IE瓣膜选择

DOI: 10.1510/icvts.2010.234450 2010; 2010;11:784-788; originally published online Aug 16,Interact CardioVasc Thorac Surg Sophie Newton and Steven Hunter What type of valve replacement should be used in patients with endocarditis? http://icvts.ctsnetjournals.org/cgi/content/full/11/6/784 located on the World Wide Web at: The online version of this article, along with updated information and services, is 1569-9293. (ESCVS). Copyright © 2010 by European Association for Cardio-thoracic Surgery. Print ISSN: for Cardio-thoracic Surgery (EACTS) and the European Society for Cardiovascular Surgery is the official journal of the European AssociationInteractive Cardiovascular and Thoracic Surgery by on June 3, 2011 icvts.ctsnetjournals.orgDownloaded from ARTICLE IN PRESS www.icvts.org doi:10.1510/icvts.2010.234450 Interactive CardioVascular and Thoracic Surgery 11 (2010) 784–788 � 2010 Published by European Association for Cardio-Thoracic Surgery Best evidence topic - Valves What type of valve replacement should be used in patients with endocarditis? Sophie Newton *, Steven Huntera, b St George’s University of London, London, UKa Department of Cardiothoracic Surgery, James Cook University Hospital, Middlesbrough, UKb Received 1 March 2010; received in revised form 13 July 2010; accepted 26 July 2010 Summary A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘in patients undergoing a surgery for endocarditis is a biological valve or mechanical valve superior for achieving long-term low rates of reinfection?’ Altogether more than 41 papers were found using the reported search, of which nine represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Out of the studies that include statistical comparisons, in mechanical valve replacement the average endocarditis recurrence rate ranged from approximately 3 to 9% and in biological valves from approximately 7 to 29%. Out of the studies that specifically compared the outcomes of the two valves, 50% concluded there to be no significant difference when separated from other risk factors and 50% recommended a mechanical valve for lower recurrence and higher survival rates. The Euro Heart Survey found that 63% of valve replacements were mechanical, due to young age (90%) and physician preference (75%) and only 21% bioprosthetic. Current guidelines from American College of Cardiology/American Heart Association (ACC/AHA) recommend a mechanical valve in patients -65 years old and a bioprosthetic valve if )65, without risk factors for thromboembolism, but this is based on class II evidence (conflicting evidence or opinion). These guidelines are not specific to patients with infective endocarditis, so it is vital to review the literature related to this. Three of the studies in the search specify that for patients under 60–65 years old, a mechanical valve has greater benefit, but this was not found to be true for the over 65 years. It can be concluded that for patients under 65 years old, a mechanical valve may offer greater freedom from reoperation and increased long-term survival when compared to a bioprosthetic valve (assuming no other co-morbidities), although this divide is narrowing with the use of newer generation bioprosthetic valves and has to be off-set against potential bleeding risks. For patients over 65 years, other important variants need to be considered including patient choice, correct protocols of antibiotics and radical debridement. � 2010 Published by European Association for Cardio-Thoracic Surgery. All rights reserved. Keywords: Review; Endocarditis; Bioprosthetic valve; Mechanical valve; Reinfection 1. Introduction A best evidence topic was constructed according to a structured protocol. This is fully described in the ICVTS w1x. 2. Three-part question In wpatients undergoing a surgery for endocarditisx is wa biological valvex or wmechanical valvex superior wfor achiev- ing long-term low rates of reinfectionx? 3. Clinical scenario You are an a multi-disciplinary team (MDT) meeting dis- cussing the case of a young patient with infective endocar- ditis and a senior consultant states that a biological valve must be inserted to reduce the risk of reinfection, even though the patient will require a mechanical valve replace- *Corresponding author. 57A St Stephens Avenue, London, W12 8JA, UK. Tel.yfax: q44-208-740-7318. E-mail address: sophielnewton@gmail.com (S. Newton). ment in the future when the biological valve wears out. You resolve to check the latest evidence yourself on rates of reinfection between mechanical and prosthetic valve replacements in endocarditis to help determine which would be best for this patient. 4. Search strategy Medline 1950–August 2009 using OVID interface wendocarditis.mp or exp endocarditisyx AND wexp biopros- thesisyOR bioprosthesis.mpx AND wmechanical valve.mp OR mechanical prosthesis.mpx. Limit to English language AND full text. All reference lists of relevant papers were also checked for additional papers. 