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): Toshifumi Murashita Yasuhiro Kamikubo Keishu Yasuda Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Murashita, T. Articles by Yasuda, K. Search for Related Content PubMed PubMed Citation Articles by Murashita, T. Articles by Yasuda, K. Related Collections Valve disease

Eur J Cardiothorac Surg 2004;26:1104-1111
© 2004 Elsevier Science NL

Surgical results for active endocarditis with prosthetic valve replacement: impact of culture-negative endocarditis on early and late outcomes

Department of Cardiovascular Surgery, Hokkaido University Graduate School of Medicine, Kita 14, Nishi-5, Kita-Ku, Sapporo 060-8648, Japan

Received 11 June 2004; received in revised form 23 July 2004; accepted 2 August 2004.

^* Corresponding author. Tel.: +80 11 716 1161x6042; fax: +81 11 747 0476. (E-mail: muratosh{at}med.hokudai.ac.jp).

	Abstract

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusion References

 
Objective: Surgical treatment of active infective endocarditis requires not only hemodynamic repair, but also special emphasis on the eradiation of the infectious focus to prevent recurrence. This goal can be achieved by the combination of aggressive debridement of infective tissue and appropriate and adequate antibiotic treatment. We reviewed our experience with active endocarditis and identified factors determining early and late outcomes, particularly focusing on the factor of culture-negative endocarditis. Methods: Sixty seven patients with clinical evidence of active endocarditis who underwent operation between 1991 and 2001 were evaluated. The aortic valve was infected in 28 (42%), the mitral valve in 23 (34%), and multiple valves in 16 (24%). Native valve endocarditis was present in 58 (87%) and prosthetic valve endocarditis in 9 (13%). Mean follow-up was 5.7 years (range, 0.2–11.5 years). Results: Microorganisms were detected in 46 (69%): Staphylococcus aureus in 9 (13%), other staphylococci in 9 (13%), streprococcus species in 19 (28%), and others in 9 (28%), whereas 21 (31%) patients had culture-negative endocarditis. Operative mortality was 17.8% (12 patients). Reoperation was required in 8 (12%), while 3 late deaths (5.5% of hospital survivors) occurred. All events, including death, reoperation, periprosthetic leak, and recurrence of infection, occurred within 2 years after operation. Actuarial freedom from reoperation, late survival, and events at 5 years were 81.6, 76.4, and 68.6%, respectively. On multivariate analysis, no independent adverse predictor was detected for hospital death, whereas the following independent adverse predictors were identified: preoperative heart failure (P=0.0375), prosthetic valve endocarditis (P=0.0391) and culture-negative endocarditis (P=0.0354) for poor late survival; culture-negative endocarditis (P=0.0354) and annular abscess (P=0066) for poor event-free suvival. Freedom from events was similar between patients with Staphylococcus aureus infection (3-year freedom 55.6%) and culture-negative endocarditis (3-year freedom 47.6%), whereas events were significantly low in patients with streptococcus infection (3-year freedom 100%). Conclusions: In our analysis, no independent adverse predictor was detected for hospital death; however, culture-negative endocarditis was identified as an independent predictor for both late survival and events after surgery. Event-free survivals were similar between staphylococcus infection and culture-negative endocarditis, and all events occurred within 2 years after operation, suggesting the necessity of close follow-up during that period.

	1. Introduction

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusion References

 
Despite advances in the diagnosis and antibiotic treatment of infective endocarditis, eradication of the septic focus and abolition of the accompanying systemic manifestations frequently require surgical intervention. In spite of appropriate antibiotic treatment and improved surgical techniques, hospital mortality in patients with active endocarditis is higher than expected and the incidence of recurrence is still significant [1–3]. Since recurrent endocarditis is a dreadful complication and targeted postoperative antibiotic treatment for more than 4 weeks carries a better prognosis according to recent reports [4,5] the determination of microorganisms could affect early and late outcomes after surgery.

