HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Kiyofumi Morishita Tomio Abe Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Morishita, K. Articles by Abe, T. Search for Related Content PubMed PubMed Citation Articles by Morishita, K. Articles by Abe, T.

Ann Thorac Surg 1998;65:696-699
© 1998 The Society of Thoracic Surgeons

---

Original Articles: Cardiovascular

Re-Replacement for Prosthetic Valve Dysfunction: Analysis of Long-Term Results and Risk Factors

Department of Thoracic and Cardiovascular Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan

Accepted for publication September 3, 1997.

Dr Morishita, Department of Thoracic and Cardiovascular Surgery, Sapporo Medical University School of Medicine, South 1, West 16, Chuo-ku, Sapporo, Japan 060.

	Abstract

Top Abstract Introduction Patients and Methods Results Comment References

 
Background. Prosthetic heart valve re-replacement still remains a challenging situation. Although some studies have examined the early results, the long-term survival has not yet been well analyzed. The aim of this study was to detect the factors that affect the long-term outcome of operation.

Methods. Between April 1964 and September 1996, 231 prosthetic valve re-replacements were performed including 16 cases of third valve replacement. There were 100 men and 131 women with a mean age of 47 ± 14 years.

Results. The actuarial survival rate was 65% ± 4% at 5 years and 41% ± 7% at 10 years. Multivariate analysis revealed that New York Heart Association class IV and left ventricular ejection fraction were found to be independent predictors of late death.

Conclusions. Our study showed that advanced New York Heart Association functional class and lower left ventricular ejection fraction were found to be independent predictors of late death. If operation is performed before patients reach such a deteriorated condition, long-term results are excellent.

	Introduction

Top Abstract Introduction Patients and Methods Results Comment References

 
At present, none of the prosthetic valves available fulfill the requirements of an ideal valve. Consequently, with time some valve-related complications develop and patients must be reoperated. As a result of accumulated surgical experience and improved myocardial protection, the success rate of prosthetic valve replacements has increased considerably [1][2]. However, problems such as advanced age, deterioration of cardiac function, and limited organ reserve, remain to be solved. To further improve the survival rate of patients undergoing cardiac valve re-replacement, we have reviewed the clinical records of the patients we have reoperated to detect the factors that affect the long-term outcome of operation.

	Patients and Methods

Top Abstract Introduction Patients and Methods Results Comment References

 
Patient Selection
From April 1964 through September 1996, 231 prosthetic valve reoperations were performed including 16 cases of third valve replacement. When patients required a third valve replacement, they were computed as a new patient. These 231 reoperations represented 16% of all valve replacements performed during the same period (231 of 1,405). Excluded from the study were those patients who underwent primary valve replacement due to congenital abnormalities. There were 100 men and 131 women with a mean age of 47 ± 14 years. There were 102 cases of mitral valve replacement, 63 of aortic valve replacement, 43 of aortic and mitral valve replacement, 10 of mitral and tricuspid valve replacement, 6 of composite graft replacement, 5 of translocation [3], and 2 cases of tricuspid valve replacement. The concomitant procedures performed included four cases of coronary artery bypass grafting and aortic graft replacement each. Indications for reoperation were structural valve deterioration in 103 patients (biological prostheses 87, mechanical prostheses 16), tissue ingrowth in 47, valve thrombosis in 34, prosthetic valve endocarditis in 18, paravalvular leak in 19, and prophylactic reasons in 10 patients. The prostheses explanted were 138 mechanical valves and 105 bioprostheses. Preoperatively, 59 (26%) patients were in the New York Heart Association (NYHA) functional class IV, 155 (67%) were in class III, and 17 (7%) were in class II. Thirty-five patients (15%) underwent emergency operations.

Surgical Procedures
In general, all operations were carried out through a median sternotomy. The femoral artery and vein were cannulated in patients with a hypertensive right ventricle and dilated aneurysmal aorta. In most patients, perfusion for cardiopulmonary bypass was achieved through cannulation of the ascending aorta. Myocardial cardioplegic protection was modified in 1981 when crystalloid cardioplegia and local hypothermia were initiated. Since 1985, cold blood cardioplegia has been used. Whenever possible, the entire heart was isolated and mobilized by careful dissection in a patient requiring mitral valve replacement. The prosthesis was removed using an annular preservation technique and a new prosthesis with horizontal mattress sutures was inserted after the native annulus was debrided from previous sutures, sewing ring, pledgets, and fibrous pannus [4].

Data Analysis
Twenty-one variables were tested to detect predictors of long-term survival: age, sex, body weight, prosthetic procedure, type of prosthesis, cause of prosthetic failure, NYHA class before operation, need for an emergency reoperation, type of myocardial protection, kind of concomitant procedure, number of valve replacements, presence of tricuspid insufficiency [5], aortic cross-clamp time, bypass time, left ventricular ejection fraction (LVEF), interval from implantation, presence of chronic obstructive pulmonary disease, renal dysfunction (serum creatinine value >2.0 mg/dL), cerebrovascular disease, diabetes (patients receiving insulin or medication), and hepatic dysfunction (serum bilirubin value >2.0 mg/dL). Forty-four operations performed between 1964 and 1980 were excluded from this analysis to avoid biases because until 1981 there was no established protocol for myocardial protection. To assess the risks of reoperation, we also compared patients who had been reoperated on with those operated on for the first time during the same period (1985 to 1996).

