WELCOME TO THE CHILDREN'S CARDIAC REGISTRY CENTER

Supported by the Lebanese National  Council for Scientific Research

The objective of this registry center is to study the epidemiology of cardiac disease in children and their outcome in Lebanon, a developing country.

INTRODUCTION:

Cardiac disease, including both congenital and acquired heart disease, contributes significantly to death and morbidity in children. The estimated rate of Congenital Heart Disease (CHD) and the distribution of specific lesions have been reported in different regions of the world with a frequency of 2 to 10/1000 live born infant. A number of factors influence the reported incidence of CHD, including consanguinity, ethnic background and environmental factors. The exact incidence of cardiac malformations may be difficult to determine accurately and several factors cause underestimation of the true incidence. First, there has to be an efficient medical system that allows diagnosis of these lesions and that is accessible by the whole population. Second, some congenital lesions like small Atrial Septal Defects (ASD) or Ventricular Septal Defects (VSD) may be asymptomatic and thus may not be diagnosed by ordinary clinical examination and so would not be included in any series.
Worldwide, heart disease in children continues to be a major public health problem. Largely this is because of Rheumatic Heart Disease (RHD). The incidence of rheumatic heart disease seems to be directly related to social circumstances and poverty. However, in the United States, CHD accounts for almost all heart disease in children.
The incidence of heart disease in developing countries is not clearly known. In particular, the frequency of congenital and acquired heart disease in Lebanon and their outcomes have not been well studied previously. The spectrum of CHD and its epidemiology may differ from that in the literature, possibly due to incomplete prenatal care and frequent inter-family marriage in our society.
Therefore, appropriate identification of the cardiac disease, its epidemiology, genetic background and outcome in our society is important for adequate care, allocating financial resources, research, educational and prevention policies. This study describes the epidemiology of heart disease affecting children enrolled in the Children’s Cardiac Registry Center (CCRC) established at the American University of Beirut-Medical Center.

POPULATION STUDY:

The CCRC included prospectively all patients with congenital and/or acquired heart disease, who were seen at the service of Pediatric Cardiology at the AUBMC between March 1, 1997 and July 31, 2000. A pediatric Cardiologist evaluated all patients and diagnosis was confirmed at least by echocardiography. Patients were referred from pediatricians, general practitioners, cardiologists, cardiac surgeons, outlying hospitals or self referred.To study the incidence of CHD at our center, we retrospectively reviewed all newborns with CHD born at our center during the year 1996. Stillbirth and premature infants with the diagnosis of patent ductus arteriosus were excluded from that group. We elected to study the incidence of CHD during the year 1996, since after 1996 the fetal echocardiography service at our hospital became active. A referral bias was noted after 1996, which affected the incidence of CHD at AUBMC and thus made it an inaccurate reflection of the real incidence of CHD in our society.

METHODS:

RESULTS:

The CCRC was divided into two categories. The group with congenital heart disease (CHD) and the group with acquired heart disease (AHD) were analyzed. The data about the incidence of CHD during the year 1996 at our center was reported.

Congenital Heart Disease

Age And Sex:

Out of the 1000 patients with cardiac abnormalities included in the CCRC, 917 (91.7%) had congenital heart disease. Of these, 476 patients (51.9%) were males. 406 patients (44.3%) were less than or equal to one year of age when first included in the CCRC.

Patent Ductus Arteriosus and Atrial Septal Defects were more frequently noted in females, at 67.9% and 63%, respectively. While, most of the other cardiac malformations were more noted in males. (Table 1).

Frequency of CHD:

The diagnoses listed for any event were generalized to a single diagnosis for that event, using a hierarchical system of assigning a label. These diagnoses were recorded for all events for each patient and were compared and used to assign an overall categorical diagnosis for that patient. If there was discordance among event diagnoses, the combination of data from cardiac catheterization, echocardiograms, surgery, or autopsy was used to provide the best possible diagnosis.
Defects were considered by their presumed embryonic times to establish a single principal diagnosis for each case (Table 2). This order was based on anatomic criteria without regard to clinical and hemodynamic changes. This practice was followed by the example of the New England Regional Infant Cardiac Program and the Baltimore- Washington Infant Study 1981-1989.
The frequency of congenital heart disease is shown in (Figure 1). Ventricular septal defect was the most common cardiac malformation with a relative frequency at 25.3 %, followed by pulmonary stenosis (14.6 %),aortic anomalies (8%), atrial septal defect (8 %) and  tetralogy of Fallot (7.8%). Pulmonary atresia accounted for 2.6 % of the studied patients. The relative frequencies of some of the complex cardiac disease like hypoplastic left heart syndrome (HLHS), transposition of the great arteries, and atrioventricular canal were 0.4%, 3.7 %, and 3.5 % respectively. The relative frequencies of these complex cardiac lesions were less than the reported frequencies in the literature (Figure 2). Others accounted for 16.1 % (Table 3). The relative frequencies of the CHD by age in shown in (Figure 3) and (Table 4).