Because of the heterogeneity of the clinical and pathologic makeup of patients undergoing surgical treatment for active endocarditis, operative mortality ranges widely between 3.8 and 22% [6–16] and many risk factors for hospital mortality were reported: age above 60 years, delayed diagnosis, Staphylococcus infection, aortic valve endocarditis, large valvular vegetations, congestive heart failure, cerebral or coronary embolism, prosthetic valve infection, recurrent events, and failed antibiotic therapy. In this study, therefore, we reviewed our 12-year experience in the treatment of diagnosed active endocarditis and identified factors determining operative mortality, reoperation, and events, particularly focusing on the factor of culture-negative endocarditis.

	2. Materials and methods

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusion References

 
Cases of infective endocarditis were classified retrospectively according to the Duke criteria [17]. For the definitions of active, healed, native, prosthetic and culture-negative endocarditis, the modified criteria reported by Renzulli et al. [13] were used. Endocarditis was labeled ‘active’ if the patient had fever and/or leukocytosis at the time of surgery or required surgical treatment before completion of a standard course of antibiotic treatment. The presence of acute or chronic inflammatory changes on microscopy confirmed the diagnosis of endocarditis, and ‘active’ endocarditis was finally determined when bacterial colony and/or infiltration of neutrophils were confirmed. Prosthetic valve endocarditis was defined as infection occurring on any type of tissue or mechanical valve device. ‘Early’ prosthetic valve endocarditis was present if recurrent or residual endocarditis occurred within 60 days after surgery, while prosthetic valve endocarditis occurring after 60 days was labeled ‘late’. Culture-negative endocarditis was present when no microorganism could be identified either in serial blood cultures or in cultures from the explanted valvular tissue in patients presenting with a clinical picture of active endocarditis, particularly in the presence of a new regurgitant murmur, congestive heart failure and/or vegetation on echocardiogram. Early mortality was defined as death occurring within 30 days or during the same hospital stay after surgery, while treatment failure (event) was defined as any of the following postoperative events: early and late mortality, reoperation, periprosthetic leak, or recurrence of infection.

2.1. Patients' characteristics
We retrospectively reviewed 67 patients who underwent prosthetic valve replacement for treatment of active infective endocarditis between 1991 and 2001,during which time, no homograft valve was implanted. There were 17 women and 50 men, with ages ranging between 16 and 88 years (mean 50.9±15.3 years). All patients received at least 4 weeks of postoperative multidrug antibiotic treatment, and all underwent operation before completion of antibiotic treatment. The infection involved a native valve (NVE) in 58 cases (86.6%) and a prosthetic valve (PVE) in 9 patients (13.4%). All patients were followed prospectively at our institute or its affiliated hospital with yearly visits and clinical and echocardiographic controls. The mean follow-up period averaged 5.7±3.4 years (range: 0.2–11.5 years) and follow-up was completed for all patients.

As far as the site of infection is concerned, endocarditis involved the aortic valve in 28 cases (41.8%) and the mitral valve in 23 cases (34.3%). Multiple valvular involvement was reported in the other 16 cases (23.9%); the infection was localized on the aortic and mitral valves in 14 cases, on the aortic and pulmonary valves in 1 case, and on the aortic, mitral, and tricuspid valve in 1 case.

2.2. Preoperative assessment
New York Heart Association (NYHA) status was evaluated in all patients: 21 patients (31.3%) were in NYHA class III and 19 (28.4%) in NYHA class IV, while 27 patients (40.3%) did not complain of dyspnea, being in NYHA class I or II. Heart failure was defined when NYHA class was more than III. One patient required percutaneous cardiopulmonary support preoperatively. Two patients had been on hemodialysis due to chronic renal failure, while one patient was pregnant. Ten patients with NVE and 2 patients with PVE had embolic events, 7 with cerebral embolism, 2 with splenic embolism, 2 with peripheral embolism, and one with renal embolism. Transthoracic echocardiography was performed in all cases, and from mid-1990s transesophageal echocardiography was performed routinely. Typical findings of infective endocarditis were recorded at echocardiography: significant valvular regurgitation was observed in 63 cases, vegetation in 57 cases, valvular tearing in 16 cases, mitral chorda rupture in 5 cases, and periprosthetic leakage in 2 cases. Blood cultures were performed routinely for all patients with fever or active infection, while tissue culture was performed for 52 patients.

