St. Jude prosthesis for aortic and mitral valve replacement: a ten-year experience

Management of prosthetic valve thrombosis with unfractionated heparin

BACKGROUND

Prosthetic valve thrombosis (PVT) is a severe and life-threatening complication. Surgery and thrombolytic therapy (TT) carry a high risk, and in several circumstances, optimal anticoagulation with unfractionated heparin (UFH) infusion may be an alternative treatment. This study aimed to assess the results of UFH in patients diagnosed with both obstructive and non-obstructive PVT.

METHODS

This observational retrospective study enrolled patients who had contraindications for TT and surgery underwent UFH therapy.

RESULTS

A total of 136 patients were enrolled [male: 55 (40.4%), mean age: 50.3 ± 14.6 years] in the study. In the successful group, 66 patients (48,5%) showed >75% regression in the thrombus burden without facing death or major non-fatal complications.In the unsuccessful group, 56 had less than a 50% reduction in thrombus load and 14 (10.3%) suffered major complications. The presence of obstruction (27.1% vs. 12.1%; p = 0.028), thrombus area 1.1 cm2 vs. 0.8 cm2; p = 0.005] and the duration of UFH treatment (15.1 vs. 11.8 (days); p = 0.005) were significantly higher in the unsuccessful UFH group.In multivariate regression analyses the presence of obstruction (RR: 3.088, p = 0.020), increased thrombus area (RR: 2.400; p = 0.015), and increased duration of UFH therapy (RR: 1.073 95%, p = 0.012) were identified as independent predictive parameters for a failed UFH therapy.

CONCLUSIONS

This study suggests that UFH therapy may be considered a relatively beneficial treatment strategy for some patients with PVT. The most significant factors affecting success are the obstructive nature and area of the thrombus.

Survival and long-term outcomes after concomitant mitral and aortic valve replacement in patients with rheumatic heart disease

Introduction

Double valve replacement (DVR) with a mechanical prosthesis is associated with a higher risk of mortality. We planned to study the survival rate, early and late mortality and major adverse cardiac and cerebrovascular events (MACCE) in patients undergoing DVR for rheumatic heart disease, with various generations of prosthetic valves ranging from ball in cage to bileaflet prosthesis and tilting disc valves.

Materials and methodology

We followed up 277 patients with rheumatic heart disease who underwent DVR between August 1999 and November 2009, retrospectively, at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram. Two hundred and fifty-nine patients were followed up for a minimum period of 10 years, and the follow-up period varied between 10 and 20 years. Eighteen patients were lost to follow-up after the surgery and could not be contacted. Their data was included till the time they appeared for follow-up last, for survival analysis. Survival analysis was carried out using the life table method to calculate the freedom from reoperation, survival rates and freedom from MACCE at 1 year, 5 years and 10 years post-DVR.

Results

The median duration of hospital stay was 8 days. The number of patients with stroke was 11 (4.26%), 21 (8.7%) and 29 (12%) at the end of 1 year, 5 years, and 10 years, respectively. A total of 5 (2%) patients underwent reoperation by the end of 10 years. Seven patients died either in hospital or in the first 30 days following operation, making the early mortality 2.5%. At the end of 1 year, a total of 16 patients (5.8%) died. The mortality at the end of 5 years was 6.8% (19 patients), and at the end of 10 years, it was 7.2% (20 patients). The survival rate of the study population was 94.9%, 93.02% and 93.02% at the completion of 1 year, 5 years and 10 years, respectively. The freedom from MACCE was 93.8%, 88.6% and 85% at 1 year, 5 years and 10 years, respectively. The freedom from re-operation was 98% at 10 years. Kaplan-Meier analysis showed an overall survival time of 226.3 months in the entire study population. The mean survival time in males was 227.5 months and in females was 206.3 months, with no statistically significant difference between the two. Univariate logistic regression analysis revealed an association with mortality when DVR was combined with concomitant tricuspid valve repair procedures, with an odds ratio of 4.5 (p value 0.005). Multivariate logistic regression analysis also showed an association with mortality when tricuspid valve procedures were combined with DVR with an odds ratio of 5.25 (p value 0.003).

Conclusion

The operative mortality and morbidity for DVR have been significantly reduced with advancements in operative techniques, myocardial preservation and postoperative care. Patients can have an improved functional status following surgery, with good rates of freedom from re-operation and MACCE.

Thirty-year experience with a bileaflet mechanical valve prosthesis

BACKGROUND

The objective was to evaluate the long-term outcomes of the St Jude Medical (Saint Paul, Minn) mechanical valve prosthesis implantation.

METHODS

Since 1979, every patient receiving this prosthesis has been followed annually.

RESULTS

From January 1979 to December 2014, 1023 patients were accrued. Patients' ages ranged from 18 to 85 years. Aortic valve replacement was performed in 584 patients, and mitral valve replacement was performed in 439 patients. Follow-up was 95% complete. Operative mortality was 3% (17/584, aortic valve replacement) and 4% (18/439, mitral valve replacement). In patients undergoing aortic valve replacement, late actuarial survival was 62% ± 2%, 32% ± 2%, and 14% ± 3% at 10, 20, and 30 years, respectively. Thirty-year freedom from reoperation, thromboembolism, valve thrombosis, bleeding, and endocarditis was 92% ± 2%, 79% ± 3%, 96% ± 1%, 56% ± 5%, and 92% ± 2%, respectively. In patients undergoing mitral valve replacement, late actuarial survival was 64% ± 3%, 28% ± 3%, and 14% ± 3% at 10, 20, and 30 years, respectively. Thirty-year freedom from reoperation, thromboembolism, valve thrombosis, bleeding, and endocarditis was 85% ± 5%, 55% ± 6%, 99% ± 1%, 57% ± 6%, and 95% ± 2%, respectively. The incidence of bleeding was 2.5% and 2.0% per patient-year for aortic valve replacement and mitral valve replacement, respectively. The incidence of thromboembolism was 1.6% and 2.9% per patient-year for aortic valve replacement and mitral valve replacement, respectively.

CONCLUSIONS

Annual follow-up of all of our patients receiving a St Jude Medical mechanical valves prosthesis has allowed better identification valve-related issues and events. After 3 decades of observation with close follow-up, the St Jude Medical mechanical valve continues to be a reliable prosthesis.

Determinants of Late Tricuspid Regurgitation After Aortic-Mitral Double Valve Replacement

The aims of this study are to evaluate the long-term outcomes of double valve replacement (aortic and mitral valves) and to investigate the determinants of late tricuspid regurgitation (TR). A total of 239 consecutive patients who underwent double valve replacement were enrolled. Valve pathology was rheumatic in 86.6% (207/239) and degenerative in 13.4% (32/239) of patients. Among these patients, 116 patients underwent concomitant tricuspid annuloplasty, and follow-up was completed for all 239 patients (mean = 7.3 ± 4.1, maximum = 15.9 years). We used propensity score matching to match 67 patients without tricuspid annuloplasty to the 114 patients who underwent annuloplasty. There was 1 in-hospital death and 9.7% (23/238) of patients experienced late cardiac-related mortality. Analysis of aortic valves indicated that the transprosthetic mean pressure gradient increased with time (13.4 ± 5.2 vs 15.4 ± 9.0 mm Hg, p = 0.002). Aortic transprosthetic mean pressure gradient increased more notably in woman and was associated with late TR (odds ratio 1.1, p = 0.010). In patients with mild TR, those who underwent tricuspid valve repair were less likely to experience a cardiac-related death within 10 years of surgery (hazards ratio 6.1, p = 0.036).

