Christian Seiler. Valve disease MANAGEMENT AND FOLLOW UP OF PROSTHETIC HEART VALVES OF PATIENTS WITH PROSTHETIC VALVES

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1 818 Valve disease MANAGEMENT AND FOLLOW UP OF PROSTHETIC HEART VALVES MANAGEMENT Correspondene to: Professor Christian Seiler, University Hospital, Swiss Cardiovasular Center Bern, Freiburgstrasse, CH-3010 Bern, Switzerland; hristian. F Christian Seiler Heart 2004; 90: doi: /hrt or most haemodynamially relevant heart valve lesions, surgial therapy remains the treatment of hoie. It has been onsistently shown to provide long lasting relief of symptoms, and its superiority over medial treatment in this regard has been well established. However, in patients undergoing the most prevalent type of heart valve surgery, prostheti valve replaement, survival rate analysis late after treatment has revealed an impaired prognosis (10 year survival rates of 65% for aorti valve replaement, 55% for mitral and ombined valve replaement) in all but a minority. 1 2 This omprises patients older than 65 years undergoing aorti valve replaement for aorti stenosis, in whom survival relative to an age and sex mathed population is normalised following the first postoperative year. It is similarly well known that late mortality is greater in patients undergoing replaement of the mitral than the aorti valve, and for regurgitant versus stenoti valvar lesions. Thus, prognosis after valve replaement is predominantly refleted by the underlying disease with its preoperative ondition of the myoardium as well as the state of the oronary irulation. Consequently, the ourse after valve replaement may be determined deisively by early reognition of signifiant valvar lesions, in partiular, valve insuffiieny. In turn, improved follow up an be ahieved by timely seletion of the appropriate surgial therapy that is, mitral valve reonstrution instead of replaement in the ase of valve prolapse with severe regurgitation. 3 Furthermore, good management of prostheti heart valves starts preoperatively with the hoie of the right valve for example, a bioprosthesis, thus avoiding the risks of oral antioagulation in patients requiring aorti valve replaement > 65 years (without atrial fibrillation, severe left ventriular dysfuntion, previous thromboembolism, hyperoagulable state), or in patients undergoing mitral valve replaement. 70 years. 4 6 Finally, and in the majority of patients with prostheti valves, postoperative management aiming at an enhaned prognosis onsists of ontrolling antithromboti and antibioti mediation, of performing the first and subsequent follow up visits, and in a minority, of promptly reognising potentially devastating ompliations. OF PATIENTS WITH PROSTHETIC VALVES Antithromboti treatment All patients with a mehanial valve prosthesis require antioagulant treatment using warfarin or oumadin. Current guidelines reommend a treatment intensity at an international normalised ratio (INR) of for bileaflet or Medtroni Hall valves in the aorti position (after the first three postoperative months), and of in the vast majority of other situations inluding disk valves, Starr Edwards valves, mehanial prostheses in mitral position, the presene of risk fators for thrombosis (see below), or the first three postoperative months following bioprostheti valve replaement. 5 Patients with a biologial valve and risk fators for thrombosis, suh as atrial fibrillation, severe left ventriular dysfuntion (ejetion fration, 0.30), previous thromboembolism, or hyperoagulable state, should ontinue to be treated by antioagulation, aiming at an INR of There is evidene that in most ases (exept for those patients intolerant of aspirin), the addition of aetyl saliyli aid (ASA) mg daily to antioagulation is benefiial in reduing the risk of thromboembolism, with only a small inreased risk of bleeding. 7 When ASA annot be used in high risk patients (that is, in the presene of the aforementioned fators), INR may be adjusted to In patients who experiene an emboli event during adequate antithromboti treatment, antioagulant treatment should be inreased to ahieve an INR of (if previous INR was ) or even (if previous INR was ). ASA may have to be added or inreased in dosage. 5 Exessive antioagulation is managed by withholding warfarin or oumadin, by administering vitamin K or, in the ase of bleeding, by the use of fresh frozen plasma. Haemorrhagi and thromboti ompliations are a major soure of morbidity and mortality, and therefore may substantially influene the long term ourse of the disease following prostheti Heart: first published as /hrt on 14 June Downloaded from on 17 Marh 2019 by guest. Proteted by opyright.

