow-up.     

Hemodynamic and hemolytic features of the St. Jude Medical valve prostheses

We performed valvular replacement in 86 cases (108 valves, 43 males, 43 females) from July 1978 to July 1981 with St. Jude Medical valves which utilize two discs made of pyrolytic carbon and employ a bileaflet central opening system. Ages ranged from 13 to 68 years (average 42.3). For all cases in this study, we performed anti-coagulant therapy. The incidence of thromboembolic complication was zero. With regard to postoperative clinical evaluation on valve function and chronic hemolysis, we compared the cases of St. Jude Medical valves with those of Starr-Edwards (S.E.) valves (aortic: Model 2320, mitral: Model 6400), Carpentier-Edwards (C.E.) valves and cases of open mitral commissurotomy. As for valve function such as left atrioventricular diastolic pressure gradient, mitral effective orifice area both at rest and on exercise, the St. Jude Medical valve yielded best results. Next was the C.E. and third was the S.E. The results of the St. Jude Medical valve group and those of the open mitral commissurotomy group were equivalent. In comparison with ball type cardiac valve prostheses and bioprostheses, the St. Jude Medical valve has excellent hemodynamic characteristic. Concerning hemolysis, the St. Jude Medical was below only the C.E., however the degree of hemolysis was so low that the St. Jude Medical valve holds great promise as central flow mechanical valve prostheses.     

Prospective randomized comparison of CarboMedics and St Jude Medical bileaflet mechanical heart valve prostheses: an interim report.

OBJECTIVE: This is a midterm report of a study comparing the clinical performance of CarboMedics and St Jude Medical heart valve prostheses through a projected 10-year period. METHODS: Between 1992 and 1996, a total of 485 patients undergoing mechanical valve replacement were prospectively randomly assigned to receive either CarboMedics (n = 234) or St Jude Medical (n = 251) prostheses for aortic (n = 288), mitral (n = 160), or double (n = 37) valve replacements and were followed up annually. RESULTS: Baseline and operative characteristics were similar between the two groups with respect to major demographic characteristics, preoperative clinical status, and operative data. Mean follow-up was 50 +/- 22 months for the CarboMedics group (97% complete) and 47 +/- 20 months for the St Jude Medical group (96% complete), yielding a total of 1959 patient-years. The 30-day mortality, and 5-year actuarial survival, and linearized survival were 6.0%, 82.4% +/- 2.6%, and 4.3% per patient-year in the CarboMedics group and 4.4%, 79.9% +/- 2.8%, and 4.7% per patient-year in the St Jude Medical group (log-rank P =.7). Freedom at 5 years from valve-related mortality, major thromboembolism, hemorrhage, and other nonstructural valve dysfunction was, respectively, 96.7% +/- 1.4% (0.7% per patient-year), 90.9% +/- 2.1% (2.2% per patient-year), 87.3% +/- 2.5% (3.6% per patient-year), and 96.1% +/- 1.4% (0.7% per patient-year) in the CarboMedics group and 95.9% +/- 1.5% (1.0% per patient-year), 92.5% +/- 1.8% (2.0% per patient-year), 82.6% +/- 2.8% (4.3% per patient-year), and 96.0% +/- 1.3% (0.6% per patient-year) in the St Jude Medical group, with no overall intergroup differences. No statistically significant intergroup differences in international normalized ratio values were detected during the study period. CONCLUSIONS: This study shows no significant differences in the early and midterm clinical outcomes between patients who received CarboMedics valve prostheses and those who received St Jude Medical mechanical prostheses. Choices with respect to valve type can be based on considerations other than patient outcome.     

Carpentier-Edwards pericardial aortic valve in middle-aged patients comparison with the St. Jude medical valve

