Congenital Cardiac Patients Research Articles

The grown-up congenital cardiac patient

Long-term survival of patients with congenital heart disease has dramatically improved during the last 50 years and the number of adults with congenital heart disease is therefore increasing in all developed countries. Grown-up patients with congenital heart disease (GUCH) often present difficult and challenging problems. Patients with both native unoperated and operated malformations contribute to the GUCH population. Survivors without surgical treatment mainly have simple malformations; but a few have complex diseases, and some have survived with secondary pulmonary hypertension. Among operated malformations there are patients with a 'complete' repair (anatomical and physiological), others with a definitive palliation (physiological repair) and some with a simple palliation. The clinical spectrum is obviously diversified, depending on the underlying anomaly, surgical outcome, presence of residua, sequelae and/or complications, length of follow-up, comorbidities. Arrhythmias, bacterial endocarditis, cyanosis, polycythemia, heart failure, anomalies of pulmonary circulation, deterioration or malfunction of devices, need of cardiac and non-cardiac surgery, intercurrent non-cardiac diseases, and a need for cardiac and non-cardiac diagnostic procedures are common problems of adults with congenital heart disease. Physiological events such as pregnancy and childbearing deserve a careful multidisciplinary approach. While most simple native and well corrected GUCH do not require very specialized treatments throughout their life, the abnormalities and complexities of postoperative anatomy are often beyond the expertise of the adult cardiologist, requiring multidisciplinary competence in specialized tertiary centers. The problem is still unresolved and involves cultural, medical, technological and economically relevant issues.

Successful extracardiac total cavo pulmonary connection (TCPC) after external tracheobronchial stenting for tracheobronchomalacia

A girl who was diagnosed with cyanotic congenital heart disease in a newborn, showed anoxic spell attacks which we thought were correlated with the congenital heart disease. Although she underwent the palliative operation at 8 months old and her SpO2 was increased, she experienced severe and life-threatening respiratory dysfunction many times after that. After careful examinations, the respiratory complaint was proved to be not only due to cyanotic congenital heart disease but also tracheobronchomalacia. She had undergone the external stenting to the trachea and right bronchus at 1 year old. After that, she was examined by cardiac catheterization and the Fontan-type operation was successful using a tissue-engineered graft at 2 years old. Her post-operative course was uneventful and she was discharged. It is very important to remember the possible existence of tracheobronchomalacia and prevent a life-threatening attack when congenital cardiac patients experience a prolonged respiratory failure or abnormal respiration.

Prioritization of congenital cardiac surgical patients using fuzzy reasoning – a solution to the problem of the waiting list?

Surgical waiting lists are of high importance in countries, where the national health system is unable to deliver surgical services at a rate that would allow patients to avoid unnecessary periods of waiting. Prioritization of these lists, however, is frequently arbitrary and inconsistent. The objective of our research was to analyze the medical decision-making process when prioritizing patients with congenital cardiac malformations for cardiac surgical procedures, identifying an appropriate representation of knowledge, and transferring this knowledge onto the design and implementation of an expert system ("PrioHeart"). The medical decision-making process was stratified into three stages. The first was to analyze the details of the procedure and patient to define important impact factors on clinical priority, such as the risk of adverse events. The second step was to evaluate these impact factors to define an appropriate "timing category" within which a procedure should be performed. The third, and final, step was to re-evaluate the characteristics of individual patients to differentiate between those in the same timing category. We implemented this decision-making process using a rule-based production system with support for fuzzy sets, using the FuzzyCLIPS inference engine and expert system shell as a suitable development environment for the knowledge base. The "PrioHeart" expert system was developed to give paediatric cardiologists a tool to allow and facilitate the prioritization of patients on the cardiosurgical waiting list. Evaluation of "PrioHeart" on limited sets of patients documented appropriate results of prioritization, with a significant correlation between the prioritization made using "PrioHeart" and those results obtained by the individual consultant specialist. We conclude that our study has demonstrated the feasibility of using an expert system approach with a fuzzy, rule-based production system to implement the prioritization of cardiac surgical patients. The approach may potentially be transferable to other medical subspecialities.

Risk stratification with the aristotle score and the risk adjusted congenital heart surgery scoring system

Aims: The Risk Adjusted Congenital Heart Surgery (RACHS) system and the Aristotle Score were developed to compare outcomes of congenital cardiac surgical patients. Both scoring systems have not been validated independently.

Abnormal Platelet Function Is Common in Pediatric Congenital Cardiac Surgery Patients.

