Mortality from Congenital Heart Disease in Mexico: A Problem on the Rise

Infant congenital heart disease prevalence and mortality in French Guiana: a population-based study

Background

Few studies have assessed the prevalence and mortality of simple or complex congenital heart diseases (CHD) in newborns. In Latin America and Caribbean (LAC), CHD epidemiology seems highly variable, with few population-based assessments and different methodologies between studies. To date, the situation in French Guiana, a French overseas territory located in South America between Brazil and Suriname, has never been described.

Methods

We analysed CHD prevalence, characteristics and related infant mortality in French Guiana, with a population-based registry analysis of all fetal and live birth CHD cases in infants under 1 year (January 2012-December 2016).

Findings

Overall, 33,796 births (32,975 live births) were registered, with 231 CHD (56 fetuses), including 215 live births. Most frequent CHD categories were anomalies of the ventricular outflow tract and extra-pericardial trunks, and ventricular septal defects. 18.6% (43/231) chromosomal or genetic anomalies, and 6.5% (15/231) terminations of pregnancy were observed. Total CHD prevalence was 68.4 [95% CI: 67.9-68.8] per 10,000, while live birth prevalence was 65.2 [95% CI: 64.7-65.7] per 10,000. Total infant mortality was 9.4/10,000 live births [95% CI 9.1-9.7], with highest rates for functionally univentricular hearts (FUH).

Interpretation

A distinct profile for CHD is highlighted in French Guiana with elevated mortality linked to FUH. A potential determinant of the recognized excess mortality risk might be the presence of chromosomal or genetic anomalies in about a fifth of all CHD. This helps us to better understand CHD burden in this part of South America and provides future keys towards reducing CHD-related infant mortality.

Funding

The authors received no financial support for the present research, authorship, and/or publication of this article.

Predictors of ICU Admission in Children with COVID-19: Analysis of a Large Mexican Population Dataset

Children, although mostly affected mildly or asymptomatically, have also developed severe coronavirus disease 2019 (COVID-19). This study aims to assess potential predictors of intensive care unit (ICU) admission in a large population (n = 21,121) of children aged 0-9 years with laboratory-confirmed disease. We performed a cross-sectional analysis of a publicly available dataset derived from the normative epidemiological surveillance of COVID-19 in Mexico. The primary binary outcome of interest was admission to the ICU due to respiratory failure. Results showed that immunosuppressed children and those with a personal history of cardiovascular disease had a higher likelihood of being admitted to the ICU, while increasing age and the pandemic duration were associated with a lower likelihood of admission. The study's results have the potential to inform clinical decision-making and enhance management and outcomes for children affected by COVID-19 in Mexico.

Congenital Heart Diseases: Genetic Risk Variants and Their Methylation Status

(1) Background: The interaction between single nucleotide variants (SNVs) associated with congenital heart diseases (CHDs) and their gene methylation status has not been well researched. The aim of the present study was to determine if there is a relationship between the methy lation status (MS) of genes and the allelic variants associated with CHDs. (2) Methods: Seven SNVs of the genes AXIN1, TBX1, TBX20, and MTHFR were selected from the literature. DNA extraction, genotyping, and a methylation analysis were performed on healthy subjects and subjects with CHDs. (3) Results: Twenty-two subjects with CHDs were selected as the case group (15 with ventricular septal defects (VSDs) and 7 with atrial septal defects (ASDs)), and 44 healthy subjects comprised the control group. The MTHFR and AXIN1 genes were hypermethylated in the control group when compared to the case group. When analyzed separately, those with atrial septum defects exhibited greater methylation, except for the gene MTHFR where there were no differences. Only the alternate alleles of MTHFR showed a significantly different methylation status in those without cardiopathy. (4) Conclusions: The MTHFR and AXIN genes were hypermethylated in the control group; however, only the alternate alleles of MTHFR (rs1801133 and rs1801131) showed a significantly different methylation status.

Reduction of infant mortality from congenital heart defects in a middle-income country: Costa Rican experience

BACKGROUND

We aimed to analyze recent infant and neonatal mortality from congenital heart defects (CHD) in Costa Rica, a middle-income country where CHD mortality was above expectations.

