[Temporal variation and geographical distribution: congenital heart defects in the Comunitat Valenciana]

Tetralogy of Fallot in Spain: a nationwide registry-based mortality study across 36 years

BACKGROUND

Tetralogy of Fallot (TOF) is the most frequent cyanotic congenital heart defect. TOF mortality has fallen remarkably in recent years due to therapeutic advances. Accordingly, the aim of this study was to assess temporal and spatial variability in TOF-related mortality in Spain across the period 1981-2016, using data drawn from the nationwide population-based registry.

METHODS

Annual deaths due to TOF were sourced from the Spanish National Institute of Statistics database by reference to International Classification of Diseases (ICD), 9th and 10th Revision codes, namely, ICD-9 code 745.2 (period 1981-1998) and ICD-10 code Q21.3 (period 1999-2016). Age-specific and age-adjusted mortality rates were calculated, as were standardised mortality ratios (SMRs) by province, district and municipality for the period 1999-2016.

RESULTS

A total of 1035 deaths were attributed to TOF (57.78% of them were men and 42.22% were women). The age-adjusted mortality rate ranged from 0.75 per 1,000,000 inhabitants (95% confidence interval [CI]: 0-1.36) in 1981 to 0.03 per 1,000,000 (95% CI: 0.01-0.06) in 2016 for both sexes. In 2011, there was a change in the mortality trend, with a significant decrease of 49.22% per year (p < 0.001). In terms of geographical analysis, some areas with a significantly higher risk of TOF mortality were identified in the south of Spain, though no specific spatial pattern was in evidence.

CONCLUSION

The decrease in TOF mortality may be related to improvements in diagnostic and treatment techniques. More studies are needed to analyse regions with a higher mortality risk, in order to improve medical planning and resource allocation, and identify risk factors and preventive measures.

Spatial pattern and variations in the prevalence of congenital heart disease in children aged 4-18 years in the Qinghai-Tibetan Plateau

PURPOSE

This study aimed to investigate the spatial distribution pattern of the prevalence of congenital heart disease (CHD) in children in Qinghai-Tibetan Plateau (QTP), a high-altitude region in China.

METHODS

Epidemiological data from a survey on the prevalence of CHD in Qinghai Province including 288,066 children (4-18 years) were used in this study. The prevalence and distribution pattern of CHD was determined by sex, CHD subtype, and nationality and altitude. Spatial pattern analysis using Getis-Ord Gi^⁎ was used to identify the spatial distribution of CHD. Bayesian spatial binomial regression was performed to examine the relationship between the prevalence of CHD and environmental risk factors in the QTP.

RESULTS

The prevalence of CHD showed a significant spatial clustering pattern. The Tibetan autonomous prefecture of Yushu (average altitude > 4000 m) and the Mongolian autonomous county of Henan (average altitude > 3600 m) in Huangnan had the highest prevalence of CHD. Univariate analysis showed that with ascending altitude, the total prevalence of CHD, that in girls and boys with CHD, and that of the subtypes PDA and ASD increasing accordingly. Thus, environmental factors greatly contributed to the prevalence of CHD.

CONCLUSIONS

The prevalence of CHD shows significant spatial clustering pattern in the QTP. The CHD subtype prevalence clustering pattern has statistical regularity which would provide convenient clues of environmental risk factors. Our results may provide support to make strategies of CHD prevention, to reduce the incidence of CHD in high altitude regions of China.

[Incidence and evolution of congenital heart disease in Spain from 2003 until 2012]

INTRODUCTION AND OBJECTIVES

Congenital heart disease (CHD) represents the most common congenital malformation. The objective of this study was to analyse the incidence of CHD in Spain, and it is the first nationwide study so far.

METHODS

A retrospective observational study was performed in order to evaluate the incidence of CHD in Spain. The administrative database (minimum basic data set) from 2003 to 2012 was analysed in children less than one year old admitted to hospital with codes of CHD (International Classification of Diseases, 9th Revision, clinical modification). Cumulative incidence, Incidence relative risk, and standardised incidence ratio were calculated to study geographic variations.

