Mitral valve replacement: randomized trial of St. Jude and Medtronic-Hall prostheses

Mitral Valve Replacement-Current and Future Perspectives

The favorable outcomes achieved with modern mitral valve repair techniques redefined the role of mitral valve replacement. Various international databases report a significant decrease in replacement procedures performed compared with repairs, and contemporary guidelines limit the application of surgical mitral valve replacement to pathology in which durable repair is unlikely to be achieved. The progressive paradigm shift toward endoscopic and robotic mitral valve surgery is also paralleled by rapid developments in transcatheter devices, which is progressively expanding from experimental approaches to becoming clinical reality. This article outlines the current role and future perspectives of contemporary surgical mitral valve replacement within the context of mitral valve repair and the dynamic evolution of exciting transcatheter alternatives.

The real impact of randomized clinical trials in heart valve surgery

PURPOSE OF REVIEW

The aim of this article is to evaluate the findings of clinical trials in cardiac valve surgery and to determine the real impact in standard of care. Also, publications on randomized clinical trials were reviewed as to integrity and validity. Nineteen randomized clinical trials were identified in 11 areas of operative and clinical management.

RECENT DEVELOPMENTS

The Veterans Affairs and Edinburgh Heart Valve Trials confirmed the guidelines for indications for bioprostheses and mechanical prostheses. Even current prostheses have advanced technologies but the same valve-related complications determine indications. Randomized clinical trials of mechanical prostheses failed to determine prosthesis superiority. Bioprostheses of specific manufacturers contribute sub-optimal hemodynamics in small sizes. Two trials showed lack of superiority between aortic stented and stentless bioprostheses. Autografts, not allografts, are indicated for children because of structural valve deterioration of allografts. Atrial ablation surgery with concomitant mitral valve reconstruction/replacement is safe and efficacious with at least two energy sources. Minimally invasive aortic valve replacement does not provide superior results to conventional surgery. Patient-managed anticoagulation provides the most favourable thromboembolic and hemorrhagic rates with mechanical prostheses. Prosthesis sewing cuff impregnation with a bactericidal agent to reduce the incidence of prosthetic valve endocarditis was stopped because of increased incidence of major paravalvular leak requiring reoperation.

SUMMARY

Randomized clinical trials, although limited in number, have provided advancement of the standard of care. Randomized clinical trials are indicated in the management of mild to moderate ischemic mitral regurgitation and evaluation of new transcatheter technologies to conventional surgery.

Effects of giant left atrium on thromboembolism after mitral valve replacement

The aim of this study was to evaluate the incidence of thromboembolic events in patients with giant left atrium ( > 6.5 cm) after mitral valve replacement. From January 2000 to September 2002, a total of 126 patients who had undergone mitral valve replacement were divided into two groups according to the presence or absence of giant left atrium. Group A comprised 34 patients with left atrium over 6.5 cm without compression symptoms and Group B comprised 92 patients. The preoperative variables did not distinguish the patients in each group, except for atrial fibrillation; Group A 85.2% and Group B 61.9% ( p < 0.01). After mitral valve replacement, left atrium mean diameter was significantly decreased in Group A from 8.1 +/- 1.3 mm to 6.2 +/- 1.6 mm ( p < 0.01). There were no significant differences in thrombosis, hemorrhage and thromboembolism rates in both groups. Postoperative clinical and hemodynamic parameters demonstrated a positive clinical response to mitral valve replacement in patients with giant left atrium. During follow-up no direct relationship between thromboembolism and giant left atrium was evident.

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.

Mitral valve replacement in children: mortality, morbidity, and haemodynamic status up to medium term follow up

OBJECTIVE

To investigate the outcome of mechanical mitral valve replacement in children after up to 11 years of follow up.

DESIGN

Retrospective analysis of case records. Operative survivors underwent echocardiographic studies to define current haemodynamic status and prosthetic valve function.

SETTING

Tertiary referral centre.

PATIENTS

All 54 children who underwent mitral valve replacement between January 1987 and December 1997.

RESULTS

30 day mortality was 20.3% and was associated with small valve size and supra-annular position. The actuarial freedom from the following events at five years (70% confidence interval (CI)) was: death, including 30 day mortality and transplantation, 68% (70% CI 62% to 75%); bleeding, 89% (70% CI 84% to 94%); non-structural valve dysfunction and reoperation, 92% (70% CI 87% to 97%). The incidence of endocarditis and thromboembolism was low and there was no structural valve failure. Event-free survival was 52% (70% CI 45% to 60%). Low weight, young age, and small valve size increased the chance of death or reoperation. On echocardiography, left ventricular dilatation and wall motion abnormalities were often observed. A high mean gradient over the prosthesis was associated with small valve size but not with length of follow up.