2 valve replaement. Overall, the risk of bleeding outweighs that of prostheti valve thrombosis with obstrution (fig 1), thromboembolism, or peripheral ishaemi ompliations. 8 Thrombosis ours in 1 3% of ases annually with thromboemboli events in 0.7% of ases; the annual risk of bleeding is equal to 2.7%. 8 Mortality is higher in patients with bleeding ompliations from antioagulant treatment (0.3% per year) ompared with patients with thromboemboli ompliations (0.03% per year). These ompliations may have as muh to do with the inreasing age of the patient as with the valve prosthesis itself. Patients over the age of 70 years have an inreased risk of bleeding as do patients reently antioagulated or when antioagulation is started. 9 Risk fators for prostheti valve thrombosis are periods of insuffiient antioagulation, the position of the mitral valve as ompared with aorti valve (relative risk of mitral position twie as high), low ardia output, the presene of atrial fibrillation, atrial thrombus, previous emboli episodes, and hyperoagulable states inluding pregnany. The inidene of thromboemboli events with ball age, tilting disk, and bileaflet prostheses is estimated to be 2.5%, 0.7%, and 0.5% per year, respetively. 2 Prostheti valve obstrution may be aused by either valve thrombosis or pannus ingrowth. In the latter ase thrombolyti treatment is ineffetive, and the valve needs to be replaed. This implies that thrombolyti treatment is a viable option in patients with thrombotially obstruted valve prosthesis whih is, however, not orret in 12 18% of patients; the aute mortality rate in this situation is 6% Risk of thromboembolism during thrombolysis with streptokinase, tissue plasminogen ativator, or urokinase is also high and amounts to 12%; stroke 3 10%; major bleeding events 5%; minor, non-disabling bleeding events 14%; reurrent thrombosis 11%. 5 Patients with prostheti heart valve thrombosis who are in unstable haemodynami ondition (New York Heart Assoiation (NYHA) funtional lass III IV) should undergo reoperation. Thrombolyti treatment is reserved for patients who are haemodynamially stable. The duration of thrombolyti treatment depends on the resolution of the obstrution, whih is best assessed by transoesophageal ehoardiography (TOE) yielding transvalvar veloity gradients (that is, pressure gradients by the simplified Bernoulli equation) and two dimensional and olour Doppler images of the prostheti valve opening (fig 1). Thrombolysis should be stopped at 24 hours if no haemodynami improvement is deteted or after 72 hours even if it is inomplete. It was reently reported that a first dose of thrombolysis was suessful in only 53% of ases, but repeated sessions were able to augment the rate of suess to 88%. 10 Using a single lyti infusion, suess was ahieved in 40% of the obstrutive thrombi and in 75% of the nonobstrutive thrombi. Rapid (three hours) and slow (15 24 hours) infusion of streptokinase resulted in similar suess rates, whereas major ompliations (3/32 patients) ourred only in the rapid infusion group. 10 If thrombolysis is suessful, it ought to be followed by a ombination of heparin until INR values of 3 4 are ahieved in aorti valve prostheses and for mitral valve prostheses. 5 If partially suessful, thrombolysis may be followed by subutaneous heparin (twie daily) plus warfarin or oumadin (INR ) for three months. The latter may also serve as an alternative to thrombolysis in patients who are haemodynamially stable. Furthermore, Amerian College of Cardiology/Amerian Heart Assoiation guidelines reommend short term intravenous heparin treatment in patients who are in NYHA lass I and II, or a ontinuous infusion of thrombolyti treatment over several days. 5 This multitude of different therapeuti regimens for the treatment of prostheti valve thrombosis reflets the rarity of the problem (0.5 8% of left sided mehanial prostheses 10 ), oupled with a lak of large sale, randomised ontrolled