Objective The objective of the present study was to compare long-term results of single aortic valve replacement (AVR) with mechanical (St. Jude Medical valves: standard) and biologic (the Carpentier-Edwards pericardial) prostheses. Method: Between 1995 and 2002, 95 patients who underwent single AVR with mechanical (n=46) or biologic (n=49) prostheses were enrolled in this study. The mean age at the operation was 54.0±9.6 years (range: 20 to 69 years) with the mechanical and 68.8±7.1 years (range: 44 to 85 years) with the biologic prosthesis. Results: The 9-year actuarial survival rate, which was calculated by taking perioperative mortality into account, was 90.3±4.6% for patients with mechanical valves and 87.6 ±4.8% for patients with bioprostheses, with no difference between the two groups (p=0.342). The 9-year freedom rate from thromboembolism, reoperation, endocarditis was 94.8+3.6%, 100% and 97.8 ±2.2% for patients with mechanical valves and 98.0 ±2.0%, 97.5 ±3.4% and 95.0 ±3.4% for those with bioprostheses, respectively. After 9 years, freedom from cardiac death averaged 97.8% in the group with mechanical valves compared with 95.3% in those with bioprostheses (p=0.541). Conclusion: We conclude that the mid-term durability of the Carpentier-Edwards pericardial valve in the aortic position for the elderly is excellent. Nevertheless, the risk of tissue valve reoperation progressively increases with time, and a longer follow-up may be necessary to provide its value compared with the mechanical valves in a country like Japan with a high life expectancy. (Jpn J Thorac Cardiovasc Surg 2005; 53:465-469)     

Bivalvular mechanical mitral-aortic valve replacement in 254 patients: long-term results--a 22-year follow-up

BACKGROUND: We have retrospectively studied 254 patients who underwent a bivalvular mechanical mitral-aortic replacement in the cardiovascular and thoracic surgery unit of Nantes from 1979 to 1989. The follow-up was 22 years (1979 to 2001). The last patient was operated on 12 years before the end of the follow-up. METHODS: All mitral prostheses were St. Jude Medical (SJM) bileaflet valves, and the aortic prostheses were 124 monodisc Bj?rk-Shiley valves, 3 Sorin prostheses, and 127 St. Jude Medical bileaflet prostheses. The mean age was 56.8 +/- 8.5 years with a sex ratio equal to 1. Rheumatism as the etiology predominated with 79.5%. Ninety-seven percent of the patients were followed for a total of 2,779 patient-years and a mean of 11.7 years. RESULTS: Operative mortality was 7.08%. Freedom from overall mortality and valve-related mortality at 22 years were 45.7% +/- 3.6% and 73.1% +/- 3%, respectively. The linearized rates of thromboembolic and hemorrhagic events were 1.07% and 0.9% per patient-year, respectively. Multivariate analysis showed age (p < 0.002), sex (p < 0.01), and degenerative etiology (p = 0.04) as independent factors of late mortality, and age, sex, degenerative disease, and tricuspid pathology were related to valve-related mortality. CONCLUSIONS: This study shows good results after mechanical mitral-aortic replacement in terms of survival rate and quality of life in surviving patients, and outlines the factors influencing long-term results as compared with isolated mitral valve replacement.     

"Our complication rates are lower than theirs": statistical critique of heart valve comparisons

OBJECTIVES: From the widely differing complication rates published for every heart valve, is it possible to determine a true rate for each valve and to compare the rates of two different valves? We investigated this question for the two most popular bileaflet valves. METHODS: Aortic valve data were abstracted from 14 St Jude Medical (St Jude Medical Inc, Minneapolis, Minn; 33,125 patient-y) and 11 Carbomedics (Sulzer Carbomedics Inc, Austin, Tex; 19,141 patient-y) series, and mitral valve data were abstracted from 11 St Jude Medical (21,553 patient-y) and 8 Carbomedics (8368 patient-y) series. Regression analysis was used to accommodate heterogeneity among rates with the same valve model, to estimate hazard ratios and 95% confidence intervals for the valve model effect, and to incorporate other series-level risk factors. RESULTS: Most of the complication rates with both valve models exhibited significant heterogeneity. For thromboembolism and bleeding, the relative risks for valve model were not significantly different from unity. Valve thrombosis rates exhibited less heterogeneity: the Carbomedics valve had a lower rate in the aortic position (hazard ratio 0.2, 95% confidence interval 0.1-0.6) and a higher rate in the mitral position (hazard ratio 1.9, 95% confidence interval 1.0-3.8). CONCLUSIONS: Unlike simple weighted averages of valve complication rates, regression methods can incorporate heterogeneity related to center effects and allow for inclusion of other risk factors. Thromboembolism and bleeding rates were not significantly different with St Jude Medical and Carbomedics valves. Valve thrombosis appeared to differ between the two valves, but the absolute differences in rates were small. Because of the variability among rates with the same valve, statistical comparisons must be interpreted cautiously.     

