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

Mitral valve replacement in children: balancing durability and risk with mechanical and bioprosthetic valves

OBJECTIVES

To investigate if there is still a place for bioprosthetic mitral valve replacement in children by comparing the prosthetic durability and transplant-free survival after bioprosthetic and mechanical mitral valve replacement.

METHODS

We reviewed all mitral valve replacements in children between 1981 and 2020. Bioprosthetic mitral valve replacement cases were individually matched to mechanical mitral valve replacement cases. The incidence rate of a 2nd replacement was calculated using the cumulative incidence function that considered death or transplantation as a competing risk.

RESULTS

The median age at implantation was 3.6 years (interquartile range 0.8-7.9) for the bioprosthetic valve cohort (n = 28) and 3 years (interquartile range 1.3-7.8) for the mechanical valve cohort (n = 28). Seven years after bioprosthetic mitral valve replacement, the cumulative incidence of death or transplantation was 17.9% [95% confidence interval (CI) 6.3-34.1] and the cumulative incidence of a 2nd replacement was 63.6% (95% CI 39.9-80.1). Seven years after mechanical mitral valve replacement, the cumulative incidence of death or transplantation was 28.6% (95% CI 13.3-46) and the cumulative incidence of a 2nd replacement was 10.7% (95% CI 2.6-25.5). Fifteen years after mechanical mitral valve replacement, the cumulative incidence of death or transplantation was 33.6% (95% CI 16.2-52.1) and the cumulative incidence of a 2nd replacement was 41.1% (95% CI 18.4-62.7). The cumulative incidence curves for bioprosthetic and mechanical mitral valve replacement were statistically different for a 2nd valve replacement (P < 0.001) but not for death or transplantation (P = 0.33).

CONCLUSIONS

There is no difference in transplant-free survival after bioprosthetic and mechanical mitral valve replacement in children. The lifespan of bioprosthetic mitral valves remains limited in children because of structural valve failure due to calcification. After 15 years, 40% of mechanical valves were replaced, primarily because of patient-prosthesis mismatch related to somatic growth.

Infective Endocarditis among Pediatric Patients with Prosthetic Valves and Cardiac Devices: A Review and Update of Recent Emerging Diagnostic and Management Strategies

Infective endocarditis (IE) is a disease of the endocardium, which leads to the appearance of vegetation on the valves, cardiac structures, or, potentially, vascular endothelium of the heart. The risk of IE can be increased more than 140 times by congenital heart disease (50-59% of all IE), particularly if cyanotic. An increase in mortality may result from IE in patients with a complex cardiac pathology or patients with an implanted prosthetic material, most frequently conduits in a pulmonary position. Cardiac implantable electronic devices (CIED) infective endocarditis is a life-threatening complication representing 10% of all cases of endocarditis. Common signs of presentation are often fever and chills; redness and swelling at the pocket of the pacemaker, including the erosion and exteriorization of the device; and life-threatening sepsis. The use of intracardiac echocardiography for the diagnosis of IE is an innovative method. This may be needed, especially in older children undergoing complex cardiac surgery, when transthoracic echocardiography (TTE) and transesophageal echocardiography (TOE) failed to provide a reliable diagnosis. The 2018 European Heart Rhythm Association (EHRA) experts' consensus statement on transvenous lead extraction recommends complete device removal and antimicrobial therapy for any device-related infection, including CIED-IE. The most detected microorganism was Staphylococcus Aureus. In addition, cardiac surgery and interventional cardiology associated with the placement of prostheses or conduits may increase the risk of IE up to 1.6% for Melody valve implantation. Our manuscript presents a comprehensive review of infective endocarditis associated with cardiac devices and prostheses in the pediatric population, including recent advances in diagnosis and management.

Extracorporeal membrane oxygenation after prosthetic valve replacement in a child with neonatal Marfan syndrome: a case report

BACKGROUND

Neonatal Marfan syndrome (nMFS), the most severe form of Marfan syndrome, is a rare condition that presents a clinical and treatment challenge. nMFS has high infant mortality related to progressive valvular dysfunction. Valve replacement in this setting improves long-term prognosis but carries high morbidity and mortality. Thus, sharing clinical experience in treating such patients is valuable.

CASE SUMMARY

A 2 year old with nMFS underwent tricuspid valve annuloplasty and prosthetic mitral valve replacement. Postoperative management was complicated by pulmonary hypertension, cardiogenic shock, and arrythmias. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) helped overcome these challenges but posed a high risk for prosthetic valve thrombosis (PVT). Despite decompression of the left atrium (LA) with an LA vent, the left ventricle (LV) was distended because of aortic regurgitation and no native cardiac output. We lowered the ECMO flow under echocardiographic guidance; used inodilators and pacing to encourage transmitral flow and reduce LV afterload. The patient completed a successful 6-day ECMO run with good end-organ perfusion. At last follow up, she was 6 years old, enjoying school, home-ventilated through the tracheostomy, and mobilizing with walking aids/wheelchair.

DISCUSSION

Valve replacement can improve life quality and expectancy for patients with nMFS. Lowering ECMO flow under echocardiography guidance till the aortic valve is seen to open; coupled with inodilators, pacing and adequate anticoagulation can be a safe way to deliver VA-ECMO for cardiogenic shock after prosthetic valve replacement. Further research is needed to show if this strategy prevents prosthetic valve thrombosis and provides sufficient haemodynamic support and myocardial rest.

Paediatric mitral valve disease - from presentation to management

Mitral valve diseases are relatively rare in the paediatric population; however, they can cause considerable mortality and morbidity worldwide. Acquired causes are a major contributor to cardiovascular disease burden in the paediatric population. Diseases can be detected before birth, at birth, or when the child is older and presents with symptoms of advanced heart failure. Definitive management consists of surgical intervention, with mitral valve replacement being the gold standard.Conclusion: Repair has been gaining popularity; however, its outcomes require further study. Percutaneous mitral balloon valvuloplasty is an emerging technique which holds promise as a bridge to surgical treatment. The effect of these interventions on quality of life must be emphasised and requires further study. What is Known: • The epidemiology of mitral valve disease in the paediatric population - predominant causes include rheumatic disease and congenital defects.  • Mitral valve repair and replacement are the standard treatment methods for paediatric mitral valve disease.  What is New: • Emergence of percutaneous mitral valve interventions and their potential as bridge-to-surgery or definitive treatment in high-risk surgical candidates.  • Recent evidence comparing mitral valve repair and replacement in the paediatric population demonstrates increasing popularity of repair techniques.