METHODS

A descriptive analysis of infant and neonatal mortality rates from CHD (IMR-CHD and NMR-CHD) during 2000-2019 was performed, according to province, sex, specific CHD, and sub-period, using data from the National Institute of Statistics and Censuses. We used joinpoint regression to identify any calendar-year where a significant change in trend occurred; the average annual percent change (AAPC) was determined. Using Poisson regression, marginal means and mortality ratios (MR) for IMR-CHD and NMR-CHD by sub-period (2000-2006-referent-, 2007-2013, 2014-2019) were estimated and compared using Wald's chi-square tests (α ≤ .05).

RESULTS

During 2000-2019, CHD accounted for 12% of overall infant mortality. IMR-CHD and NMR-CHD decreased linearly over the study period (AAPC = -3.4; p < .01). IMR-CHD decreased by 41%, from 13.6 per 10,000 in 2000-2006 (13.4% of infant mortality) to 8.1 per 10,000 in 2014-2019 (10% of infant mortality) (MR = 0.59; 95% confidence intervals [CI] = 0.52-0.68). NMR-CHD decreased by 38%, from 7.9 per 10,000 in 2000-2006 (11.1% of neonatal mortality) to 4.9 per 10,000 in 2014-2019 (7.9% of infant mortality) (MR = 0.59; 95% CI = 0.52-0.68). Male presented significantly higher NMR-CHD. The main causes of mortality (2014-2019) were total anomalous pulmonary venous connections, hypoplastic left heart syndrome, and double inlet ventricle.

CONCLUSIONS

IMR-CHD, NMR-CHD, and their proportional contribution to mortality by all causes and by birth defects decreased significantly, demonstrating that all improvements implemented in the last decades have yielded favorable results.

Critical CHD screening programme: a 3-year multicentre experience in Mexico

INTRODUCTION

CHDs are the most common type of birth defect. One in four newborns with a heart defect has a critical CHD. In Mexico, there is a lack of data available to determine its prevalence. Pulse oximetry screening programmes have been implemented worldwide, reporting opportunity areas in algorithm interpretation and data management. Our study aims to share preliminary results of a 3-year experience of a multicentre pulse oximetry screening programme that addresses critical challenges.

MATERIALS AND METHODS

This retrospective study examined the reports of newborns screened from February 2016 to July 2019 from five hospitals. Two algorithms -the New Jersey and the American Academy of Pediatrics- were implemented over consecutive periods. The algorithms' impact was assessed through the calculation of the false-positive rate in an eligible population.

RESULTS

A total of 8960 newborns were eligible for the study; from it, 32.27% were screened under the New Jersey and 67.72% under the American Academy of Pediatrics algorithm - false-positive rate: 1% (CI 95: ± 0.36%) and 0.71% (CI 95: ± 0.21%), respectively. Seventy-nine newborns were referred, six were diagnosed with critical CHD, and six with CHD. The critical CHD estimated prevalence was 6.69:10,000 newborns (CI 95: ± 5.36). Our results showed that the algorithm was not related to the observable false-positive rate reduction.

DISCUSSION

Other factors may play a role in decreasing the false-positive rate. Our experience implementing this programme was that a systematic screening process led to more confident results, newborn's report interpretation, and follow-up.

CCHD Screening Implementation Efforts in Latin American Countries by the Ibero American Society of Neonatology (SIBEN)

Congenital heart disease (CHD) is among the four most common causes of infant mortality in Latin America. Pulse oximetry screening (POS) is useful for early diagnosis and improved outcomes of critical CHD. Here, we describe POS implementation efforts in Latin American countries guided and/or coordinated by the Ibero American Society of Neonatology (SIBEN), as well as the unique challenges that are faced for universal implementation. SIBEN collaborates to improve the neonatal quality of care and outcomes. A few years ago, a Clinical Consensus on POS was finalized. Since then, we have participated in 12 Latin American countries to educate neonatal nurses and neonatologists on POS and to help with its implementation. The findings reveal that despite wide disparities in care that exist between and within countries, and the difficulties and challenges in implementing POS, significant progress has been made. We conclude that universal POS is not easy to implement in Latin America but, when executed, has not only been of significant value for babies with CHD, but also for many with other hypoxemic conditions. The successful and universal implementation of POS in the future is essential for reducing the mortality associated with CHD and other hypoxemic conditions and will ultimately lead to the survival of many more Latin American babies. POS saves newborns' lives in Latin America.