Performance by Age Groups in Biological and Mechanical Cardiac Valve Replacement

A group of 1195 patients who received biological valve prostheses (mean age 57.3 years, range 8 to 85 years) and a group of 1345 patients who received mechanical heart valves (mean age 56.1 years, range 13 to 91 years) were analyzed for complications by age group (less than or equal to 54 years, 55 to 65 years, and over 65 years). The freedom from thromboembolism and anticoagulant-related hemorrhage at 8 years after aortic valve replacement was significantly higher in patients who received a biological prosthesis in all age groups. The freedom from thromboembolism and anticoagulant-related hemorrhage at 8 years after mitral valve replacement was significantly higher in patients who received a biological prosthesis in the age groups less than or equal to 54 years and over 65 years. The freedom from all valve-related complications at 5 and 8 years after aortic or mitral valve replacement showed the same trend of greater freedom from complications in biological prostheses patients compared with mechanical prostheses in most age groups. However, freedom from valve-related reoperation, mortality, and residual morbidity for aortic and mitral valve replacement for all age groups was not significantly different. These results show that biological prostheses can be considered for patients aged 55 years and older. The prostheses by age group or position at 8 years were not differentiated by valve-related reoperation, mortality, and residual morbidity. t 8 years there is a demonstrated price to pay for a presumed increase in longevity for patients with mechanical valves in the aortic position, reflected by an increase in thromboembolism and anticoagulant-related hemorrhage in all age groups.

Fifteen years of experience with ATS mechanical heart valve prostheses

BACKGROUND

ATS Medical, Inc, developed a mechanical heart valve that has been in use since 1992. In this article, we present the results of 15 years of follow-up of patients who have undergone ATS heart valve replacement at our hospital.

METHODS AND RESULTS

We performed ATS heart valve replacements on 231 patients between September 1993 and March 2008. Our operative mortality rate for the study period was 2.2%. The survival for postoperative thromboembolic events was 0.29%/pt-y for aortic valve replacement, 0.48%/pt-y for mitral, 0.80%/pt-y for double valve replacement, and overall 0.44%/pt-y. The survival after bleeding events was 0.29%/pt-y for aortic valve replacement, 0.16%/pt-y for mitral, 0%/pt-y for double valve replacement, and overall 0.19%/pt-y. Patient-prosthesis mismatch, as determined by echocardiography, was found in 83.3% of patients at 19 mm, but other sizes showed good valve function. Prosthetic valve noise was undetectable in 92.8% of patients, and quality of life was excellent.

CONCLUSIONS

Few prosthetic valve-related complications were seen with ATS heart valve replacements in this study, and the follow-up results were favorable. The international normalized ratio was maintained in the range 1.6 to 2.0 in patients with aortic valve replacement in sinus rhythm. Not only bleeding events, seen at a rate of 0.19%/pt-y, but also thromboembolic events, at 0.44%/pt-y, were low when compared with conventional mechanical valves. Prosthetic valve noise is low, and this appears to be an excellent mechanical valve from the quality of life standpoint. The ATS valve has an excellent safety profile when compared with other mechanical valves.

[Short- and long-term results of mitral valve replacement by caged-ball and bileaflet mechanical prosthesis (series of 236 consecutive patients with average follow-up of 11 years)]

OBJECTIVES

To study the early and late results of mitral valve replacement (MVR) by Starr-Edwards caged-ball and bileaflet mechanical prosthesis.

MATERIAL AND METHODS

We retrospectively analyzed 236 MVR performed in 236 patients: 127 by Starr-Edwards prosthesis (group 1) and 109 by bileaflet prosthesis (group 2).

RESULTS

During the early period (30 days), the mortality rate was higher in group 1 (6.3% vs 1.8%; p=0.0001), while hemorrhagic, thromboembolic and infectious complications were comparable in the two groups. In the late period (>30 days) and with an average follow-up of 11.5+/-5.7 years, mortality was higher in group 1 (9.4% vs 4.6%; p<0.0001). The same was true for thromboembolic complications (20.8% vs 6.4%; p<0.0001), hemorrhagic complications (13.4% vs 7.3%; p=0.02), infectious complications (3.1% vs 0.9%; p=0.02) and cardiac complications that were not due to the prosthesis (32.3% vs 14.7 %; p=0.02). The hemodynamic profile of the bileaflet prostheses was better than that of the Starr-Edwards prostheses (average functional prosthetic surface area was 2.37+/-0.44 cm(2) and average pressure gradient was 5.6+/-1.1 mmHg vs 2.04+/-0.52 cm(2) and 7.6+/-4.9 mmHg).

CONCLUSION

Our work confirms the superiority of bileaflet mechanical prostheses, with rates of early and late mortality, thromboembolic and hemorrhagic complications lower than those of the Starr-Edwards prostheses in more than 11 years of follow-up. However, one should not forget that the prevention of infective endocarditis, good observance of oral anticoagulant treatment and early surgery before left ventricular dysfunction occurs remain the best guarantee a good result of the MVR.

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.

The Edwards MIRAtm Heart Valve Prosthesis:. A 2-Year Study

BACKGROUND

The Edwards MIRA mechanical heart valve is designed to optimize hemodynamics, reduce thrombogenicity, and avoid mechanical failure with a special hinge mechanism. The purpose of the study was to investigate the clinical performance and postoperative hemodynamic results of the first European patients receiving Edwards MIRA mechanical heart valves.

METHODS

From March 1998 to March 1999 a total of 54 Edwards MIRA valves model numbers 3600 (aortic, n = 44) and 9600 (mitral, n = 10) were implanted in 52 (36 male, 16 female; mean age 61 +/- 10.1 years) consecutive patients undergoing mechanical valve replacement in a prospective study. Follow-up of the patients including physical examination, ECG, blood tests, and Doppler were performed prior to discharge, at 6 months, at 1 year, and at least 2 years postoperatively.

RESULTS

Through October 2001 a total of 172 follow-up examinations were completed (51 patients at discharge, 46 patients at 6 months, 43 patients at 12 months, 32 patients at 2 years or beyond). All patients were in NYHA class I and II at the 6-month and 2+-year follow-up. All the patients stated an improved quality of life. Hospital mortality was 1.9%. There were no complications related to anticoagulation. Mean international normalized ratio at 6 months was 3.2 (range 1.9 to 4.3); lactate dehydrogenase was slightly increased with 264 +/- 103 U/L on average (normal value 80 to 240 U/L). No signs of valvular dysfunction or paravalvular leakage were observed. Mean pressure gradients were related to valve diameter: after mitral valve replacement (size 27, 29, 31 mm: 4.8, 3.2, 2.1 mmHg); after aortic valve replacement (size 19, 21, 23, 25 mm: 12.1, 13.1, 9.3, 8.2 mmHg).