trials, whih would be impratial. Management of prostheti valves during pregnany The management of women with prostheti heart valves during pregnany poses a partiular hallenge as there are no available ontrolled linial trials to provide guidelines for antithromboti treatment. Oral antioagulants ause fetal embryopathy. Subutaneous administration of heparin is ineffetive in preventing thromboemboli events. A systemati review of the literature to determine pooled estimates of fetal and maternal risks has found that the use of oral antioagulants throughout pregnany is assoiated with embryopathy in 6.4% of live births. 11 The substitution of heparin between week 6 and 12 of pregnany eliminated this risk. The risk of fetal wastage was similar in the two mentioned groups. Overall, maternal mortality was 2.9%, and major bleeding events ourred in 2.5%. The regimen assoiated with the lowest frequeny of valve thrombosis (3.9%) was oral antioagulation throughout pregnany, the risk of whih substantially inreased to 9.2% under heparin during the first trimester. Current guidelines reommend that the deision whether to use heparin during the first trimester or to ontinue oral antioagulation throughout pregnany should be made after full disussion of the aforementioned fats with the patient and her partner. 5 Women with a history of thromboembolism or an older generation mehanial mitral prosthesis who hoose not to take oral antioagulation during the first trimester should reeive ontinuous unfrationated heparin intravenously. Oral antioagulation should be stopped no later than week 36 and heparin substituted. If labour begins during oral antioagulation, a aesarean setion ought to be performed. 5 In the absene of bleeding, heparin an be resumed 4 6 hours after delivery and oral antioagulation begun. FOLLOW UP OF PATIENTS WITH PROSTHETIC VALVES First postoperative follow up visit Patients undergoing ardia valve replaement should undergo Doppler ehoardiography before hospital disharge. Ehoardiographi evaluation at baseline is ruial, sine it serves as a referene for subsequent examinations. In this ontext, knowledge about regional and global left and right ventriular systoli funtion and size, diastoli left ventriular funtion (not assessable with mitral valve prosthesis), atrial size, funtion of the native valves, estimates of pulmonary artery pressure, and, above all, the pressure gradient aross the newly implanted prosthesis together with determination of the effetive valvar orifie area (ERO, m 2 ), as well as the presene of paravalvar leaks, is useful. ERO is measured using the ontinuity equation, whereby, in the ase of aorti valve prosthesis, the following parameters may be obtained: mean gradient aross the valve (by CW Doppler); left ventriular outflow trat diameter and veloity time integral (by PW Doppler); the produt of veloity time integral times 819 Heart: first published as /hrt on 14 June Downloaded from on 17 Marh 2019 by guest. Proteted by opyright.

3 820 Heart: first published as /hrt on 14 June Downloaded from Figure 1 Thrombosis of a mitral valve prosthesis. Panel A depits a transoesophageal two dimensional image (longitudinal setion) of the left atrium (LA) and left ventrile (LV) of a patient suffering a thromboti obstrution of a bileaflet mitral valve prosthesis (Carbomedis 31). Before thrombolysis (left side), the anterior prostheti leaflet was ompletely immobile (arrow), and the posterior leaflet partially immobile. After thrombolysis (right side), both leaflets opened. Panel B illustrates the same situation in the same patient using olour Doppler imaging. The imaging planes are idential to those in panel A. Panel C shows ontinuous wave Doppler flow veloity spetra aross the mitral prosthesis in the same patient before (left) and after (right) thrombolysis. Mean pressure gradient was 14 mm Hg before streptokinase treatment and 2 mm Hg after. on 17 Marh 2019 by guest. Proteted by opyright.