Genetic Variants at the rs4720169 Locus of TBX20 and the rs12921862 Locus of AXIN1 May Increase the Risk of Congenital Heart Defects in the Mexican Population: A Pilot Study

Background: Congenital heart defects (CHDs) are the most common type of birth defects and a major cause of infant mortality. Although knowledge of genetic risk variants for CHDs is scarce, most cases of CHDs are considered to be due to multifactorial inheritance. Objective: To analyze the association of 14 single nucleotide polymorphic variants previously associated with a risk of CHDs in a Mexican population with isolated CHDs. Materials and Methods: DNA samples obtained from healthy subjects and from subjects with isolated atrial, ventricular, or atrioventricular septal defects living in Northeastern Mexico were analyzed by real time-polymerase chain reaction for allelic discrimination of genetic variants of the genes TBX1, TBX20, ASTX-18-AS1, AXIN1, MTHFR, NKX2.5, BMP4, and NFATc1. The odds ratios (ORs) for allele and genotype frequencies and inheritance models were obtained. Results: Forty-two patients and 138 controls were included. Two variants were found to confer a risk of CHDs: variant rs4720169 of TBX20 in which the OR for the heterozygous state was 1.88 (95% confidence interval [CI]: 1.12-3.14, p = 0.010), whereas the OR for the homozygous state was 3.82 (95% CI: 1.18-12.3, p = 0.010); and variant rs12921862 of AXIN1 in which the OR for the heterozygous state was 4.15 (95% CI: 2.42-7.10; p ≤ 0.001), whereas the OR for the homozygous state was 9.2 (95% CI: 1.31-64.7, p = 0.008) for allele A. Conclusion: Genetic variants of the TBX20 and AXIN1 genes confer a significantly increased risk of congenital septal heart defects in a population from Northeastern Mexico.

Prenatal diagnosis of congenital heart defects: experience of the first Fetal Cardiology Unit in Mexico

OBJECTIVE

The purpose of this article was to describe our experience with the prenatal diagnosis of CHD in patients referred to our Fetal Cardiology Unit.

METHODS

Prospective cohort study of consecutive fetuses referred for advanced fetal echocardiography to our Fetal Cardiology Unit during a 3-year period (September 2015-September 2018).

RESULTS

Totally 809 fetuses were evaluated, with 1263 fetal advanced echocardiographies performed. Suspected cardiac abnormality was the most common indication for referral (62.2%). Only 7.3% of patients had known morbidities or risk factors for CHD. Mean gestational age at first examination was 25.6 ± 6.4 weeks. A total of 528 (65.3%) fetuses were found to have a cardiac defect: 40.7% had isolated CHD while 24.6% had associated anomalies. The most common defects found were ventricular septal defects (20.3%), followed by conotruncal defects (9.7%), hypoplastic left heart syndrome (9.3%), fetal arrhythmias (8.9%), and venous anomalies (8.7%). 31.6% presented abnormal genetic studies, the most frequent being Down syndrome (23/212, 10.8%), followed by DiGeorge syndrome (11/212, 5.2%).

CONCLUSIONS

Prenatal screening and diagnosis of CHD in Mexico are feasible, with suspected cardiac abnormality being the main reason for referral to a specialized Fetal Cardiology Unit. Efforts must be made to make screening available to the general population in the first and second trimesters of pregnancy by fetal medicine or trained specialists, in order to identify fetal CHD and offer advanced echocardiography, genetic studies, timely fetal cardiac intervention in selected cases, and delivery in tertiary centers, to improve overall survival.

Outcomes of hypoplastic left heart syndrome and fetal aortic valvuloplasty in a country with suboptimal postnatal management

BACKGROUND

Fetal aortic stenosis (AoS) may progress to hypoplastic left heart syndrome (HLHS) in utero. There are currently no data, prenatal or postnatal, describing survival of fetuses or neonates with AoS or HLHS in a country with suboptimal postnatal management.

STUDY DESIGN

Prospective cohort study performed in Mexico, including cases diagnosed with AoS and HLHS within a 6-year period. AoS patients fulfilling previously published criteria for evolving HLHS (eHLHS) were offered fetal aortic valvuloplasty. Outcome variables were perinatal mortality, postnatal management, type of postnatal circulation, and overall survival.