Consanguinity:

The prevalence of consanguinity among the parents of the studied population was 34.6 %. Out of the 317 patients with consanguineous parents, 59 % were first degree relatives, 22.4% were second degree relatives and 16.7% were third degree relatives. 20.4 % of the studied population were first degree relatives.

Family History:

15.9 % of the patients with congenital heart disease had positive family history for CHD.

Geographic Distribution:

The geographic distribution of patients with CHD is shown in (Figure 4). 42 % of the patients were from Beirut and the rest were distributed all over the country.

Paternal and Maternal Education:

The paternal and maternal educational levels of the children with congenital heart disease are shown in (Figure 5). Approximately 23.9 % of the fathers had university education and 7.5% were illiterate, while 19.6% of the mothers had university education and 9.6 % were illiterate.

Paternal and Maternal Smoking Habits:

There was a high frequency of parental smoking. Maternal smoking was reported at 30.3% and Paternal smoking at 53.5%.

Maternal Age:

Of the mothers of children with CHD whose ages were available, 10.5 % were between the ages of 14-20 years, 61.5 % were between the ages of 21-30 years and 25.9 % between the ages of 31-42 years.

Cardiac Catheterization:

Two hundred and thirty eight patients (26 %) underwent cardiac catheterizations. 41 interventional cardiac catheterization procedures occurred (17.2%). The interventional procedures included: balloon atrial septostomies , aortic and pulmonary valvuloplasty , angioplasty of COA , PDA coil embolization and others. There was no mortality or significant complication from the cardiac catheterization procedures during the study period.

Surgery:

378 surgical procedures occurred on 329 patients (34.9%) out of the 917 patients registered. Our center performs almost all types of pediatric cardiac surgeries, including complex cardiac anomalies (i.e, repair of TAPVR, right ventricular –pulmonary conduit, Cavo-pulmonary anastomosis, repair of aorto-pulmonary window, arterial switch procedure), and other less complex procedures (ie, repair of TOF, AVC, shunts, septal surgeries, etc.). Only cardiac transplantation and the Norwood procedure for HLHS are not performed at our center.
The in-hospital surgical mortality rate during the study period at our center was 8.5%. It was 9.9% during the year 1997 and decreased to 5% during the last year. For children with a CHD, who underwent surgery at our center during the study period, the risk of dying in-hospital was comparable to that risk of dying in-hospital in a cardiac program in California or Massachusetts performing a comparable number of pediatric cardiac surgeries to our hospital ( percent in-hospital deaths ranged from 6.9%-9.3%, in USA). However, the risk of dying in-hospital was higher at our center as compared to a program in the USA performing more than 300 cases per year (in hospital death is 6.0%). The all hospitals percent of in-hospital deaths for children with a CHD undergoing surgery in California or Massachusetts in 1990 was 7.7%.

Outcome:

44 patients in the CCRC (4.8 %) with CHD died during the 40-months study period. None of the patients who underwent diagnostic or intervention cardiac catheterization procedure died during the study period.

Acquired Heart Disease

Age and Sex:

Out of the 1000 patients with cardiac abnormalities included in the CCRC, 83 patients (8.3 %) had acquired heart disease. 39.8% of the patients were female and 60.2% were males. Sixteen patients were less than or equal to one year of age when first registered and 80.7% were older than 1 year.

Frequency of AHD:

The relative frequencies of the acquired heart diseases revealed twenty two patients (26.5%) with arrhythmias, 26 patients (31.3%) with dilated cardiomyopathy and the rest (42.2%) had rheumatic fever.

Consanguinity:

The prevalence of consanguinity among the parents of the studied population was 30.1%. Out of the 25 patients whose parents were consanguineous, 60% were first degree relatives, 8% were second degree relatives and 28% were third degree relatives. 18.1 % of the studied population were first degree relatives.

Family History:

10.8 % of the patients with Acquired heart disease had positive family history.

Paternal or Maternal smoking:

Maternal smoking occurred in 33.7%, and paternal smoking in 56.6% of the studied patients

Cardiac catheterization:

Five patients (6%) underwent 5 cardiac catheterization procedures.

Paternal or Maternal Education:

Paternal and maternal educational levels of the children with acquired heart disease are shown in (Figure 6). 25.3 % of the fathers had University education and 7.3% were illiterate, while 13.2% of the mothers had University education and 19.3 % of were illiterate.