4 Management of prostheti valves: key points Management of valve prostheses (partiularly in patients with valve regurgitation) begins with seletion of the optimal time point for valve replaement Aorti prosthesis patient mismath (effetive orifie area, 0.85 m 2 /m 2 ) is prevented by hoosing a properly sized prosthesis ring diameter Generally, antioagulation in patients with aorti bileaflet prostheses should be kept at an INR ; other mehanial valves and bioprostheses three months postoperatively at Bleeding in patients with valve prostheses is more frequent than valve thrombosis Prostheti valve thrombosis in haemodynamially stable patients should be primarily treated with thrombolytis Oral antioagulation throughout pregnany is related to a 6 7% rate of embryopathy Intravenous heparin during the first trimester of pregnany eliminates the risk of embryopathy, but is related to a 9% risk of valve thrombosis ross setional area taken at the same plae remains onstant (onversation of mass). A body surfae area normalised ERO of, 0.85 m 2 /m 2 for an aorti valve prosthesis indiates prosthesis patient mismath a term whih desribes the fat that the prosthesis hosen is too small for the patient s body size. This, of ourse, should have been prevented during the seletion of the valve prosthesis, but is nevertheless important to know for the follow up of the patient, beause it may be assoiated with an inreased inidene of morbidity and mortality. 12 Other reasons for a high transvalvar gradient after aorti valve replaement are septal left ventriular hypertrophy or postoperative high ardia output. The detetion of paravalvar leaks (fig 2) early after operation is important beause it alters subsequent follow up (monitoring for haemolysis) and management (possibility of reoperation), and it may be relevant in the diagnosti workup of suspeted endoarditis. It is generally reommended that the first outpatient workup should inlude the patient s history, physial examination, ECG, hest x ray, omplete blood ount, reatinine, eletrolytes, latase dehydrogenase, INR, and Figure 2 Paravalvar leak. Transoesophageal, two dimensional, olour Doppler image (longitudinal setion) of the left atrium (LA) and left ventrile (LV) showing a bileaflet mitral prosthesis with the sewing ring marked by arrows and a posteriorly loated paravalvar leak ausing mild mitral regurgitation. Doppler ehoardiography. As outlined above, the latter is the most important omponent of the first postoperative visit beause it assesses the effets and results of surgery. 5 Follow up visits in patients without ompliations Follow up visits in asymptomati patients without ompliations and with a normal initial ehoardiogram an be performed at yearly intervals and should onsist of a detailed history taking and a physial examination. There is not muh evidene in the literature to support the strategy of performing Doppler ehoardiography annually in unompliated patients. 5 Ehoardiography is ertainly indiated whenever there is evidene of a new heart murmur, when there are questions of prostheti valve integrity or funtion, or there are onerns about ventriular funtion. Follow up visits in patients with ompliations Any patient with a prostheti heart valve who does not improve after surgery or who later develops deterioration of funtional apaity should undergo appropriate testing inluding transthorai or transoesophageal Doppler ehoardiography and, if ultrasound is not onlusive, ardia atheterisation and oronary angiography. Late ompliations following heart valve surgery an inlude: thromboemboli and bleeding ompliations (see above), left and/or right ventriular failure, pulmonary hypertension, sudden death, arrhythmias, ondution abnormalities, mehanial ompliations, and infetive endoarditis (see below). A previous artile in this series provides a detailed and omprehensive review of late ompliations after surgery of valve disease. 