Exposure to Low-Dose Ionizing Radiation From Cardiac Procedures and Malignancy Risk in Adults With Congenital Heart Disease.

BACKGROUND: Adults with congenital heart disease (CHD) are exposed to increasing amounts of low-dose ionizing radiation (LDIR) from cardiac procedures. Cancer prevalence in this population is higher than in the general population. This study estimates the association between LDIR exposure from cardiac procedures and incident cancer in adult patients with CHD. METHODS: The study population derived from the Quebec Congenital Heart Disease Database. We measured cumulative numbers of LDIR-related cardiac procedures for each patient until 1 year before the time of cancer diagnosis or administrative censoring. To assess the association between LDIR exposure and cancer risk, we conducted a nested case-control study and matched cancer cases with controls on sex, CHD severity, birth year, and age. RESULTS: The study included 24 833 adult patients with CHD aged 18 to 64 years from 1995 to 2009. In >250 791 person-years of follow-up, 602 cancer cases were observed (median age, 55.4 years). The cumulative incidence of cancer estimated up to 64 years of age was 15.3% (95% confidence interval [CI], 14.2-16.5). Cases had more LDIR-related cardiac procedures than controls (1410 versus 921 per 1000 adult patients with CHD, P<0.0001). Cumulative LDIR exposure was independently associated with cancer (odds ratio [OR], 1.08 per procedure; 95% CI, 1.04-1.13). Similar results were obtained by using dose estimates for LDIR exposure (OR, 1.10 per 10 mSv; 95% CI, 1.05-1.15) with a possible dose-related response. The effect measure was in the same direction, and the association was persistent for exposure from ≥6 procedures in all sensitivity analyses: after excluding most smoking-related cancer cases (OR, 1.10 per procedure; 95% CI, 1.05-1.16 and OR when exposure from ≥6 procedures, 3.08; 95% CI, 1.77-5.37), and after applying a 3-year lag period (OR, 1.09 per procedure; 95% CI, 1.03-1.14 and OR when exposure from ≥6 procedures: 2.58; 95% CI, 1.43-4.69). CONCLUSIONS: To our knowledge, this is the first large population-based study to analyze and document the association between LDIR-related cardiac procedures and incident cancer in the population of adults with CHD. Confirmations of these findings by prospective studies are needed to reinforce policy recommendations for radiation surveillance in patients with CHD where no regulation currently exists. Physicians ordering and performing cardiac imaging should ensure that exposure is as low as reasonably achievable without sacrificing quality of care.

Flexible Modeling of the Association Between Cumulative Exposure to Low-Dose Ionizing Radiation From Cardiac Procedures and Risk of Cancer in Adults With Congenital Heart Disease.

Adults with congenital heart disease are increasingly being exposed to low-dose ionizing radiation (LDIR) from cardiac procedures. In a recent study, Cohen et al. (Circulation. 2018;137(13):1334-1345) reported an association between increased LDIR exposure and cancer incidence but did not explore temporal relationships. Yet, the impact of past exposures probably accumulates over years, and its strength may depend on the amount of time elapsed since exposure. Furthermore, LDIR procedures performed shortly before a cancer diagnosis may have been ordered because of early symptoms of cancer, raising concerns about reversal causality bias. To address these challenges, we combined flexible modeling of cumulative exposures with competing-risks methodology to estimate separate associations of time-varying LDIR exposure with cancer incidence and all-cause mortality. Among 24,833 patients from the Quebec Congenital Heart Disease Database, 602 had incident cancer and 500 died during a follow-up period of up to 15 years (1995-2010). Initial results suggested a strong association of cancer incidence with very recent LDIR exposures, likely reflecting reverse causality bias. When exposure was lagged by 2 years, an increased cumulative LDIR dose from the previous 2-6 years was associated with increased cancer incidence, with a stronger association for women. These results illustrate the importance of accurate modeling of temporal relationships between time-varying exposures and health outcomes.

Rationale and Design of the FREQUENCY Study: The Fetal Cardiac Registry of Québec to Improve Resource Utilization in Fetal Cardiology.