2.3. Operative procedures
All patients underwent cardiopulmonary bypass and with moderate hypothermia before 1994, wheras tepid temperature has been used since 1995. Cold antegrade crystaloid cardioplegia before 1992, and cold antegrade and retrograde blood cardioplegia have been used since 1993. Resection of all infected valvular and paravalvular tissue was followed by annular reconstruction if needed and valve replacement. All abscess cavities were opened, largely resected, and cleaned with iodine solution. When tissue destruction was severe, patch reconstruction using autologous pericardium (n=7), or glutaraldehyde-fixed equine pericardium (n=3) was performed. The choice between mechanical or biologic prosthesis depended on the surgeon. Sixty-five patients (97%) underwent bileaflet mechanical valve replacement and 2 patients (3%) had bioprostheses. The aortic valve was replaced in 46 cases with a bileaflet mechanical prosthesis in all except one who had a stentless porcine bioprosthesis. The mitral valve was replaced in 36 cases: with a bileaflet mechanical prosthesis in all but one who had a porcine bioprosthses. Mitral repair was performed in 6 patients, and two of them had annuloplasty only because of significant regurgitation without infection of the mitral valve. The tricuspid valve was replaced in one. Concomitant coronary artery bypass grafting was performed in 2 patients with NVE, while one had a closure of ventricular septal defect and one required simultaneous splenectomy due to an abscess seen on abdominal CT.

2.4. Statistical analysis
The data were analyzed using StatView for Macintosh, version 5.01 (SAS Institute, Cary, NC). Continuous variables were provided as mean±SD. Categorical data were analyzed univariately by ² test or Fischer's exact test. To identify significant independent risk factors influencing early mortality, all factors with a significance of less than 0.1 were entered into multivariate logistic regression analysis. Actuarial survival and freedom from events were calculated by the Kaplan–Meier method, and were compared using the log-rank statistic. To identify significant independent risk factors influencing late mortality or events, all factors with a significance of less than 0.1 were entered into multivariate analysis. Risk ratios and 95% confidence intervals were calculated using the Cox proportional hazards model. A P value of less than 0.05 was considered statistically significant.

	3. Results

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusion References

 
3.1. Microbiology
The results of the blood cultures and valve cultures are shown in Table 1. Streptococcus species were the most common infecting microorganisms in NVE (31%), while Staphylococcus species were the most common infecting microorganism in PVE (55%). Staphylococcus aureus was found in 9 patients (13%), and in three of them it was methicillin-resistant. Culture-negative endocarditis occurred in 24 (31%) patients, and was equally distributed between NVE (31%) and PVE (33%).

3.2. Early outcomes
Hospital death occurred in 12 patients (17.8%), including 9 patients with NVE (15.5%) and 3 patients with PVE (33.3%). The main reasons for death were cardiac failure in 6 patients, septic multiorgan failure in 5 patients, and bleeding in 1 patient. The infecting microorganisms in hospital deaths were Staphylococcus aureus in 4 patients, Staphylococcus epidermidis in one, and the other 7 patients were culture-negative. With regard to morbidity, three patients were known to have perivalvular leakage soon after operation, and two required re-do aortic valve replacement (AVR) during hospitalization. One of them was complicated with sepsis due to methicillin-resistant Staphylococcus aureus.