Revisiting prosthesis choice in mitral valve replacement in children: Durable alternatives to traditional bioprostheses

OBJECTIVE

To determine risk factors for re-replacement and death or transplant following mitral valve replacement (MVR) in children METHODS: This is a retrospective 26-year review of patients younger than 20 years of age undergoing MVR between 1992 and 2018 at single institution. Outcomes included freedom from re-MVR and transplant-free survival. Cox proportional hazards regression models assessed association between outcomes and potential risk factors.

RESULTS

At median age 4.2 years, 190 children underwent 290 MVR: 180 mechanical, 63 porcine, 13 pericardial, and 34 stented bovine jugular vein valves. Re-MVR occurred in 100 valves. Freedom from re-MVR at 5 and 10 years was 76% and 44%. Times to re-MVR were associated with prosthesis type (P < .001), with porcine and pericardial valves at greatest risk. Other risk factors for prosthetic failure included smaller prosthesis size and left ventricular hypoplasia. There were 9 transplants and 44 deaths. Transplant-free survival at 5 and 10 years was 81% and 76%. Prosthesis type was significantly associated with time to death/transplant in univariate analysis only (P = .021), with porcine at greater risk than mechanical. Independent risk factors for death/transplant included larger indexed geometric orifice area and longer bypass time.

CONCLUSIONS

In pediatric patients undergoing MVR, mechanical and stented bovine jugular vein valves were associated with increased durability compared with fixed-diameter bioprosthetic alternatives.

Outcomes of Supra-annular Mechanical Atrioventricular Valve Replacement with Polytetrafluoroethylene Graft in Infants and Children

Despite improvements in valve repair techniques, conditions in which infants and children need for mechanical valve replacement (MVR) are still present. We analyzed supra-annular MVR outcomes in infants and children with small annulus and compared them with conventional annular MVR outcomes. Data were collected retrospectively from medical records of infants and children (weighing < 20 kg) who underwent atrioventricular valve replacement with mechanical valve in Seoul National University Children's Hospital between December 1984 and January 2019. We identified 8 patients (median age 20 months, median weight 10.2 kg) who underwent supra-annular MVR with polytetrafluoroethylene graft (supra-annular group). The patients were diagnosed with congenital mitral valve malformation (5 patients), complete atrioventricular septal defect (2 patients), and functional single ventricle (1 patient). The implanted mechanical valve size ranged from 16 to 23 mm. Thirty-three patients (median age 40 months, median weight 13 kg) underwent conventional annular MVR (annular group). The survival rate was not significantly different between the supra-annular and annular groups (75.0 vs 78.8%, P = 0.816). In patients with biventricular repair (7 patients with supra-annular MVR and 28 patients with annular MVR), mechanical valve-to-mitral valve annulus size ratio was higher in the supra-annular group than in the annular group (1.24 ± 0.30 vs 0.96 ± 0.22, P = 0.035). No coronary complication or heart block were observed in the supra-annular group. Supra-annular MVR with polytetrafluoroethylene graft may be a feasible surgical option in children with a small annulus when valve repair is unsuccessful.

Midterm Results of Mitral Valve Repair With Pericardial Leaflet Augmentation: A Single-Center Experience

In certain pathologies, mitral valve repair is complicated by a paucity of tissue caused by fibrosis or destruction. Utilization of autologous pericardium for leaflet augmentation may be the only option to repair these valves. We present the midterm results of mitral valve leaflet augmentation with glutaraldehyde-fixed autologous pericardium. One hundred thirty consecutive patients undergoing mitral valve repair with glutaraldehyde-fixed pericardial augmentation of leaflets were followed up clinically and by echocardiography at 6-month intervals. Mean age was 24.8 years (range 2-64). The etiology was rheumatic in 75.3%, indeterminate in 8.4%, and other in 16.1%. Out of the rheumatics, 57.1%, 24.4%, and 18.3% had combined mitral stenosis and mitral regurgitation, isolated mitral regurgitation, and mitral stenosis, respectively. About 21.5% had a recent history of rheumatic activity. Eight were operated emergently for intractable heart failure. Majority of the patients required repair of multiple components of the mitral valve apparatus. Leaflet peeling was done in 52.3%. Pericardial patch augmentation of anterior mitral leaflet, posterior mitral leaflet, or both were carried out in 61.5%, 34.6%, and 3.8% patients respectively. Sixty percent got chordal procedures, while 92.3% got annuloplasty. There were no deaths during the mean follow-up period of 28 months. Ninety-three percent of our patients were in New York Heart Association class I and II on follow-up. There were 11 repair failures. Seven patients underwent a reoperation, while 4 patients are being managed conservatively (reoperation rate 5.38%). Augmentation of mitral valve leaflets with autologous pericardium allows many significantly fibrosed and destroyed valves to be reliably repaired with good midterm durability and hemodynamics.

Prosthesis-Patient Mismatch Negatively Affects Outcomes after Mitral Valve Replacement: Meta-Analysis of 10,239 Patients

OBJECTIVE

This study sought to evaluate the impact of prosthesis-patient mismatch on the risk of perioperative and long-term mortality after mitral valve replacement.

METHODS

Databases were researched for studies published until December 2018. Main outcomes of interest were perioperative and 10-year mortality and echocardiographic parameters.

RESULTS

The research yielded 2,985 studies for inclusion. Of these, 16 articles were analyzed, and their data extracted. The total number of patients included was 10,239, who underwent mitral valve replacement. The incidence of prosthesis-patient mismatch after mitral valve replacement was 53.7% (5,499 with prosthesis-patient mismatch and 4,740 without prosthesis-patient mismatch). Perioperative (OR 1.519; 95%CI 1.194-1.931, P<0.001) and 10-year (OR 1.515; 95%CI 1.280-1.795, P<0.001) mortality was increased in patients with prosthesis-patient mismatch. Patients with prosthesis-patient mismatch after mitral valve replacement had higher systolic pulmonary artery pressure and transprosthethic gradient and lower indexed effective orifice area and left ventricle ejection fraction.

CONCLUSION

Prosthesis-patient mismatch increases perioperative and long-term mortality. Prosthesis-patient mismatch is also associated with pulmonary hypertension and depressed left ventricle systolic function. The findings of this study support the implementation of surgical strategies to prevent prosthesis-patient mismatch in order to decrease mortality rates.