Surgery:

Nine patients underwent surgical procedures (10.8%). All had cardiac valve replacement.

Outcome:

2 patients (2.4%) with AHD died during the study period of 40 months.

DISCUSSION:

91.7 % in the registry center had congenital heart disease. The frequency of many of the congenital cardiac malformation in our study population was similar to that reported in the literature, in particular when compared with patients seen at the Children’s Hospital in Boston between the year 1973 and 1987. VSD was the most common cardiac malformation at 25.3 %, followed by pulmonary stenosis (14.6 %). This is in accordance with other studies. There was relatively higher prevalence of pulmonary atresia lesions in our population. The relative frequencies of some of the complex cardiac disease, like Hypoplastic left heart syndrome (HLHS) and transposition of the great arteries were less than the reported frequencies in the literature. The slightly lower frequencies of the more complex CHD in our study group, may be that these patients were unrecognized and died early in life or were not referred. When assessed by the status of age, the relative frequencies of the more complex lesions were higher in the subgroup whose age was less than or equal to one year.
The prevalence of CHD has been remarkably constant throughout the world and over the years. The prevalence of CHD in Lebanon appears to follow that rule, based on our experience at the AUB-MC. There is no reason to suspect a change in the recent years. Not only is the incidence of CHD relatively predictable, but also the relative frequency of various congenital cardiac defects varies a little. The rank of cardiac defects seen at a particular hospital may vary somewhat over time, reflecting a referral bias or a change in the interest of the cardiology department when introducing new interventional techniques.
Most of the cardiac malformations in the CCRC were more commonly seen in males, except for patent ductus arteriosus and atrial septal defects, which were more frequent in females. However 60.2% of patient with AHD were males. Also 80.7% of patients with AHD were above the age of 1 year, and this is explained by the fact that rheumatic fever, which accounts for 42.2 % of patients with AHD in our study, is rarely seen in patients less than 3 years of age. As reported in a previous study, rheumatic fever still appears to be a concern for children with AHD in our society.
The high prevalence of consanguinity among parents of patients with CHD and AHD is of interest. Consanguinity occurred in 34.6% and 30% of the parents of the patients with CHD and AHD, respectively. 20.4 % and 18.1 % of the parents of the studied population were first-degree relatives in the CHD and AHD groups, respectively. The incidence of CHD reported at our center in the year 1996 was estimated to be 11.5/1000 live birth and this is higher than that reported in the literature. This may be related to higher incidence of consanguinity in our society. More data are needed to test this hypothesis. The incidence of consanguinity in the general population appears to be less than that seen in our studied population.
Family history of CHD was reported in 15.9% of patients with CHD. There was a family with three female siblings, all having tetralogy of Fallot, and another family with four siblings, two girls and two boys, all having atrioventricular canal. A genetic evaluation of such families may help to identify a particular gene responsible for a particular cardiac malformation. It has been reported that approximately 5 to 8 % of patients with CHD have a gross chromosomal defect, usually trisomy 21, 13, 18 and Turner’s syndrome as well as other less common chromosomal abnormalities. In addition, about 3% of CHD is due to classical Mendelian gene effects, with corresponding high recurrence risks in first-degree relatives. A national registry center will allow us to identify more families with similar cardiac disorders and help in genetic evaluation.
There was a high frequency of parental smoking in both groups of patients. Maternal smoking was reported at 30.3 % in the CHD group as compared to 33.7 % in the AHD group, and paternal smoking was comparable at 53.5 % and 56.6 %, in the CHD group and AHD group, respectively. Cigarette smoking may be an important preventable risk factor for the development of congenital heart disease.
The paternal educational level of the CHD and AHD groups was comparable. 23.9 % of fathers of patients with CHD had a university education and 7.5 % were illiterate as compared to 25.3 % with paternal university education and 7.3 % illiterate in the group with AHD. The maternal educational levels of the patients with CHD were better than the maternal educational levels of the patients with AHD. 19.6% of mothers of patients with CHD had a university education and 9.6 % were illiterate as compared to 13.2% with university education and 19.3% illiterate in the group with AHD.
Cardiac catheterization was performed in a total of 243 patients (24.3%) . 41 patients ( 17.2%) underwent interventional cardiac catheterization procedures. This is less than the percentage of interventional catheterization procedures at major centers in the USA, although most of these procedures are available at our center. In the United States, there was a steady increase in the total number of cardiac catheterizations over the past 20 years and this is directly related to the increase in interventional procedures. It might be that the increasing number of diagnostic echocardiograms would have resulted in decreased number of diagnostic cardiac catheterizations. However, we believe that the major reason for the low frequency of interventional procedures is related to financial restraints since such procedures are still not covered by almost all of the insurance companies. This, however, represents a major disadvantage to patients with CHD. The increasing number of interventional cardiac catheterization in the US resulted in fewer cardiac operations with lower rates of complications. The expected financial savings as well as the improved impact on rates of surgical complications resulting from interventional catheterization procedures have yet to be realized in our society. These procedures cost less and have comparable results to surgical intervention. Many patients with conditions formerly corrected by surgical operations are now being treated with interventional catheter techniques.
34.9% of patients with CHD underwent surgical intervention compared to 10.8 % of patients with AHD. The nature of this population, with respect to age and degree of disease, reflected by the percentage of surgical intervention, illustrates the need of indefinite follow up and the importance of the availability of polices and medical services to address the potential problems and complications, that may develop in this young population. The outcome of the AHD and CHD groups is acceptable, with 4.9 % and 2.4 % mortality rates in both groups, respectively. The in-hospital surgical mortality rate during the study period at our center was 8.5 %. It was 9.9% during the year 1997 and decreased to 5% during the last year. For children with a CHD, who underwent surgery at our center during the study period, the risk of dying in-hospital was comparable to the risk of dying in-hospital in a cardiac program in Massachusetts performing a comparable number of pediatric cardiac surgeries to our hospital. However, the risk of dying in-hospital was higher at our center as compared to hospitals in the USA with an annual volume of more than 300 cases per year.
Studies from USA revealed that health care delivery strategies that direct children requiring surgical correction of congenital heart defects to high-volume centers may substantially reduce overall mortality. Centralization of the surgical management of children with heart disease in our country is of outmost importance, and will improve our results at the National level