Long-term results of valve replacement in the right side of the heart in congenital heart disease--comparative study of bioprosthetic valve and mechanical valve

Valve replacements in the right side of the heart (TVR and PVR) were done on 16 patients with congenital heart disease, mainly tetralogy of Fallot and Ebstein anomaly. Including reoperations, 19 operations were performed on them and 20 artificial valves were inserted. Ten mechanical valves (7 St. Jude Medical valves, 3 Starr-Edwards valves) and 10 bioprosthetic valves (7 Carpentier-Edwards valves, 3 Ionescu-Shiley valves) were used. Age at valve replacement ranged from 9 to 52 years (mean 23.0 years), and the follow-up period was 1.28-19.8 years (mean 5.7 years). Including 2 sudden deaths, late death occurred in 4 patients, on all of whom mechanical valve replacements were done at the primary operation. Five-year survival rate of all patients was 76.4 +/- 12.1%, and 10-year survival rate was 63.6 +/- 15.4%. All the patients who received bioprosthesis at the primary operation survived at the time of this follow-up study. On the contrary, long-term results of mechanical valve was unsatisfactory with the 5-year survival of 62.5 +/- 17.1%. In spite of anti-coagulation therapy with warfarin, three patients with mechanical valve complicated thrombotic valves, which necessitated re-operations. Calcified bioprosthetic valve occurred in one patient with I-S valve 8.5 years after the implantation. Five-year complication-free rate was 87.5 +/- 11.7% for bioprosthesis, whereas it was 50.0 +/- 15.8% for mechanical valve (p less than 0.056). It is concluded that the bioprosthesis is the first choice for the valve replacement in the right side of the heart in congenital heart disease.     

Left ventricular outflow tract obstruction with mitral valve replacement in small ventricular cavities

The inference that mitral valve replacement (MVR) may produce left ventricular outflow tract (LVOT) obstruction has been made, but no comparative hemodynamic studies with various types of prostheses have been done. The purpose of the present study was to compare the gradients created across the LVOT with MVR in young sheep with small left ventricular cavities. Mitral valve replacement was accomplished using cardiopulmonary bypass and hypothermic cardioplegic arrest. Five animals were used for each of the following valves studied: 25-mm Ionescu-Shiley bovine pericardial valve, 25-mm Hancock porcine aortic valve, 2M-6120 28-mm Starr-Edwards ball-valve prosthesis, 25-mm Bj?rk-Shiley 60-degree flat tilting-disc prosthesis, and 25-mm St. Jude Medical hemidisc valve. Gradients across the LVOT were measured after MVR and then during infusion of isoproterenol hydrochloride (0.05 micrograms/kg/min). Following MVR, only the Starr-Edwards valve produced an LVOT gradient (32 +/- 23 mm Hg). Substantial gradients after MVR were seen, however, with isoproterenol administration with the Ionescu-Shiley (47 +/- 4 mm Hg), Hancock (13 +/- 8 mm Hg), and Starr-Edwards (65 +/- 30 mm Hg) valves but not with the low-profile valves (Bj?rk-Shiley and St. Jude Medical). The results of the present study demonstrate that MVR can produce LVOT obstruction. The greatest degree of obstruction was with the high-profile mechanical and bioprosthetic valves.     

Ten-year experience with the St. Jude Medical valve for primary valve replacement

The St. Jude Medical valve is a bileaflet prosthesis with excellent hemodynamic characteristics, but the long-term surgical experience with this valve, its durability, and its biocompatibility are unknown. During a 10-year period from March 1978 to 1988, 690 prostheses (290 aortic, 252 mitral, and 74 double aortic-mitral) were inserted as the initial valve replacement substitute in 616 patients (mean age 63 years). Coronary atherosclerosis was present in 58%. Follow-up totaled 2031 patient-years (mean 3.3 years) and was 95% complete (32 lost). Early (30-day) mortality rates were 5.2%, 11.9%, and 8.1% after aortic, mitral, and double valve replacement; 5- and 9-year actuarial survival rates were 71% +/- 3% and 51% +/- 8%, 59% +/- 4% and 41% +/- 6%, and 69% +/- 6% and 47% +/- 15%, respectively. Deaths were associated with extensive coronary atherosclerosis (p less than 0.001), older age (p less than 0.001), advanced preoperative New York Heart Association functional class (p less than 0.05), and malignant ventricular arrhythmias (p less than 0.05). No structural failures have been observed. Embolism (40 events) occurred at a rate of 2.0%/pt-yr (2.3% aortic, 1.6% mitral, 2.0% double). There were six cases of valve thrombosis (0.3%/pt-yr; one fatal). Hemorrhage was the most frequent complication (2.6%/pt-yr); 13 (25%) of 52 events were fatal, accounting for 62% of all valve-related deaths. After the target prothrombin time ratio was lowered, the rate of hemorrhage decreased by 44% (2.7% to 1.5%/pt-yr), while the combined rate of embolism and valve thrombosis increased slightly (2.2% to 2.5%/pt-yr, a 14% change). In summary, the St. Jude Medical valve remains a durable valve substitute. Survival was strongly related to the presence of associated coronary atherosclerosis. The most common complication has been hemorrhage; a less intensive warfarin regimen may reduce hemorrhagic risk while maintaining thromboembolic protection.     

