Up to eight years' follow-up of 997 patients receiving the CarboMedics prosthetic heart valve

Late Mortality and Morbidity in Elderly Patients with Mechanical Heart Valves

A retrospective study was performed in patients under and over 65 years old implanted with a mechanical valve, to compare late mortality and morbidity. Of 381 patients who underwent mechanical valve replacement at Nagoya University in the 1990s, 357 (11 hospital deaths and 13 lost to follow-up; 96.4% follow-up rate) were followed up for 7.9 ± 3.3 years (2,811 patient-years). They were divided into two groups either side of 65 years of age at operation. The young and elderly patient groups contained 275 and 82 patients, respectively. The survival rate in the young group was 96.1% (95% confidence interval, 93.7%–98.5%) at 5 years and 92.0% (95% confidence interval, 88.3%–95.7%) at 10 years, which was significantly better than 88.0% (95% confidence interval, 80.6%–95.4%) at 5 years and 73.8% (95% confidence interval, 66.2%–85.4%) at 10 years in the elderly group. The two groups did not differ significantly in the incidence of thromboembolic events, bleeding events, endocarditis, or reoperation. We are also encouraged by the fact that mechanical valves are not a risk factor for late mortality or morbidity, even in elderly patients.

Early postoperative bridging anticoagulation after mechanical heart valve replacement: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis of studies evaluating anticoagulation during the early postoperative period following mechanical heart valve implantation.

METHODS

Five literature databases were searched to assess the rates of bleeding and thromboembolic events among patients receiving oral anticoagulation (OAC), both with and without bridging anticoagulation therapy with unfractionated heparin (UFH) or subcutaneous low molecular weight heparin (LMWH). The studies' results were pooled via a mixed effects meta-analysis. Heterogeneity (I(2) ) and publication bias were both evaluated.

RESULTS

Twenty-three studies including 9534 patients were included. The bleeding rates were 1.8% (95% confidence interval CI 1.0-3.3) in the group receiving OAC, 2.2% (95% CI 0.9-5.3) in the OAC + UFH group, and 5.5% (95% CI 2.9-10.4) in the OAC + LMWH group (P = 0.042). The thromboembolic event rate was 2.1% (95% CI 1.5-2.9) in the group receiving OAC, as compared with 1.1% (95% CI 0.7-1.8) when the bridging therapy groups were combined as follows: OAC + UFH and OAC + LMWH (P = 0.035). Most of the analyses showed moderate heterogeneity and negative test results for publication bias.

CONCLUSIONS

Bridging therapy following cardiac valve surgery was associated with a lower thromboembolic event rate, although the difference was small, with considerable overlap of the CIs. Direct comparisons are missing. Bridging therapy with UFH appears to be safe; however, this observation has a risk of bias. Early bridging therapy with LMWH appears to be associated with consistently high bleeding rates across multiple analyses. On the basis of the quality of the included studies, more trials are necessary to establish the clinical relevance of bridging therapy and the safety of LMWH.

Clinical outcomes of Carbomedics Top Hat valve with a robust follow-up system

AIM

Late failure of bioprosthetic valves may limit their use in patients < 60 years. The superior hemodynamic performance offered by the Carbomedics Top Hat supraannular valve enables greater effective orifice areas to be achieved. The aim of this study was to assess the clinical outcomes of this valve, using a robust follow-up system.

METHODS

Patients who underwent aortic valve replacement with or without coronary artery bypass grafting between July 1997 and January 2010 with Carbomedics supraannular Top Hat valves were identified. Details of readmissions and late deaths were obtained from the National Hospital Episodes Statistics data and the Office of National Statistics, tracked by the Quality and Outcomes Research Unit. Late complications associated with this prosthesis were evaluated.

RESULTS

Of 253 patients identified, 181 underwent isolated aortic valve replacement and 72 had aortic valve replacement with coronary artery bypass grafting. The 30-day mortality was 1.6%, and 5- and 10-year survival rates were 91.4% and 80.5%, respectively. Detailed readmission data were available after 2001 (n = 170). Two (1.2%) patients required reoperation for endocarditis and pannus formation. Of the 17 late deaths in this subset, 4 were attributable to cardiac causes. One patient was treated for heart failure, and 2 developed bleeding complications.

CONCLUSIONS

Implantation of the Carbomedics Top Hat supraannular valve in our unit resulted in satisfactory in-hospital and midterm survival with low incidences of endocarditis and late heart failure.