5. Search outcome Forty-one papers were found using the reported search. From these nine papers were identified that provided the best evidence to answer the question. These are presented in Table 1. by on June 3, 2011 icvts.ctsnetjournals.orgDownloaded from ARTICLE IN PRESS 785S. Newton, S. Hunter / Interactive CardioVascular and Thoracic Surgery 11 (2010) 784–788 Best Evidence Topic Table 1. Best evidence papers Author, date and Patient group Outcomes Key results Comments country of publication Study type Sweeney et al., 185 patients who Actuarial rate for – Mechanical: 94.6% This paper concludes that (1985), J Thorac had undergone freedom from – Bioprosthetic: 75% mechanical valve replacement Cardiovasc Surg, valve replacement reoperation at four years (P-0.01) leads to a reduced reoperation USA, w2x for life-threatening rate and rate of recurrent active valvular Actuarial survival rate – Mechanical: 87.4% endocarditis compared to Retrospective native or at four years – Bioprosthetic: 78.7% bioprosthesis valve cohort study prosthetic (P-0.05) replacement (level 2b) endocarditis during 1979–1984 Recurrent – Mechanical: 3.3% A limitation to this study is were identified endocarditis – Bioprosthetic: 7.4% that it did not separate the (P-0.01) native valve endocarditis patients from the prosthetic valve endocarditis patients, which may have impacted the results. Also, the bioprosthetic valves used during the study were an early pericardial valve which is no longer on the market Wos et al., (1996), 71 patients were Four-year mortality – Mechanical: 20% This review recommends the J Cardiovasc reviewed who – Bioprosthetic: 28.6% use of mechanical valve Surg, Poland, w3x were treated (P)0.05 – not significant) replacement after active between 1988 and valvular endocarditis due to Prospective 1993 for active Recurrency rate – Mechanical: 8.5% the reduced recurrency and cohort study endocarditis with – Bioprosthetic: 28.6% reoperation rate (level 2b) either a (P-0.028) mechanical or Limitations to the study bioprosthetic Reoperations rate – Mechanical: 4.2% included that out of the 71 valve – Bioprosthetic: 21% patients studied, only 17 had (Ps0.028) bioprosthetic valves, therefore the conclusions are based on a very small sample size. Also, this was not a random trial Edwards et al., 322 patients with Significant No evidence that the type The conclusions to be made (1998), Eur J valve replacement determinants of of prosthesis used for from this study are that using Cardiothorac for prosthetic 30-day mortality reoperation determines either a mechanical or Surg, UK, w4x valve endocarditis survival or freedom from bioprosthetic valve between 1986 and reoperation. Age was the replacement makes no Retrospective 1996 only significant determinant difference to short-term cohort study (Ps0.04) survival or reoperation in (level 2b) cases of prosthetic valve endocarditis. The main limitation of this study is that it researched only the first 30 days following surgery Hammermeister et 575 patients Reoperation rate – Bioprosthesis: 29"5% This study was not focused al., (2000), J Am undergoing aortic – Mechanical: 10"3% on infective endocarditis, but Coll Cardiol, USA, or mitral valve (Ps0.004) simply the differences of w5x replacement were valve replacements in general randomised to 15-year mortality – Bioprosthesis: 66"5% Randomised receive either a – Mechanical: 79"3% It found that the advantages prospective bioprosthetic or (Ps0.02) of using a mechanical valve cohort trial mechanical valve, for aortic valve replacement (level 1b) between 1977 and Primary valve failure -65 years: (lower mortality, primary 1982 – Bioprosthesis: 26"6% valve failure and reoperation) – Mechanical: 0% were off-set by a greater (Ps0.0001) bleeding risk. It also found that primary valve failure )65 years: accounted for the high – Bioprosthesis: 9"6% mortality in bioprosthetic – Mechanical: 0% valves in patients -65 years, but (Ps0.16) not those aged )65 years (Continued on next page) by on June 3, 2011 icvts.ctsnetjournals.orgDownloaded from ARTICLE IN PRESS 786 S. Newton, S. Hunter / Interactive CardioVascular and Thoracic Surgery 11 (2010) 784–788 Table 1. (Continued) Author, date and Patient group Outcomes Key results Comments country of publication Study type Moon et al., 306 patients were Linearised rate of – Mechanical valves: This review demonstrated (2001), Ann identified who recurrent or residual 0.5"0.5% that the use of bioprosthetic Thorac Surg, underwent valve endocarditis – Bioprosthetic valves: valves in older patients ()60) USA, w6x replacement for 1.1"0.4% led to a greater freedom from left-sided (P)0.25 – insignificant) reoperation, but mechanical Retrospective endocarditis valves lead to greater freedom cohort study between March Overall long-term – Mechanical: 50"8% from