Mitral valve replacement in the first year of life

From 1973 through 1987 25 patients underwent mitral valve replacement in the first year of life for mitral stenosis and mitral regurgitation. The patients with mitral stenosis included two with mitral arcade, two with supravalvular mitral stenosis with hypoplastic mitral valve, and one with parachute mitral valve. Included in the group of patients with mitral regurgitation were 12 with atrioventricular canal defect, six with chordal and leaflet defects, one with Marfan's syndrome, and one with bacterial endocarditis. Prostheses included 12 Bj?rk-Shiley (17 mm), seven St. Jude Medical (19 mm in four, 21 mm in three), five stent-mounted dura mater valves (12 mm to 16 mm), and one porcine xenograft (19 mm). In four patients the valves were placed in the left atrium in a supraannular location. There were nine operative (atrioventricular canal defect seven, mitral regurgitation two) and five late (atrioventricular canal defect four, mitral stenosis one) deaths, giving actuarial 1- and 5-year survival rates of 52% and 43%, respectively. All 6 patients with tissue valves died; the four with supraannular mitral valve replacement survived. Since 1983 operative mortality has been reduced to 0% (70% confidence limits 0% to 24%). Nine patients required a second mitral valve replacement for prosthetic stenosis 5 to 69 (mean 30) months after the original mitral valve replacement (one operative death). Because of improvements in repair of atrioventricular canal defect in infancy, the need for mitral valve replacement at atrioventricular canal defect repair has decreased. Although valvuloplasty has been advocated for repair of congenital mitral valve disease and is applicable in some infants with mitral regurgitation, mitral valve replacement is frequently unavoidable for congenital mitral disease and can now be accomplished at a low operative risk, even when the prosthesis has to be positioned supraannularly.     

Baseline Platelet Aggregation and Major Receptor Expression Predict Subsequent Activity Following Thrombolysis for Acute Myocardial Infarction

Objective - To compare the long-term clinical outcome of patients who underwent aortic valve replacement with St. Jude Medical and Medtronic-Hall mechanical prostheses. Design - From June 1978 to June 1982, 43 Medtronic-Hall and 48 St. Jude Medical mechanical valves were implanted in 90 consecutive patients with aortic valve disease, and their clinical outcome was retrospectively assessed. Results - At 20 years in the St. Jude Medical group and in the Medtronic-Hall group the actuarial rates of overall survival were 50 and 49% ( p = NS), of cardiovascular survival 66 and 63% ( p = NS), of valve-related survival 95 and 91% ( p = NS), of freedom from major valve-related complications 83 and 45% ( p = 0.005), from major cerebrovascular events 93 and 71% ( p = 0.06), from valve thrombosis 97 and 89% ( p = NS), from aortic valve reoperation 93 and 88% ( p = NS), from major bleeding 96 and 82% ( p = 0.04), and from endocarditis 93 and 82% ( p = NS), respectively. The linearized rate of overall major aortic valve prosthesis-related complications was 3.47%/year in the Medtronic-Hall valve group and 1.53%/year in the St. Jude Medical valve group ( p = 0.003). Multivariate analysis showed that the type of prosthesis was predictive of freedom from valve-related complications ( p = 0.01; 2.849; C.I. 95%: 1.246-6.516). Conclusion - The aortic St. Jude Medical mechanical valve seems to be associated with a slightly lower rate of longterm valve-related morbidity than the aortic Medtronic-Hall mechanical valve. Because of the small patient population and the retrospective nature of the study, the choice between these two prostheses should not be made only on the basis of these findings. However, these results suggest a reappraisal for further comparative studies with such an extended follow-up.     