Children with post-rheumatic valvulopathies in natural history: five years follow-up in the cardiac centre, St. Elizabeth Catholic General hospital Shisong (Cameroon)

The aim of the study was to investigate the pattern of valvular lesions, the mortality and the challenges in five years follow-up in children with post-rheumatic valvulopathies in natural history in St. Elizabeth Catholic General hospital Shisong, cardiac centre. This retrospective analysis included 270 patients aged between 5 and 16 years old suffering from post-rheumatic valvulopathies who consulted in the cardiac centre from July 2008 through July 2013. Postrheumatic valvulopathies were diagnosed according to the World heart federation criteria. Data from patients' records, two-dimensional echocardiographic studies, and electrocardiograms were reviewed. Patients and their family were contacted every six months. The duration of the follow-up was 60months. Patients aged between 5 and 16 years old with a mean age of 12.4±4.5 years. Female gender was representing 63% (n=170) of the population. Surgery was indicated in 256 cases. Lesions of the valves needing prophylaxis with penicillin was diagnosed in 14 cases. In 95 patients surgical correction could not be performed. Mitral regurgitation was the commonest echocardiographic diagnosis present in 61.5%, n=164 patients; 38.5%, n=103 patients had aortic regurgitation. Mitral stenosis and mitral disease were also represented in 6%, n=16, and 8%, n= 21 patients respectively. Pulmonary hypertension was the common echocardiographic complication of the disease in=234, 87% of cases. Clinically, complications of the disease included congestive heart failure (n=229, 85%), growth retardation (n=162, 60%), sudden death (n=27, 10%). On presentation, n=210, 78% of cases were admitted. Mortality in two years was 35%, (p≤0.05, 95% CI=2.5-6.5), in five years was 65% (p≤ 0.05, 93% CI= 2.7-7.21). The challenges faced are patients' negligence and poor discipline, wrong beliefs, poverty. Post-rheumatic mitral valve regurgitation is the pathology the most encountered. Pulmonary hypertension is the most common echocardiographic complication of the disease. Five years mortality is very high in our setting. Due to financial limitation and illiteracy of parents, the follow up of patients is difficult.

Supra-annular mitral valve implantation in very small children

OBJECTIVE

Mitral valve replacement (MVR) is a surgical option when mitral valvuloplasty is not feasible/successful. This study reviews our experience with MVR in very young children.

METHODS

From July 2004 to January 2014, seven children (mean age 13.3 ± 11.2 months; range 4 months to 35 months; mean body weight 6.0 ± 2.2 kg) underwent MVR with a mechanical prosthesis in the supra-annular position. To provide better exposure in the left atrium, we performed in all but one case a biatrial transeptal incision according to Guiraudon. Six patients had congenital defects of the mitral valve and one had rheumatic. Six patients had undergone previous cardiosurgical procedures.

RESULTS

All patients were implanted with a CarboMedics (CarboMedics, Austin, TX, USA) mechanical prosthesis. Mean prosthesis size was 19.0 ± 3.1 mm (range 16 to 25). There were no cases of operative or late mortality. At follow-up (mean 67.1 ± 34.8 months; range 25 to 108 months) two patients (28.6%) required reoperation both for thrombotic pannus formation over the disc at two and three months from first operation, respectively; only in one case was replacement necessary.

CONCLUSION

Supra-annular MVR may be considered a feasible secondary surgical option in children with a small annulus when mitral valvuloplasty is unsuccessful or unsuitable. Early and mid-term outcomes are acceptable but complications are not uncommon, especially related to thrombotic events.

Mitral valve replacement using mechanical prostheses in children: early and long-term outcomes

Compared with mitral repair, mitral valve replacement is an uncommon procedure in children due to associated high mortality and morbidity rates. The present study investigated early and late outcomes after MVR with mechanical prostheses in children at our institution. Between January 1994 and December 2009, 19 children underwent MVR. Mean patient age was 7.6 ± 5.5 years (range 3 months-16 years), and mean body weight was 23.7 ± 15.1 kg (range 5.0-58.1 kg). Mean prosthesis size was 25.8 ± 4.2 mm (range 19-31 mm). There were no operative or late mortalities. Three patients showed decreased left-ventricular function before surgery, and one of them underwent successful heart transplantation due to progressive LV dysfunction at 10 months after MVR. The proportion of patients with freedom from reoperation at 10 years was 94.7 ± 5%. There were no major thromboembolic or bleeding episodes. Although the small number of patients in our study was a limitation, MVR in children was found to result in excellent early and long-term outcomes. It appears that MVR could be considered in children before LV dysfunction develops.

Clinical characteristics of acute mitral regurgitation due to ruptured chordae tendineae in infancy-experience at a single institution

In infants, acute mitral regurgitation resulting from ruptured chordae tendineae is very rare, but often fatal. There are a few case reports, but the characteristics and etiology of chordae tendineae rupture have not been elucidated. Our aim was to determine the clinical characteristics of idiopathic acute mitral regurgitation due to chordal rupture in infancy. A retrospective analysis was performed on ten consecutive patients, with a mean onset age of 4.6 ± 1.3 months. Despite nonspecific initial symptoms, all patients developed respiratory distress and four required resuscitation within a few days (mean, 1.8 ± 1.8 days). Chest radiographs showed pulmonary congestion with a normal or mildly increased cardiothoracic ratio in all ten patients. Laboratory data and electrocardiograms showed nonspecific findings. Echocardiography revealed ruptured chordae in all patients; locations were anterior (50%), posterior (20%), and both (30%). Surgical intervention was performed within 24 h of admission in eight patients (mean, 3.6 ± 5.1 h). Pathological findings included inflammatory cells in six specimens and myxomatous degeneration in two. No bacteria were isolated from preoperative blood cultures, pathological tissues, or excised tissue cultures. Autoantibody levels were insignificant. Three preoperatively resuscitated patients developed neurological sequelae and arrhythmias occurred in four after mitral valve replacement. Acute onset and rapid deterioration in patients with ruptured chordae tendineae necessitates early surgical intervention to improve outcomes. Though the etiology remains unknown, onset is in infants approximately 4 months of age, suggesting a definite disease entity.