reoperation in those (level 2b) 1964 and survival at 10 years – Bioprosthetic: 51"4% patients -60 (who have an December 1995 otherwise normal life Overall long-term – Mechanical: 38"9% expectancy) survival at 20 years – Bioprosthetic: 34"5% (P)0.27) There was no significant difference in long-term Overall freedom – Mechanical: 74"9% at survival, operative mortality from reoperation 10 years, 74"9% at and rate of recurrent or 15 years residual endocarditis – Bioprosthetic: 56"5% at according to whether a 10 years, 22"6% at mechanical or bioprosthetic 15 years valve was selected (P)0.64) Limitations to this study include the long-term accrual period (1964–1995), with a probable therapeutic process confounding effect Renzulli et al., 271 patients Incidence of The type of valve substitute No statistical values are given (2001), Ann received valve recurrence of implanted did not affect the to support this conclusion Thorac Surg, replacement endocarditis incidence of recurrence Italy, w7x surgery for infective Retrospective endocarditis cohort study between 1979 and (level 2b) 2000 Tornos et al., 45 patients who Choice of valve – Bioprosthesis: 21% The most frequent reasons (2005), Heart, Spain, w8x underwent valve replacement – Mechanical: 63% for using the mechanical replacement for – Homografts: 5% valve were young age in 90%, Prospective infective physician’s preference in survey endocarditis were 75%, other indication for (level 2c) selected out of treatment with an 5001 patients with anticoagulant in 15% and valvular heart renal failure in 10% disease enrolled onto the Euro The limited number of Heart Survey patients does not allow for between April and robust conclusions to be July 2001 made Fedoruk et al., 358 patients Unadjusted survival at – Mechanical: 56.5"8.1% This paper concludes that the (2009), J Thorac having had valve 20 years – Bioprosthetic: 26.4"4.9% type of prosthesis implanted Cardiovasc Surg, replacement for (Ps0.007) does not influence long-term Canada, w9x native valve outcome, however, the endocarditis Prosthesis type as Not predictive when unadjusted survival rates Retrospective between 1975 and predictor of separated from IV drug would suggest that this study cohort study 2000 reoperation useyHIV (hazard ratio 3.268, provides evidence for better (level 2b) P 0.088) long-term survival with mechanical prostheses Nguyen et al., 167 patients were Five-year mortality – Bioprosthesis: 58.1% The conclusions of this study (2009), Eur J identified who – Homograft: 14.8% are that patients receiving a Cardiothorac underwent aortic – Mechanical: 24.4% bioprosthetic valve had a Surg, France, w10x replacement for (Ps0.0004) significantly lower overall aortic valve five-year survival rates than Prospective endocarditis Early mortality – Bioprosthesis: 19.4% those patients receiving a cohort study between – Homograft: 7.4% mechanical valve. This (level 1b) December 1998 – Mechanical: 10.1% finding was more pronounced and March 2000 (Ps0.27) in patients F65 years, but not proven in patients G65 due to (Continued on next page) by on June 3, 2011 icvts.ctsnetjournals.orgDownloaded from ARTICLE IN PRESS 787S. Newton, S. Hunter / Interactive CardioVascular and Thoracic Surgery 11 (2010) 784–788 Table 1. (Continued) Author, date and Patient group Outcomes Key results Comments country of publication Study type lack of statistically significant evidence Limitations include the observational design and imbalance of patients across the three treatment groups, with over 65% of patients receiving a mechanical valve HIV, human immunodeficiency virus; IV, intravenous. 6. Results Sweeney et al. w2x reviewed 185 patients who had under- gone valve replacement for active bacterial endocarditis, 88 had a bioprosthetic valve and 97 a mechanical valve. There was a significant reduction in recurrent infection leading to reoperation in the mechanical valve group, compared to bioprosthetic (3.3% vs. 7.4%, P-0.01). The actuarial rate of freedom from reoperation was also higher for mechanical at four years (94.6% vs. 75% bioprosthetic, P-0.01), as was four-year actuarial survival rate (87.4% mechanical vs. 78.7% bioprosthetic, P-0.05). Wos et al. w3x found similar results when reviewing 71 patients with valve replacements following endocarditis. There was a statistical difference in the recurrence rate of endocarditis, with higher rates in the patients with bio- prosthetic valves, compared to the patients with mechani- cal valves (28.6% vs. 8.5%, Ps0.028), with concurrent higher rates of reoperation (21% vs. 4.2%, Ps0.022). Fedoruk et al. w9x found that unadjusted survival rates at 20 years were greater for patients with mechanical valves (56.5"8.1% vs. 26.4"4.9% for bioprosthetic valves, Ps0.007), but overall they concluded that prosthesis type was not an independent predictor of reoperation. The key independent predictors of outcome