Early postoperative anticoagulation after mechanical valve replacement: a systematic review

The optimal approach to early postoperative anticoagulation after mechanical valve implantation remains controversial. This review article examines the pathogenesis of thrombus formation and the different strategies for early postoperative anticoagulation. The most commonly reported anticoagulation regimens had the after estimates of early postoperative thromboembolism and hemorrhage: oral anticoagulation alone (0.9%, 3.3%); oral anticoagulation with intravenous unfractionated heparin (1.1%, 7.2%); and oral anticoagulation with low molecular weight heparin (0.6%, 4.8%). Although intravenous heparin may be associated with a higher incidence of hemorrhage, a randomized trial is needed to provide the best evidence regarding early postoperative anticoagulation after mechanical valve implantation. Nearly four decades have passed since the first mechanical prosthetic valves were implanted. Frequent thromboembolic complications with the first mechanical valves led to recommendations of universal anticoagulation for these patients. Since then, several design changes and modifications have been made to improve the longevity, hemodynamics, and thrombogenicity of newer generation mechanical valves. With improved blood flow, less stasis, and less thrombogenic materials, lower rates of thromboembolism have been reported. Despite these advances however, thromboembolism and anticoagulant-related bleeding continue to account for 75% of all complications after mechanical valve replacement. Occurring most commonly within six months after implantation, these complications can adversely affect mortality and quality of life. Furthermore, the threat of their occurrence creates a psychological burden for each patient with a mechanical valve. The need for life-long anticoagulation in patients with mechanical valves is not in dispute, and the perioperative management of anticoagulation during non-cardiac surgery has been reviewed extensively. However, the approach to early postoperative anticoagulation after mechanical valve implantation is still a matter of debate. The optimal intensity and timing of anticoagulation to prevent early thromboembolism after valve replacement surgery without postoperative bleeding complications is unknown. Hence, many anticoagulation protocols have been proposed, but a lack of consensus remains. The objectives of this study were (1) to reexamine the pathogenesis of thrombus formation and the need for anticoagulation; (2) to critically review the literature on early postoperative anticoagulation strategies; and (3) provide an estimate of the incidence of bleeding and thromboembolism for each approach to early postoperative anticoagulation.

Estimated risk of endocarditis in adults with predisposing cardiac conditions undergoing dental procedures with or without antibiotic prophylaxis

BACKGROUND

Although antibiotic prophylaxis for infective endocarditis (IE) has been recommended for persons with predisposing cardiac conditions (PCCs) for many years, its efficacy, which has not been demonstrated, has been recently challenged. To assess its usefulness, we estimated the risk of developing IE after undergoing a dental procedure for which subjects would be eligible for prophylaxis, both in subjects having (protected procedure) or not having (unprotected procedure) received antibiotic prophylaxis.

METHODS

The number of French persons with PCCs, the annual number of dental procedures in which subjects would be eligible for antibiotic prophylaxis, and the number of procedures that were unprotected were estimated on the basis of a survey performed on a sample of 2805 subjects aged 25-84 years. The annual number of IE cases possibly due to an unprotected procedure was estimated on the basis of a 1-year epidemiological study of IE conducted in an area inhabited by 16 million people.

RESULTS

After standardization, extrapolation of results to the age-equivalent general population (39 millions subjects) indicated the following: first, 3.3% (95% confidence interval [CI], 2.6%-4%) of the subjects had PCC, 2.7 million (95% CI, 2.3-3.2 million) of whom had undergone at least 1 at-risk dental procedures within the survey year, and the procedures were unprotected in 62% of cases; second, 37 (95% CI, 18-68; 2.7%) of the 1370 annual IE cases in France were possibly related to unprotected procedures. Thus, the risks of developing IE were estimated to be 1 in 46,000 for unprotected procedures (1 in 10,700 and 1 in 54,300 for subjects with prosthetic and native valve PCC, respectively) and 1 in 150,000 for protected procedures.

CONCLUSIONS

A huge number of prophylaxis doses would be necessary to prevent a very low number of IE cases.

The CarboMedics prosthetic heart valve: experience with 180 implants

At Jichi Medical School Hospital, three types of mechanical prosthetic valves (CarboMedics, Omnicarbon, Bicarbon) were used without randomization from 1991 to 2000. A retrospective study of valve replacements done between June 1991 and November 2000 utilizing 180 CarboMedics valves in 145 patients who had not previously undergone prosthetic valve replacement or aortic root and/or arch replacement was conducted to evaluate midterm patient outcomes to assess the future continuous use of CarboMedics valves. Women made up 47.6% of the patients and the mean age was 57.5 years (range 12-80 years). Preoperative New York Heart Association functional class was III or IV in 92.4% (134/145) of patients. Mean follow-up of 4.5 years (range 0-10.0 years) was 95.9% complete, with a total of 628 patient-years (PY). Early (within 30 postoperative days) mortality was 5.5% (8 of 145): 3 from hemorrhage, 3 from nonvalve-related heart failure, 1 from infection, and 1 from arrhythmia. There were 16 late deaths (2.54%/PY): 1 from hemorrhage, 4 from unknown causes/sudden death, 4 from nonvalve-related heart failure, and 7 from other noncardiac causes. A total of 121 patients (83.0%) were alive at the last follow-up, done in November 2000. The linearized death rate was 3.82%/year (including 1.11%/year for valve-related deaths). Linearized death rates from various causes were: bleeding, 0.96%/year; thromboembolism, 1.11%/year; thrombosis, 0.39%/year; perivalvular leak, 0.96%/year; endocarditis, 0%/year; hemolysis, 0%/year; and reoperation, 0.63%/year. No structural valve failure was observed. Comparative early mortality rates of valve replacement without aortic root replacement or arch replacement, excluding repeat valve replacement operations, in our institute, were 3.5% (12/307) for all valve types used contemporaneously, 2.6% (2/76) for Omnicarbon valves, and 2.3% (2/86) for Bicarbon valves. Although the CarboMedics valve had a rather high mortality rate of 5.5% (8/145) compared with the total early mortality rate of 3.5%, the low incidence of valve-related complications might support the continued use of the CarboMedics valve for valve replacement.