Mitral Annular Growth in Children Following Early Mechanical Mitral Valve Replacement

Irreparable mitral pathology may lead to early mitral valve replacement (MVR) in children. Often, a small mechanical prosthesis (<23 mm) is required, raising concerns about annular growth in patients who may eventually require subsequent mitral valve re-replacement (MVRR). The aim of this study was to evaluate interval mitral annular growth in this cohort. Between January 1972 and December 2006, 164 children underwent MVR with a mechanical prosthesis; 110 of these children (median age, 4 years; range, 7 days to 14 years) received a small mechanical prosthesis (<23 mm). The most common diagnoses were congenital mitral stenosis (10%), regurgitation (46%), and left atrioventricular valve dysfunction after previous atrioventricular septal defect repair (44%). The cohort was analyzed for age, body surface area (BSA), prosthesis size, and Z score at the time of MVR and MVRR. At the time of MVR, 78 patients had a BSA of 0.77 ± 0.06 m2, had an annular size of 24 ± 0.62 mm ( Z score, 2.91 ± 0.23), and ultimately did not require MVRR. Another cohort, who eventually did require MVRR (n = 24), had an initial BSA at the time of MVR of 0.62 ± 0.05 m2 ( P = NS vs MVR only) and an annular size of 20 ± 0.49 mm ( Z score, 1.85 ± 0.22) ( P = .008 vs MVR only). In the interval between MVR and MVRR (7.8 ± 1.1 years), BSA increased to 1.12 ± 0.07 m2, and annulus size increased to 24 ± 0.47 mm ( Z score, 1.80 ± 0.28). These data suggest growth of the mitral annulus following MVR with a small mechanical prosthesis, as evidenced by an unchanged Z score in the setting of normal interval increase in BSA. Additionally, there was a statistically significant difference in initial Z scores between the cohorts requiring MVRR and those who have not needed re-replacement, suggesting that the feasibility of placement of a slightly larger prosthesis may be associated with a decreased need for MVRR.

Ross-kabbani operation in an infant with mitral valve dysplasia

Background. Mitral valve replacement can be very difficult to obtain in infants because the valve annulus diameter can be smaller than the available prosthesis. Case Report. We describe the case of a 2-month-old female weighing 3.5 kg affected by mitral valve dysplasia leading to severe valve stenosis. Despite full medication, the clinical conditions were critical and surgery was undertaken. The mitral valve was unsuitable for repair and the orifice of mitral anulus was 12 mm, too small for a mechanical prosthesis. Therefore, a Ross-Kabbani operation was undertaken, replacing the mitral valve with the pulmonary autograft and reconstructing the right ventricular outflow tract with an etherograft. Results. The postoperative course was uneventful and the clinical conditions are good at 4-month follow-up. Conclusion. The Ross-Kabbani operation can be an interesting alternative to mitral valve replacement in infants when valve repair is not achievable and there is little space for an intra-annular mechanical prosthesis implant.

Edge-to-edge technique: is it also useful in children?

OBJECTIVE

Mitral valve prolapse is a rare condition and represents a challenge for cardiac surgeons. Many techniques have been described to treat the wide spectrum of abnormalities causing mitral valve regurgitation but the low incidence of these abnormalities is the cause of the relatively poor experience of many institutions.

METHODS

From April 2005 to September 2006, five patients underwent isolated mitral valve repair with the edge-to-edge technique for anterior or bileaflet prolapse. Three patients also had a Gore-Tex strip to reinforce the posterior annulus, whereas two had a 26-size soft incomplete ring annuloplasty.

RESULTS

There was no death and none of the patients required reoperation. None of the patients had mitral regurgitation more than 1+ at a mean follow-up of 30 months. None of the patients had mitral stenosis or any valve-related event.

CONCLUSION

The edge-to-edge technique is a well tolerated and useful technique for the anterior or bileaflet prolapse of the mitral valve. Although many techniques have been described with good results, in many anatomical settings and in small patients, edge-to-edge is a good option and might not interfere with the growth of the valve. Early results are encouraging but a longer follow-up is needed to evaluate the long-term prognosis.

Effectiveness of balloon valvuloplasty for palliation of mitral stenosis after repair of atrioventricular canal defects

Closure of a mitral valve (MV) cleft, small left-sided cardiac structures, and ventricular imbalance all may contribute to mitral stenosis (MS) after repair of atrioventricular canal (AVC) defects. MV replacement is the traditional therapy but carries high risk in young children. The utility of balloon mitral valvuloplasty (BMV) in postoperative MS is not established and may offer alternative therapy or palliation. Since 1996, 10 patients with repaired AVC defects have undergone BMV at a median age of 2.5 years (range 8 months to 14 years), a median of 2 years after AVC repair. At catheterization, the median value of mean MS gradients was 16 mm Hg (range 12 to 22) and was reduced by 34% after BMV. Before BMV, there was mild mitral regurgitation in 9 of 10 patients, which increased to severe in 1 patient. All patients were alive at follow-up (median 5.4 years). Repeat BMV was performed in 4 patients, 10 weeks to 18 months after initial BMV. One patient underwent surgical valvuloplasty; 3 underwent MV replacement 2, 3, and 28 months after BMV. In the 6 patients (60%) with a native MV at most recent follow-up (median 3.2 years), the mean Doppler MS gradient was 9 mm Hg, the median weight had doubled, and weight percentile had increased significantly. In conclusion, BMV provides relief of MS in most patients with repaired AVC defects; marked increases in mitral regurgitation are uncommon. Because BMV can incompletely relieve obstruction and increase mitral regurgitation, it will not be definitive in most patients but will usually delay MV replacement to accommodate a larger prosthesis.

Comparison of mechanical and biological prostheses when used to replace heart valves in children and adolescents with rheumatic fever

OBJECTIVE

To assess the outcomes in children and adolescents with rheumatic fever of the implantation of mechanical as opposed to biological heart valves.

METHODS

We assessed 73 patients with rheumatic heart disease under the age of 18 years, who underwent replacement of heart valves between January, 1996, and December, 2005, at the National Institute of Cardiology in Rio de Janeiro, Brazil. Of the group, 71 patients survived, and were divided into a group of 52 receiving mechanical prostheses, and 19 with biological prostheses. We compared endpoints between the groups in terms of mortality, reoperation, haemorrhage, and stroke. Survival curves were estimated using the Kaplan-Meier method and were compared by the Mantel (log-rank) test.