OBJECTIVE: Prenatal detection of congenital heart diseases (CHD) decreases morbidity and cost. To improve detections rates, most physicians refer pregnant women with high-risk pregnancies to fetal cardiologists even when there is no suspicion of CHD at the second trimester screening. This paper presents the rationale and detailed method of the Fetal Cardiac Registry of Québec to Improve Resource Utilization in Fetal Cardiology (FREQUENCY) study. The overall objective is to assess the impact of second trimester ultrasound screening (U/S) and referral pattern in fetal cardiology on detection rates, health care costs, and resource utilization, as well as perinatal morbidity and mortality. METHODS: This multicentre retrospective population-based cohort study will link fetal echocardiography data from all centres performing fetal echocardiography in Québec with administrative health care data. This data linking will allow the determination of a true denominator (all women in Québec who underwent second trimester U/S) with complete follow-up of up to 2 years for offspring. This protocol meets Canadian Task Force Classification II-2. RESULTS: The study investigators have collected and cleaned fetal echocardiography data for 24 259 eligible pregnancies referred to fetal cardiology. These data will be matched to approximately 860 000 pregnancies between 2007 and 2015. CONCLUSION: The results of the FREQUENCY study will shed light on the impact of the current prenatal CHD screening strategy in Canada.

Administrative health databases for addressing emerging issues in adults with CHD: a systematic review.

The need for population-based studies of adults with CHD has motivated the growing use of secondary analyses of administrative health data in a variety of jurisdictions worldwide. We aimed at systematically reviewing all studies using administrative health data sources for adult CHD research from 2006 to 2016. Using PubMed and Embase (1 January, 2006 to 1 January, 2016), we identified 2217 abstracts, from which 59 studies were included in this review. These comprised 12 different data sources from six countries. Of these, 55% originated in the United States of America, 28% in Canada, and 17% in Europe and Asia. No study was published before 2007, after which the number of publications grew exponentially. In all, 41% of the studies were cross-sectional and 25% were retrospective cohort studies with a wide variation in the availability of patient-level compared with hospitalisation-level episodes of care; 58% of studies from eight different data sources linked administrative data at a patient level; and 37% of studies reported validation procedures. Assessing resource utilisation and temporal trends of relevant epidemiological and outcome end points were the most reported objectives. The median impact factor of publication journals was 4.04, with an interquartile range of 3.15, 7.44. Although not designed for research purposes, administrative health databases have become powerful data sources for studying adult CHD populations because of their large sample sizes, comprehensive records, and long observation periods, providing a useful tool to further develop quality of care improvement programmes. Data linkage with electronic records will become important in obtaining more granular life-long adult CHD data. The health services nature of the data optimises the impact on policy and public health.

Exposure to Low-Dose Ionizing Radiation From Cardiac Procedures in Patients With Congenital Heart Disease: 15-Year Data From a Population-Based Longitudinal Cohort.

BACKGROUND: The burden of low-dose ionizing radiation (LDIR) exposure from medical procedures among individuals with congenital heart disease (CHD) is unknown. In this longitudinal population-based study, we sought to determine exposure to LDIR-related cardiac imaging and therapeutic procedures in children and adults with CHD. METHODS AND RESULTS: In an analysis of the Quebec CHD database, exposure to the following LDIR-related cardiac procedures was recorded: catheter-based diagnostic procedures, structural heart interventions, coronary interventions, computed tomography scans of the chest, nuclear procedures, and pacemaker/implantable cardioverter-defibrillator insertion and repair. From 1990 to 2005, there were 16 253 LDIR-exposed patients with CHD with 317 988 patient-years of available follow-up. The total number of LDIR-related procedures increased from 18.5 to 51.9 per 1000 CHD patients per year (P<0.0001). This increase was attributable to increases in rates per 1000 CHD patients in diagnostic cardiac catheterizations (11.7 to 13.7 per 1000), structural heart interventions (1.0 to 5.2 per 1000), coronary interventions (1.0 to 2.4 per 1000), pacemaker/implantable cardioverter-defibrillator insertions (1.6 to 4.4 per 1000), nuclear procedures (4.2 to 13.8 per 1000), and computed tomography scans of the chest (2.5 to 12.3 per 1000). Over time, among children with CHD, the median age at first LDIR procedure decreased from 5.0 years to 9.6 months. Severity of CHD significantly predicted extent of exposure. CONCLUSIONS: From 1990 to 2005, patients with CHD were exposed to increasing numbers of LDIR-emitting cardiac procedures. This exposure occurred at progressively younger ages. These findings provide an important perspective on longitudinal LDIR exposure in this at-risk population.

Congenital Heart Defects in the United States: Estimating the Magnitude of the Affected Population in 2010.