Long-Term Result of 1144 CarboMedics Mechanical Valve Implantations

BACKGROUND

It has been reported that the CarboMedics mechanical valve has acceptable valve-related complication rates. The aim of this study was to evaluate the long-term performance of the CarboMedics valve.

METHODS

Between August 1988 and September 1999, we implanted 1144 CarboMedics valves in 850 patients (aortic, 179; mitral, 385; double-valve, 234; tricuspid, 52). Mean patient age was 44.5 +/- 12.5 years. Follow-up was completed in 95.3% and the median follow-up period was 7.9 years (6753 patient-years). Patients were divided into four groups according to implanted valve location and number (aortic, mitral, double, and tricuspid valve groups).

RESULTS

The overall hospital mortality rate was 3.4%, and the mortality rates in these groups were 1.7% in the aortic, 2.6% in the mitral, 4.7% in the double, and 9.6% in the tricuspid valve. The tricuspid valve group revealed a significantly higher mortality rate than the aortic and mitral valve groups (p < 0.05). Overall 10-year survival was 87.1% +/- 2.6%, 88.9% +/- 1.7%, 82.4% +/- 2.9%, and 77.5% +/- 7.0% in the aortic, mitral, double, and tricuspid valve groups, respectively. Age and tricuspid valve replacement were identified as significant risk factors of long-term survival by multivariate analysis (p < 0.05), and 99.4% +/- 0.6%, 98.2% +/- 0.8%, 99.2% +/- 0.8%, and 87.6% +/- 0.5% in the aortic, mitral, double, and tricuspid valve groups were free of valve thrombosis at 10 years. The tricuspid valve group demonstrated a significantly higher rate of valve thrombosis (p < 0.05).

CONCLUSIONS

This long-term study of patients that received CarboMedics valve implantation demonstrates that the CarboMedics prosthetic valve has an acceptable incidence of valve-related complications. However, it should be noted that tricuspid valve replacement indicated a higher level of overall mortality and valve thrombosis.

A 10-Year Experience With the Carbomedics Cardiac Prosthesis

BACKGROUND

There are few reports on the long-term results of Carbomedics prosthetic heart valves.

METHODS

Five hundred five patients who underwent valve replacement with this prosthesis in the aortic or mitral position were chosen for this study. Patients' mean age was 57 years. There were 173 aortic (AVR), 253 mitral (MVR), and 79 double (DVR) valve implants. The mean follow-up was 5.1 years, and cumulative follow-up was 2,590 patient-years with an overall follow-up rate of 99.2%.

RESULTS

The early mortality rate for the total population was 2.8% (AVR 1.2%, MVR 3.6%, DVR 3.8%). Actuarial freedom from thromboembolism at 10 years was 81.8% +/- 5.1%, 85.7% +/- 3.2%, and 88.8% +/- 6.8% for AVR, MVR, and DVR, respectively. At 10 years, 92.7% of AVR, 85.4% of MVR, and 94.7% of DVR patients were free of valve-related death. Overall survival rate at 10 years was 77.6% +/- 4.6%, 71.8% +/- 4.2%, and 81.3% +/- 5.8% for AVR, MVR, and DVR, respectively. The linearized rate of thromboembolism was 1.45%/patient-year, 1.78%/patient-year, 0.67%/patient-year; of major bleeding events, 0.52%/patient-year, 0.85%/patient-year, 0.45%/patient-year; of valve thrombosis, 0%/patient-year, 0.25%/patient-year, 0%/patient-year; of prosthetic valve endocarditis, 0.1%/patient-year, 0.25%/patient-year, 0.22%/patient-year; and of all reoperations, 0.31%/patient-year, 0.93%/patient-year, 1.1%/patient-year for AVR, MVR, and DVR, respectively.