RESULTS

Overall mortality was 8.2%. In those receiving mechanical prostheses, 2 (3.8%) patients died, 5 (9.6%) underwent reoperation, 2 (3.8%) suffered severe haemorrhage, and 3 (5.8%) had strokes. In those receiving biological valves, 2 (10.5%) patients died, and 4 (21%) underwent reoperation. After 2, 4, and 8 years, overall survival was 96%, 93% and 86%, respectively, with a borderline difference between the groups (p = 0.06). The probabilities of remaining free from reoperation (p = 0.13), and from combined endpoints, showed no statistically significant difference between the groups (p = 0.28).

CONCLUSIONS

Patients with mechanical prostheses had lower mortality and required fewer reoperations, but when all combined endpoints were considered, the groups did not differ. The biological prosthesis proved to be a good option for cardiac surgery in children and adolescents with difficulties or risks of anticoagulation.

Outcomes of reparative and transplantation strategies for multilevel left heart obstructions with mitral stenosis

BACKGROUND

Conventional management for multilevel left heart obstructions and mitral stenosis (Shone's complex) involves multiple operations that carry additive risks. This study reviews our experience with reconstructive and transplantation approaches for Shone's complex.

METHODS

Between 1987 and 2007, 43 patients with mitral stenosis and one or more left-sided obstructions were identified: supramitral ring (n = 13), subaortic stenosis (n = 25), aortic stenosis (n = 24), hypoplastic arch (n = 20), and coarctation (n = 38). Thirty patients underwent a staged reparative approach, including 27 mitral and 51 left ventricular outflow tract operations. Thirteen patients were referred for transplantation. Patients with severe hypoplasia of the left ventricle were excluded.

RESULTS

There was one in-hospital death (2.5%) and six late deaths (14.2%). Actuarial 5- and 10-year survival for staged surgical and transplantation was 88% vs 61.3% and 83.1% vs 61.3% (p = 0.035). At a mean follow-up of 7.9 years, freedom from mitral reoperation was 83.3% and freedom from reoperation for subaortic stenosis was 78.0%. Wait-list mortality was 13.3% (2 of 13). Wait-list time exceeding 90 days was an incremental risk factor for death after transplantation (p = 0.005).

CONCLUSIONS

Despite the challenges of a reparative strategy for Shone's complex, favorable survival and durability outcomes can be expected. Heart transplantation, although avoiding the pitfalls of staged repair, confers increased risks from ongoing physiologic derangements due to uncorrected left heart inflow and outflow obstructions during the wait for donor heart availability.

[Surgical management with mitral valve replacement in young infants with congenital mitral valve diseases and complete atrioventricular septal defect]

OBJECTIVES

The mechanical valve replacement may be the only option if the failing mitral valve cannot be repaired in complete AV septal defect (CAVSD), or congenital mitral valve stenosis and regurgitation in infants. In young infants the small mitral annulus-prosthesis mismatch is a big problem.

AIM

To assess the possibility of the left AV orifice repair and the necessity of mechanical valve replacement in CAVSD in young infants.

METHODS

Single center, retrospective study of 82 infants (13 pts under 3 months) who underwent complete repair of CAVSD between 2001 and 2007. Mechanical (bileaflet) valve replacement was required in 7 pts (5 weeks-7 months, 3.5-5 kg). The time interval between the two operations was 0-7 days, but the smallest baby spent 38 days in the intensive care unit waiting for increasing of his mitral annulus size from 11 to 15 mm. (Types of implanted valves: 2 Carbomedics 16 mm, 3 ATS 16 mm, 1 Sorin 17 mm, 1 Sorin 19 mm.) ATS 16 mm valves were implanted in 2 infants each with congenital mitral valve stenosis and regurgitation.

RESULTS

Early mortality (30 days) was 0, but 2 pts died in sepsis on the 46th and 71st postoperative day, respectively. In the follow-up period of 1-6 (mean 3) years 1 child (18 months later) needed reoperation (pannus removal), now all pts are doing well. Anticoagulation therapy was difficult in some cases without complication.

CONCLUSIONS

The surgical repair of congenital mitral valve diseases and CAVSD can be performed successfully in very young infants. If the anatomic characteristics of the mitral valve is not suitable for repair, only mechanical mitral valve replacement can be performed successfully even in sometimes hopeless situation (one of our pts of 3.5 kg weight, is the smallest baby mentioned in the literature). Our early and mid-time results are good, but the re-replacement will be an unavoidable problem in the future.

Antithrombotic therapy in neonates and children: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)

This chapter about antithrombotic therapy in neonates and children is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs, and Grade 2 suggests that individual patient values may lead to different choices (for a full understanding of the grading, see Guyatt et al in this supplement, pages 123S-131S). In this chapter, many recommendations are based on extrapolation of adult data, and the reader is referred to the appropriate chapters relating to guidelines for adult populations. Within this chapter, the majority of recommendations are separate for neonates and children, reflecting the significant differences in epidemiology of thrombosis and safety and efficacy of therapy in these two populations. Among the key recommendations in this chapter are the following: In children with first episode of venous thromboembolism (VTE), we recommend anticoagulant therapy with either unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) [Grade 1B]. Dosing of IV UFH should prolong the activated partial thromboplastin time (aPTT) to a range that corresponds to an anti-factor Xa assay (anti-FXa) level of 0.35 to 0.7 U/mL, whereas LMWH should achieve an anti-FXa level of 0.5 to 1.0 U/mL 4 h after an injection for twice-daily dosing. In neonates with first VTE, we suggest either anticoagulation or supportive care with radiologic monitoring and subsequent anticoagulation if extension of the thrombosis occurs during supportive care (Grade 2C). We recommend against the use of routine systemic thromboprophylaxis for children with central venous lines (Grade 1B). For children with cerebral sinovenous thrombosis (CSVT) without significant intracranial hemorrhage (ICH), we recommend anticoagulation initially with UFH, or LMWH and subsequently with LMWH or vitamin K antagonists (VKAs) for a minimum of 3 months (Grade 1B). For children with non-sickle-cell disease-related acute arterial ischemic stroke (AIS), we recommend UFH or LMWH or aspirin (1 to 5 mg/kg/d) as initial therapy until dissection and embolic causes have been excluded (Grade 1B). For neonates with a first AIS, in the absence of a documented ongoing cardioembolic source, we recommend against anticoagulation or aspirin therapy (Grade 1B).