BACKGROUND: Because of advancements in care, there has been a decline in mortality from congenital heart defects (CHDs) over the past several decades. However, there are no current empirical data documenting the number of people living with CHDs in the United States. Our aim was to estimate the CHD prevalence across all age groups in the United States in the year 2010. METHODS: The age-, sex-, and severity-specific observed prevalence of CHDs in Québec, Canada, in the year 2010 was assumed to equal the CHD prevalence in the non-Hispanic white population in the United States in 2010. A race-ethnicity adjustment factor, reflecting differential survival between racial-ethnic groups through 5 years of age for individuals with a CHD and that in the general US population, was applied to the estimated non-Hispanic white rates to derive CHD prevalence estimates among US non-Hispanic blacks and Hispanics. Confidence intervals for the estimated CHD prevalence rates and case counts were derived from a combination of Taylor series approximations and Monte Carlo simulation. RESULTS: We estimated that ≈2.4 million people (1.4 million adults, 1 million children) were living with CHDs in the United States in 2010. Nearly 300 000 of these individuals had severe CHDs. CONCLUSIONS: Our estimates highlight the need for 2 important efforts: planning for health services delivery to meet the needs of the growing population of adults with CHD and the development of surveillance data across the life span to provide empirical estimates of the prevalence of CHD across all age groups in the United States.

Stroke in Adults With Congenital Heart Disease: Incidence, Cumulative Risk, and Predictors.

BACKGROUND: Stroke is an important cause of morbidity and mortality, although there is a lack of comprehensive data on its incidence, cumulative risk, and predictors in patients with adult congenital heart disease. METHODS AND RESULTS: This retrospective study of 29 638 Quebec patients with adult congenital heart disease aged 18 to 64 years between 1998 and 2010 was based on province-wide administrative data. The cumulative risk of ischemic stroke estimated up to age 64 years was 6.1% (95% confidence interval [CI], 5.0-7.0%) in women and 7.7% (95% CI, 6.4-8.8%) in men; the risk of hemorrhagic stroke was 0.8% (95% CI, 0.4-1.2%) and 1.3% (95% CI, 0.8-1.8%), respectively. Compared with rates reported for the general Quebec population, age-sex standardized incidence rates of ischemic stroke were 9 to 12 times higher below age 55 years and 2 to 4 times higher in the age group 55 to 64 years; hemorrhagic stroke rates were 5 to 6 times (age <55 years) and 2 to 3 times higher. Using a combination of stepwise model selection and Bayesian model averaging, the strongest predictors of ischemic stroke were heart failure (odds ratio for age group 18-49 years, 5.94 [95% CI, 3.49-10.14], odds ratio for age group 50-64 years, 1.68 [95% CI, 1.06-2.66]), diabetes mellitus (odds ratio, 2.33 [95% CI, 1.66-3.28]), and recent myocardial infarction (odds ratio, 8.38 [95% CI, 1.77-39.58]). CONCLUSIONS: Among patients with adult congenital heart disease, 1 in 11 men and 1 in 15 women experienced a stroke between ages 18 and 64 years. Stroke incidence was considerably higher than in the general population, especially at a younger age. The most important predictors of ischemic stroke were heart failure, diabetes mellitus, and recent myocardial infarction. Additional research is required to see whether advances in the management of adult congenital heart disease may reduce this substantial stroke rate.

Lifetime prevalence of congenital heart disease in the general population from 2000 to 2010.

BACKGROUND: Our objective was to obtain contemporary lifetime estimates of congenital heart disease (CHD) prevalence using population-based data sources up to year 2010. METHODS AND RESULTS: The Quebec CHD database contains 28 years of longitudinal data on all individuals with CHD from 1983 to 2010. Severe CHD was defined as tetralogy of Fallot, truncus arteriosus, transposition complexes, endocardial cushion defects, and univentricular hearts. We used latent class bayesian models combining case definitions from physician claims, hospitalization, and surgical data to obtain point and interval prevalence estimates of CHD in the first year of life, in children (<18 years of age) and in adults. We identified 107 559 CHD patients from 1983 to 2010. Prevalence of CHD in the first year of life was 8.21 per 1000 live births (95% confidence interval, 7.47-9.02) from 1998 to 2005. In 2010, overall prevalence of CHD was 13.11 per 1000 (95% confidence interval, 12.43-13.81) in children and 6.12 per 1000 (95% confidence interval, 5.69-6.57) in adults. CHD prevalence increased by 11% in children and 57% in adults from 2000 to 2010. Prevalence in the severe CHD subgroup increased by 19% (95% confidence interval, 17%-21%) in children and 55% (51%-62%) in adults. By 2010, adults accounted for 66% of the entire CHD population. CONCLUSIONS: With an increase of >50% in CHD prevalence since 2000, by 2010 adults accounted for two thirds of patients with severe and other forms of CHD in the general population. Our findings should inform allocation of resources and the planning of workforce needs for the predominantly adult CHD population.