A retrospective comparative study of aortic valve replacement with St. Jude medical and medtronic-hall prostheses: a 20-year follow-up study

OBJECTIVE: To compare the long-term clinical outcome of patients who underwent aortic valve replacement with St. Jude Medical and Medtronic-Hall mechanical prostheses. DESIGN: From June 1978 to June 1982, 43 Medtronic-Hall and 48 St. Jude Medical mechanical valves were implanted in 90 consecutive patients with aortic valve disease, and their clinical outcome was retrospectively assessed. RESULTS: At 20 years in the St. Jude Medical group and in the Medtronic-Hall group the actuarial rates of overall survival were 50 and 49% (p = NS), of cardiovascular survival 66 and 63% (p = NS), of valve-related survival 95 and 91% (p = NS), of freedom from major valve-related complications 83 and 45% (p = 0.005), from major cerebrovascular events 93 and 71% (p =0.06), from valve thrombosis 97 and 89% (p = NS), from aortic valve reoperation 93 and 88% (p = NS), from major bleeding 96 and 82% (p = 0.04), and from endocarditis 93 and 82% (p = NS), respectively. The linearized rate of overall major aortic valve prosthesis-related complications was 3.47%/year in the Medtronic-Hall valve group and 1.53%/year in the St. Jude Medical valve group (p = 0.003). Multivariate analysis showed that the type of prosthesis was predictive of freedom from valve-related complications (p = 0.01; 2.849; C.I. 95%: 1.246-6.516). CONCLUSION: The aortic St. Jude Medical mechanical valve seems to be associated with a slightly lower rate of long-term valve-related morbidity than the aortic Medtronic-Hall mechanical valve. Because of the small patient population and the retrospective nature of the study, the choice between these two prostheses should not be made only on the basis of these findings. However, these results suggest a reappraisal for further comparative studies with such an extended follow-up.     

Valve replacement in the elderly. Is the mechanical valve a good alternative?

The controversy surrounding the choice of a prosthesis for valve replacement in the elderly patient prompted me to review the performance of mechanical (Medtronic Hall [Medtronic, Inc., Minneapolis, Minn.] and St. Jude Medical [St. Jude Medical, Inc., St. Paul, Minn.]) valves implanted in 213 patients 65 years and older (mean 70.4 years) from 1980 to 1985. There were 63 mitral, 131 aortic, and 19 double (aortic and mitral) valve replacements. Most patients undergoing aortic valve replacement had stenotic lesions, but half of the patients in the mitral valve replacement group had regurgitation with or without stenosis. Early mortality rates for mitral, aortic, and double valve replacement were 4.8%, 6.1%, and 21.1%, respectively (p less than 0.01). The mortality rate for patients 65 to 74 years old was 6.5% and that for those older than 75 years was 9.1%. The cumulative follow-up for the survivors was 850 patient-years. The late mortality rate was 8.1% per patient-year but was valve-related in only 1.3% per patient-year. Noncardiac causes accounted for 43.5% of the late deaths. The late mortality rate was significantly higher in patients who had regurgitant lesions than in those who had stenotic or mixed disease. It was also higher in the older patients (10.3% per patient-year) than in the younger group (7.6% per patient-year; p less than 0.05). Reoperation was required in only six patients (0.7% per patient-year). Thrombotic obstruction of the prosthesis and systemic thromboembolism occurred at linearized rates of 0.6% per patient-year and 2.5% per patient year, respectively, and significant anticoagulant-related hemorrhage at a rate of 0.6% per patient-year. With the exception of late mortality, the incidence of all late complications was similar to that of patients younger than 65 years operated on during the same period. Actuarially, global survival (58% +/- 4%) and freedom from reoperation (95% +/- 2%), from thrombotic obstruction (96% +/- 1%), from thromboembolism (92% +/- 2%), from all valve-related mortality and morbidity (82% +/- 3%), and from valve failure (93% +/- 2%) were also similar to those of the younger patients. Mechanical prostheses perform well in elderly patients. I could not confirm an increase in thromboembolic or hemorrhagic episodes, and the respective mortality and morbidity indexes were similar to those observed in younger patients.     