CONCLUSIONS

These preliminary data suggest good hemodynamic function and a low rate of valve-related complications of the Edwards-MIRA mechanical prosthesis.

High-intensity transient signals due to prosthetic valve obstruction: diagnostic and therapeutic implications

BACKGROUND

High-intensity transient signals (HITS) can be detected by transcranial Doppler ultrasonography (TCD) in patients carrying a mechanical prosthetic valve. The HITS counts and a frequency analysis were evaluated in patients with prosthetic valve obstruction in the aortic position.

METHODS

Simultaneous echocardiographic, cineradiographic, and TCD evaluations for a St. Jude Medical valve were performed in 108 patients. All patients were asymptomatic and had no significant stenosis of the carotid artery. The HITS were identified according to criteria established by consensus of the International Cerebral Hemodynamics Symposium.

RESULTS

The HITS counts in 69 patients with normal prosthetic valve function were 2.2 +/- 4.4, and the counts in 39 patients with prosthetic valve obstruction (group D) were 8.3 +/- 10.8. This difference was significant (p = 0.0002). In 2 patients of group D who had a greater rate of less than 400 Hz HITS, which were produced by solid microemboli, thrombolysis resulted in a mitigation of restricted leaflet movement equal to or greater than 10(o). The total number of HITS decreased and the rate of less than 400 Hz HITS also markedly decreased after thrombolysis in these 2 patients. On the other hand, 4 patients who obtained no improvement of leaflet movement by thrombolysis had lower rates of less than 400 Hz HITS than did the 2 patients.

CONCLUSIONS

These results suggest that measurement of HITS counts is useful for detection of prosthetic valve obstruction, and that a frequency analysis of HITS may be valuable to clarify the cause of the obstructed prosthetic valves.

Twenty-year experience with the St Jude Medical mechanical valve prosthesis

BACKGROUND

We have prospectively followed all adult St Jude Medical mechanical valve recipients at the Medical University of South Carolina since the initial implant in January 1979 and now present our 20-year experience.

METHODS

We prospectively followed 837 valve recipients (aortic valve replacement; n = 478; mitral valve replacement; n = 359) from January 1979 to December 2000 at 12-month intervals.

RESULTS

Ages ranged from 19 to 84 years. Follow-up averaged (mean +/- standard deviation) 7 +/- 5 years (98% complete). Patients were in New York Heart Association class III or IV in 77% (aortic valve replacement) and 89% (mitral valve replacement) preoperatively. A 19-mm valve was implanted in 15.5% of aortic valve replacement patients. Coronary bypass was required in 31% of aortic valve replacements and 20% of mitral valve replacements. Operative mortality was 17/478 (3.6%) in aortic valve replacement and 19/359 (5.3%) in mitral valve replacement, and multivariable predictors were 19-mm valve size, 3 or more coronary bypass grafts, and New York Heart Association class IV for aortic valve replacement and New York Heart Association class IV and age for mitral valve replacement. Actuarial survivorship at 10 and 20 years was 57% +/- 3% and 26% +/- 5% for aortic valve replacement and 61% +/- 3% and 39% +/- 4% for mitral valve replacement. Multivariable predictors of late death were African-American ethnicity, New York Heart Association class III or IV, coronary bypass, and age for aortic valve replacement and New York Heart Association class III or IV, coronary bypass, and age for mitral valve replacement. For aortic valve replacement, effective orifice area was univariately (P =.002) but not multivariately (P =.378) predictive of late death. Structural valve deterioration was not observed. For aortic valve replacement, actuarial freedom (at 10 and 20 years) from reoperation was 93% +/- 1% and 90% +/- 2%; thromboembolism, 82% +/- 3% and 68% +/- 8%; bleeding events, 77% +/- 3% and 66% +/- 6%; prosthetic valve endocarditis, 94% +/- 1% and 94% +/- 1%; valve-related mortality, 94% +/- 2% and 86% +/- 4%; and valve-related mortality or morbidity, 58% +/- 3% and 32% +/- 8%. For mitral valve replacement, actuarial freedom (at 10 and 20 years) from reoperation was 96% +/- 1% and 90% +/- 3%; thromboembolism, 77% +/- 3% and 59% +/- 7%; bleeding events, 86% +/- 2% and 65% +/- 8%; prosthetic valve endocarditis, 98% +/- 1% and 96% +/- 2%; valve-related mortality, 89% +/- 0.2% and 74% +/- 8%; and valve-related mortality or morbidity, 63% +/- 3% and 29% +/- 7%.

CONCLUSIONS

After 2 decades of observation with close follow-up, the St Jude Medical mechanical valve continues to be a reliable prosthesis.

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 Björk-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.

A prospective controlled trial of St. Jude versus Starr Edwards aortic and mitral valve prostheses

BACKGROUND

There is a paucity of controlled trials comparing the merits of different heart valve prostheses. In this prospective randomized trial we compared Starr Edwards and St. Jude prostheses in the aortic and mitral positions.

METHODS

Two hundred sixty-seven patients and 122 patients undergoing aortic and mitral valve replacement, respectively, were allocated by minimization to receive either St. Jude or Starr Edwards prostheses. Patients (2 patients were lost to follow-up) were followed up in a special clinic. Event definition, recording, and reporting were in accordance with published guidelines.

RESULTS

There were no demographic differences between patients receiving the two different valve models. With the exception of infective endocarditis, we found no differences in the rates of death or complication between patients receiving a Starr Edwards prosthesis or a St. Jude prosthesis in either position. Neither were there any differences between the two valve models in either position, in terms of symptomatic relief 5 years after surgery.

CONCLUSIONS

We found no differences in rates of complication or of symptomatic improvement between the Starr Edwards and St. Jude valve prostheses in either aortic or mitral position. Left ventricular function had such a marked effect on long-term survival that it overwhelmed any differences that might exist between different prosthetic designs. This confirms that historical comparisons are of limited value in deciding the respective merits of heart valve prostheses. The most reliable method of assessing surgical procedures is through prospective controlled trials.

Follow-up study of aortic-valve replacement surgery in patients with Takayasu's disease complicated by aortic regurgitation

Aortic regurgitation (AR) is not a rare complication of Takayasu's disease and is now considered as an important risk factor related to mortality. Aortic-valve replacement surgery is the only curative treatment, but cardiac function and mortality after surgery have not been reported, so a follow-up study in 10 patients with Takayasu's disease complicated by AR was performed. Six patients underwent aortic-valve replacement surgery and all had improvement of the ejection fraction and a decrease in the size of the left ventricle size on echocardiography. Three of the 6 cases had a remote cardiovascular event. Detailed pathological examination carried out in one case of the aortic valve and aortic specimen from surgery showed only lymphoid cell infiltration around the capillary in the ascending aorta, and no other inflammatory change. Inflammation was well controlled at surgery by pre-operative steroid therapy, so early and aggressive aortic-valve replacement surgery with peri-operative immunosuppressive therapy should be considered for patients with Takayasu's disease.