RESULTS

Fifty-four patients were included: 16 AoS and 38 HLHS. Eighteen patients had associated anomalies and/or an abnormal karyotype. Seventy-four percent of HLHS received comfort measures, with only three cases reporting an attempt at surgical palliation, and one survivor of the first stage. Fetal aortic valvuloplasty was performed successfully in nine cases of eHLHS. Overall postnatal survival was 44% in AoS with fetal aortic valvuloplasty, and one case (ongoing) in the HLHS group.

CONCLUSIONS

HLHS in Mexico carries more than a 95% risk of postnatal death, with little or no experience at surgical palliation in most centers. Fetal aortic valvuloplasty in AoS may prevent progression to HLHS and in this small cohort was associated with ≈50% survival.

Survival and Associated Risk Factors for Mortality Among Infants with Critical Congenital Heart Disease in a Developing Country

Critical congenital heart disease (CCHD) is associated with significant morbidity and mortality. However, data on survival of CCHD and the risk factors associated with its mortality are limited. This study examined CCHD survival and the risk factors for CCHD mortality. Using a retrospective cohort study of infants born with CCHD from 2006 to 2015, survival over 10 years was estimated using Kaplan-Meier analysis, and the risk factors for mortality were analyzed using multivariate Cox proportional hazards regression. A total of 491 CCHD cases were included in the study, with an overall mortality rate of 34.8% (95% confidence interval [CI] 30.6-39.2). The intervention/surgical mortality rate was 9.8% ≤ 30 days and 11.5% > 30 days after surgery, and 17% died before surgery or intervention. The median age at death was 2.7 months [first quartile: 1 month, third quartile: 7.3 months]. The CCHD survival rate was 90.4% (95% CI 89-91.8%) at 1 month, 69.3% (95% CI 67.2-71.4%) at 1 year, 63.4% (95% CI 61.1-65.7%) at 5 years, and 61.4% (95% CI 58.9-63.9%) at 10 years. Weight of < 2 kg at diagnosis, associated syndromes, poor pre-operative condition, and non-duct-dependent CCHD were independent risk factors for poor survival, with hazard ratios of 2.61, 2.10, 2.22, and 1.70, respectively. CCHD is associated with a high mortality rate. Low weight, poor pre-operative condition, associated syndromes, and non-duct-dependent CCHD are significant risk factors affecting the survival of infants with CCHD.

Mortality for Critical Congenital Heart Diseases and Associated Risk Factors in Newborns. A Cohort Study

Background

Congenital heart diseases are the most common type of congenital defects, and account for more deaths in the first year of life than any other condition, when infectious etiologies are ruled out.

Objectives

To evaluate survival, and to identify risk factors in deaths in newborns with critical and/or complex congenital heart disease in the neonatal period.

Methods

A cohort study, nested to a randomized case-control, was performed, considering the Confidence Interval of 95% (95% CI) and significance level of 5%, paired by gender of the newborn and maternal age. Case-finding, interviews, medical record analysis, clinical evaluation of pulse oximetry (heart test) and Doppler echocardiogram were performed, as well as survival analysis, and identification of death-related risk factors.

Results

The risk factors found were newborns younger than 37 weeks (Relative Risk - RR: 2.89; 95% CI [1.49-5.56]; p = 0.0015), weight of less than 2,500 grams (RR: 2.33 [; 95% CI 1.26-4.29]; p = 0.0068), occurrence of twinning (RR: 11.96 [95% CI 1.43-99.85]; p = 0.022) and presence of comorbidity (RR: 2.27 [95% CI 1.58-3.26]; p < 0.0001). The incidence rate of mortality from congenital heart disease was 81 cases per 100,000 live births. The lethality attributed to critical congenital heart diseases was 64.7%, with proportional mortality of 12.0%. The survival rate at 28 days of life decreased by almost 70% in newborns with congenital heart disease. The main cause of death was cardiogenic shock.

Conclusion

Preterm infants with low birth weight and comorbidities presented a higher risk of mortality related to congenital heart diseases. This cohort was extinguished very quickly, signaling the need for greater investment in assistance technology in populations with this profile.

Risk factors for nosocomial infections after cardiac surgery in newborns with congenital heart disease

BACKGROUND

Congenital heart diseases are among the most common congenital malformations. Approximately 50% of the patients with congenital heart disease undergo cardiac surgery. Nosocomial infections (NIs) are the main complications and an important cause of increased morbidity and mortality associated with congenital heart diseases. This study's objective was to identify the risk factors associated with the development of NIs after cardiac surgery in newborns with congenital heart disease.