Infective endocarditis in children with congenital heart disease: cumulative incidence and predictors.

BACKGROUND: The American Heart Association guidelines for prevention of infective endocarditis (IE) in 2007 reduced the groups of congenital heart disease (CHD) patients for whom antibiotic prophylaxis was indicated. The evidence base in CHD patients is limited. We sought to determine the risk of IE in children with CHD. METHODS AND RESULTS: We performed a population-based analysis to determine the cumulative incidence and predictors of IE in children (0-18 years) with CHD by the use of the Quebec CHD Database from 1988 to 2010. In 47 518 children with CHD followed for 458 109 patient-years, 185 cases of IE were observed. Cumulative incidence of IE was estimated in the subset of 34 279 children with CHD followed since birth, in whom the risk of IE up to 18 years of age was 6.1/1000 children (95% confidence interval, 5.0-7.5). In a nested case-control analysis, the following CHD lesions were at highest risk of IE in comparison with atrial septal defects (adjusted rate ratio, 95% confidence interval): cyanotic CHD (6.44, 3.95-10.50), endocardial cushion defects (5.47, 2.89-10.36), and left-sided lesions (1.88, 1.01-3.49). Cardiac surgery within 6 months (5.34, 2.49-11.43) and an age of <3 years (3.53, 2.51-4.96; reference, ages 6-18) also conferred an elevated risk of IE. CONCLUSIONS: In a large population-based cohort of children with CHD, we documented the cumulative incidence of IE and associated factors. These findings help identify groups of patients who are at the highest risk of developing IE.

The epidemiology of heart failure in adults with congenital heart disease.

The impact of lifelong exposure to myocardial dysfunction in populations with congenital heart disease (CHD) is becoming increasingly recognized. Most children born with CHD now reach adulthood and the long-term sequelae of treatment are contributing to substantial comorbidity. The combination of structural changes present at birth with changes resulting from cardiac surgery can result in heart failure. This article reports on the current state of knowledge on the epidemiology of heart failure in this patient population.

CanCHD Study of Hematopoietic Cancers in Children With and Without Genetic Syndromes.

BACKGROUND: Individuals with genetic syndromes can manifest both congenital heart disease (CHD) and cancer attributable to possible common underlying pathways. To date, reliable risk estimates of hematopoietic cancer (HC) among children with CHD based on large population-based data remain scant. This study sought to quantify the risk of HC by the presence of genetic syndrome among children with CHD. METHODS AND RESULTS: Data sources were the Canadian CHD database, a nationwide database on CHD (1999-2017), and the CCR (Canadian Cancer Registry). Standardized incidence ratios were calculated for comparing HC incidences in children with CHD with the general pediatric population. A modified Kaplan-Meier curve was used to estimate the cumulative incidence of HC with death as a competing risk. A total of 143 794 children (aged 0-17 years) with CHD were followed up from birth to age 18 years for 1 314 603 person-years. Of them, 8.6% had genetic syndromes, and 898 HC cases were observed. Children with known syndromes had a substantially higher risk of incident HC than the general pediatric population (standardized incidence ratio, 13.4 [95% CI, 11.7-15.1]). The cumulative incidence of HC was 2.44% (95% CI, 2.11-2.76) among children with a syndrome and 0.79% (95% CI, 0.72-0.87) among children without a syndrome. Acute myeloid leukemia had a higher cumulative incidence during early childhood than acute lymphoblastic leukemia. CONCLUSIONS: This is the first large population-based analysis documenting that known genetic syndromes in children with CHD are a significant predictor of HC. The finding could be essential in informing risk-stratified policy recommendations for cancer surveillance in children with CHD.

Machine Learning Informed Diagnosis for Congenital Heart Disease in Large Claims Data Source.

