Transplantation for adults with congenital heart disease.

Heart transplantation is a recognised treatment for end-stage heart failure of any cause including congenital heart disease. Congenital heart disease has contributed relatively little to the adult heart transplant activities in the past two decades. However, this is likely to change as an increasing number of children with congenital heart disease reach adulthood because of the advances in paediatric cardiology and surgery. Some of these grown-ups with congenital heart disease (GUCH patients) will need transplantation for late myocardial dysfunction either secondary to uncorrected lesions, or despite previous repair or palliative surgery. These patients are managed along the same clinical principles as those with cardiac failure of other aetiologies, despite the lack of any evidence to support this approach. Nevertheless, they introduce new challenges. First, some may have pulmonary vascular disease and require heart-lung transplantation, or lung transplantation combined with repair of their cardiac defects. Second, those with failing Fontan circulation are usually much sicker than other transplant candidates, with protein-losing enteropathy along with renal and hepatic dysfunction. Third, a suitable donor organ may not be found due to elevated levels of antibodies in response to previous blood transfusions and possibly the previous implantation of homografts. Fourth, the operation may be technically difficult because of the presence of adhesions secondary to previous operations, collaterals, and unusual anatomy. Fifth, postoperative care may be complicated because of predisposition to bleeding, infection and pulmonary hypertension, and the presence of residual aortopulmonary collaterals resulting in a significant left-to-right shunt. Despite a higher early mortality, the overall results of heart transplantation so far have been encouraging with survivals similar to that of adults with acquired heart disease and that of the paediatric population. However, this may change as the proportion of high-risk patients (failing Fontans) increases. GUCH patients with Eisenmenger's syndrome may be offered lung transplantation with repair of the cardiac defect or heart-lung transplantation. However, because of the limited success of these approaches, and improved management of pulmonary hypertension, patient selection remains difficult.     

Assessment of operability for common arterial trunk without cardiac catheterisation

Pulmonary vascular disease is a risk factor for the surgical management of common arterial trunk. Surgical repair, therefore, is usually performed in early infancy, before irreversible changes can occur in the epulmonary vasculature. Because of this, there has been an increasing tendency to dispense with cardiac catheterisation as a means of assessing pulmonary vascular disease. Cardiac catheterisation, nonetheless, is still performed when there is a risk of pulmonary vascular disease, such as in older children. There are no clear guidelines, however, as to who should be catheterised. We have developed a simple screening test to help make this decision.     

Congenitally corrected transposition: size of the pulmonary trunk and septal malalignment

BACKGROUND: In hearts with congenitally corrected transposition of the great arteries, the atrial and ventricular septums are usually malaligned. This is associated with an abnormal location of the atrioventricular conduction system. However, well-aligned septums and normally positioned atrioventricular conduction tissues have been found in a few cases, some of which also happened to have a small or atretic pulmonary trunk. Our aim was to determine whether septal alignment could be predicted on the basis of the size of the pulmonary trunk. Potentially this could provide a guide to the disposition of the atrioventricular conduction tissues. METHODS: We examined 14 hearts. In all cases there was usual atrial arrangement. We carried out histologic examination of the sites of the atrioventricular conduction tissues in 1 heart. RESULTS: We found a statistically significant correlation between the size of the pulmonary trunk and the degree of septal malalignment. In the presence of a small or atretic pulmonary trunk, the septums were well aligned. Our histologic study of one such specimen revealed dual atrioventricular nodes connecting to a sling of conduction tissue. This suggests that presence of a postero-inferiorly situated atrioventricular conduction bundle in addition to an anteriorly located bundle may be anticipated when the septums are well aligned. CONCLUSIONS: The presence of a small or atretic pulmonary trunk in congenitally corrected transposition of the great arteries is associated with good septal alignment. This should alert the surgeon to the possibility of a slinglike arrangement of the atrioventricular conduction system.     