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.

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.

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.

Prosthesis Size in Aortic Valve Replacement: Surgeon-Related Variable

A retrospective analysis was performed to determine the surgeon's impact on the selection of the size of prosthesis in aortic valve replacement. From January 1993 through December 1997, 748 patients underwent either isolated aortic valve replacement (530) or double valve replacement (218) with bileaflet valves. Depending on the operating surgeon, patients were divided into group A (367) or group B (381). Preoperative, intraoperative, and postoperative variables in both groups were compared. Groups A and B were identical in demographic and clinical profiles. Cardiopulmonary bypass time, ischemic time, and early and late results in both groups were similar. Significantly more patients undergoing isolated aortic valve replacement in group A (169; 67.9%) received a large (≥25 mm) prosthesis compared with group B (69; 24.5%). Compared with group B, a large prosthesis was used in a significantly greater proportion of all patients in group A, irrespective of etiology, predominant aortic valve lesion, and age of the patient. Overall, the operating surgeon was identified as the most important predictor (odds ratio 3.5; p < 0.0001) of use of a large valve.

Obstruction of St Jude Medical valves in the aortic position: significance of a combination of cineradiography and echocardiography

BACKGROUND

Obstruction of the St Jude Medical valve (St Jude Medical, Inc, St Paul, Minn) is a rare but serious complication.

METHODS

Cineradiographic and echocardiographic evaluations of aortic St Jude Medical valves were simultaneously performed on 54 patients, with no signs of prosthetic valve dysfunction late after surgery.

RESULTS

Although closing angles of the leaflets corresponded closely with the manufacturer data, restricted opening of the leaflets (opening angle >/= 20 degrees ) was found in 16 (group D) of the 54 patients by means of cineradiography. The opening angles were equal to or less than 14 degrees in the other 23 patients (group N) and between 15 degrees and 19 degrees in the remaining 15 (group M). Doppler-derived transprosthetic pressure gradients were significantly higher (P =.03) and the velocity index was significantly lower (P =.003) in group D than in group N. However, no significant differences were found in those values between group N and group M. Replacement of the aortic St Jude Medical valves was performed in 5 of the 16 patients, and the remaining 11 have been followed up because of relatively low pressure gradients. The cause of restricted leaflet movement was pannus formation without thrombosis in 4 patients and valve thrombosis with pannus formation in one.

CONCLUSIONS

Reduced valve orifice area and restricted opening of the leaflets resulting from excess growth of pannus probably led to obstruction of the aortic St Jude Medical valves. A combination of cineradiography and echocardiography makes it possible to provide an accurate and detailed diagnosis of obstruction of the valve.

Long-term experience with the St. Jude Medical valve prosthesis

BACKGROUND

All patients undergoing St. Jude Medical valve replacement at the Medical University of South Carolina since January 1979 have been followed prospectively at 12-month intervals.

METHODS

This report describes long-term experience in 710 adult patients undergoing isolated aortic (AVR) (418) or mitral valve replacements (MVR) (292) with this prosthesis from January 1979 to December 1996.

RESULTS

Ages ranged from 19 to 84 years (54.8 +/- 15.1 AVR, 51.8 +/- 12.9 MVR; mean +/- SD). Male gender predominated in the AVR group (70%) and female gender in the MVR group (62%). One hundred and fifty-seven patients (22%) had associated coronary artery bypass grafting (AVR 27%, MVR 15%). Thirty-day operative mortality was 5.3% (22/418) in the AVR group and 5.1% (15/292) in the MVR group. Follow-up is 96.9% complete and ranges from 1 month to 16.9 years (AVR, 2,376 patient-years, mean 5.7 +/- 4.5 years; MVR, 1,868 patient-years, mean 6.4 +/- 4.8 years). In the AVR group, 120 late deaths have occurred and actuarial survival was 78.0 +/- 2.3%, 58.0 +/- 3.2%, and 36.8 +/- 4.8%; at 5, 10, and 15 years, respectively. Forty-six patients have sustained 55 thromboembolic (TE) events (2.3%/patient-year). Fifty-one patients had anticoagulant-related bleeding complications (2.7%/patient-year). The mean improvement in New York Heart Association (NYHA) functional class from preoperative to postoperative was 3.0 +/- 0.8 to 1.7 +/- 0.1 (p < 0.05). In the MVR group, there have been 84 late deaths, and the actuarial survival was 79.3 +/- 2.5%, 60.1 +/- 3.5%, and 49.3 +/- 4.1% at 5, 10, and 15 years, respectively. Fifty-two patients have had 64 TE events (3.5%/patient-year). Twenty-three patients had anticoagulant-related bleeding complications (1.6%/patient-year). The mean improvement in NYHA functional class was from 3.3 +/- 0.6 to 1.8 +/- 0.1. There were no mechanical failures in either group.

CONCLUSIONS

With a follow-up now extending to 17 years, the St. Jude Medical valve continues to be a reliable mechanical prosthesis with low and stable rates of valve-related complications.

Long-term clinical experience with the Omnicarbon prosthetic valve

BACKGROUND

From February 1985 to December 1994, 781 Omnicarbon valve prostheses were implanted in 647 patients. These were 357 male and 290 female patients with a mean age of 53.5+/-10.5 years (range, 4 to 78 years). Before operation, 81% of the patients were in New York Heart Association class III or IV, 16% were in class II, and only 3% were in class I.

METHODS

There were 227 aortic valve replacements (AVR) (35%), 286 mitral valve replacements (MVR) (44%), and 134 double-valve replacements (DVR) (21%) (AVR + MVR). Follow-up was 96.3% complete and consisted of 2,746 patient-years (mean follow-up, 4.6 years, and maximum follow-up, 10.7 years).

RESULTS

Hospital mortality rates were 7.0% for AVR, 8.0% for MVR, and 8.2% for DVR. The annualized rate of anticoagulant-related hemorrhage was 0.8% per patient-year, and thromboembolism occurred at a rate of 0.7% per patient-year. No structural failure was observed during 10-year follow-up. Twenty-one instances of nonstructural dysfunction (two, pannus growth, and 19, dehiscence) of the Omnicarbon valve occurred in 20 patients, an incidence of 0.8% per patient-year. Hemolytic anemia was observed only in the presence of valvular dehiscence (6 of 19). Eight patients (0.3% per patient-year) had development of prosthetic valve endocarditis (4, AVR; 2, MVR; and 2 DVR). At the end of 10 years of follow-up, 91% of the survivors were in New York Heart Association class I or II. The overall survival rate at 10 years was 82.5%+/-2.6% (85.0%+/-3.9%, AVR; 81.0%+/-4.1%, MVR; and 82.5%+/-2.6%, DVR). Considering only valve-related deaths, the survival rate at 10 years was 91.9%+/-2.4% (90.0%+/-2.7%, AVR; 93.1%+/-3.8%, MVR; and 90.0%+/-1.8%, DVR).