Total follow-up covered 749 years and 98% of all patients (226 of 231) (range, 1 month to 24 years). Clinical information was obtained from hospital records or telephone interviews. Mortality and morbidity were defined based on guidelines for reporting morbidity and mortality after cardiac valvular operations [6].

Statistical Analysis
Data were analyzed using Stat View J 4.11 (Abacus Concepts Inc, Berkeley, CA) on a Power Macintosh computer 7200 (Apple, Inc, Cupertino, CA). All values were expressed as the mean ± standard deviation. Categorical variables were compared by use of ² statistics and Fisher’s exact test. Continuous variables were compared by use of unpaired Student’s t test. Actuarial survival curves were calculated by the Kaplan-Meier method, and the log-rank test was used to compare subgroups. The Cox proportional hazards regression model was used for the multivariable analysis. Risk factors that were significant or nearly so (p < 0.2) by univariate analysis were entered into a forward stepwise regression [7]. A p value of less than 0.05 was considered significant.

	Results

Top Abstract Introduction Patients and Methods Results Comment References

 
Survival
The actuarial survival rate was 82% ± 3% at 30 days, 65% ± 4% at 5 years, and 41% ± 7% at 10 years. In the 65 patients who were reoperated on before 1985, the survival rate was 53% ± 6% at 5 years. After 1985, 162 patients were operated on using cold blood cardioplegia; the survival rate was 70% ± 5% at 5 years. There was a marked increase in the survival rate (p < 0.0005).

Risk Factors
The variables significantly associated with long-term survival were sex, concomitant procedure, NYHA class, age at the time of operation, aortic cross-clamp time, and bypass time on univariate analysis. Twelve variables were included in the multivariate analysis: age, sex, cause of prosthetic failure, NYHA class before operation, need for an emergency reoperation, type of concomitant procedure, presence of tricuspid insufficiency, aortic cross-clamp time, bypass time, LVEF, interval from implantation, and presence of chronic obstructive pulmonary disease. Male sex, NYHA class IV, and tricuspid insufficiency were adversely associated with long-term survival including hospital deaths.

However, when hospital deaths were excluded from these analyses, LVEF less than 0.40 and type of prosthesis used were associated with long-term survival on univariate analysis (Table 1). Seven variables were entered into the multivariate analysis: sex, NYHA class before operation, type of myocardial protection, aortic cross-clamp time, bypass time, LVEF, and type of prosthesis used. LVEF and NYHA class were independent predictors of late deaths (Table 2).

Primary Versus Re-Replacement
In the group of 681 patients operated on from 1985 to 1996, 162 patients who had been reoperated on were compared with 519 patients undergoing primary procedures, with regard to survival rate. The 5-year survival rates were 86% ± 2% versus 70% ± 5% (primary versus re-replacement, p < 0.001). The clinical profiles were outlined in Table 3. The reoperated patients required more cross-clamp time and were in more advanced NYHA class.

	Comment

Top Abstract Introduction Patients and Methods Results Comment References

In the present study multivariate analysis demonstrated that higher NYHA class IV, male and tricuspid insufficiency affected long-term survival, including hospital deaths. However, these factors were generally considered as contributors to greater operative risk. Consequently, it is likely that these variables led to higher rates of in-hospital death and as a result the subsequent survival was depressed. Thus, to identify the real determinants of late deaths, it is fair to exclude hospital deaths from this analysis.

Advanced NYHA class and lower LVEF were independent predictors of late deaths, excluding hospital deaths. These factors probably represent left ventricular dysfunction and this dysfunction probably affected negatively the long-term survival rate. We have a 5-year survival rate of 65% and a 10-year survival rate of 41% in this study, which are in agreement with other studies [1][4][8][9][11]. However, compared with the primary operation, the long-term outcome of reoperations is still worse. This is probably reflected by a higher percentage of patients with NYHA class IV in the reoperated group. Therefore, some researchers claim that patients should be operated on before their condition is jeopardized [4][8][11]. The reasons for this claim are as follows; (1) reoperations are unavoidable if patients have prosthetic valve-related complications, and (2) mortality and late death remain high in advanced NYHA class or lower LVEF. However, there is a general tendency to delay operation until NYHA class IV because patients or physicians believe that prosthetic valve rereplacement carries high risks. Most class IV patients included in this study were not referred to our institution until they were moribund. When we were forced to reoperate on patients with NYHA class IV, operative mortality was high and even if they survived, their life expectancy was poor.

We recognize that this retrospective study does not allow the conclusion that patients should undergo reoperation before they reach such a deteriorated condition. To prove the validity of this strategy, it would be necessary to perform a clinical trial in which relatively healthy patients are randomly picked and, in approximately equal numbers, either operated on immediately or operated on when their condition has degenerated to class IV. However, we believe that patients are given a good chance of survival by performing reoperation, not at NYHA class IV, but at class II or III.