CONCLUSIONS

The Carbomedics prosthetic heart valves showed comparable or even better results than those of other mechanical valves with respect to morbidity and mortality. These results may justify the use of Carbomedics valves as one of the mechanical heart valves.

Twenty-Two Year Experience with the Omniscience Prosthetic Heart Valve

This study was designed to evaluate the long-term clinical results of the Omniscience tilting disc valve. Omniscience valves were implanted in 51 patients (mean age, 50 +/- 10 years); 18 had aortic valve, 24 had mitral valve, and 9 had both aortic and mitral valve replacements. Oral warfarin potassium and dipyridamole were prescribed as our anticoagulant therapy. Preoperatively, 42 patients were in New York Heart Association class III or IV, and 23 of 25 surviving patients were in class I or II after operation. There were 2 (3.9%) early deaths and 23 late deaths (3.5 +/- 0.7% per patient-year). Cardiac related mortality including congestive heart failure, sudden death, and thromboembolism, and hemorrhagic complications were seen in 16 patients. Overall survival at 10, 15, and 20 years was 77 +/- 6%, 62 +/- 7%, and 46 +/- 7%, respectively. Thromboembolic complications were seen in 5 patients, for a rate of 0.8 +/- 0.3% per patient-year; similarly, hemorrhagic complications were also seen in 5 patients. Nonstructural prosthetic valve dysfunction was seen in 4 patients, for a rate of 0.6 +/- 0.3% per patient-year, and sudden death was seen in 2, a rate of 0.3 +/- 0.2% per patient-year. The Omniscience prosthesis demonstrated excellent postoperative clinical status with low rates of valve related complications.

The optimal intensity of vitamin K antagonists in patients with mechanical heart valves: a meta-analysis

OBJECTIVES

The purpose of this study was to compare two different intensities of vitamin K antagonists (VKA) among patients with mechanical heart valves using meta-analytic techniques.

BACKGROUND

Patients with mechanical heart valves are at increased risk for valve thrombosis and systemic embolism, which can be reduced by VKA. The range of optimal intensity of VKA is still a matter of debate.

METHODS

A computerized search in the PubMed database was made for relevant articles. A meta-analysis was performed of all eligible studies with data on the incidences of thromboembolic and bleeding complications in patients with mechanical heart valve prostheses during different intensities of VKA therapy. The studies were classified into low-intensity VKA therapy (mean target international normalized ratio [INR] of 3.0 or lower) or high-intensity VKA therapy (mean target INR above 3.0).

RESULTS

Thirty-five eligible studies were identified, including in total 23,145 patients, who were studied for 108,792 patient-years. For patients with an aortic valve, high intensity resulted in a lower incidence of thromboembolic events (risk ratio [RR] = 0.73, p < 0.0001); however, the incidence of bleeding was increased (RR = 1.23, p < 0.0001). In the mitral valve group, the incidence rate for thromboembolism was lower in the high-intensity group (RR = 0.74, p < 0.0001), without a significantly increased bleeding incidence (RR = 1.08, p = 0.0524). The total number of thromboembolic and bleeding events was decreased in the high-intensity group compared with low-intensity VKA therapy for both aortic and mitral valve prostheses (RR = 0.94 [p = 0.0067] and 0.84 [p < 0.0001]), respectively.

CONCLUSIONS

This meta-analysis shows that both aortic and mitral valves will benefit from a treatment strategy with a target INR higher than 3.0.

Mechanical heart valve prostheses:

Mechanical heart value prostheses have been in use since the 1950s. Many prostheses have been used for a while and then discontinued. Today, there are a large number and variety of prostheses in use and an even larger variety that are in place in patients. These may be explanted at any time for a number of reasons. It is essential for the practicing pathologist to be able to identify the prosthesis and be aware of some of its reported complications and modes of failure. This article, and a second one on bioprosthetic heart valves, is designed as a ready reference guide to heart valve prostheses, their important identifying features, their common complications, and modes of failure. It should help in the accurate identification of explanted prosthetic valves and more definitive reports. This accuracy of identification as well as tracking of abnormalities noted will, we hope, permit the identification of new failure modes and the recording of causes of failure of new (or even modified) prosthetic heart valves.

When and how does nonstructural mechanical prosthetic heart valve dysfunction occur?

OBJECTIVE

We discuss the clinical aspects related to mechanical valve dysfunction based upon 20 years' experience of our cases.

METHODS

Between January 1982 and December 2001, 21 patients underwent surgical interventions because of mechanical valve dysfunction. Thirteen men and 8 women (mean age 47 +/- 20, range 3-75 years-old), were included.