CONCLUSIONS

Clinical results over a 10-year follow-up are excellent with the Omnicarbon prosthesis.

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.

Three-Year Experience with the Ultracor Valve Prosthesis

From February 1992 to October 1995, 504 patients aged 3 to 69 years (median, 36 years) received 663 Ultracor prostheses (103 aortic, 259 mitral, 12 tricuspid, and 130 multiple). Early mortality was 2.77% with a rate of 3.88% for aortic valve replacement, 3.47% for mitral, 0% for tricuspid, and 0.99% for double valve replacement. Follow-up was 100% (719.5 patient-years) and the overall mortality (early and late deaths) was 3.76% with a rate of 4.85% after aortic valve replacement, 3.85% after mitral valve replacement, 8.33% after tricuspid valve replacement, and 2.97% after double valve replacement. There were no deaths among 29 patients who had triple valve replacement. All patients including 33 children (3.5 to 18 years of age) received sodium warfarin. The linearized risk per patient-year for all embolic events (major and minor) was 0.69%, 1.11%, and 0.69% for aortic, mitral, and multiple valve replacement respectively. When only major events were considered, the linearized risks were 0.27%, 0.13%, and 0% per patient-year respectively. Freedom from major systemic embolism was 99% ± 0.07% after aortic valve replacement, 99% ± 0.07% after mitral valve replacement, and 99% ± 0.06% after multiple valve replacement. Five patients suffered valve thrombosis, 4 of whom definitely received inadequate anticoagulation therapy. Sixteen patients had 25 episodes of anticoagulant-related hemorrhage. No structural failure was recorded and no significant hemolysis was found in the absence of periprosthetic leak. This experience encourages us to continue using the Ultracor prosthesis.

Outcome analysis of 245 CarboMedics and St. Jude valves implanted at the same institution

BACKGROUND

Thromboembolism and valve-related death are major complications associated with prosthetic valve implants, but it is difficult to evaluate the relative incidence of these complications based on studies in which the implantation of only one valve is reported from any given institution. We therefore report the outcome of patients implanted at our institution during the same time period with either the recently released CarboMedics (CM) or the St. Jude Medical (SJ) valve prostheses.

METHODS

Between October 1994 and January 1996, 245 consecutive patients received either SJ (116 patients) or CM (129 patients) valves at our institution. Follow up of these patients was 99.6% complete, for a total of 318.5 cumulative patient-years (median follow-up, 1.4 years).

RESULTS

The 30-day mortality rates for SJ and CM implants were 3.4% and 3.1%, respectively. Actuarial survival and freedom from valve related mortality rates at 1.5 years for SJ and CM valves were 94%+/-2% versus 86%+/-3% (p = 0.03) and 100% versus 94%+/-2% (p = 0.005), respectively. There was no structural valve failure for either implant, but there were five thrombosed valves in the CM group and none in the SJ group (p = 0.04). All thrombosed valves were mitral (four mitral valve replacement, one aortic and mitral valve replacement). Two of the thrombosed valves were successfully explanted, whereas the three remaining patients died. Freedom from a thromboembolic event in the mitral position at 1.5 years, including thrombosed valves was 97%+/-3% and 83%+/-5% for SJ and CM valves, respectively (p = 0.04).

CONCLUSIONS

The results of this study suggest that further evaluation of thromboembolic outcomes after CM compared with SJ valve implantation is warranted.

Mitral valve replacement with the St. Jude Medical prosthesis: a 15-year follow-up

BACKGROUND

A retrospective study was conducted to analyze the results of St. Jude Medical mitral valve replacement.

METHODS

From January 1979 to December 1989, 870 patients (54% women, 46% men; mean age, 55.8 +/- 6.2 years) underwent mitral valve replacement with the St. Jude Medical prosthesis. Of these operations 616 were isolated mitral valve replacements and 254 were double valve replacements. Coronary artery bypass grafting was performed concomitantly in 55 patients (6.3%).

RESULTS

Overall, early mortality was 5.05%, with 4.2% for the isolated mitral valve procedure and 7.08% for the double valve replacement. Follow-up at 15 years was complete in 859 patients (98.74%). Mean follow-up time was 93.5 months, for a total of 6,436 years. Actuarial survival at 15 years was 59.5% +/- 5%, 60.5% +/- 6%, and 56.9% +/- 9%, for the entire group, the isolated mitral valve and double valve procedures, respectively. Multivariate analysis identified age, sex, hospital stay, and preoperative mitral regurgitation as independent prognosis factors for overall mortality. Of 606 patients alive at the latest follow-up, the New York Heart Association class improved significantly (from 67% class III/IV before the operation to 88% class I/II after the operation). All patients received warfarin to maintain an international normalized ratio between 3.5 and 4. The linearized rates (% per patient-year) of thrombosis, thromboembolism, and major hemorrhage were, respectively, 0.21, 0.75, and 0.94 for the entire group; 0.18, 0.67, and 0.88 for the isolated mitral valve operation; and 0.15, 0.92, and 1.08 for the double valve replacement. For the entire group the freedom from thrombosis and thromboembolism at 15 years was 98.1% +/- 1% and 88% +/- 4%, respectively. No case of structural dysfunction occurred. The freedom from paravalvular leak and endocarditis at 15 years was 95.3% +/- 2% and 97.3% +/- 2.4%, respectively. The probability of remaining free from reoperation at 15 years was therefore 95.6% +/- 2.5%.

CONCLUSIONS

These results confirm that the St. Jude Medical valve is a reliable prosthesis with very low thrombosis and thromboembolism rates, allowing the use of a low dose of anticoagulation with an international normalized ratio of about 3.

Hemodynamic performance of the 21-mm St. Jude BioImplant prosthesis using dobutamine Doppler echocardiography

This study examines the hemodynamic performance of small size St. Jude BioImplant aortic prostheses using dobutamine echocardiography. Eleven patients (3 women, mean age 75 years) who had undergone aortic valve replacement with a size 21-mm St. Jude BioImplant aortic prostheses at 10.8 +/- 5.1 months (SD) previously were studied. Dobutamine infusion was started at a rate of 5 microg/kg/min and increased to 10 microg/kg/min, and subsequently to 20 microg/kg/min at 15-minute intervals. Pulsed and continuous-wave Doppler studies were performed at rest and at the end of each stage. Effective orifice area, mean gradient, and the performance index across each prosthesis were calculated and cardiac output was determined by Doppler measurement of flow in the left ventricular outflow tract. Stress dobutamine increased heart rate and cardiac output by 51% and 56%, respectively (both p <0.0001), and the mean transvalvular gradient increased from 30.1 +/- 7.5 mm Hg at rest to 49.3 +/- 11.5 mm Hg at maximum stress (p <0.0005). The performance index increased progressively from 0.29 +/- 0.05 at rest to 0.40 +/- 0.10 at maximum stress (p <0.0005). Regression modeling analyses demonstrated that the maximum stress gradient was independent of all variables except the resting gradient (p = 0.03). Body surface area had no effect on the changes in cardiac output, effective orifice area, or transprosthetic gradient at maximum stress. Thus, these data demonstrate that the size 21-mm St. Jude BioImplant prosthesis exhibits suboptimal hemodynamic performance with transvalvular gradients consistent with mild to moderate aortic stenosis, both at rest and under stress conditions.