METHODS

This was a nested case-control study that included 112 newborns, including 56 cases (with NI) and 56 controls (without NI). Variables analyzed included perinatal history, associated congenital malformations, Risk-Adjusted Congenital Heart Surgery (RACHS-1) score, perioperative and postoperative factors, transfusions, length of central venous catheter, nutritional support, and mechanical ventilation.

STATISTICAL ANALYSIS

Differences were calculated with the Mann-Whitney-U test, Pearson X², or Fisher's exact test. A multivariate logistic regression was used to determine the independent risk factors.

RESULTS

Sepsis was the most common NI (37.5%), and the main causative microorganisms were gram-positive cocci. The independent risk factors associated with NI were non-cardiac congenital malformations (OR 6.1, CI 95% 1.3-29.4), central venous catheter indwelling time > 14 days (OR 3.7, CI 95% 1.3-11.0), duration of mechanical ventilation > 7 days (OR 6.6, CI 95% 2.1-20.1), and ≥5 transfusions of blood products (OR 3.1, CI 95% 1.3-8.5). Mortality attributed to NI was 17.8%.

CONCLUSION

Newborns with non-cardiac congenital malformations and with >7 days of mechanical ventilation were at higher risk for a postoperative NI. Efforts must focus on preventable infections, especially in bloodstream catheter-related infections, which account for 20.5% of all NIs.

Maternal Obesity as a Risk Factor for the Development of Total Anomalous Pulmonary Venous Connection in Their Offspring

The incidence of total anomalous pulmonary venous connection (TAPVC) in the Caucasian population is 2.5/100,000 live births (LB), and the incidence in the Hispanic population is 19.8/100,000 LB. Without knowing the exact etiology for the development of congenital heart disease, our objective was to determine the maternal factors associated with the development of TAPVC.

METHODS

55 mother-child binomials with isolated TAPVC (group I) and 152 healthy mother-child binomials (group II) were included. Both groups had no maternal history of addiction, pre-eclampsia, or type 1, 2 or gestational diabetes mellitus. Complete clinical histories were obtained for the women in both groups and perinatal and birth data were recorded. In addition, genealogies across three generations were constructed to determine affected first- or second-degree relatives with complex congenital heart disease.

RESULTS

Among the maternal characteristics analyzed, women in group I had a higher number of pregnancies before gestation of the index case (p = <0.05), and the Body Mass Index (BMI) before pregnancy was higher compared to Group II (p < 0.05), with an adjusted risk of OR = 3.6 (p = 0.011). The family history showed a higher prevalence in the group of patients with TAPVC compared to healthy children (p < 0.05).

CONCLUSION

Maternal obesity before pregnancy is a risk factor for the development of CATVP in children in the Mexican population.

[Demographic analysis of a congenital heart disease clinic of the Mexican Institute of Social Security, with special interest in the adult]

INTRODUCTION

Congenital heart disease (CHD) has an incidence of 8-10 cases per 1000 live births. In Mexico, there are 18,000-20,000 new cases per year. Most tertiary care centers for CHD attend only pediatric population; the Mexican Institute of Social Security (IMSS) has a clinic that attends pediatric and adult population.

OBJECTIVE

To analyze the demographic aspects of the CHD clinic of IMSS.

METHODS

From 2011 to 2016 a cross-sectional study of the CC clinic of a third level hospital of the IMSS, including all patients with confirmed structural heart disease of recent diagnosis was carried out. The sex, age, reference entity, antecedent of pregnancy and treatment were registered. The population was divided into age ranges (<2 years, 2.1-6 years, 6.1-10 years, 10.1-17 years and >17.1 years). Descriptive statistics and χ² test were used in qualitative variables.

RESULTS

3,483 patients with CHD (male:female ratio, 0.8:1.2) were included. Increased pulmonary flow acyanogenic cardiopathies were the most frequent CHD group (47.2%), with atrial septal defect being the most frequent diagnosis overall; 25.6% were adults and 35% of women with a history of pregnancy. Chiapas was Federal entity with greater proportion of patients diagnosed in the adult stage (33.82%); 7% were not candidates for any treatment for complications of the disease.

CONCLUSIONS

CHD is a late diagnosis; it is necessary to create a national register to promote new health policies and a rational distribution of resources for these patients.