RESULTS

Mitral valve dysfunction was observed in 12 patients. Prosthetic valve stenosis occurred in 6 patients between 2 and 224 months, and paravalvular leaks in 4 between 1 and 71 months after surgery. The other 2 patients suffered from hemolytic anemia with mild paravalvular leaks between 102 and 104 months after surgery. Aortic valve dysfunction was observed in 8 patients including 3 stenotic lesions between 48 and 97 months and 5 paravalvular leaks between 3 and 150 months after surgery. Tricuspid regurgitation was seen in 1 patient with a huge right atrium at 42 months after surgery. Early death was seen in 1 patient. Late death occurred in 1 patient, 17 years after operation. Survival, including early death, was 95.2%, at 10 and 15 years. One valve-related complication of bioprosthetic valve endocarditis at the mitral and tricuspid positions occurred 12 years after a reoperation. The freedom from complications was 95.2% at 10 years, and 76.2% at 15 years.

CONCLUSIONS

Paravalvular leaks without overt endocarditis had latency periods of up to 12 years, and pannus formation was observed 20 years after surgery. Early and late clinical results after surgery for mechanical valve dysfunction were excellent.

The Carbomedics Top Hat supraannular aortic valve: a multicenter study

BACKGROUND

Introduced in 1993, the Carbomedics Top Hat (Sulzer, Carbomedics, Austin, TX) valve is a bileaflet mechanical aortic prosthesis designed to be placed in a supraannular position. Five institutions pooled their clinical experiences to evaluate early outcome in patients with this prosthesis.

METHODS

From 1994 to 2000, 639 patients underwent aortic valve replacement with Top Hat (Sulzer Carbomedics) valves at 5 institutions. Mean age was 60 +/- 13 years. In this heterogeneous population, 28% of patients had previous cardiac operations and 64% had concomitant procedures, including procedures involving more than 1 heart valve in 32%. Implanted prostheses sizes included the 19 mm (15%), 21 mm (37%), 23 mm (33%), 25 mm (13%), and 27 mm (2%). Mean follow-up was 2.0 +/- 1.5 years, and there were 1,206 patient-years of follow-up available for analysis.

RESULTS

Thirty-day mortality was 5.3%. Five-year survival was 74%. Risk factors for death included older age (p = 0.01), decreased ejection fraction (p = 0.007), and increased New York Heart Association functional class (p = 0.003). Five-year freedoms from thromboembolism and hemorrhage were 90% and 85%, respectively. Five-year freedoms from explant and endocarditis were both 99%. There were no structural valve failures.

CONCLUSIONS

The Top Hat valve outcomes have been similar to those of the standard Carbomedics intraannular prostheses. The unique design of the Top Hat valve, with all its components in the aortic sinuses, has particular advantages in the small aortic root, in settings where leaflet entrapment may occur, and in multiple 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.

Single-center experience with the bicarbon bileaflet prosthetic heart valve in Japan

We analyzed midterm results using the Bicarbon valve in a single center. Forty-four patients had aortic valve replacement (AVR), 48 had mitral valve replacement (MVR), and 13 had both aortic and mitral valve replacement (DVR). The mean age of the 105 patients was 61.2 +/- 11.3 years. The mean follow-up was 1.8 +/- 1.1 years with a cumulative follow-up of 188 patient-years. There were 5 early deaths (4.7%: 4 in the AVR group and 1 in the MVR group) and 5 late deaths (2.7% per patient-year: 3 malignancy, 1 cerebral hemorrhage, 1 myocardial infarction). Survival at 3 years was 91 +/- 4% in the AVR group, 92 +/- 5% in the MVR group, and 66 +/- 23% in the DVR group. The linearized incidence of thromboembolic complications, hemorrhagic complications, and paravalvular leaks in all patients was 1.06 +/- 2.34%, 1.60 +/- 2.53%, and 0.53 +/- 2.22% per patient-year, respectively. No other complications were observed. In conclusion, the Bicarbon prosthetic heart valve has shown excellent clinical results associated with a low incidence of valve-related complications.

Ten year clinical experience with the CarboMedics heart valve implants

We reviewed the histories of 144 patients who underwent heart valve replacement with the CarboMedics prosthesis from 1990 to 2000. There were 74 males and 70 females, with a mean age of 52 years, including 69 aortic valve replacements, 48 mitral valve replacements, and 27 double (aortic and mitral) valve replacements. The mean duration of follow-up was 6.5 years. Early mortality was 7.6% (11 patients). Late deaths occurred in 14 patients, including cardiac-related late deaths in 9 and valve-related deaths in 3. The survival rate including early deaths was 84.7 +/- 3.2% at 5 years and 78 +/- 4.1% at 10 years. Preoperative New York Heart Association Class IV (p = 0.0001) was found to be a significant predictor of cardiac-related late death. Freedom rate from complications at 10 years were embolism 84.7 +/- 4.2% (linearized rate 1.8% per patient year), valve thrombosis 92.7 +/- 2.7% (linearized rate 0.8% per patient year), bleeding 95.6 +/- 2.6% (linearized rate 0.4% per patient year), reoperation 85.9 +/- 4% (linearized rate 1.5% per patient year), valve endocarditis 98.7 +/- 1.3% (linearized rate 0.1% per patient year), and nonstructural dysfunction 90 +/- 3.5% (linearized rate 1% per patient year). There was no structural deterioration. The early and long-term results with the CarboMedics heart valve implantation were acceptable, but valve thrombosis remains a concern in the present study. Further investigation for optimal anticoagulation therapy is necessary to reduce the incidence of valve thrombosis as well as embolic and bleeding complications.