Mitral valve replacement in infants and children 5 years of age or younger: evolution in practice and outcome over three decades with a focus on supra-annular prosthesis implantation

OBJECTIVE

Successful mitral valve replacement in young children is limited by the lack of small prosthetic valves. Supra-annular prosthesis implantation can facilitate mitral valve replacement with a larger prosthesis in children with a small annulus, but little is known about its effect on the outcomes of mitral valve replacement in young children.

METHODS

One hundred eighteen children underwent mitral valve replacement at 5 years of age or younger from 1976-2006. Mitral valve replacement was supra-annular in 37 (32%) patients.

RESULTS

Survival was 74% +/- 4% at 1 year and 56% +/- 5% at 10 years but improved over time (10-year survival of 83% +/- 7% from 1994-2006). Factors associated with worse survival included earlier mitral valve replacement date, age less than 1 year, complete atrioventricular canal, and additional procedures at mitral valve replacement, but not supra-annular mitral valve replacement. As survival improved during our more recent experience, the risks of supra-annular mitral valve replacement became apparent; survival was worse among patients with a supra-annular prosthesis after 1991. A pacemaker was placed in 18 (15%) patients within 1 month of mitral valve replacement and was less likely in patients who had undergone supra-annular mitral valve replacement. Among early survivors, freedom from redo mitral valve replacement was 72% +/- 5% at 5 years and 45% +/- 7% at 10 years. Twenty-one patients with a supra-annular prosthesis underwent redo mitral valve replacement. The second prosthesis was annular in 15 of these patients and upsized in all but 1, but 5 required pacemaker placement for heart block.

CONCLUSIONS

Supra-annular mitral valve replacement was associated with worse survival than annular mitral valve replacement in our recent experience. Patients with supra-annular mitral valve replacement were less likely to have operative complete heart block but remained at risk when the prosthesis was subsequently replaced.

Replacement of the systemic atrioventricular valve with a mechanical prosthesis in children aged less than 6 years: Late clinical results of survival and subsequent replacement

OBJECTIVE

We analyzed the survival, clinical course, and role of prosthesis-patient mismatch after systemic atrioventricular valve replacement in children.

METHODS

From 1974 to 2006, 69 patients underwent systemic atrioventricular valve replacement (median age 1.2 years, range 1.1 months to 5.4 years), with 17 patients requiring re-replacement of the systemic atrioventricular valve. Prosthesis-patient relationship was analyzed by comparing (1) the prosthetic valve diameter and the predicted annulus diameter based on the body surface area and (2) the prosthetic valve diameter and the measured annulus diameter.

RESULTS

Survival was 73% at 1 year and 65% at 5, 10, and 15 years. Age, weight, body surface area, predicted annulus diameter, prior surgery, underlying disease, and ratio of prosthetic valve diameter to body weight were significant predictors of death. Variables associated with re-replacement of the systemic atrioventricular valve were body surface area, prosthetic valve diameter, predicted annulus diameter, and presence of multiple left-sided obstructive lesions. The majority of patients received a prosthesis larger than the predicted annulus diameter. There was good correlation between the prosthetic valve diameter and the measured annulus diameter (r = 0.85). Mismatch, as described by the difference in z scores of prosthetic valve diameter and measured annulus diameter, was not a significant predictor of death or re-replacement of the systemic atrioventricular valve.

CONCLUSIONS

Although valve replacement is considered the last therapeutic option after failed attempts of valvuloplasty, long-term outcome is favorable. Selection of the prosthesis is made on the basis of the measured annulus diameter. An elevated ratio of prosthetic valve diameter to body weight is associated with patients with low body weight or a large native annulus in dilated ventricles.

When reconstruction fails or is not feasible: valve replacement options in the pediatric population

Valvular pathology in infants and children poses numerous challenges to the pediatric cardiac surgeon. Without question, valvular repair is the goal of intervention because restoration of valvular anatomy and physiology using native tissue allows for growth and a potentially better long-term outcome. When reconstruction fails or is not feasible, valve replacement becomes inevitable. Which valve for which position is controversial. The goal of this article is to address valve replacement options for all four valve positions within the pediatric population. We will draw from our institutional experience and review current literature to support our preferences.

Medium-term follow-up of mechanical valves inserted in children

OBJECTIVE

We reviewed our experience with mechanical valves inserted between 1988 and 2002 in children aged 15 years or younger.

METHODS

Hospital files were extracted retrospectively. Follow-up was completed by March 2005.

RESULTS

Of 41 patients, we inserted a valve in atrioventricular position in 27 children, having a median age of 3.1 years, ranging from 0.4 to 14.5 years, and in aortic position in the remaining 14, having a median age of 13.5 years, and a range from 7.0 to 14.9 years. For the valves inserted in atrioventricular position, the underlying disease was congenital in 23, rheumatic in two, post-endocarditic in one, and Marfan's syndrome in one. Mean follow-up was 7.7 years, with standard deviation of 5.3, giving a total follow-up of 209 patient years. Mortality at 30 days was 7%, and survival was 73% at up to 16 years follow-up. Events related to anticoagulation were seen in 3 patients, corresponding to 1.4% per patient year. In 6 patients (22%), heart block ensued which required implantation of a pacemaker treatment, and 5 patients (19%) had reoperations. For the implantations in aortic position, the underlying disease was congenital in 13, stenosis in 10 and insufficiency in three, and post-endocarditis in one. Mean follow-up was 6.8 years, with standard deviation of 4.6, giving a total of 95 patient years. We lost one patient within 30 days (7.7% mortality), and survival was 77% at up to 13 years follow-up. There were no incidents of thrombosis, nor events related to anticoagulation, but one patient (7%) needed insertion of a pacemaker due to a perioperative heart block, and one (7%) required new valvar replacement.

CONCLUSIONS

Although preferably avoided, mechanical valves can be implanted in children with an acceptable mortality and morbidity, and good long-term results.