Multiple mechanical valve replacement surgery comparison of St. Jude Medical and CarboMedics prostheses

OBJECTIVE

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

METHODS

From 1989 to 1994, a total of 246 patients had multiple valve replacement (SJM, 140; CM, 106); concomitant procedures 20.3% (50) [coronary artery bypass 10.6% (26)] and 53.7% (132) previous cardiac surgery, primarily valve replacement procedures. The pre-operative variables [coronary artery disease, previous cardiovascular surgery, concomitant procedures, valve lesion (except mitral stenosis), status, atrial fibrillation, and NYHA III/IV] did not distinguish the prosthesis-type (pNS).

RESULTS

The prosthesis-type and the pre-operative variables, including atrial fibrillation, were not predictive of overall thromboembolism (TE). The linearized rate of total TE events for overall multiple replacements (MR) was 5.4%/patient-year (minor, 2.52; major 2.85); the total TE for CM and SJM was 5.4%/patient-year, respectively. The < or = 30 day major TE crude rate was 0.82%, while the > 30 day major event rate was 2.7%/patient-year. Of the total (major and minor) TE events 100% (3) of < or = 30 days and 72% (29), > 30 days had an INR < 2.5 at or immediately prior to the event. The thrombosis rate (included in total TE events) was 0.67%/patient-year (4 events, 100% INR < 2.5). Of the various TE event categories the prosthesis-types (CM and SJM) were not differentiated (pNS). The freedom, at 5 years, from major/fatal TE, thrombosis and hemorrhage from anticoagulation was 89.3 +/- 3.8% for CM and 87.9 +/- 3.7% for SJM and, 91.3 +/- 3.5% and 89.3 +/- 3.7%, respectively, (pNS) exclusive of early events.

CONCLUSIONS

The performance of the CarboMedics and St. Jude Medical prostheses in multiple valve replacement surgery in this non-randomized prospective study revealed no significant differences in performance with regard to thromboembolic and hemorrhagic complications.

Aortic valve replacement with the St. Jude Medical prosthesis and fixed dose anticoagulation

Over a 10-year period, between 1986 and 1996, 865 patients underwent primary aortic valve replacement (AVR) with the St. Jude Medical mechanical prosthesis. Patients who had undergone valve replacement with a different type of prosthesis previously were excluded from this study. Patient age ranged from 11 to 79 years. The mean age was 42.9 +/- 14.54. The gender distribution was 396 men (45.8%) and 469 women (54.2%). All patients received 2.5 mg/day Coumadin after extubation. A combination of the antiaggregant therapy (Dypridamole 3X 75 mg/day, Asprine 100 mg/day) was added after removal of the chest tubes. The dosage of Coumadin was maintained constant regardless of the prothrombin time (PT) or cardiac rhythm. There were 101 valve-related complications (4.2% per patient year [ppy]) occurring in the late follow-up period. Of these complications; 38 were anticoagulant-related hemorrhage (1.58% ppy), 3 were paravalvular leak (0.12% ppy), and 36 were thromboembolism (1.4% ppy). There were 24 reoperations (0.99% ppy) and 17 late deaths. The linearized late mortality rate was 0.7% ppy. Long-term survival estimates at 5 and 10 years were 97.14 +/- 0.82% and 94.86 +/- 1.54%, respectively. We conclude from the data that the St. Jude Medical valve may allow the use of a low level of anticoagulation. This study shows that fixed dose oral anticoagulation does not increase the rate of thromboembolism in patients with the St. Jude aortic valve. This protocol does not result in reduction of bleeding complications, however.

Increased pulmonary flow velocities in oversized homografts in patients after the Ross procedure

OBJECTIVE

Between September 1991 and July 1996, 60 patients (mean age 29.8 +/- 9 years; range 5-57) underwent aortic root replacement with pulmonary autograft, a viable biologic and nondegenerating substitute. The pulmonary root was replaced with cryopreserved homografts from cardiac transplant recipients. The aim of this study was to evaluate differences in early valve function of viable and cryopreserved allografts.

METHODS

All patients had Doppler echocardiographic examinations preoperatively, at discharge from hospital and 54 patients at 1 year follow-up. We measured aortic and pulmonary peak flow velocities with continuous and pulsed-wave Doppler, and graded aortic and pulmonary insufficiency (AI, PI) with color Doppler flow (grade 0-IV). Intraoperatively, the diameters of the pulmonary root and the pulmonary homograft were measured with standard valve probes and matched to body surface area.

RESULTS

Pulmonary peak flow velocity (PVmax) increased significantly from preoperative 0.87 +/- 0.11 m/s to 1.30 +/- 0.34 m/s postoperatively (P < 0.001). The implanted homografts (mean 25.9 +/- 2.4 mm) were larger than their native pulmonary diameter (mean 23.3 +/- 1.8 mm) in all patients. Homograft size matched for body surface area (BSA) did not correlate with increased PVmax. There was a significant increase of PVmax at follow-up (FU) since discharge, also (1.83 +/- 0.53 m/s; P < 0.001). Pulsed-wave Doppler demonstrates that increase of PVmax is located directly at the homograft leaflets and not at the anastomoses. Aortic peak flow velocities (AVmax) were normal postoperatively and at FU (post = 1.35 +/- 0.35 m/s; FU = 1.17 +/- 0.27 m/s). There was no significant change in AI or PI since discharge (AI FU = 0.8 +/- 0.4; PI FU = 0.7 +/- 0.5). Eight patients with fever and symptoms diagnosed as post-pericardiotomy syndrome had significantly higher PVmax at FU (PVmax = 2.41 +/- 0.40 m/s; P < 0.02).

CONCLUSIONS

The Ross procedure leads to normal AVmax but significant increase of PVmax even in oversized cryopreserved homografts immediately after surgery. Further increase of PVmax without changes in AVmax in the first year demonstrates that changes in flow velocities are valve related and not due to increase in cardiac output. Further investigations will be necessary to determine whether this observation is due to valve rejection or early leaflet degeneration and treatment with immunosuppressive therapy is warranted.

Hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve

The hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve (HP) for a small aortic annulus was compared to that of the standard St. Jude Medical valve (SJM). Doppler echocardiographic parameters were evaluated in patients undergoing aortic valve replacement with either a 19 mm HP (HP19, n = 7), a 21 mm HP (HP21, n = 8), a 19 mm SJM (SJM19, n = 16), or a 21 mm SJM (SJM21, n = 34). The peak and mean pressure gradients and peak flow velocity were significantly (p < 0.05) lower in both patients with the HP21 and those with the HP19 than patients with the SJM21 and those with the SJM19, respectively. The echocardiographic parameters of the patients with the HP19 corresponded closely to those of patients with the SJM21. The left ventricular mass index regressed markedly in patients with the HP19 during the late postoperative period. The results suggested that the hemodynamic performances of certain sizes of the HP were superior to those of the same size SJMs and were considered to be equivalent to those of the next size larger SJM.