2 Left ventriular dysfuntion Left ventriular (LV) systoli dysfuntion, and onsequently also diastoli dysfuntion, are most often a onsequene of the longstanding preoperative pressure or volume overload. In the ase of pure pressure overload as in aorti stenosis, exlusive impairment of LV diastoli funtion may manifest itself as ongestive heart failure after aorti valve replaement. Under the ondition that the size of the prosthesis has been hosen to math the patient s body size (see above), LV hypertrophy ausing diastoli dysfuntion will regress over the ourse of months and even years. 13 Doppler ehoardiographi assessment of diastoli LV funtion is hallenging beause there is an abundane of different veloity parameters obtained during mitral and/or pulmonary vein inflow and at the mitral annulus, whih all have to be interpreted in light of the patient s atual preload ondition. 14 Measurement of early diastoli mitral annular motion veloity (normal value. 9 m/s) is likely the most preload independent Doppler parameter available for LV diastoli funtion assessment. 15 LV dysfuntion may, alternatively or additionally, be due to the influene of oronary artery disease, poorly ontrolled systemi hypertension, or oinident ardiomyopathy. LV systoli funtion is estimated by measuring ventriular ejetion fration. However, it not only reflets myoardial ontratility but is also very suseptible to hanges in ventriular pre- and afterload. Altered ventriular loading onditions aused by the valve replaement itself influene the ehoardiographially obtained ejetion fration as muh as real postoperative hanges in myoardial ontratility. For example, in the ase of severe predominant aorti regurgitation, augmented ventriular preload in the ompensated myoardial struture leads to an enhaned ontratility 821 Heart: first published as /hrt on 14 June Downloaded from on 17 Marh 2019 by guest. Proteted by opyright.

5 822 before valve replaement (Frank Starling mehanism); systoli funtion will be redued postoperatively without neessarily refleting a poor outome following valve replaement. Likewise, a blunted postoperative versus preoperative ejetion fration after mitral valve replaement for severe insuffiieny is not by itself an ominous sign, but rather reflets the pathophysiology of a substantial inrease in afterload as a onsequene of the operation. Conversely, the timing of valve surgery in ases of predominant valvar insuffiieny has to aount for the pathophysiology of supranormal ejetion fration by hoosing still normal values (, 65% in mitral valve regurgitation and, 55% in aorti valve regurgitation; LV end diastoli diameter > 45 mm and > 55 mm, respetively) as thresholds for surgery even in the absene of symptoms. 3 Right ventriular dysfuntion Haemodynamially relevant triuspid regurgitation with or without systoli right ventriular (RV) dysfuntion is detetable by ehoardiography in up to two thirds of patients late after mitral valve replaement, and it is linially manifest in more than one third. 16 RV dysfuntion may be the result of persistent LV pathology and the presene of pulmonary artery hypertension, but it may also be aused by unorreted triuspid regurgitation with RV volume overload. In this regard, ehoardiographi assessment of triuspid insuffiieny and of RV size and systoli funtion is an integral part of every Doppler ehoardiographi examination following valve replaement. Ehoardiographi measurement of RV systoli funtion is inaurate and insuffiiently validated. The latter is true for eho derived RV ejetion fration measurement whih is hampered by the resent-like shape of the RV. A systoli versus diastoli RV area hange of less than 20% is generally regarded as an indiator of redued systoli RV funtion. 17 Measuring (free wall) triuspid annular motion veloity during systole by tissue Doppler imaging has some potential to beome a pratial tool for non-invasive assessment of systoli RV funtion (fig 3; with a motion veloity of, 12 m/s refleting redued RV ejetion fration, 50% 18 ). Pulmonary hypertension The pathophysiology of pulmonary artery hypertension is illustrated by Ohm s law, PAP = PVR 6 Q p + LAP, where PAP denotes pulmonary artery pressure, PVR is pulmonary vasular resistane, Q p is pulmonary arterial volume flow rate, and LAP is left atrial pressure. Pulmonary hypertension (mean pulmonary artery pressure. 