Univariate analysis for early mortality is shown in Table 2. There was a significant influence of age of more than 70 years (P=0.0069), preoperative NYHA class III/IV (P=0.0202), and annular abscess requiring patchplasty (P=0.0464), while the culture-negative endocarditis was marginally significant (P=0.0904). However, multivariate analysis did not show any independent predictors for early mortality, although preoperative NYHA class III/IV had the highest odds ratio of 8.87 (P=0.0594), followed by culture-negative endocarditis (odds ratio 4.57).

View larger version (14K): [in this window] [in a new window]   Fig. 1. Actuarial survival for all patients with active endocarditis.

View larger version (14K): [in this window] [in a new window]   Fig. 2. Freedom from reoperation for patients with active endocarditis.

View larger version (14K): [in this window] [in a new window]   Fig. 3. Freedom from events, including death, periprosthetic leakage, reoperation, and recurrence of infection, for patients with active endocarditis.

View larger version (17K): [in this window] [in a new window]   Fig. 4. Freedom from events, including death, periprosthetic leakage, reoperation, and recurrence of infection, for patients with streptococcus infection (dotted line), Staphylococcus aureus infection (solid line with closed circles), and culture-negative endocarditis (solid line with open circles).

	4. Discussion

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusion References

4.1. Early outcome
In this study, the hospital mortality was high, 17.8%, including NVE in 15.5% and PVE in 33.3%, although the number of patients with PVE was as small as 9 patients. In a recent report, the early mortality of patients with NVE was reduced to less than 10%, although operative mortality ranges widely between 3.8 and 22% [7–16] because of the heterogeneity of this disease. In contrast to NVE, the early mortality from PVE remains as high as 13 to 33% [6,8,9,14,18]. It has been demonstrated that Staphylococcus aureus and annular abscess may significantly increase the risk of early mortality [6,8,10,11,14]. In this study, univariate analysis showed advanced age, preoperative heart failure, and annular abscess requiring a patch were risk factors for hospital mortality, whereas Staphylococcus infection was not a significant variable, although culture-negative endocarditis was marginally significant. The reason why the factor of Staphylococcus infection did not reach significance was the unfavorable outcomes in patients with culture-negative endocarditis. Although multivariate analysis did not show any independent predictors, preoperative heart failure (P=0.0594, odds ratio 8.87) and culture-negative endocarditis (P=0.0642, odds ratio 4.57) showed strong trend. This is probably due to small sample size of our study to show statistical significance. In fact, significant risk factors of advanced age and preoperative heart failure have been reported by many authors [6,10–12,14].

4.2. Late outcome
Although improvements in diagnosis, surgical techniques, and postoperative care have reduced hospital mortality, the recurrence rate is still high [1–3]. Inevitably, reinfection or other mainly valve-related events such as periprosthetic leakage will lead to a need for reintervention in some patients. The 11.7% reoperation rate in this series and the 81.6% freedom from reoperation at 5 and 10 years (Fig. 2) are within the reported ranges of 8.2–19.8% and 64.0–92.0%, respectively [8–10,19]. Use of a homograft for aortic valve or root replacement has been shown to provide good results in terms of operative mortality and freedom from recurrence of infection [20,21] although the availability is limited, particularly in Japan. In contrast, however, others maintained that the type of prosthesis used is not so important because early and late good results can be achieved by adequate debridement of the infected tissues, reconstruction of the resulting defects, and administration of appropriate postoperative antibiotics [9,11,22]. It has, nonetheless, a serious impact on the outcome, being a determinant of late cardiac death.