The CarboMedics prosthetic heart valve in the mitral position: results of the multicenter international trial

Isolated mitral valve replacement using the CarboMedics prosthetic mitral valve (CarboMedics, Inc., Austin, TX) was studied in 13 centers in the United States, Canada, and Scandinavia between 1987 and 1993 in 428 patients with a mean age of 57 +/- 14 years. Actuarial survivals at 1, 2, and 5 years were 88.2% and 75.8%. Freedom from events at 5 years were 94.8% for major thromboembolism, 96.6% for thrombosis, and 96.7% for endocarditis. Linearized morbidity rates (events per 100 patient years) for events at > 30 days postoperatively were .51 thrombosis, 1.1 major thromboembolism, and .37 endocarditis. These results at early to mid-term compare favorably with the first generation bileaflet valve.

St. Jude Medical valve prosthesis: an analysis of long-term outcome and prognostic factors

Between 1979 and 1984, 321 patients received 354 St. Jude Medical prostheses (194 aortic, 94 mitral, 1 tricuspid, and 32 multiple valve replacements). Follow-up was 96% complete (2967 patient-years; mean 9.5 years per patient). Actuarial event-free rates at 10 years and linearized rates (in parentheses) of late complications were as follows: embolism, 85.0% +/- 2.3% (2.3% per patient-year); anticoagulant-related hemorrhage, 74.8% +/- 2.7% (3.3% per patient-year); cerebrovascular accident, 81.8% +/- 2.5% (2.6% per patient-year); prosthesis thrombosis, 98.5% +/- 0.7% (0.1% per patient-year); endocarditis, 97.2% +/- 1.1% (0.4% per patient-year); prosthesis dysfunction, 97.1% +/- 1.0% (0.4% per patient-year); hemolytic anemia, 98.5% +/- 0.7% (0.1% per patient-year); reoperation, 97.4% +/- 1.0% (0.4% per patient-year); overall mortality, 63.3% +/- 2.7% (4.2% per patient-year); and valve-related death (including sudden death), 84.7% +/- 2.2% (1.4% per patient-year). Independent preoperative risk factors were as follows: (1) for embolism, cardiac failure as indication for operation and history of prior systemic embolism; (2) for cerebrovascular accidents, the same two factors and age; (3) for endocarditis, diabetes, chronic alcoholism, and aortic valve replacement; (4) for overall mortality, age, ejection fraction (or cardiac index or cardiothoracic index), chronic alcoholism, and history of systemic embolism; and (5) for valve-related death, chronic alcoholism, degenerative cause of valve disease, and prosthetic diameter 23 mm or smaller. Ninety percent of survivors were in New York Heart Association functional class I or II at the end of follow-up. In conclusion, this study confirms the excellent durability of the St. Jude Medical valve and the remarkable functional benefit for the majority of the patients. However, prosthesis-related complications are still common, particularly for small-diameter prostheses. Outcome is strongly related to the patient's preoperative cardiac condition and to the adequacy of anticoagulation control.

Clinical experience with the CarboMedics valve: early results with a new bileaflet mechanical prosthesis

Between January 1989 and August 1992, 612 CarboMedics mechanical prostheses (CarboMedics, Inc., Austin, Tex.) (295 mitral, 308 aortic, and 9 tricuspid) were implanted in 504 patients: 189 patients had isolated mitral valve replacement, 209 had isolated aortic valve replacement, and 106 had multiple valve replacement. The total follow-up was 1182 patient-years. The hospital mortality rate was 7.4% for mitral valve replacement, 5.3% for aortic valve replacement, and 13.2% for multiple valve replacement. Linearized rates for the different complications for mitral valve replacement, aortic valve replacement, and multiple valve replacement (in events per 100 patient-years) were, respectively, as follows: late mortality, 2.6 +/- 0.8, 1.5 +/- 0.5, and 3.9 +/- 1.3; thromboembolism [correction of thromboembolim], 3.7 +/- 0.9, 3.1 +/- 0.8, and 3.9 +/- 1.3; valve thrombosis, 0.5 +/- 0.3 for mitral valve replacement and 0.4 +/- 0.4 for multiple valve replacement; anticoagulant-related hemorrhage, 2.8 +/- 0.8, 1.9 +/- 0.6, and 2.6 +/- 1.1; nonstructural dysfunction, 1.6 +/- 0.6, 0.8 +/- 0.4, and 3.5 +/- 1.2; and reoperation, 1.1 +/- 0.5, 0.4 +/- 0.3, and 3.1 +/- 1.1. Actuarial estimates of freedom from the different complications for mitral valve replacement, aortic valve replacement, and multiple valve replacement (at 5 years of follow-up for mitral valve replacement and aortic valve replacement and 4.5 years for multiple valve replacement) were, respectively, as follows: overall death, 83% +/- 4%, 89% +/- 2%, and 76% +/- 4%; thromboembolism or valve thrombosis, 88% +/- 3%, 91% +/- 2%, and 86% +/- 5%; anticoagulant-related hemorrhage, 89% +/- 3%, 95% +/- 2%, and 90% +/- 5%; nonstructural dysfunction, 97% +/- 1%, 98% +/- 1%, and 91% +/- 3%; and reoperation, 96% +/- 2%, 99% +/- 1%, and 87% +/- 5%. There were no instances of prosthetic structural dysfunction. The performance of the CarboMedics valve is satisfactory at 5 years of follow-up but thromboembolic and hemorrhagic phenomena are still serious complications of mechanical prostheses.

Results with mechanical cardiac valvular prostheses

Mechanical cardiac valvular prostheses continue to be more popular than bioprostheses for heart valve replacement operations. Five different brands of mechanical heart valves are now approved for implantation in the United States: Starr-Edwards models 1260 and 6120, Medtronic-Hall, St. Jude Medical, Omniscience, and CarboMedics. Each model of mechanical valve has certain positive and negative attributes, but none is functionally mechanically perfect. A review of the published long term results with these valves favors the Medtronic-Hall and St. Jude Medical valves. A new method of assessing the thrombogenic potential and requirement for anticoagulation of the different mechanical valves, namely the composite thromboembolism and bleeding index, is proposed. Evaluation of the new index demonstrates a modest advantage for the Medtronic-Hall valve, particularly in the aortic position.

The CarboMedics valve: midterm follow-up with analysis of risk factors

BACKGROUND

This study examined the midterm results with the CarboMedics prosthetic valve.

METHODS

From 1987 through 1991 a total of 569 patients received the CarboMedics prosthesis.

RESULTS

Early mortality was 4.9% and related to emergency operation, presence of diabetes mellitus, coronary artery disease, preoperative New York Heart Association class, duration of cardiopulmonary bypass, and aortic cross-clamp time. Midterm follow-up with respect to mortality was 100% complete. All patients were followed up in the hospital after 1 year. In addition 86% of the patients responded to a questionnaire. Mean follow-up was 3 years (range, 0 to 5.6 years). Cumulative survival at 1 and 4 years was 91.2% +/- 1.2% and 83.7% +/- 1.8%, respectively. Five patients experienced obstructive valve thrombosis (0.3%/patient-year), 16 patients had major thromboembolic events (0.9%/patient-year), and 10 patients had major warfarin-related bleeding (0.6%/patient-year) requiring hospitalization or blood transfusions. Eight patients were reoperated on for paraprosthetic leak (0.4%/patient-year). Prosthetic valve endocarditis developed in 4 patients (0.2%/patient-year). No structural valve failure was observed.