In conclusion, our study showed that advanced NYHA class and lower LVEF were found to be independent predictors of late deaths. If operation is performed before patients reach such a deteriorated condition, long-term results are excellent.

	References

Top Abstract Introduction Patients and Methods Results Comment References

 

1. Bosch X, Pomar JL, Pelletier LC Early and late prognosis after reoperation for prosthetic valve replacement. J Thorac Cardiovasc Surg 1984;88:567-572.[Abstract]
2. Cohn LH, Aranki SF, Rizzo RJ, et al. Decrease in operative risk of reoperative valve surgery. Ann Thorac Surg 1993;56:15-21.[Abstract]
3. Abe T, Sugiki K, Komatsu S Successful surgical treatment of prosthetic valve endocarditis and aortic root abscesses. Chest 1984;85:832-834.[Abstract/Free Full Text]
4. Bortolotti U, Milano A, Mossuto E, et al. Early and late outcome after reoperation for prosthetic dysfunction: analysis of 549 patients during a 26-year period. J Heart Valve Dis 1994;3:81-87.[Medline]
5. Abe T, Tukamoto M, Yanagiya M, et al. De Vega’s annuloplasty for acquired tricuspid disease: early and late results in 110 patients. Ann Thorac Surg 1989;48:670-676.[Abstract]
6. Edmunds LH, Jr, Clark RE, Cohn LH, Grunkemeier GL, Miller DC, Weisel RD Guidelines for reporting morbidity and mortality after cardiac valvular operations. Ann Thorac Surg 1996;62:932-935.[Abstract/Free Full Text]
7. He G-W, Grunkemeier GL, Starr A Aortic valve replacement in elderly patients: influence of concomitant coronary grafting on late survival. Ann Thorac Surg 1996;61:1746-1751.[Abstract/Free Full Text]
8. Husebye DG, Pluth JR, Piehler JM, et al. Reoperation on prosthetic heart valves. An analysis of risk factors in 552 patients. J Thorac Cardiovasc Surg 1983;86:543-552.[Abstract]
9. Rutledge R, Applebaum RE, Kim JB, Engler MB, Engler MM Actuarial analysis of the risk of undergoing repeat cardiac valve replacement. Am J Surg 1984;148:357-361.[Medline]
10. Piehler JM, Blackstone EH, Bailey KR, et al. Reoperation on prosthetic heart valves. Patient-specific estimates of in-hospital events. J Thorac Cardiovasc Surg 1995;109:30-48.[Abstract/Free Full Text]
11. Pansini S, Ottino G, Forsennati PG, et al. Reoperations on heart valve prostheses: an analysis of operative risks and late results. Ann Thorac Surg 1990;50:590-596.[Abstract]

This article has been cited by other articles:

				N. Luciani, G. Nasso, A. Anselmi, F. Glieca, M. Gaudino, F. Girola, M. Piscitelli, M. Perisano, L. Martinelli, and G. Possati Repeat Valvular Operations: Bench Optimization of Conventional Surgery Ann. Thorac. Surg., April 1, 2006; 81(4): 1279 - 1283. [Abstract] [Full Text] [PDF]

				K. Matsuyama, M. Matsumoto, T. Sugita, J. Nishizawa, Y. Kawansihi, and K. Uehara Long-term results of reoperative mitral valve surgery in patients with rheumatic disease Ann. Thorac. Surg., December 1, 2003; 76(6): 1939 - 1943. [Abstract] [Full Text] [PDF]

				T. Bottio, D. Casarotto, G. Thiene, L. Caprili, A. Angelini, and G. Gerosa Leaflet Escape in a New Bileaflet Mechanical Valve: TRI Technologies Circulation, May 13, 2003; 107(18): 2303 - 2306. [Abstract] [Full Text] [PDF]

				Y. Hamanaka, N. Mitsui, and S. Hirai Repeat Tricuspid and Mitral Valve Replacement for Enterococcal Endocarditis Asian Cardiovasc Thorac Ann, December 1, 2001; 9(4): 318 - 319. [Abstract] [Full Text] [PDF]

				K. Hasnat, E. J. Birks, J. Liddicoat, J. K. F. Hon, S. Edwards, S. Glennon, and M. H. Yacoub Patient Outcome and Valve Performance Following a Second Aortic Valve Homograft Replacement Circulation, November 9, 1999; 100 (2009): II-42 - II-47. [Abstract] [Full Text] [PDF]

				G. S. Carr-White, S. Glennan, S. Edwards, F. D. Ferdinand, A. C. Desouza, J. R. Pepper, and M. H. Yacoub Pulmonary Autograft Versus Aortic Homograft for Rereplacement of the Aortic Valve : Results From a Subset of a Prospective Randomized Trial Circulation, November 9, 1999; 100 (2009): II-103 - II-106. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Kiyofumi Morishita Tomio Abe Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Morishita, K. Articles by Abe, T. Search for Related Content PubMed PubMed Citation Articles by Morishita, K. Articles by Abe, T.