Systemic mechanical heart valve replacement in children under 16 years of age

We report the early and late outcome following left-sided mechanical heart valve replacement in children. Between 10/1981 and 02/2001, 27 children (13 male, mean age 7.2 +/- 5.2 years, range 0.53-15.7 years) underwent mechanical mitral (MVR 16), aortic (AVR 9) or double valve replacement (DVR 2) with St. Jude Medical valves. Eighteen children (66.7%) had undergone previous cardiac surgery. Valve disease was congenital in 23, due to endocarditis in 2 and rheumatic in 2 patients. Concomitant cardiac surgery was performed in 12 patients (44.4%). Operative mortality was 3.7% (1/27). Perioperative complications were complete heart block (5) and myocardial infarction (1). Mean follow-up was 6.5+/-5.9 years (range 0.4-19 years, total 169.9 patient-years). There was one valve-related late death due to mitral valve thrombosis without phenprocoumon. Actuarial survival after 1, 5 and 10 years was 93, 93 and 93%. Late complications included endocarditis (2), minor hemorrhagic event (1) and stroke (1). Overall 10-year freedom from any anticoagulation-related adverse event under phenprocoumon was 91% (1.3%/patient year). Eight patients required reoperations: re-MVR (5; outgrowth of the prostheses (3), pannus overgrowth (2)), closure of paravalvular leak after AVR (2), and re- DVR (1; endocarditis). Actuarial freedom from reoperation after 1, 5 and 10 years was 96, 88 and 76%.

CONCLUSION

Mechanical valve prostheses are a valuable option for left-sided heart valve replacement in pediatric patients with good results. Operative mortality and the incidence of any valve-related events as endocarditis, reoperation, thromboembolism or anticoagulation related bleeding is acceptable.

Congenital mitral valve surgery: techniques and results

PURPOSE OF REVIEW

Congenital lesions of the mitral valve are rare. Conservative surgery is recognized as the best option. In complex anatomy, however, replacement is the only solution to achieve an acceptable result. This review aims to study the long-term follow-up of classical treatments, conservative or replacement, and to examine new technical advances.

RECENT FINDINGS

The long-term results of conservative surgery are confirmed with a low incidence of reoperation except in mitral valve stenosis. The Ross II operation using a pulmonary autograft is a difficult technique that may be useful in the youngest patient group when prosthetic devices cannot be used.

SUMMARY

In the last few years, surgery of congenital mitral valve lesions has gained from echocardiography, which shows the exact function and anatomy of the mitral valve. The tendency is to avoid multistage operations. Valve replacement by biologic material (Ross II) is still under clinical evaluation.

Mitral valve replacement in children under 3 years of age

OBJECTIVE

This study was undertaken to review our experience of mitral valve replacement in children under 3 years of age.

METHODS

Between January 1990 and May 2004, 18 patients under 3 years of age underwent a total of 20 mitral valve replacements using a bileaflet mechanical prosthetic valve. There were 9 males and 11 females. The age at surgery ranged from 3 months to 3 (mean=1.02 +/- 0.72) years and body weight varied between 3.4 and 13.2 (mean=7.08 +/- 2.74) kg.

RESULTS

There were 4 early and 2 late deaths, and these occurred in severe cases aged less than 1 year of age. Re-replacement of mitral valve was required in 3 patients (valve thrombosis in 2 and pannus formation in 1). Orifice size of the implanted prosthesis (OS) as compared with the predicted normal size of the mitral valve (NS) was well correlated with maximum transprosthetic flow velocity estimated by Doppler echocardiography. In this study, the OS/NS>0.65 was maintained in all patients, and none required re-replacement because of prosthesis-patient mismatch.

CONCLUSION

Patients less than 1 year of age had significant mortality and morbidity. The results were satisfactory in the remainder (1-3 years). During this follow-up period, none required re-replacement due to somatic growth, but it will be an unavoidable problem in the future. The OS/NS, which can be checked with a regular physical examination, may serve as a guide to determine the most appropriate timing for the second surgery.

Development of left atrioventricular valve regurgitation after correction of atrioventricular septal defect

BACKGROUND

Left-sided atrioventricular valve regurgitation is the main indication for reoperation in patients after repair of both partial and complete atrioventricular septal defect. Until now, the timing for reoperation is difficult. We sought to determine the outcome of severe residual left-sided atrioventricular valve regurgitation, either medically treated or reoperation. In this regard risk factors were determined for severe residual left-sided atrioventricular valve regurgitation and reoperation, and the most appropriate strategy for patients with postoperative severe left-sided atrioventricular valve regurgitation was identified.

METHODS

Retrospective review of clinical, operative, and echocardiographic data was performed. From 1990 until 2001 164 patients underwent correction of their atrioventricular septal defect.

RESULTS

Five patients died in the immediate postoperative period, and 2 patients were lost to follow-up. During follow-up (median, 66 months; range, 9 months to 12 years), 30 patients (19%) had severe left-sided atrioventricular valve regurgitation. Sixteen patients had severe left-sided atrioventricular valve regurgitation in the immediate postoperative period; 4 of them showed spontaneous regression to near-normal valve function during follow-up. Fourteen patients exhibited left-sided atrioventricular valve regurgitation during follow-up; 8 of them remained stable with medication only. Fifteen of the 30 patients with severe left-sided atrioventricular valve regurgitation underwent reoperation. A significant risk factor for the development of severe left-sided atrioventricular valve regurgitation and reoperation was the presence of preoperative severe left-sided atrioventricular valve regurgitation.

CONCLUSIONS

Severe left-sided atrioventricular valve regurgitation develops in a significant number of patients after correction of atrioventricular septal defect, and preoperative severe left-sided atrioventricular valve regurgitation is an important risk factor. Although reoperation usually results in good valve function, spontaneous regression after the immediate postoperative period is possible and should be given a fair chance.

Current Management of Severe Congenital Mitral Stenosis

Background— Severe congenital mitral stenosis (MS) is a rare anomaly that is frequently associated with additional left heart obstructions. Anatomic treatments for congenital MS include balloon mitral valvuloplasty (BMVP), surgical mitral valvuloplasty (SMVP), and mitral valve replacement (MVR), although the optimal therapeutic strategy is unclear.

Methods and Results— Between 1985 and 2003, 108 patients with severe congenital MS underwent BMVP or surgical intervention at a median age of 18 months (range 1 month to 17.9 years). Anatomic subtypes of MS were “typical” congenital MS in 78 patients, supravalvar mitral ring in 46, parachute mitral valve in 28, and double-orifice mitral valve in 11, with multiple types in ≈50% of patients. Additional left heart anomalies were present in 82 patients (76%). The first MS intervention was BMVP in 64 patients, SMVP in 33, and MVR in 11. BMVP decreased peak and mean MS gradients by a median of 33% and 38%, respectively ( P <0.001), but was complicated by significant mitral regurgitation in 28%. Cross-sectional follow-up was obtained at 4.8±4.2 years. Overall, Kaplan-Meier survival was 92% at 1 month, 84% at 1 year, and 77% at 5 years, with 69% 5-year survival during the first decade of our experience and 87% since ( P =0.09). Initial MVR and younger age were associated with worse survival. Survival free from failure of biventricular repair or mitral valve reintervention was 55% at 1 year among patients who underwent BMVP and 69% among patients who underwent supravalvar mitral ring resection initially. Among patients who underwent BMVP, survival free from failure of biventricular repair or MVR was 79% at 1 month and 55% at 5 years, with worse outcome in younger patients and those who developed significant postdilation mitral regurgitation.