CONCLUSIONS

With the use of mechanical prostheses for mitral valve replacement in children, the problem of structural valve failure is no longer an issue. However, the procedure is still associated with a high complication rate, both at surgery and during follow up, and should therefore be reserved for patients in whom valve repair is not technically feasible.

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.

Evaluation of the Sorin bicarbon bileaflet valve in 488 patients (519 prostheses)

The Sorin bicarbon bileaflet prosthesis was introduced in 1990. To evaluate the clinical performance of this prosthesis, we reviewed 519 prostheses that were implanted in 488 patients (275 men, 213 women; mean age 59 years; SD 10.8, range 19 to 88) from 1993 to 1997. Preoperatively, 82% of patients were in New York Heart Association (NYHA) functional class III or IV. There were 263 aortic valve replacements (AVRs) (54%), 194 mitral valve replacements (MVRs) (40%), and 31 AVRs and MVRs (both) (6%). Concomitant procedures were performed in 82 patients (17%). Follow-up was complete in 471 (97%) with a total cumulative follow-up of 866 patient-years. The 30-day mortality for patients with AVR was 5.7% (95% confidence interval [CI] 2.9 to 8.5), MVR 17.5% (CI 9.9 to 19.7), and both 19% (CI 7.6 to 51.1), with no early valve-related deaths. Patient survival at 55 months was 76% (SE 2.27%), with patients with AVR being 90%, MVR 63%, and both 61%. This was influenced by the following: (1) valve position, which was higher for MVR (p = 0.0001); (2) poor NYHA functional class (p = 0.0006); (3) reoperation (p = 0.02); and (4) age >70 years (p = 0.0001). Valve-related complications (expressed as percentage per patient year and number of events) were major thromboembolism at 0.9% per year (8), with AVR rates being 1.2% per year (6) and MVR 0.7% per year (2); major hemorrhage at 2.3% per year (20) with AVR rates being 2.4% per year (12) and MVR 2.5% per year (7); bacterial endocarditis at 0.2% per year (2); and nonstructural dysfunction rate of 0.7% per year (6). The reoperation rate was 0.9% per year (8) with AVR being 0.6% per year (3) and MVR 1.7% per year (5). At 55 months, actuarial freedom from major thromboembolism was 97% (SE 1.1%) with AVR being 96% and MVR 98%; major hemorrhage 89% (SE 3.1%) with AVR being 88.6% and MVR 91%; structural valve dysfunction 100% (SE 0.0%); and reoperation 97.1% (SE 1.10%) with AVR being 98.5% and MVR 94.6%. At follow-up, 88% of survivors were in NYHA class I or II. In this series, hospital mortality and overall survival in patients were influenced by the patients' clinical characteristics. There were no early valve-related deaths. Valve-related complications were similar to previously reported series with no episode of structural failure. Our experience with the Sorin bicarbon bileaflet prosthesis suggests that it has a satisfactory clinical performance, with low complication rates.

Mitral valve replacement: randomized trial of St. Jude and Medtronic Hall prostheses

BACKGROUND

This study was designed to better define the merits of the bileaflet and tilting-disc valves.

METHODS

We prospectively randomized 156 patients (mean age, 59 years) to receive either the St. Jude (n = 80) or the Medtronic Hall (n = 76) mitral valve prosthesis between September 1986 and December 1997. The two groups were not significantly different with respect to preoperative New York Heart Association class, left ventricular ejection fraction, incidence of mitral stenosis or insufficiency, extent of coronary artery disease, completeness of revascularization, or cross-clamp or bypass time.

RESULTS

The operative mortality (11.2% versus 13.1%, St. Jude versus Medtronic Hall, respectively) and late mortality (27% versus 22%, St. Jude versus Medtronic Hall, respectively) were not significantly different. Follow-up was complete in all hospital survivors with a mean of 60.7 months (range, 1 to 133 months). The analysis of 10-year actuarial survival and freedom from valve-related events demonstrated no significant differences between the cohorts. Freedom from reoperation was higher in the St. Jude group (p < 0.01). Comparisons of patient functional status and echocardiographic hemodynamic parameters obtained at the time of follow-up demonstrated no significant differences between the two prostheses.