RESULTS

There were 64,831 infants with CHD among the 4,766,325 births analysed during the period studied, with an incidence of 13.6‰. The incidence excluding atrial septal defect was 7.29 ‰.The most frequent CHD were atrial septal defect (6.31‰), ventricular septal defect (3.48‰), patent ductus arteriosus (2.71‰), coarctation of the aorta (0.55‰), pulmonary stenosis (0.50‰), transposition of the great arteries (0.49‰), atrioventricular septal defect (0.45‰), and tetralogy of Fallot (0.41‰). Castilla and Leon, together with Extremadura, showed the highest risks for severe and very severe CHD, while Madrid and Cantabria showed the lowest.

CONCLUSIONS

An increase of mild CHD was observed during the period analysed. This could have been influenced by improvements in diagnostic techniques, extended use of echocardiography, and the International Classification of Diseases, 9th Revision, clinical modification coding system, and to a decrease in very severe CHD, which is less influenced by external factors. Significant geographical differences were found in the incidence of severe and very severe CHD.

[Chromosomal anomalies: The experience of the Congenital Anomalies Registry of the Valencia Region]

OBJECTIVE

To describe the temporal trend and distribution of chromosomal congenital abnormalities (CA) in the Valencia Region, in less than one year olds, during the period 2007-2011.

METHODOLOGY

Live births, still births and termination of pregnancy due to foetal anomaly between 2007 and 2011 with chromosomal CA (Q90-Q99.9 codes of the 10th International Classification of Diseases -British Paediatric Association) were selected from the CA population-based Registry of Valencia Region The prevalence per 10,000 births for the chromosomal CA and for the different types of chromosomal syndromes with 95% confidence intervals was calculated. The analysis was performed by calculating prevalences and data were compared using Pearson Chi-squared test.

RESULTS

A total of 895 cases were found, representing a prevalence of 33.5 per 10,000 births (95% CI: 31.0-35.9), highlighting five syndromes: Down's, Edward's, Patau, Turner and Klinefelter. The prevalence of chromosomal CA and Down's syndrome were stable over the period, except in 2010. Down's was the most frequent chromosomal CA (67% of the cases), and the most frequent termination of pregnancy type was for foetal anomaly (69%). Cardiac heart defects represented 70.3% of the associated congenital anomalies. Mothers of children with chromosomal CA were mainly Spanish (73.3%). The age group of mothers over 39 years had a higher prevalence (133.0 per 10,000 births). The province of Castellón had the highest prevalence, 39.1 per 10,000 births.

CONCLUSIONS

The prevalence has remained stable over the five years, excluding the significant decline in 2010, for chromosomal CA detected and two of the major syndromes. The chromosomal CA are an important public health problem as they represent 15% of all CA identified in the Valencia Region, and agrees with the European data.

Spatial patterns of the congenital heart disease prevalence among 0- to 14-year-old children in Sichuan Basin, P. R China, from 2004 to 2009

Background

Congenital heart disease (CHD) is the most common type of major birth defects in Sichuan, the most populous province in China. The detailed etiology of CHD is unknown but some environmental factors are suspected as the cause of this disease. However, the geographical variations in CHD prevalence would be highly valuable in providing a clue on the role of the environment in CHD etiology. Here, we investigate the spatial patterns and geographic differences in CHD prevalence among 0- to 14-year-old children, discuss the possible environmental risk factors that might be associated with CHD prevalence in Sichuan Basin from 2004 to 2009.

Methods

The hierarchical Bayesian model was used to estimate CHD prevalence at the township level. Spatial autocorrelation statistics were performed, and a hot-spot analysis with different distance thresholds was used to identify the spatial pattern of CHD prevalence. Distribution and clustering maps were drawn using geographic information system tools.

Results

CHD prevalence was significantly clustered in Sichuan Basin in different spatial scale. Typical hot/cold clusters were identified, and possible CHD causes were discussed. The association between selected hypothetical environmental factors of maternal exposure and CHD prevalence was evaluated.

Conclusions

The largest hot-spot clustering phenomena and the CHD prevalence clustering trend among 0- to 14-year-old children in the study area showed a plausibly close similarity with those observed in the Tuojiang River Basin. The high ecological risk of heavy metal(Cd, As, and Pb)sediments in the middle and lower streams of the Tuojiang River watershed and ammonia–nitrogen pollution may have contribution to the high prevalence of CHD in this area.