CONCLUSIONS

Midterm follow-up demonstrates that the CarboMedics mechanical prosthesis is reliable and has an acceptable rate of valve-related complications.

Clinical performance of biological and mechanical prostheses

Prosthetic valve replacement remains the most viable alternative for the treatment of severely diseased heart valves. The cumulative experience of mechanical protheses and bioprostheses was evaluated for a 10-year performance comparison: Carpentier-Edwards standard porcine bioprosthesis (CE-S), 1,214 operations; Carpentier-Edwards supraannular porcine bioprosthesis (CE-SAV), 2,489; and mechanical prostheses, 1,364 operations (St. Jude Medical, Carbomedics, Duromedics, and Björk-Shiley Monostrut). The freedom from thromboembolism and hemorrhage at 10 years was 82% for CE-S, 78% for CE-SAV, and 65% for mechanical prostheses (p < 0.05). The relationship existed for major thromboembolism and hemorrhage, 91% (CE-S), 87% (CE-SAV), and 88% (mechanical) (p < 0.05), without clinical relevance. The freedom from structural valve deterioration and valve-related reoperation favored mechanical prostheses (p < 0.05) at 10 years (structural failure: 78% for CE-S, 81% for CE-SAV, and 99% for the mechanical group; reoperation: 74% for CE-S, 76% for CE-SAV, and 88% for mechanical prostheses). The freedom from fatal reoperation was not clinically different: 96% for CE-S, 99% for CE-SAV, and 99% for mechanical prostheses (p < 0.05) at 10 years. The freedom from valve-related mortality was not different (p = not significant) at 10 years: 87% for CE-S; 92% for CE-SAV; and 91% for mechanical. The freedom from permanent impairment or residual morbidity, primarily from thromboembolism, was 95% for CE-S, 92% for CE-SAV, and 95% for mechanical group (p < 0.05) but not clinically relevant.(ABSTRACT TRUNCATED AT 250 WORDS)

Optimal oral anticoagulant therapy in patients with mechanical heart valves

BACKGROUND

The optimal intensity of oral anticoagulant therapy for patients with mechanical heart valves (i.e., the level at which thromboembolic complications are effectively prevented without excessive bleeding) is not known. We attempted to determine the optimal intensity by calculating the incidence of both complications at different levels of anticoagulation.

METHODS

Data were collected on all patients with mechanical heart valves who have been seen at four regional Dutch anticoagulation clinics since 1985. The primary outcome events were episodes of thromboembolism or major bleeding. The intensity-specific incidence of each type of event was calculated as the number of events that occurred at a certain intensity of anticoagulation (expressed in terms of the international normalized ratio [INR]) divided by the number of patient-years during which the INR was at this level in the total patient population.

RESULTS

A total of 1608 patients were followed during 6475 patient-years. Cerebral embolism occurred in 43 patients (0.68 per 100 patient-years) and peripheral embolism in 2 (0.03 per 100 patient-years). Intracranial and spinal bleeding occurred in 36 patients (0.57 per 100 patient-years) and major extracranial bleeding in 128 (2.1 per 100 patient-years). The optimal intensity of anticoagulation, at which the incidence of both complications was lowest, was achieved when the INR was between 2.5 and 4.9.

CONCLUSIONS

The intensity of anticoagulant therapy for patients with prosthetic heart valves is optimal when the INR is between 2.5 and 4.9. To achieve this level of anticoagulation, a target INR of 3.0 to 4.0 is recommended.

Double-valve replacement with Medtronic-Hall or St. Jude valve

To define better the performance of the bileaflet St. Jude and the tilting-disc Medtronic-Hall valves, we retrospectively analyzed 122 patients (St. Jude, 80 patients; Medtronic-Hall, 42 patients) who received simultaneous aortic and mitral replacement from May 1984 until June 1994. The two groups were not different with respect to preoperative clinical and hemodynamic parameters and New York Heart Association functional class. The hospital mortality and late mortality were not significantly different. Risk analysis identified advanced age and previous myocardial revascularization as predictors of operative death. Follow-up was complete in 96 of 103 hospital survivors (93%) and was similar in both groups. The actuarial survival, linearized rates of valve-related complications, and actuarial freedom from valve-related complications were similar in both cohorts. The presence of coronary artery disease negatively influenced the actuarial survival after simultaneous aortic and mitral valve replacement. Postoperative New York Heart Association functional class was not significantly different in either group. These data indicate that the Medtronic-Hall and St. Jude prostheses are not significantly different with respect to their clinical performance and valve-related complications for simultaneous double-valve replacement.

Long-term results of valve replacement with the St. Jude Medical prosthesis

To assess with truly long follow-up the long-term results of valve replacement with the St. Jude Medical prosthesis (St. Jude Medical, Inc., St. Paul, Minn.), we reviewed the case histories of the first 1112 patients undergoing 1244 valve replacements with this valve between June 12, 1978, and June 12, 1987: 690 male (62%) and 422 female patients, mean age 56 years. A total of 773 patients (69%) had the aortic valve replaced, 207 (19%) the mitral valve, and 132 (12%) the aortic and mitral valves. There were 42 hospital deaths (3.8%). Follow-up was 97.5% complete (8988 patient-years). There were 213 late deaths. Ninety-one (43%) were considered valve-related: sudden death, n = 27; anticoagulant-related hemorrhage, n = 22; thromboembolism, n = 19; prosthetic valve endocarditis, n = 13; valve thrombosis, n = 9; and noninfectious perivalvular leak, n = 1. Overall actuarial survival, including hospital mortality, was 68% +/- 6% (95% confidence limits) 14 years after the operation. Linearized rates of late valve-related events were as follows: thromboembolism, 1.09% per patient-year; anticoagulant-related hemorrhage, 0.94% per patient-year; prosthetic valve endocarditis, 0.32% per patient-year; valve thrombosis, 0.33% per patient-year; and perivalvular leak, 0.19% per patient-year. Actuarial freedom, at 14 years, from thromboembolism was 89% +/- 3%, anticoagulant-related hemorrhage 83% +/- 8%, valve thrombosis 97% +/- 1%, and reoperation 95% +/- 3%. Actuarial freedom from all valve-related deaths and valve-related morbidity and mortality, at 14 years, was 84% +/- 6% and 61% +/- 8%, respectively. We conclude that, because of its low thrombogenicity, low incidence of valve-related events, and low valve-related mortality, the St. Jude Medical valve is one of the best performing mechanical prosthesis currently available. Nevertheless, the late valve-related complications and deaths illustrate that the quest for a "perfect" prosthesis remains unfulfilled.