Background: Hemostasis in cardiac surgery patients requires functional platelets. Acquired platelet function defects are well recognized in high shear aortic lesions in adults and have been described in some congenital cardiac patients with ventricular septal defects (VSDs) and with pulmonary hypertension. Abnormal shear flow is characteristic of many congenital cardiac defects. We hypothesized that platelet function abnormalities might be common in this patient group. The Platelet Function Analyzer -100 (PFA-100) is commonly used to test for platelet function defects. Pediatric reference ranges are the same as adult. Prolongation of closure times to collagen/epinephrine are common in patients on aspirin and related antiplatelet agents, with prolongation to collagen/ADP being characteristic of many clinically significant platelet disorders (congenital and acquired vonWillebrand's disease, other platelet function defects).Methods: We used the PFA-100 to preoperatively screen pediatric patients aged 2 mos-18 years coming to surgical repair of cardiac lesions at our institution. All aortic valve surgery patients were screened as of July 2004, and all cardiac surgery cases as of Jan 2005. For analysis only patients with platelet counts of > 100 and hematocrits of > 28 were included. If PFA-100 closure times to collagen/epi were normal, collagen/ADP testing was not performed. For study purposes PFA-100 results were counted as abnormal only when closure times for collagen/ADP were prolonged beyond the 95% confidence intervals for normal controls. No special hematological interventions were ordered preoperatively on the basis of an abnormal PFA-100 alone.Results: PFA-100 results were available on 38 patients. 28 of 38 (74%) were abnormal, with underlying cardiac pathology strongly correlated with abnormal PFA-100 values (see table). 6 patients were on aspirin, discontinued preoperatively, and none on other antiplatelet agents. 3 of these 6 had normal PFAs to collagen/epi when tested. Although patient groups were not homogeneous, patients with abnormal PFA-100 results had higher overall intraoperative and postoperative red cell and platelet transfusion requirements on a cc/kg basis (55.3 vs 17.6 for RBCs p=.008 and 12.8 vs 6.5 for platelets p=.038). 24 hour post-operative chest tube drainage (cc/kg) did not differ between groups (23.2 vs 22.7 p=0.95). There were 2 reexplorations for hemorrage, both in patients with abnormal PFAs.Conclusions: Prevalence of platelet function abnormalities appears high in pediatric congential cardiac surgery patients. The etiology of these abnormalities is unclear and there may possibly be a correlation with aortic valve pathology and other high shear lesions. Patients with abnormal platelet function also had increased transfusion requirements. However it is unclear is this finding is related to the platelet function defect or to differences in patient age and complexity of surgery. Larger studies that better define the population at-risk for bleeding and the significance of abnormal platelet function are needed.Correlation of abnormal PFA-100 and cardiac lesion typeSurgical repair% AbnormalTotalL ventricular outflow tract and aortic valve100%9Tetralogy of Fallot100%4Other VSD repair100%4Coarctation of aorta100%2Right ventricular outflow tract and pulmonary artery stenosis86%7Operations for hypoplastic ventricles33%3AV septal defect50%2Isolated ASD closure0%4Other33%3Total38

Pharmcokinetics of Fondaparinux by Anti-Xa Levels and Clinical Response to Anticoagulation in a 4-Month Old Congenital Cardiac Patient with Heparin-Induced Thrombocytopenia (HIT) and Established Venous Thrombosis Transitioned from Argatroban to Fondaparinux.