The survival after surgical treatment for active endocarditis is known to be good, with reported 10-year rates ranging from 52.0 to 71.3% [6,8–10,12]. Predictors of long-term survival in previous studies were reported to be cardiac failure, renal impairment, PVE [8], NYHA class IV, renal failure, mitral valve endocarditis [10], advanced age [18,10], staphylococcus infection, and annular abscess [12]. The differences in survival and risk factors in these reports are likely to reflect differences in the clinical and pathologic makeup of the patients involved, and comparisons should, therefore, be undertaken cautiously. The 68.6% actuarial 5 and 10-year survival for all patients in our series is rewarding considering the 17.8% early mortality rate. Thus, late mortality in hospital survivors was 5.5% and all deaths occurred within 2 years after surgery in this series. Therefore, the predictors of survival shown in this study, preoperative heart failure, PVE, and culture-negative endocarditis, may imply those of intermediate results. With regard to events after surgery, including all deaths, reoperation, and prosthetic valve leakage, annular abscess (P=0.0066) and culture-negative endocarditis (P=0.0155) were the independent predictors in this study. Previous perivalvular involvement with abscess has been supposed to represent a risk factor for recurrence. Although annular abscess was not an independent predictor for hospital death, this was a significant risk factor in poor late results, implying incomplete intraoperative debridement and/or unsuccessful antibiotic treatment.

4.3. Impact of culture-negative endocarditis on surgical outcome
The microbiologic findings were in accordance with previous reports showing a preponderance of streptococcal and staphylococcal species (Table 1), but their impact on the outcome was different. Staphylococcus aureus, a notoriously virulent and invasive microorganism, has been in previous studies shown to increase the operative risk [6,10,11,14]. Infection by Staphylococcus aureus in this series did not affect any aspect of early or late outcome; in fact, culture-negative endocarditis emerged as an independent predictor of poor late survival and event-free survival. Or rather, nonsteptococcal infection could be significantly associated with unfavorable surgical results in the present study (Fig. 4).

If infective endocarditis was caused by staphylococci, the operative mortality was higher than with other microorganisms because staphylococci are prone to cause early invasion of tissue surrounding valves, forming annular abscesses, while some reported that nonstreptococcal infection was independently associated with an increased risk of recurrence [19]. The incidence of negative blood cultures ranges in the medical literature between 20 and 60% [4,17,23] of patients who undergo surgical treatment. In this study, microorganisms were not detected in 31% of patients in blood or tissue cultures although all tissue samples were not cultured routinely. Controversial observations about the prognostic impact of positive blood and tissue cultures are still issued. Aranki et al. [6] reported that long-term survival was not influenced by activity of infection nor by the type (native or prosthetic endocarditis), whereas Dehler et al. [4] reported a significantly worse prognosis in patients with positive intraoperative cultures than in patients with negative intraoperative cultures. Renzulli [13] reported a higher incidence of reoperation in patients with positive intraoperative cultures although no difference were found in short- and long-term survivals. Lack of germ isolation and sensitivity test results precludes specific postoperative antibiotic therapy, and targeted postoperative antibiotic treatment for more than 4 weeks carries a better prognosis according to a recent report [4]. In this study, culture-negative endocarditis was an independent predictor for poor late survival and event-free survival. It is of note, however, that no predictor was detected to affect the hospital mortality. This would suggest that although surgical techniques and appropriate preoperative multidisciplinary management can avert an unfavorable early outcome, there remains a continuous risk for recurrence and survival.

In 1998, the ACC/AHA Task Force [24] reported the guideline for Evaluation and Management of Infective Endocarditis, and it recommends antibiotic regimens for NVE and PVE caused by each organism and for negative-culture endocarditis as well. If there is no success with the initial treatment in staphylococcal infection, the antibiotic regimen is switched to vancomycin and rifampicine/gentamicin. The proposed regimen for culture-negative, presumed bacterial endocarditis, is vancomycin plus gentamicin. This implies culture-negative endocarditis should treat as staphylococcus infection. Before 2000, we did not follow this guideline, and the choice of antibiotics for culture-negative endocarditis was varied among physicians. This regimen may improve the late outcome in patients with culture-negative endocarditis.

Finally, since all events occurred within 2 years after surgery in patients with nonstreptococcal infection (Fig. 4), close follow-up is required during that period and oral antibiotic treatment for 2 years after surgery may partly contribute the improvement of late outcome in patients with active endocarditis.