CONCLUSIONS

This study suggests that there is no difference between the St. Jude and Medtronic Hall prostheses with respect to late clinical performance or hemodynamic results and therefore does not support the preferential selection of either prosthesis.

Valve repair versus replacement for mitral insufficiency: when is a mechanical valve still indicated?

OBJECTIVES

Although many advantages of mitral valve reconstruction have been demonstrated, whether specific subgroups of patients exist in whom mechanical valve replacement offers advantages over mitral reconstruction remains undetermined.

METHODS

This study examined the late results of mitral valve surgery in patients with mitral insufficiency who received either a St. Jude Medical valve (n = 514) or a mitral valve reconstruction with ring annuloplasty (n = 725) between 1980 and 1996.

RESULTS

Overall operative mortality was 7.2% in the patients receiving a St. Jude Medical mitral valve and 5.4% in those undergoing mitral valve reconstruction (no significant difference); isolated mortality was 2.5% in the St. Jude Medical group and 2.2% in the valve reconstruction group (no significant difference). The follow-up interval was more than 5 years for 340 patients with a mean of 39.8 months (98.5% complete). Overall 8-year freedom from late cardiac death, reoperation, and all valve-related complications was 72.8% for the St. Jude Medical group and 64.8% for valve reconstruction group (no significant difference). For patients with isolated, nonrheumatic mitral valve disease, 8-year freedom from late cardiac death and reoperation was better in the mitral valve reconstruction group (88.3%) than in the St. Jude Medical valve group (86.0%; p = 0.05). Furthermore, Cox proportional hazards regression revealed that mitral valve reconstruction was independently associated with a lesser incidence of late cardiac death (p = 0.04), irrespective of preoperative New York Heart Association class. However, the St. Jude Medical valve offered better 8-year freedom from late cardiac death, reoperation, and all valve-related complications than did mitral valve reconstruction in patients with multiple valve disease (77.0% vs 45.3%; p < 0.01).

CONCLUSIONS

Therefore, mitral valve reconstruction appears to be the procedure of choice for isolated, nonrheumatic disease, whereas insertion of a St. Jude Medical valve should be preferred for patients with multiple valve disease.

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.

Ten years' experience of aortic valve replacement with the Omnicarbon valve prosthesis

BACKGROUND

There are few clinical studies on late follow-up of the Omnicarbon monoleaflet valve. We report our 10-year experience with this valve in the aortic position and also compare late hemodynamic performance of this valve with that of the CarboMedics valve in the aortic position.

METHODS

From January 1985 to June 1995, 117 consecutive patients underwent aortic valve replacement (AVR) with the Omnicarbon valve. There were 66 men and 51 women aged 13 to 69 years (mean age, 50 +/- 12 years). They were divided into three groups: group 1 (43 patients) had isolated AVR, group 2 (36) had AVR and concomitant operations, and group 3 (38) had combined AVR and mitral valve replacement. Follow-up was 96.6% complete and consisted of 882.7 patient-years (range, 2.5 to 10.6 years; mean follow-up, 7.5 +/- 2.7 years).

RESULTS

There were three early deaths (2.6%) and 18 late deaths (2.0%/patient-year) ten of which were due to valve-related causes and eight, non-valve-related causes. Survival rates at 10 years in groups 1, 2, and 3 were 77.6%, 82.4%, and 78.6%, respectively. The overall rates of freedom from valve-related complications in groups 1, 2, and 3 at 10 years were 77.4%, 100%, and 80.9%, respectively. The rates of freedom from the following complications in groups 1, 2, and 3 at 10 years were as follows: thromboembolism--94.8%, 100%, and 89.4%, respectively; valvar thrombosis--95.0%, 100%, and 100%; anticoagulant-related hemorrhage--93.6%, 100%, and 93.4%; prosthetic valve endocarditis--93.0%, 100%, and 97.2%; and reoperation--90.6%, 100%, and 97.2%. There were no significant differences between groups. All survivors showed marked improvement in New York Heart Association functional class, from 86% in classes III and IV preoperatively to 96% in classes I and II postoperatively. The Omnicarbon valve exhibited no significant difference in hemodynamic performance after isolated AVR compared with the CarboMedics bileaflet valve at the same follow-up periods.