Long-term results of valve replacement with the CarboMedics prosthetic heart valve

This study examined the long-term results of the CarboMedics prosthetic heart valve. Between July 1990 and May 2000, 256 CarboMedics valve prostheses (120 single aortic, 62 single mitral, and 34 double aortic/mitral) were implanted into 216 patients (mean age 57.8 years). The mean follow-up was 57.7 +/- 36 months (maximum 133 months) with a total of 1,038.4 patient years. Patient survival, including operative deaths, was 85.1% at 10 years. Linearized rates for various complications were thromboembolism 0.39% per patient year, bleeding events 0.39% per patient year; prosthetic valve endocarditis 0.29% per patient year, nonstructural dysfunction 0.87% per patient year, and reoperation 0.39% per patient year. There were no valve thrombosis or structural valve failures in this series. The probabilities of freedom from thromboembolism and reoperation at 10 years were 96.3% and 93.1%, respectively. In conclusion, the CarboMedics valve can be used satisfactorily with a low incidence of thromboembolism and valve thrombosis.

Up to 8-year follow-up of valve replacement with carbomedics valve

BACKGROUND

The aim of this study was to report midterm valve replacement (VR) results with the Carbo-Medics valve (Sulzer Carbomedics, Austin, TX).

METHODS

From 1991 to 1999, 468 patients aged 13 to 76 years (mean 56 years) underwent VR with CarboMedics valve: 239 aortic (A), 167 mitral (M), and 62 A+M or double valve replacement (DVR). Mean follow-up time was 4.4 years; follow-up was 99.1% complete for 2,016 patient-years (PY). The anticoagulation level was targeted to an international normalized ratio of 1.47 to 2.8.

RESULTS

The hospital mortality rate was 1.2%. Actuarial analysis for the entire group at 7 years for survival was 87%+/-2.3%. Freedom from valve-related death was 94%+/-1.9%. Freedom from thromboembolic and bleeding events, respectively, were as follows: for AVR, 82%+/-4.9% (2.4%/PY) and 88%+/-2.9% (1.6%/PY); for MVR, 95%+/-2.1% (0.8%/PY) and 91%+/-3.1% (1.3%/PY); and for DVR, 96%+/-3.2% (0.7%/PY) and 85%+/-9.7% (1.0%/PY). Actuarial freedom from reoperation was 98%+/-1.4%.

CONCLUSIONS

The CarboMedics valve can be implanted with satisfactory early mortality and a low incidence of valve-related events even under low-intensity anticoagulation, as shown in a Japanese population.

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.

Aortic root replacement versus aortic valve replacement: a case-match study

BACKGROUND

There is increasing evidence that patients with aortic valve disease and dilatation of the ascending aorta are at risk for later dissection or rupture of the aortic wall when the dilated ascending aorta is not replaced or reinforced at the time of aortic valve replacement. In order to find out whether the more complex surgical procedure of aortic root replacement carries a higher early or late postoperative risk than isolated aortic valve replacement, we conducted a matched-pair study with patients of both groups.

METHODS

Between June 1993 and August 1998, 100 consecutive patients with aortic valve disease and ectasia/aneurysm of the ascending aorta underwent replacement of the aortic valve and the ascending aorta with a CarboSeal composite graft (CarboSeal; Sulzer Carbo-Medics Inc, Austin, TX). Identical bileaflet valve prostheses (CarboMedics; Sulzer CarboMedics Inc, Austin, TX) were implanted during the same time period in 928 patients for aortic valve disease. On the basis of various preoperative clinical variables 100 patients with aortic valve replacement were matched to the 100 patients with replacement of the aortic root. The duration of follow-up for both groups was similar with 37 + 17 months (range, 9 to 70) for the CarboSeal group and 38 + 14 months (range, 13 to 65) for the CarboMedics group. Survival and morbidity were calculated by Kaplan-Meier analysis and risk-adjusted mortality was evaluated by multivariate analysis in a Cox regression model.

RESULTS

The early postoperative mortality of 1% in the CarboSeal group and 4% in the CarboMedics group was insignificantly different. Although the overall survival rate at 5 years was lower (60.7% vs 86.3%; p = 0.13) in the CarboSeal group, the freedom from cardiac mortality and valve-related morbidity was similar in the two groups.