were age, intravenous (IV) drug useyhuman immunodeficiency virus (HIV) and surgical technique. Similarly, Renzulli et al. w7x found that the choice of valve substitute used in patients with infective endocarditis did not affect recurrence rate of infection. Instead, the multi- variate analysis demonstrated that prosthetic endocarditis (Ps0.00001), positive valvular cultures (Ps0.0039), and persistence of postoperative fever (Ps0.000001) were independent risk factors for recurrence of endocarditis. Edwards et al. w4x investigated determinants of reopera- tion for prosthetic valvular endocarditis (PVE) and found that age was the only significant independent predictor in outcome (specifically in 30-day mortality, Ps0.04), with no evidence to suggest that one type of prosthesis was superior in determining survival or freedom from reoperation. Moon et al. w6x investigated further into the effects of age in valvular replacement following endocarditis and found survival was independent of type of prosthesis used (P)0.27). The different rates of linearised reinfection or residual endocarditis after five years between mechanical and bioprosthetic were insignificant among the collective group (P)0.25). There was also no difference in medium and long-term survival with mechanical or bioprosthetic valves (four-year survival 82"6% vs. 79"3% and 20 years 46"10% vs. 41"6%, P)0.50). Among those patients under 60 years old with a biological valve, the long-term freedom from reoperation was low (51"5% at 10 years, 19"6% at 15 years), therefore leading to the conclusion that mechan- ical valves are most suitable for young patients with endo- carditis. In the older age group ()60 years old), however, there were similar results with freedom from reoperation at 15 years with both bioprosthetic and mechanical valves (84"7% vs. 74"9%). Nguyen et al. w10x concluded that a bioprosthetic valve replacement for infective endocarditis is associated with a lower five-year survival than the use of a mechanical valve in patients )65 years old wadjusted hazard ratio (HR) 4.14, Ps0.018x, but no such statistical significant relationship was observed in patients )65 years old. Hammermeister et al. w5x explained similar findings as due to a greater rate of primary valve failure with bioprosthetic valves compared to mechanical valves in patients -65 years old, but not in those aged G65 years. None of the papers are randomised controlled trails (RCTs), but more importantly despite attempts to adjust for differences in the patient populations in many of the papers, the groups of endocarditis patients receiving bio- logical and mechanical valves are often quite different. Young patients receiving biological valves may more often be current IV drug abusers, or the patients may have incompletely treated endocarditis and both of these factors may in themselves cause an increased rate of infection whatever type of valve is used. 7. Clinical bottom line Out of the studies that include statistical comparisons, in mechanical valve replacement the average endocarditis recurrence rate ranged from approximately 3 to 9% and in biological valves from approximately 7 to 29%. Out of the studies that specifically compared the outcomes of the two valves, 50% concluded there to be no significant difference when separated from other risk factors and 50% recom- mended a mechanical valve for lower recurrence and higher survival rates. It is worth noting that the older studies compare mechanical valves to first-generation bioprosth- Best Evidence Topic by on June 3, 2011 icvts.ctsnetjournals.orgDownloaded from ARTICLE IN PRESS 788 S. Newton, S. Hunter / Interactive CardioVascular and Thoracic Surgery 11 (2010) 784–788 etic valves, such as Ionescu–Shiley pericardial valves, which were removed from the market due to clinical failure and replaced with improved second-generation bioprosthetic valves. Three of the studies in the search specify that for patients under 60–65 years old, a mechanical valve has greater benefit, but this was not found to be true for the over 65 years. It can be concluded that for patients under 65 years old, a mechanical valve may offer greater freedom from reoperation and increased long-term survival when com- pared to a bioprosthetic valve (assuming no other co- morbidities), although this divide is narrowing with the use of newer generation bioprosthetic valves and has to be offset against potential bleeding risks. For patients over 65 years, other important variants need to be considered including patient choice, correct protocols of antibiotics and radical debridement. References w1x Dunning J, Prendergast B, Mackway-Jones K. Towards evidence-based medicine in cardiothoracic surgery: best BETS. Interact CardioVasc Thorac Surg 2003;2:405–409. w2x Sweeney MS, Reul GJ Jr, Cooley DA, Ott DA, Duncan JM, Frazier OH, Livesay JJ. Comparison of bioprosthetic and mec