Mitral valve replacement in ischemic mitral regurgitation. Preservation of both anterior and posterior mitral leaflets

BACKGROUND: The surgical risks associated with ischemic mitral regurgitation are thought to be greater than those for other forms of mitral regurgitation. We have performed mitral valve replacement using the St. Jude Medical bileaflet prostheses with preservation of both leaflets, along with all of the chordae tendineae and papillary muscles. The aim of this study was to retrospectively evaluate mitral valve replacement with preservation of both mitral valves with respect to long-term clinical results and left ventricular performance. METHODS: Between January 1, 1988 and February 29, 2000, 15 patients were operated on for ischemic mitral regurgitation. There were 7 males and 8 females, and the mean age was 69.7+/-8.1 years. The preoperative variables showed clinical deterioration of the state, such as emergency operation in 40% of the patients, more than NYHA functional III class in 93% of patients, cardiogenic shock in 47% of the patients, a mean left ventricular ejection fraction of 36.8%, and a mean left ventricular end-systolic volume index of 116.7 ml/m2. RESULTS: There were 5 (33.3%) hospital deaths during the follow-up period including 1 early death and 1 (10%) late death during the follow-up period. Thus, the actuarial survival rate after 5 years for the whole was 60%. However, the left ventricular dimensions and left ventricular fractional shortening, even if in patients with profound depressed left ventricular function preoperatively, showed maintenance of the cardiac function. CONCLUSIONS: These results suggested that mitral valve replacement using the St. Jude Medical prostheses with preservation of both leaflets and all chordae tendineae and papillary muscles might be a procedure of choice for ischemic mitral regurgitation.     

Hemolysis after mitral valve replacement with mechanical valve prostheses

OBJECTIVE: We evaluated effects of type, size, and orientation of mechanical mitral valve prostheses on hemolysis. METHODS: Subjects were 84 patients who had undergone mitral valve replacement. Lactate dehydrogenase was mainly used as a marker of hemolysis and was measured before surgery, 1 month after surgery, and in the late postoperative period. RESULTS: Valves used included 16 Medtronic-Hall, 32 St. Jude Medical, and 36 CarboMedics valves. Medtronic-Hall valves caused less hemolysis than St. Jude Medical or CarboMedics valves in the late postoperative period. This resulted because hemolysis due to Medtronic-Hall valves was more severe 1 month after surgery than in the late postoperative period and because hemolysis due to St. Jude Medical or CarboMedics valves was more severe in the late postoperative period than 1 month after surgery. One reason for this finding is that cardiac output was greater in the late postoperative period than 1 month after surgery, making regurgitation through the pivots of bileaflet valves more severe. The orifice area and the orientation of prostheses did not affect hemolysis. CONCLUSION: St. Jude Medical or CarboMedics valves caused more severe hemolysis than Medtronic-Hall valves in the late postoperative period.     

Late results after mitral valve replacement with bileaflet mechanical prosthesis in children: evaluation of prosthesis-patient mismatch

BACKGROUND: Mechanical prosthesis is the choice of valve at the mitral position in children, although re-replacement of prostheses because of prosthesis-patient mismatch is almost inevitable when prostheses were implanted in small children. The methods to predict prosthesis-patient mismatch as a result of patients' somatic growth or pannus formation in children by noninvasive methods have not been well established. METHODS: Thirty-two children underwent mitral valve replacement with 37 bileaflet mechanical prostheses (26 St. Jude Medical prosthetic valves, and 11 CarboMedics prosthetic valves) and were followed up a mean of 6.8 years (maximum 18.3 years) with a complete follow-up rate of 94%. RESULTS: There were no operative deaths and 5 late deaths. Re-replacement of mitral valve because of prosthesis-patient mismatch was required in 5 patients. Freedom from valve-related events and re-replacement of mitral valve at 15 years were 32% +/- 23% and 54% +/- 18%, respectively. Actuarial survival rate was 63% +/- 19% at 15 years. Prosthetic valve orifice area index (manufactured geometric prosthetic valve area divided by patient's body surface area) was well correlated with maximum transprosthesis flow velocity estimated by Doppler echocardiography during follow-up, whereas valve orifice area index had no significant correlation with pulmonary artery wedge pressure assessed by cardiac catheterization. Maximum transprosthesis flow velocity had a significant correlation with pulmonary artery wedge pressure. CONCLUSIONS: Valve orifice area index itself was not a reliable index to predict prosthesis-patient mismatch. Maximum transprosthesis flow velocity was a useful index to predict pulmonary artery wedge. Invasive cardiac catheterization to determine re-replacement of the prosthesis should be considered when maximum transprosthesis flow velocity exceeds 270 cm/s.     