CONCLUSIONS

Replacement of the ascending aorta and aortic valve can be performed with similar operative risk, valve-related morbidity, and late cardiac mortality as isolated aortic valve replacement.

Aortic valve replacement with mechanical and biologic prosthesis in middle-aged patients

BACKGROUND

Mechanical prostheses are used in young patients and bioprostheses in the elderly because of the higher rate of structural failure of bioprostheses. The objective of the present study was to compare results after aortic valve replacement with mechanical (Carbo-Medics) and biologic (Carpentier-Edwards pericardial) in middle-aged patients.

METHODS

Five hundred twenty-one patients, aged between 55 and 65 years, who underwent aortic valve replacement with mechanical (n = 363) or biologic (n = 158) prostheses were reviewed.

RESULTS

The 10-year actuarial survival rate averaged 66%+/-6% in patients implanted with mechanical valves compared with 75%+/-4% in patients implanted with biologic valves (p = 0.2). The 10-year freedom rate from thromboembolism, hemorrhage, and endocarditis averaged 92%+/-7%, 97%+/-2%, and 99%+/-1%, respectively, in patients with mechanical valves compared with 91%+/-3% (p = 0.03), 99%+/-1% (p = 0.4), and 95%+/-2% (p = 0.01), respectively, in those with biologic valves. The 10-year freedom rate from all valve-related complications averaged 90%+/-7% and 83%+/-4%, respectively (p = 0.01).

CONCLUSIONS

The freedom rate from all valve-related complications was higher among patients with mechanical valves compared with biologic valves 10 years after aortic valve replacement in middle-aged patients.

Intermediate-term results with 1,019 carbomedics aortic valves

BACKGROUND

A retrospective study was conducted to evaluate the intermediate-term outcome in patients with the Carbomedics aortic valve prosthesis.

METHODS

The study included 1,019 primary valve replacements between 1989 and 1997. Seventy-two percent of patients were men; mean (standard deviation) age was 61 (10) years. The preoperative New York Heart Association functional class was III or IV in 70% of patients. Follow-up at 9 years was 99.6% complete, comprising 2,730 patient-years (mean, 2.7 years).

RESULTS

Patient survival, including operative deaths, was 80% at 7 years. The linearized death rate was 2.9%/year. Statistically significant risk factors for mortality were diabetes, pure valve insufficiency, advanced age at operation, and advanced preoperative functional class. Linearized rates were thrombosis, 0.1%/year; thromboembolism, 1.0%/year; hemorrhage, 1.7%/year; endocarditis, 0.1%/year; paravalvular leak, 0.1%/year; reoperation, 0.1%/year; and all events, 3.0%/year. The 7-year estimates of freedom from complications were thrombosis, 99%; thromboembolism, 93%; hemorrhage, 89%; endocarditis, 99%; paravalvular leak, 99.7%; reoperation, 99%; and all events, 82%. No structural valve failure was observed.

CONCLUSIONS

The low incidence of valve-related complications favors the continued use of the Carbomedics valve in the aortic position.

Mortality after aortic valve replacement: results from a nationally representative database

BACKGROUND

Nationally representative estimates of in-hospital mortality after aortic valve replacement are needed to evaluate whether results from The Society of Thoracic Surgeons National Cardiac Surgery Database are applicable to other institutions in the United States performing these procedures.

METHODS

Data from the 1994 Nationwide Inpatient Sample were used to estimate the patient characteristics and in-hospital mortality rates associated with aortic valve replacements performed in nonfederal hospitals in the United States. Procedural and hospital characteristics were examined for possible associations with in-hospital mortality.

RESULTS

An estimated 46,397 aortic valve replacements were performed. In-hospital mortality occurred in 4.3% of first-time isolated aortic valve replacements and 6.4% overall. The highest quartile of procedure-specific hospital volume, compared with the lowest quartile, was associated with lower in-hospital mortality (adjusted odds ratio, 0.58; 95% confidence interval, 0.42 to 0.81).

CONCLUSIONS

The in-hospital mortality rates observed in this study are very similar to those reported from The Society of Thoracic Surgeons database. These data provide substantial evidence that results from The Society of Thoracic Surgeons database are representative of those achieved at other institutions. However, procedure-specific hospital volume must be considered in applying these results to individual institutions.

A single-center experience with 1,378 CarboMedics mechanical valve implants

BACKGROUND

The CarboMedics bileaflet prosthetic heart valve was introduced in 1986. We first implanted it in March 1991. The purpose of this study was to analyze our clinical experience with this valve.

METHODS

Between March 1991 and December 1997, 1,378 valves were implanted in 1,247 patients, 705 men (56.5%) and 542 (43.5%) women with a mean age of 62 +/- 11.9 years (+/- the standard deviation). Follow-up is 99% complete and totals 3,978 patient-years.