CONCLUSION:

This initial data describe the epidemiology of heart disease affecting children seen at the AUB-MC. This initial step should open the door to establish the CCRC at the national level. Many of our children with cardiac disease are either diagnosed late or not at all, leading to significant morbidity and mortality. However, it is expected that with increased awareness and improved care, a larger number of patients is going to need medical attention. The establishment of a National Children’s Cardiac Registry Center (CCRC) for acquired heart disease in children and congenital heart disease is essential to better understand the needs of our population, and to develop the appropriate medical and/or surgical approaches that best fit our national priorities, research, prevention and treatment polices.
The National Registry board will include all pediatric cardiologists, pediatric cardiac surgeons and other physicians who deal with cardiac disease in children in Lebanon, and who are willing to participate and provide data about their patients. Specialists in appropriate related disciplines will also be invited. The registry will coordinate with the Ministry of Health, local and international organization to function at the highest standards. The goals and aims will be to register all pediatric patients with congenital and acquired cardiac disease in Lebanon in addition to adults with congenital cardiac disease. Also, it will document the course of the disease and its outcome, in addition to results and outcome of surgical intervention. Risk factors will be identified and medical and surgical health cost will be evaluated. The data collected through the CCRC will help to establish the most appropriate approach to cut down on medical cost and continue to deliver the highest standards of care.

RECOMMENDATION:

The support of the Lebanese National Council for Scientific Research was of great help to establish the first phase of the registry. However, the recruitments of funds supported by the Ministry of Health, local and international organization, and other agencies to expand the registry to the national level are of great importance. The following has to be available to expand the registry:

1-Research assistant (s) to gather information in coordination with the physician, and to help in collecting data from the entire country.
2-One or two conferences per year, for physicians working in the field to share, co-ordinate and set guidelines and polices.
3-Regular meetings with physicians working with children with cardiac disease to expand to the national level.
4-A centralized computer system to store and analysis the confidential data.
The above will allow further work to include genetic evaluation of patients, and the development of educational and prevention policies, information, meetings, rehabilitation , counseling, and support groups ( examples of educational pamphlets, prepared by the CCRC at AUB-MC).

EDUCATIONAL PAMPHLETS: 

In the CCRC, some educational pamphlets concerning the different congenital heart lesions were given to the parents.
An example of the pamphlets is as follows:

1-Aortic Stenosis
2-Atrial Septal Defect
3-Heart Murmurs
4-Patent Ductus Arteriosus
5-Pulmonary Stenosis
6-Tetralogy of Fallot
7-Transposition of the Great Arteries
8-Ventricular Septal Defect

Children's Heart Center-American University of Beirut Medical Center-Pediatric Department
Riad El solh Beirut 1107 2020 / P.O.Box 11-0236 Lebanon
Phone: +961 1 350000 EXT 5748