	5. Conclusion

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusion References

 
In our analysis, culture-negative endocarditis was not an independent predictor for hospital mortality; whereas this was identified as independent predictors for poor late survival and event-free survival after surgery. Even-free survivals were similar between staphylococcus infection and culture-negative endocarditis, and all events occurred within 2 years after operation, suggesting the necessity of close follow-up during that period.

	References

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusion References

 

1. McGiffin DC, Galbraith AJ, McLachlan GJ, Stower RE, Wong ML, Stafford EG, Gardner MA, Pohlner PG, O'Brien MF. Aortic valve infection. Risk factors for death and recurrent endocarditis after aortic valve replacement. J Thorac Cardiovasc Surg 1992;104:511-520.[Abstract]
2. Dajani AS, Bisno AL, Chung KJ, Durack DT, Freed M, Gerber MA, Karchmer AW, Millard HD, Rahimtoola S, Shulman ST. Prevention of bacterial endocarditis. Recommendations by the American Heart Association. J Am Med Assoc 1990;264:2919-2922.[CrossRef][Medline]
3. Renzulli A, Carozza A, Romano G, De Feo M, Della Corte A, Gregorio R, Cotrufo M. Recurrent infective endocarditis: a multivariate analysis of 21 years of experience. Ann Thorac Surg 2001;72:39-43.[Abstract/Free Full Text]
4. Dehler S, Elert O. Early and late prognosis following valve replacement for bacterial endocarditis of the native valve. Thorac Cardiovasc Surg 1995;43:83-89.[Medline]
5. Andersson P, Dubiel W, Enghoff E, Friman G, Hagg A, Nystrom SO, Aberg T. Role of surgery in infective endocarditis. Acta Med Scand 1986;219:275-282.[Medline]
6. Aranki SF, Santini F, Adams DH, Rizzo RJ, Couper GS, Kinchla NM, Gildea JS, Collins Jr. JJ, Cohn LH. Aortic valve endocarditis. Determinants of early survival and late morbidity. Circulation 1994;90:II175-II182.
7. Dodge A, Hurni M, Ruchat P, Stumpe F, Fischer AP, Van Melle G, Sadeghi H. Surgery in native valve endocarditis: indications, results and risk factors. Eur J Cardiothorac Surg 1995;9:330-334.[Abstract]
8. Mullany CJ, Chua YL, Schaff HV, Steckelberg JM, Ilstrup DM, Orszulak TA, Danielson GK, Puga FJ. Early and late survival after surgical treatment of culture-positive active endocarditis. Mayo Clin Proc 1995;70:517-525.[Medline]
9. d'Udekem Y, David TE, Feindel CM, Armstrong S, Sun Z. Long-term results of surgery for active infective endocarditis. Eur J Cardiothorac Surg 1997;11:46-52.[Abstract]
10. Jault F, Gandjbakhch I, Rama A, Nectoux M, Bors V, Vaissier E, Nataf P, Pavie A, Cabrol C. Active native valve endocarditis: determinants of operative death and late mortality. Ann Thorac Surg 1997;63:1737-1741.[Abstract/Free Full Text]
11. Bauernschmitt R, Jakob HG, Vahl CF, Lange R, Hagl S. Operation for infective endocarditis: results after implantation of mechanical valves. Ann Thorac Surg 1998;65:359-364.[Abstract/Free Full Text]
12. Alexiou C, Langley SM, Stafford H, Lowes JA, Livesey S, AMonro JL. Surgery for active culture-positive endocarditis: determinants of early and late outcome. Ann Thorac Surg 2000;69:1448-1454.[Abstract/Free Full Text]
13. Renzulli A, Carozza A, Marra C, Romano GP, Ismeno G, De Feo M, Della Corte A, Cotrufo M. Are blood and valve cultures predictive for long-term outcome following surgery for infective endocarditis?. Eur J Cardiothorac Surg 2000;17:228-233.[Abstract/Free Full Text]