Conclusions— BMVP effectively relieves left ventricular inflow obstruction in most infants and children with severe congenital MS who require intervention. However, surgical resection is preferable in patients with MS due to a supravalvar mitral ring. Five-year survival is relatively poor in patients with severe congenital MS, with worse outcomes in infants and patients undergoing MVR, but has improved in our more recent experience. Many patients have undergone second procedures for either recurrent/residual MS or mitral regurgitation resulting from dilation-related disruption of the mitral valve apparatus.

Redo Mitral Valve Replacement in Children

BACKGROUND

Despite excellent results with current techniques of mitral valve repair, some children still require mitral valve replacement (MVR). Of necessity, a certain percentage of these children need valve rereplacement (redo MVR).

METHODS

Of 82 MVRs at our institution since 1988, 22 were redo MVRs in 21 children aged 1.4-21 years (mean 9.8 +/- 5.6 years). Interval from initial MVR was 1 month to 18 years (mean 5.8 +/- 4.9 years). Reoperation indication was primarily stenosis in 13 (usually pannus formation), regurgitation in 4, valve thrombosis or embolism in 4, and endocarditis in 1. The initial valve was mechanical in 18 and xenograft in 4.

RESULTS

During redo MVR, 8 of 22 (36%) patients had additional procedures including left ventricular outflow tract obstruction relief or aortic valve replacement in 4 and tricuspid valve repair in 2. The new mitral valve was mechanical in 20 and xenograft in 2. Median valve size increased from 21 mm to 25 mm although 7 valves were not upsized on rereplacement (average valve size increase was 3.3 +/- 1 mm). Only 2 patients (9%) needed a new pacemaker. There were no hospital deaths. Six children developed end-stage heart failure and underwent successful cardiac transplantation 3 to 32 (mean 12.1 +/- 10.0) months, postoperatively. On follow-up of 1 month to 7.7 years (mean 2.5 +/- 2.3 years) there has been only one late death of an unrecognized coronary artery anomaly.

CONCLUSIONS

Redo MVR in children can be performed safely with low morbidity and mortality. A larger prosthesis can often be placed in these children. A surprisingly high percentage of patients eventually require transplantation, perhaps reflecting unnecessary delay in referral for redo MVR.

Complications of supra-annular mitral valve placement in infants

Two infants underwent supra-annular placement of prosthetic mitral valves. The objective of this strategy was to insert a larger valve and delay replacement. This approach was initially successful but by two and three years later the patients developed impairment of cardiac function. The prosthesis decreased the volume and compliance of the left atrium causing high left atrial and pulmonary venous pressures. The "ventricularised" atrium below the prosthesis dilated. In neither case was it possible to delay second valve replacement.

Late results after mitral valve replacement with bileaflet mechanical prosthesis in children: evaluation of prosthesis-patient mismatch

BACKGROUND

Mechanical prosthesis is the choice of valve at the mitral position in children, although re-replacement of prostheses because of prosthesis-patient mismatch is almost inevitable when prostheses were implanted in small children. The methods to predict prosthesis-patient mismatch as a result of patients' somatic growth or pannus formation in children by noninvasive methods have not been well established.

METHODS

Thirty-two children underwent mitral valve replacement with 37 bileaflet mechanical prostheses (26 St. Jude Medical prosthetic valves, and 11 CarboMedics prosthetic valves) and were followed up a mean of 6.8 years (maximum 18.3 years) with a complete follow-up rate of 94%.

RESULTS

There were no operative deaths and 5 late deaths. Re-replacement of mitral valve because of prosthesis-patient mismatch was required in 5 patients. Freedom from valve-related events and re-replacement of mitral valve at 15 years were 32% +/- 23% and 54% +/- 18%, respectively. Actuarial survival rate was 63% +/- 19% at 15 years. Prosthetic valve orifice area index (manufactured geometric prosthetic valve area divided by patient's body surface area) was well correlated with maximum transprosthesis flow velocity estimated by Doppler echocardiography during follow-up, whereas valve orifice area index had no significant correlation with pulmonary artery wedge pressure assessed by cardiac catheterization. Maximum transprosthesis flow velocity had a significant correlation with pulmonary artery wedge pressure.

CONCLUSIONS

Valve orifice area index itself was not a reliable index to predict prosthesis-patient mismatch. Maximum transprosthesis flow velocity was a useful index to predict pulmonary artery wedge. Invasive cardiac catheterization to determine re-replacement of the prosthesis should be considered when maximum transprosthesis flow velocity exceeds 270 cm/s.

Quality of life in children following mitral valve replacement

OBJECTIVE

To measure the health related quality of life (QoL) following mitral valve replacement in childhood.

DESIGN

Cross sectional study.

SETTING

Tertiary referral centre.

METHODS

19 patients, median age (range) 14.4 (9.7-25.4) years, were studied at a median of 7.6 (0.5-11.2) years after their most recent mitral valve replacement. General health status was measured using age specific validated questionnaires. Ten children aged between 9-15 years completed the child health related quality of life questionnaire, and for nine older patients the UK version of the short form 36 was used. Specific questions were added to the existing questionnaires to study the effect of long term anticoagulation treatment.

RESULTS

All patients in the younger age group reported impaired QoL. Five rated their QoL within the range of children with chronic physical disabilities, and in the remaining five it was worse. In the older age group, all but two patients perceived their QoL as normal or near normal compared with a reference population matched for sex and age. Having regular blood tests had a negative effect on QoL in three young children, and one older patient reported impaired QoL related to taking daily warfarin tablets.

CONCLUSIONS

In this small group, the effect of mitral valve replacement on QoL appears to be age specific, with more impairment in younger children. Long term anticoagulation treatment is well tolerated in most patients.