25 mm Hg) is ommonly present in patients with left sided valve disease and is most pronouned in rheumati mitral valve disease. It is not only the result of elevated left atrial bak pressure transmitted aross the pulmonary irulation (LAP), but also of an inrease in PVR aused by pulmonary arterial vasoonstrition and obliterative hanges of the pulmonary vasular bed. Following orretion of the left sided valvar lesion, an early fall in pulmonary artery pressure is expeted whih is the result of a redution in both PVR and LAP. The detetion and monitoring of pulmonary hypertension using Doppler derived systoli veloity gradient measurements between the RV and the right atrium is easy to perform. This is in part due to the fat that triuspid regurgitation (prerequisite for non-invasive estimation of pulmonary artery pressure) is present in 80% of the ases with a systoli pulmonary artery pressure above 30 mm Hg. 19 The late postoperative persistene or emergene of pulmonary hypertension and right heart failure may reflet delayed left sided valve replaement, new prostheti dysfuntion, or new LV pathology. Sudden death Sudden death as an event ompliating the postoperative ourse of prostheti heart valve replaement aounts for about 25% of late deaths after suh an operation, and its annual risk is estimated to be % 2 The majority of sudden deaths are aused by the natural disease proess of the valvulopathy, with the most ommon ause being ventriular arrhythmias. Causes of valve related sudden death inlude valve thrombosis, thromboembolism, endoarditis, paravalvar leak, mehanial failure of the prosthesis, and intraerebral haemorrhage. In half the ases undergoing aorti valve replaement, atrioventriular ondution problems will finally require permanent paemaker implantation. Mehanial ompliations Paravalvar leak (fig 2) in the absene of infetion represents one form of mehanial ompliation with both mehanial and biologial valves, and usually reflets suture failure. It may ause signifiant levels of haemolysis whih finally an require reoperation. In mehanial valves, sudden failure of the omponents of the valve is extremely rare but usually fatal. Gradual deterioration in valve performane aused by slow in-growth of fibrous tissue (pannus) is more frequent, is observed also with bioprostheses, leads to inreasing valve obstrution, and an be effetively treated only by reoperation. In biologial valves, late degeneration is the major ompliation. It onsists of thinning, atrophy, perforation (in Figure 3 Systoli and diastoli triuspid annular motion veloity signals. The tissue Doppler imaging signals are obtained using pulsed wave Doppler with the sample volume plaed at the free wall triuspid annulus. A systoli triuspid annular motion veloity (arrow; in this patient 22 m/s) of > 12 m/s aurately predits normal systoli right ventriular funtion. Heart: first published as /hrt on 14 June Downloaded from on 17 Marh 2019 by guest. Proteted by opyright.

6 Follow up in prostheti valves: key points Immediately after valve surgery, Doppler ehoardiography should be obtained in all patients The first outpatient workup should inlude the patient s history, physial examination, ECG, hest x ray, omplete blood ount, reatinine, eletrolytes, latase dehydrogenase, INR, and Doppler ehoardiography Follow up visits in asymptomati patients without ompliations or new murmurs an be performed at yearly intervals and without Doppler ehoardiography Compliations after valve replaement: thromboemboli bleeding, ventriular failure, pulmonary hypertension, sudden death, arrhythmias, ondution abnormalities, mehanial ompliations, and infetive endoarditis Transvalvar or paravalvar regurgitation is deteted by Doppler ehoardiography; the latter may be harmless, but may represent a haemodynami problem or may be a sign of prostheti endoarditis Infetions of prostheti heart valves are a very serious ompliation ( % per patient year). In suspeted endoarditis, the threshold for transoesophageal ehoardiography should be low allografts), usp thikening, alifiation, and tearing. Valve degeneration is aelerated by young age. Rates of aorti valve failure (porine bioprostheses) over the ourse of 10 years are reported to be 42% in patients aged years versus 0% in those aged years. 