Our group has recently reported on heparin-induced thrombocytopenia (HIT) as an emerging cause of morbidity and mortality in pediatric cardiac surgery patients (Alsoufi, Ped Card Surg Ann of Sem Thorac Cardiovasc Surg 2004: 7: 155). This has included our experience with the off-label use of the antithrombin argatroban as an initial alternative anticoagulant to heparin in neonates and young children with HIT. Our findings indicate the incidence of HIT in pediatric patients undergoing congenital cardiac surgery to be 1–2% with a thrombotic rate of 50–60%. As with adults, children > 1 year with HIT-related thrombosis needing intermediate-to-longterm anticoagulation can be transitioned to warfarin. However stable warfarinization of children < 1 year is difficult, particularly given the feeding difficulties seen in sick congenital cardiac patients. In one such 4 month old, reported here, we successfully used the pentasaccharide fondaparinux, verifying dosage according to fondaparinux levels as measured by a specific fondaparinux curve. A 3 month old 3 kg girl with Down's syndrome underwent cardiac surgery with cardiopulmonary bypass at our institution (complete atrio-ventricular canal repair, closure of patent ductus arteriosus and patent foramen ovale). Platelets did not rise to baseline levels post-operatively and functional HIT assay was positive on postoperative day (POD) 8. All heparin was stopped and anticoagulation with argatroban initiated after obtaining parental informed consent. Due to IV access issues and necessity for pacemaker insertion argatroban was administered with interruptions. On POD 11 the patient thrombosed a PICC line in her left thigh. The line was surgically removed, but residual non-occulsive thrombus was noted by vascular ultrasound in the left common and proximal femoral veins, which persisted on reimaging 1 week later despite sustained therapeutic argatroban infusion. To facilitate outpatient management a decision was made to attempt transition to fondaparinux. Renal function was normal. After obtaining parental informed consent therapy with fondaparinux ( t 1/2 =17−l20 hr) was initiated at 0.15 mg/kg q 24 hrs on POD 23. Anti-Xa levels were drawn at 2, 4, 8 hr post injection and then at intervals on days 2, 3, 4 and 7 of fondaparinux therapy (see table). Values were referenced against both a fondaparinux and a low molecular weight heparin (lovenox) curve. Coefficient of correlation between curves: r = 0.939. The patient did well clinically on fondaparinux with no evidence of bleeding and was discharged on POD 30. Vascular ultrasound showed complete resolution of thrombus at the time of discharge. Platelets remained stable. The patient continued on outpatient fondaparinux therapy for 3 months with stable platelet counts and no clinical evidence of bleeding or rethrombosis.Response to fondaparinux by anti-Xa levelsDay of therapyHour post injectionFondaparinux Level (fondaparinux curve)Corresponding level on LMWH curveDay 120.330.4140.470.5080.60.60Day 220.70.7340.660.6980.510.51Day 3pre0.180.1950.670.60Day 4pre0.180.3320.710.72Day 520.77not done

PLAIN FILM DIAGNOSIS OF COMMON CARDIAC ANOMALIES IN THE ADULT

Congenital cardiac lesions in the adult have characteristic roentgen patterns that should be recognized by the radiologist. In other instances, abnormalities in the aorta or the position of the organs can indicate the likelihood of associated cardiac anomalies. An increasing number of congenital cardiac patients are surviving into adult life because of successful treatment. Some of the complications of these repairs can be recognized on routine chest films.

Plasma histamine profiles in paediatric cardiopulmonary bypass.

We have previously reported our findings of very high plasma histamine levels in the extracorporeal blood primes of infants undergoing cardiopulmonary bypass (CPB) for correction of congenital cardiac defects and have now extended this enquiry to examine the whole peri-operative period. In this preliminary study, samples of blood for plasma histamine were drawn from a mixed group of congenital cardiac patients featuring varying degrees of cyanosis, differing hypothermic operative conditions and utilising two oxygenator systems. Despite the diversity of this group a common pattern of histamine release emerged with a clear origin at the commencement of bypass, and continuing during the operative period. Our results suggest that priming procedures using stored donor blood provide a major contributing source of histamine release with inevitable deleterious consequences to the post-operative outcome.

Anencephaly in fetuses of mother with tetralogy of Fallot; normal infant following Blalock operation.

A few congenital cardiac patients with the tetralogy of Fallot reach adult life. These persons are usually handicapped and lead restricted lives. Pregnancy in a patient so afflicted may be attended by serious consequences in both the mother and child. Black-Schaffer1reported an infant of dwarfed stature and marasmus born to a 26-year-old mother with cyanotic congenital heart disease. Talbot2believed that most congenital malformations that were the result of lack of embryonic development were not hereditary defects but were acquired in utero. He considered that these developmental defects were due to injury to the placenta during the early weeks of pregnancy, with maternal hematogenous infection of the placental blood vessels being responsible. Talbot described 20 consecutive cases of deformed babies in which there was evidence of placental damage near the base of the cord. Six of the 20 infants were anencephalic. Ingalls and associates3in 1950

Pregnancy and subacute bacterial endocarditis

There have been 10 cases with a diagnosis of subacute bacterial endocarditis complicating pregnancy in some 50,000 patients at the New York Lying-In Hospital from 1932 through 1947. The incidence of this complication is 0.02 per cent. Three cases with positive blood cultures occurred before the use of penicillin and all died during pregnancy or the puerperium. Seven cases treated with penicillin survived pregnancy and delivered normal living children. Two of the penicillin-treated cases had clinically authentic subacute bacterial endocarditis during pregnancy unconfirmed by positive blood cultures. Five of the penicillin-treated cases were proved by positive blood cultures: three had recently recovered from the disease prior to the pregnancy under consideration, and two developed the disease during pregnancy. The five proved cases are reviewed in an attempt to evaluate the significance of subacute bacterial endocarditis prior to and during pregnancy. An outline for the management of pregnancy, delivery, and the puerperium in rheumatic and congenital cardiac patients is given.