RESULTS

The early mortality rate was 4.4% (55/1,247). The survival rates at 1 year and 5 years were 91.8% +/- 0.8% (+/- the standard error of mean) (n = 1,062) and 79.2% +/- 1.4% (n = 281), respectively. Freedom from valve-related complications (linearized rate, 4.9% per patient-year) at 1 year and 5 years was 90.6% +/- 0.8% (+/- the standard error of the mean) (n = 996) and 80.6% +/- 1.4% (n = 243), respectively. Linearized rates for various complications were as follows: bleeding events, 1.73% per patient-year; embolic events, 1.76% per patient-year; operated valvular endocarditis, 0.18% per patient-year; valve thrombosis, 0.10% per patient year; and nonstructural dysfunction, 1.21% per patient-year. Freedom from reoperation at 1 year and 5 years was 98.6% +/- 0.3% (+/- the standard error of the mean) (n = 1,070) and 97.7% +/- 0.5% (n = 285), respectively.

CONCLUSIONS

Midterm results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.

Aortic root replacement with the Carboseal composite graft: 7-year experience with the first 100 implants

BACKGROUND

Aortic root replacement remains a challenging surgical procedure. A variety of techniques and prosthetic devices have thus far been used. In order to assess the performance of the Carboseal (Sultzer Carbomedics, Inc, Austin TX) composite graft, review of the experience with composite root replacement was undertaken.

METHODS

Between January 1979 and December 1998, 273 patients underwent composite aortic root replacement. One-hundred-six received the Carboseal composite prosthesis (group 1) and 84 other types of composite grafts (group 2). Demographic and operative variables were similar in the 2 patient groups, except for an older mean age in group 1 (58+/-12 versus 50+/-12 years, p = 0.001).

RESULTS

Operative mortality was lower in group 1 patients (3 of 106, 3% versus 10 of 84, 12%, p = 0.04). Follow-up of survivors was longer in group 2 due to more recent adoption of the Carboseal grafts (93+/-57 versus 36+/-23 months, p = 0.01). Late mortality was higher in group 2 (3 of 103, 3% versus 13 of 74, 18%, p = 0.04), with higher prevalence of prosthetic-related complications (2 of 103, 2% versus 12 of 74, 15%, p = 0.002). Reoperation was more prevalent in group 2 (1 of 103, 1% versus 5 of 74, 8%, p = 0.04), and limited to patients having root replacement using the inclusion technique. Functional status of survivors was comparable in the 2 groups (83 of 103, 80% versus 45 of 74, 61% of patients in New York Heart Association class I, p = 0.1).

CONCLUSIONS

Aortic root replacement using the Carboseal composite graft offers excellent long-term results, with negligible prevalence of prosthetic-related complications. Superior performance compared to other available composite grafts in the present series may be influenced by more recent adoption of the Carboseal conduit and concomitant uniform adoption of coronary button technique.

Bileaflet mechanical prostheses performance in mitral position

OBJECTIVE

The experience with the Carbomedics (CM) and the St. Jude Medical (SJM) bileaflet mechanical prostheses was evaluated to determine thromboembolic and hemorrhagic complications and predictive risk factors.

METHODS

From 1989 to 1994, a total of 625 patients had mitral valve replacement (CM, 240; SJM, 385); 32.5% (203), concomitant procedures and 32.8% (205), previous cardiac surgery, primarily valve replacement procedures.

RESULTS

The pre-operative variables did not distinguish the populations, except for previous surgery CM 37.9% and SJM 29.6% (P < 0.05). The pre-operative variables (type of prostheses, cardiac rhythm, coronary artery bypass, NYHA III/IV, advancing age, gender, urgency status and previous surgery) were not predictive of overall thromboembolism (TE), major TE, minor TE, prosthesis thrombosis and hemorrhage (P not significant; P = NS). The linearized rate of total TE events for overall MVR was 5.0%/patient-year (CM 4.4; SJM 5.4). The < or = 30 day major crude rate was 0.44%, while the > 30 day late major event rate was 2.0%/patient-year. Of the total TE events 91% of < or = 30 days and 75%, > 30 days had an INR < 2.5 at or immediately prior to the event. The thrombosis rate (included in TE events) was 0.63%/patient-year (ten events, four managed successfully with thrombolysis, five successfully with reoperation, and one fatality identified at autopsy). The freedom, at 5 years, from major/fatal TE, thrombosis and hemorrhage from anticoagulation was 88.2%, and 89.5% exclusive of early events.

CONCLUSIONS

This non-randomized prospective observational evaluation of the CarboMedics and St. Jude Medical prostheses has not revealed any differentiation in performance of the prostheses. The study serves as a single institution experience with the potential for future comparative evaluation.