CONCLUSIONS

This 10-year study confirms that the Omnicarbon valve is a durable prosthesis and provides excellent functional improvement with low rates of thromboembolism and valvar thrombosis in the aortic position.

Long-term results with the Medtronic-Hall valvular prosthesis

BACKGROUND

Although more than 170,000 Medtronic-Hall mechanical valvular prostheses have been inserted world-wide, long-term results are available on only a small percent of those valves inserted.

METHODS

A prospective data registry of all Medtronic-Hall cardiac prostheses inserted by one surgeon was used to identify 460 valves inserted during 391 operations from 1983 to 1994: single aortic (n = 210), single mitral (n = 115), or double aortic and mitral (n = 66) replacements, including three tricuspid valve replacements. Follow-up was sought five times in 10 years and was available for 280 (99%) of 283 survivors with only an isolated aortic or mitral Medtronic-Hall valve followed up for at least 1 year (1,246 patient years).

RESULTS

Hospital mortality was 4.6% (18 patients). Of 40 late deaths, eight were valve-related (0.6% per patient-year). The linearized rates of complications for aortic and mitral valve replacements (percent per patient-year) were, respectively: structural deterioration, 0 and 0; nonstructural dysfunction, 0.1 and 2.1; thromboembolism, 1.3 and 2.1; thrombosis, 0 and 0.2; anticoagulant-related bleeding, 1.7 and 1.9; and prosthetic valve endocarditis, 0.6 and 1.0. Actuarial freedom from reoperation at 10 years was 97% for aortic and 88% for mitral valves.

CONCLUSIONS

The Medtronic-Hall mechanical valvular prosthesis has excellent durability and acceptably low rates of valve-related complications and remains my mechanical prosthetic valve of choice for both aortic and mitral valve replacements.

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.

Comparative results with the St. Jude Medical and Medtronic Hall mechanical valves

This study compared the clinical performance of the St. Jude Medical and Medtronic Hall mechanical valves in isolated aortic or mitral valve replacement. From 1984 to 1993, 349 St. Jude Medical valves (aortic 237, mitral 112) and 465 Medtronic Hall valves (aortic 272, mitral 193) were implanted in 814 patients at the University of Ottawa Heart Institute. The patients had similar preoperative characteristics. The hospital mortality rate for aortic valve replacement was 3.4% with the St. Jude Medical valve and 5.8% with the Medtronic Hall valve (p = 0.26) and the rate for mitral valve replacement was 8.9% with the St. Jude Medical valve and 11.9% with the Medtronic Hall valve (p = 0.54). Actuarial estimates of survival and freedom from complications were calculated. At 5 years the actuarial probability of survival (including hospital deaths) for aortic valve replacement was 86% +/- 3% with the St. Jude Medical valve and 68% +/- 4% with the Medtronic Hall valve (p = 0.0001) and for mitral valve replacement was 75% +/- 7% with the St. Jude Medical valve and 70% +/- 4% with the Medtronic Hall valve (p = 0.54). The most common cause of late death was cardiac failure and no deaths were caused by structural failure. The 5-year probability of freedom from bleeding after aortic valve replacement was 99% +/- 1% with the St. Jude Medical valve and 95% +/- 2% with the Medtronic Hall valve (p = 0.06) and after mitral valve replacement 99% +/- 1% with the St. Jude Medical valve and 97% +/- 2% with the Medtronic Hall valve (p = 0.37). The 5-year probability of freedom from thromboembolism after aortic valve replacement was 88% +/- 4% with the St. Jude Medical valve and 81% +/- 3% with the Medtronic Hall valve (p = 0.08) and after mitral valve replacement was 85% +/- 7% with the St. Jude Medical valve and 77% +/- 5% with the Medtronic Hall valve (p = 0.17). Reoperation was uncommon and there were no cases of structural valve failure. The 5-year actuarial estimate of freedom from reoperation therefore for aortic valve replacement was 99% +/- 1% with the St. Jude Medical valve and 96% +/- 2% with the Medtronic Hall valve (p = 0.09) and for mitral valve replacement was 98% +/- 2% with the St. Jude Medical valve and 95% +/- 3% with the Medtronic Hall valve (p = 0.40).(ABSTRACT TRUNCATED AT 400 WORDS)

Immediate and late outcome of percutaneous balloon mitral valvotomy in patients with significantly calcified valves