14. Moon MR, Miller DC, Moore KA, Oyer PE, Mitchell RS, Robbins RC, Stinson EB, Shumway NE, Reitz BA. Treatment of endocarditis with valve replacement: the question of tissue versus mechanical prosthesis. Ann Thorac Surg 2001;71:1164-1171.[Abstract/Free Full Text]
15. Delay D, Pellerin M, Carrier M, Marchand R, Auger P, Perrault LP, Hebert Y, Cartier R, Page P, Pelletier LC. Immediate and long-term results of valve replacement for native and prosthetic valve endocarditis. Ann Thorac Surg 2000;70:1219-1223.[Abstract/Free Full Text]
16. Aagaard J, Andersen PV. Acute endocarditis treated with radical debridement and implantation of mechanical or stented bioprosthetic devices. Ann Thorac Surg 2001;71:100-102(discussion 104).[Abstract/Free Full Text]
17. Durack DT, Lukes AS, Bright DK. New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Duke Endocarditis Service. Am J Med 1994;96:200-209.[CrossRef][Medline]
18. Lytle BW, Priest BP, Taylor PC, Loop FD, Sapp SK, Stewart RW, McCarthy PM, Muehrcke D, Cosgrove III DM. Surgical treatment of prosthetic valve endocarditis. J Thorac Cardiovasc Surg 1996;111:198-207(discussion 207–210).[Abstract/Free Full Text]
19. Larbalestier RI, Kinchla NM, Aranki SF, Couper GS, Collins Jr. JJ, Cohn LH. Acute bacterial endocarditis. Optimizing surgical results. Circulation 1992;86:II68-II74.
20. Dearani JA, Orszulak TA, Schaff HV, Daly RC, Anderson BJ, Danielson GK. Results of allograft aortic valve replacement for complex endocarditis. J Thorac Cardiovasc Surg 1997;113:285-291.[Abstract/Free Full Text]
21. Dossche KM, Defauw JJ, Ernst SM, Craenen TW, De Jongh BM, de la Riviere AB. Allograft aortic root replacement in prosthetic aortic valve endocarditis: a review of 32 patients. Ann Thorac Surg 1997;63:1644-1649.[Abstract/Free Full Text]
22. Edwards MB, Ratnatunga CP, Dore CJ, Taylor KM. Thirty-day mortality and long-term survival following surgery for prosthetic endocarditis: a study from the UK heart valve registry. Eur J Cardiothorac Surg 1998;14:156-164.
23. Werner M, Andersson R, Olaison L, Hogevik H. A clinical study of culture-negative endocarditis. Medicine (Baltimore) 2003;82:263-273.[CrossRef][Medline]
24. Force AAT. ACC/AHA guidelines for the management of patients with valvular heart disease. A report of the American College of Cardiology/American Heart Association. Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease). J Am Coll Cardiol 1998;32:1486-1588.[Free Full Text]

This article has been cited by other articles:

				J. Lopez, A. Revilla, I. Vilacosta, E. Villacorta, C. Gonzalez-Juanatey, I. Gomez, M. J. Rollan, and J. A. San Roman Definition, clinical profile, microbiological spectrum, and prognostic factors of early-onset prosthetic valve endocarditis Eur. Heart J., March 2, 2007; 28(6): 760 - 765. [Abstract] [Full Text] [PDF]

				O. Adam, T. Kramm, H. H. Klein, and H.-J. Schafers Intraaortic Vegetations as a Manifestation of Infective Endocarditis N. Engl. J. Med., February 22, 2007; 356(8): 874 - 875. [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): Toshifumi Murashita Yasuhiro Kamikubo Keishu Yasuda Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Murashita, T. Articles by Yasuda, K. Search for Related Content PubMed PubMed Citation Articles by Murashita, T. Articles by Yasuda, K. Related Collections Valve disease