A simple model to predict coronary disease in patients undergoing operation for mitral regurgitation

BACKGROUND: Coexistent coronary disease can be identified in a third of patients with mitral valve disease. This study aims to evaluate candidate selection strategy using risk factor identification and logistic regression and to develop an additive model for the prediction of coexistent coronary disease. METHODS: The sample is a consecutive series of patients who had mitral repair from 1987 to 1999. Sensitivities and specificities were calculated for each risk factor. Variables for prediction of coronary disease were entered into a univariate analysis, and predictors were entered into a forward and backward stepwise multivariate logistic regression model to form a predictive score. An additive model was derived from transformation of the logistic model. Receiver operating characteristic curves were used to compare discrimination and precision quantified by the Hosmer-Lemeshow statistic. RESULTS: The American Heart Association and American College of Cardiology risk factor identification selection criteria for the 359 patients who had screening coronary angiography yielded 100% sensitivity and 1% specificity. Risk prediction with our logistic model produced a receiver operating characteristic curve area of 0.91 and Hosmer-Lemeshow score of 3.4 (p = 0.9). Similar discriminating ability for our patients was achieved by the Cleveland Clinic logistic model (receiver operator characteristic curve area of 0.79; Hosmer-Lemeshow score of 12; p = 0.1). Our five-item additive model produced receiver operating characteristic curve area of 0.91 and Hosmer-Lemeshow score of 3.81 (p = 0.80). CONCLUSIONS: Simple risk factor identification has excellent sensitivity but is limited by specificity. Logistic regression modeling is an accurate risk prediction method but is difficult to apply at the bedside. Simplicity and accuracy may be achieved by the logistic regression-derived simple additive model.     

The impact of altitude on early outcome following the Fontan operation

Background  

The success of a Fontan circulation depends on several factors including low pulmonary vascular resistance. Pulmonary vascular resistance rises in response to hypoxia. Hypoxia is associated with altitude. Therefore, we wondered whether altitude is a risk factor for early failure after the Fontan operation. The aim was to test this hypothesis.     

Prediction of Mortality in Pediatric Burn Injuries: R-Baux Score to Be Applied in Children (Pediatrics-Baux Score)

Objective

R-Baux score has obtained an acceptable validity and accuracy in predicting burn-related mortality. However, its usage and efficacy among pediatric burn patients has not been well documented. The aim of this study was to employ Pediatrics-Baux (P-Buax) score as modified version of R-Baux score in these patients to determine how it could be applicable in this population.

Methods

Through a prospective study, 870 pediatric burn patients were enrolled. P-Baux and R-Baux scores were calculated for each patient and they were categorized to different groups according to these scores. Mortality and further death probability were measured for each subject and then analyzed by logistic regression model to reveal how they change in relation with age in pediatric burn patients.

Findings

R-Baux score for 95% probability of death revealed a mean of 73 among patients of this study. Also P-Baux score was measured in these patients with inhalation injury which showed to be 55 for 95% probability of death. Results showed that age had a positive prognostic value in contrast to the negative prognostic value of Total Body Surface Area (TBSA) and inhalation injury.

Conclusion

Our analysis showed that in children under the age of 15 years, age has a positive prognostic value while TBSA and inhalation injuries had negative prognostic values in relation to mortality. Hence, in contrast to the adult population, burn injury related mortality may be predicted by modified R-Baux score as (TBSA - age + [18×R]) which could be named as P-Baux score.     

Efficacy of a flowable concentrate formulation of Bacillus thuringiensis (H-14) against larval mosquitoes in southern Iran.

A flowable concentrate formulation of Bacillus thuringiensis (H-14) [Bactimos FC (1000 ITU/mg)] was evaluated for the control of mosquito larvae in simulated ponds and natural breeding sites in Kazeroun (Fars Province), southern Iran. A comparison was made with Abate emulsifiable concentrate. Bactimos FC caused 93-96% anopheline and 97% culicine larval mortality 24 h posttreatment in simulated ponds and natural breeding sites, when used at the rate of 0.2 cc/m2. Abate (0.015 cc/m2) resulted in significantly higher anopheline (98.1%) and culicine (100%) mortality at 24 h posttreatment. There was a relatively sharp decline in larval mortality 48 h posttreatment when Bactimos FC was applied. Five-day applications were suggested to prevent pupal production.