We assessed immediate and late outcome in 55 patients with significantly calcified valves (group 1) after balloon mitral valvotomy and compared the results with those from 60 patients with noncalcified or minimally calcified valves (group 2). After valvotomy, mitral valve area increased from 1.03 +/- 0.30 cm2 to 1.64 +/- 0.35 cm2 (p = 0.0001) by echo planimetry in group 1 but was significantly smaller than the mitral valve area in group 2 after valvotomy (1.94 +/- 0.38 cm2; p = 0.0001). At a mean follow-up period of 30 months (range 2 to 81 months), 51% of patients in group 1 and 83% in group 2 were symptom free (p = 0.0002). In group 2, 15 (27%) patients and in group 2, 4 (7%) patients had cardiac events (p = 0.003). The risk ratio for cardiac events was 4.3 times greater in group 1 than in group 2. In group 1, the risk ratio for cardiac events was 3.2 times higher in patients age > or = 65 years and in patients with atrial fibrillation. The 6-year cumulative cardiac event-free survival rate was 64% in group 1 and 90% in group 2 (p = 0.005). In 75 (65%) patients who had follow-up echocardiographic study (35 in group 1 and 40 in group 2), mitral valve area decreased to 1.48 +/- 0.42 cm2 at follow-up in group 1 (p < 0.01) and to 1.77 +/- 0.50 cm2 in group 2 (p = 0.3). Restenosis occurred in 16 (46%) of 35 patients in group 1 and 10 (25%) of 40 in group 2 (p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Thromboembolic risk and late survival after mitral valve replacement with the St. Jude Medical valve

From January 1979 to December 1990, 397 consecutive patients (mean age, 55 +/- 11 years) underwent mitral valve replacement with the St. Jude Medical valve. Associated procedures performed were 174 multiple valve replacements, 24 coronary artery bypass graftings, 25 tricuspid repairs, and 13 left ventricular myectomies. The continuous intravenous administration of heparin was started on the first postoperative day and maintained until effective oral anticoagulation, started on the seventh day, was achieved (INR, 3 to 4.5). Follow-up consisted of 2,402 patient-years (pt-y) (mean, 6.1 +/- 0.2 years) and was 97% complete. The early (30-day) mortality was 3.5%; the 5-year and 10-year actuarial survivals were 86% +/- 4% and 73% +/- 6%, respectively. Survival was less in patients who had been in an advanced preoperative functional class (p = 0.02) and in those who underwent multiple valve replacements (p = 0.05). The 5-year and 10-year survivals in patients who underwent isolated mitral valve replacement and who were in preoperative New York Heart Association functional class II and III, were 90% +/- 5% and 82% +/- 7%, respectively. The early and late mortality and the incidence of deaths resulting from heart failure and sudden deaths were higher in patients who had undergone multiple valve replacements (p = 0.05). In terms of all deaths, 47% (36/77) were valve related (including 12 sudden deaths, 0.50%/pt-y). Thromboembolic complications occurred in 44 patients, and these were broken down as follows: embolism, 1.46%/pt-y, and valve thrombosis, 0.37%/pt-y.(ABSTRACT TRUNCATED AT 250 WORDS)

Mitral valve replacement: indications, choice of valve prosthesis, results, and long-term morbidity of porcine and mechanical valves

Indications for specific valve types, whether they be mechanical or bioprosthetic, have been rigorously defined in recent years. Candidates for bioprosthetic valves would be: older patients, patients who are noncompliant or have contraindications to anticoagulation, patients in normal sinus rhythm, and young females desirous of future pregnancy. Recent data suggest that patient age and presence of coronary artery disease may significantly alter the indications for mechanical or tissue valves. There is mounting evidence that patients without coronary disease in their 60s and 70s who require valve replacement are better served with a mechanical prosthesis. At Emory University Hospitals, 440 patients operated upon between 1974 and 1981 were followed for a mean period of 8.3 years. No patients having coronary artery disease were included in the cohort. Survival at 10 years was 64%. The actuarial freedom from all major valve related complications at the end of 10 years is compared to other series. Data suggests that patient survival for mitral valve replacement is affected by the etiology of the valve disease necessitating the operation. The best survival occurs in patients in whom the mitral valve replacement is for myxoid degeneration and may explain the excellent survival to be expected for mitral valve repair and concomitant coronary bypass. The most significant factor increasing morbidity and mortality in patients with mitral valve replacement and coronary artery disease is high end-diastolic pressure associated with significant depression of regional wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)