Clinical outcome in patients with 19-mm and 21-mm St. Jude aortic prostheses: comparison at long-term follow-up

BACKGROUND: Small-sized prostheses for aortic valve replacement may result in residual left ventricular outflow tract obstruction. Aim of the study was to verify whether implantation of 19-mm versus 21-mm St. Jude Medical standard prostheses (St. Jude Medical, Inc, St. Paul, MN) influences long-term clinical outcome. METHODS: Two hundred twenty-nine patients who underwent aortic valve replacement with 19 mm (group 1, 53 patients) or 21-mm St. Jude Medical standard prostheses (group 2, 176 patients) were included in the study. Mean follow-up of current survivors was 10+/-4 years. RESULTS: Operative mortality was 7.5% in group 1 and 8.5% in group 2. At discharge, an important patient-prosthesis mismatch (effective orifice area index < or = 0.60 cm2/m2) was present in 18% of group 1 versus 5% in group 2 (p = 0.004). Among patients with body surface area less than 1.70 m2, such mismatch was present in 15% of group 1 versus 2% of group 2 (p = 0.008). At last follow-up New York Heart Association (NYHA) functional class (p < 0.001), left ventricular mass reduction (p = 0.02), mean (p = 0.002) and peak transprosthetic gradients (p < 0.001), and effective orifice area index (p = 0.005) were significantly better in group 2. Freedom from sudden death (92%+/-5% vs 99%+/-1%, p = 0.01), valve-related death (84%+/-6% vs 90%+/-5%, p = 0.02), and cardiac events (56%+/-13% vs 86%+/-4%, p = 0.008), were significantly lower in group 1. Effective orifice area index was an independent predictor of late cardiac events. CONCLUSIONS: Although long-term results after aortic valve replacement with small-sized St. Jude Medical standard prostheses are satisfactory, 19-mm valve recipients show a high prevalence of important patient-prosthesis mismatch with less evident functional improvement and higher rate of cardiac events, suggesting a very cautious use of this prosthesis.     

Assessment of effective orifice area of prosthetic aortic valves with Doppler echocardiography: an in vivo and in vitro study

OBJECTIVES: We sought to evaluate the Doppler assessment of effective orifice area in aortic prosthetic valves. The effective orifice area is a less flow-dependent parameter than Doppler gradients that is used to assess prosthetic valve function. However, in vivo reference values show a pronounced spread of effective orifice area and smaller orifices than expected compared with the geometric area. METHODS: Using Doppler echocardiography, we studied patients who received a bileaflet St Jude Medical valve (n = 75; St Jude Medical, Inc, St Paul, Minn) or a tilting disc Omnicarbon valve (n = 46; MedicalCV, Incorporated, Inver Grove Heights, Minn). The prosthetic valves were also investigated in vitro in a steady-flow model with Doppler and catheter measurements in the different orifices. The effective orifice area was calculated according to the continuity equation. RESULTS: In vivo, there was a wide distribution with the coefficient of variation (SD/mean x 100%) for different valve sizes ranging from 21% to 39% in the St Jude Medical valve and from 25% to 33% in the Omnicarbon valve. The differences between geometric orifice area and effective orifice area in vitro were 1.26 +/- 0.41 cm(2) for St Jude Medical and 1.17 +/- 0.38 cm(2) for Omnicarbon valves. The overall effective orifice areas and peak catheter gradients were similar: 1.35 +/- 0.37 cm(2) and 25.9 +/- 16.1 mm Hg for St Jude Medical and 1.46 +/- 0.49 cm(2) and 24.6 +/- 17.7 mm Hg for Omnicarbon. However, in St Jude Medical valves, more pressure was recovered downstream, 11.6 +/- 6.3 mm Hg versus 3.4 +/- 1.6 mm Hg in Omnicarbon valves (P =.0001). CONCLUSIONS: In the patients, we found a pronounced spread of effective orifice areas, which can be explained by measurement errors or true biologic variations. The in vitro effective orifice area was small compared with the geometric orifice area, and we suspect that nonuniformity in the spatial velocity profile causes underestimation. The St Jude Medical and Omnicarbon valves showed similar peak catheter gradients and effective orifice areas in vitro, but more pressure was recovered in the St Jude Medical valve. The effective orifice area can therefore be misleading in the assessment of prosthetic valve performance when bileaflet and tilting disc valves are compared.