2 Antibioti prophylaxis and endoarditis All patients with prostheti valves need appropriate antibioti prophylaxis for the prevention of endoarditis. 20 As the risk for an infetion is muh higher in patients with prostheti heart valves than in those with valvar heart disease, more intensive prophylaxis is needed in the former. Infetive endoarditis is a feared ompliation following either early (within 60 days of initial surgery) or late after valve surgery, with the infetion usually loated on the valve prosthesis. Endoarditis in general is a rare ondition with a 10 year survival rate of 50%. 21 In partiular, prostheti valve endoarditis also ours infrequently ( % per patient year 20 ); in our reently reported series of 36 patients with prostheti valve endoarditis (out of 212 patients with endoarditis), 24 (56%) died during the ourse of 7.5 years mean follow up. 21 Thus, prostheti as ompared to native valve endoarditis was not a risk fator for poor outome. Early prostheti valve endoarditis is aused by ontamination of the valve during implantation with ulprit organisms suh as Staphyloous epidermidis, Gram negative bailli, and fungi. In late prostheti valve endoarditis, streptooi with sites of entry similar to native valve endoarditis are the most ommon ausative organisms. With mehanial prostheses, the infetion tends to be loated at the sewing ring of the valve, in bioprostheses it an also involve the usps, while in omposite grafts it may even inlude the distal anastomosis or oronary reimplantation site (fig 4). Vegetations may develop and give rise to systemi embolisation, while periannular tissue destrution may lead to paravalvar leak, and absess and fistula formation. Clinial presentation and diagnosti riteria are similar to native valve endoarditis. Transoesophageal ehoardiography is of partiular importane when prostheti valve endoarditis is suspeted beause of its high sensitivity to detet small vegetations or absesses. Prompt treatment with ombined broad spetrum antibiotis is ruial one the diagnosis is suspeted and after blood ulture sampling has been performed. Parenteral antibiotis should be given over the ourse of six weeks and modified aording to blood ulture results following an initial blind treatment period. Early surgial intervention as ompared to medial treatment alone has been found to be 823 Heart: first published as /hrt on 14 June Downloaded from Figure 4 Composite xenograft failure. A transoesophageal two dimensional image in the short axis (left panel) and the long axis projetion (right panel, olour Doppler image) shows an extended eho-free spae (*) around the aorti omposite graft with a bioprosthesis (Shelhigh porine stentless aorti prosthesis 21). In the short axis view, the left atrium (LA) and right atrium (RA) are depited as well as the three usp valve in the entre of the omposite graft wall whih itself is surrounded by haematoma (*). Both images are obtained during diastole (white lines on the ECG). There is moderately severe aorti insuffiieny. Additionally, there is a leak at the right oronary artery reimplantation site. Intraoperatively, a dehisene was also deteted at the distal suture line of the omposite graft. Both the distal and the right oronary usp leakage aused the periaorti haematoma. It was suspeted that a low grade endoarditis aused this situation. LV, left ventrile. on 17 Marh 2019 by guest. Proteted by opyright.

7 824 related to better survival. 21 Sine it is impossible to perform ontrolled linial trials in endoarditis with randomisation to medial or surgial/medial treatment arms, the benefit of early surgial therapy may reflet a seletion bias for surgery in healthier patients. Indiations for surgery inlude prosthesis dysfuntion, absess or fistula formation, systemi embolisation, persistent bateraemia, ardia failure, and multiorgan failure. For a detailed review of prostheti valve endoarditis see an earlier artile in this series. 20 REFERENCES 1 Lindblom D, Lindblom U, Qvist J, et al. Long-term relative survival rates after heart valve replaement. J Am Coll Cardiol 1990;15: A large study of survival rates in onseutive patients after heart valve replaement. Through adjustments in bakground mortality relative survival rates are presented and thereby identify important variables affeting the survival in different valve lesions. 2 Groves P. Surgery of valve disease: late results and late ompliations. Heart 2001;86: Enriquez-Sarano M. Timing of mitral valve surgery. Heart 2002;87: Bloomfield P. Choie of heart valve prosthesis. Heart 2002;87: Bonow RO, Carabello B, de Leon ACJ, et al. ACC/AHA guidelines for the management of patients with valvular heart disease: exeutive summary. A report of the Amerian College of Cardiology/Amerian Heart Assoiation task fore on pratie guidelines (ommittee on management of patients with valvular heart disease). Cirulation 1998;98: A omprehensive review of all aspets of the management of patients with valvar heart disease inluding valve replaement surgery. 6 Herzog CA, Ma JZ, Collins AJ. Long-term survival of dialysis patients in the United States with prostheti heart valves. Should ACC/AHA pratie guidelines on valve seletion be modified? Cirulation 2002;105: Massel D, Little SH. Risks and benefits of adding anti-platelet therapy to warfarin among patients with prostheti heart valves: a meta-analysis. JAm Coll Cardiol 2001;37: A meta-analysis of the use of warfarin and aspirin in patients with prostheti heart valves. It is onluded that ombining low dose aspirin with warfarin dereases the risk of systemi embolism or death in patients with prostheti heart valves. 8 Cannegieter S, Rosendaal F, Wintzen A, et al. Optimal oral antioagulant therapy in patients with mehanial heart valves. N Engl J Med 1995;333: Gohlke-Barwolf C. Antioagulation in valvar heart disease: new aspets and management during non-ardia surgery. Heart 2000;86: Oezkan M, Kaymaz C, Kirma C, et al. Intravenous thrombolyti treatment of mehanial prostheti valve thrombosis: a study using serial transesophageal ehoardiography. J Am Coll Cardiol 2000;35: Useful analysis of the results of intravenous thrombolyti treatment in 32 symptomati patients with prostheti valve thrombosis. In omparison to other data in the literature, this single entre ohort is relatively large. Initial suess using streptokinase was 53% as assessed by transoesophageal ehoardiography; it inreased to 88% following repeated thrombolyti sessions. 11 Chan WS, Anand S, Ginsberg JS. Antioagulation of pregnant women with mehanial heart valves: a systemati review of the literature. Arh Intern Med 2000;160: Pibarot P, Dumesnil J. Hemodynami and linial impat of prosthesis-patient mismath in the aorti valve position and its prevention. J Am Coll Cardiol 2000;36: A useful update on the onept of aorti prosthesis patient mismath with a review of the present knowledge regarding its impat on haemodynami status, funtional apaity, and patient morbidity and mortality. 13 Mandinov L, Eberli F, Seiler C, et al. Diastoli heart failure. Cardiovas Res 2000;45: de Marhi S, Bodenmuller M, Lai D, et al. Pulmonary venous flow veloity patterns in 404 individuals without ardiovasular disease. Heart 2001;85: Nagueh S, Sun H, Kopelen H, et al. Hemodynami determinants of the mitral annulus diastoli veloities by tissue Doppler. J Am Coll Cardiol 2001;37: Porter A, Shapira Y, Wurzel M, et al. Triuspid regurgitation late after mitral valve replaement: linial and ehoardiographi evaluation. J Heart Valve Dis 1999;8: Jaffe CC. Ehoardiography of the right side of the heart. Cardiology Clinis 1992;10: Tüller D, Steiner M, Kabok M, et al. Assessment of systoli right ventriular funtion by Doppler tissue imaging of the triuspid annulus [abstrat]. Eur Heart J 2002;23: Krowka MJ. Pulmonary hypertension. Mayo Clin Pro 2000;75: Piper C, Körfer R, Horstkotte D. Prostheti valve endoarditis. Heart 2001;85: Netzer ROM, Altwegg SC, Zollinger E, et al. Infetive endoarditis: determinants of long term outome. Heart 2002;88:61 6. Retrospetive ohort study in 212 patients with infetive endoarditis followed for an average of 7.4 years. Survival was 50% after 10 years and was predited by early surgial treatment, young age, lak of ongestive heart failure, and the presene of initial symptoms of endoarditis. Heart: first published as /hrt on 14 June Downloaded from on 17 Marh 2019 by guest. Proteted by opyright.