Background: With an increasing interest in using large claims databases in medical practice and research, it is a meaningful and essential step to efficiently identify patients with the disease of interest. Objectives: This study aims to establish a machine learning (ML) approach to identify patients with congenital heart disease (CHD) in large claims databases. Methods: We harnessed data from the Quebec claims and hospitalization databases from 1983 to 2000. The study included 19,187 patients. Of them, 3,784 were labeled as true CHD patients using a clinician developed algorithm with manual audits considered as the gold standards. To establish an accurate ML-empowered automated CHD classification system, we evaluated ML methods including Gradient Boosting Decision Tree, Support Vector Machine, Decision tree, and compared them to regularized logistic regression. The Area Under the Precision Recall Curve was used as the evaluation metric. External validation was conducted with an updated data set to 2010 with different subjects. Results: Among the ML methods we evaluated, Gradient Boosting Decision Tree led the performance in identifying true CHD patients with 99.3% Area Under the Precision Recall Curve, 98.0% for sensitivity, and 99.7% for specificity. External validation returned similar statistics on model performance. Conclusions: This study shows that a tedious and time-consuming clinical inspection for CHD patient identification can be replaced by an extremely efficient ML algorithm in large claims database. Our findings demonstrate that ML methods can be used to automate complicated algorithms to identify patients with complex diseases.

Coarctation of the aorta and coronary artery disease: fact or fiction?

BACKGROUND: Aortic coarctation (CoA) is reported to predispose to coronary artery disease (CAD). However, our clinical observations do not support this premise. Our objectives were to describe the prevalence of CAD among adults with CoA and to determine whether CoA is an independent predictor of CAD or premature CAD. METHODS AND RESULTS: The study population was derived from the Quebec Congenital Heart Disease Database. We compared patients with CoA and those with a ventricular septal defect, who are not known to be at increased risk of CAD. The prevalence of CAD in patients with CoA compared with those with ventricular septal defect was determined. We then used a nested case-control design to determine whether CoA independently predicted for the development of CAD. Of 756 patients with CoA who were alive in 2005, 37 had a history of CAD compared with 224 of 6481 patients with ventricular septal defect (4.9% versus 3.5%; P=0.04). Male sex (odds ratio [OR], 2.13; 95% confidence interval [CI], 1.62-2.80), hypertension (OR, 1.95; 95% CI, 1.44-2.64), diabetes mellitus (OR, 1.68; 95% CI, 1.09-2.58), age (OR per 10-year increase, 2.28; 95% CI, 2.09-2.48), and hyperlipidemia (OR, 11.58; 95% CI, 5.75-23.3) all independently predicted for the development of CAD. CoA did not independently predict for the development of CAD (OR, 1.04; 95% CI, 0.68-1.57) or premature CAD (OR for CoA versus ventricular septal defect, 1.44; 95% CI, 0.79-2.64) after adjustment for other factors. CONCLUSIONS: Although traditional cardiovascular risk factors independently predicted for the development of CAD, the diagnosis of CoA alone did not. Our findings suggest that cardiovascular outcomes of these patients may be improved with tight risk factor control.

Neurocognitive disorders amongst patients with congenital heart disease undergoing procedures in childhood.

BACKGROUND: Amongst children with congenital heart disease (CHD), earlier age of repair improves cardiovascular outcomes. The effects of early intervention on neurodevelopment remains unclear. We assessed the association between early life repair, cardiopulmonary bypass (CPB) and the incidence of neurocognitive disorders (NCD) amongst CHD patients. METHODS: We created two retrospective cohorts from the Quebec CHD Database; with data from 1988 to 2010. Complexity of reparative procedures for CHD lesions were used as the proxy of CPB exposure with more complex procedure means longer exposure to CPB. Study Population 1 included pediatric patients with a single reparative procedure and compared patients with complex (long CBP) versus isolated shunt (short CBP) lesions. To assess the effects of CPB alone in Study Population 2 we compared patients with isolated atrial septal defects (ASD) who had surgical (short CBP) versus percutaneous (no CBP) repairs. The primary endpoint for both cohorts was development of an NCD. RESULTS: In Study population 1, 1174 patients underwent complex surgical repair and 1620 had a shunt closure. The incidence of NCDs was 2.45/100 person-years in the complex surgery group, and 2.08/100 person-years in the shunt closure group. The following were associated with increased risk of developing a NCD: surgical complexity (Hazard Ratio [HR] = 1.20, 95% Confidence Interval [CI]: 1.01-1.42), younger age at intervention (AAI) (HR = 1.20, 95% CI: 1.16-1.25), male sex (HR = 1.91, 95% CI: 1.61-2.27), and later calendar year at intervention (HR = 1.06, 95% CI: 1.04-1.07). Study population 2 had 527 isolated ASD patients; 202 underwent surgical repair and 325 had percutaneous closure. The incidence of NCDs was not statistically different between groups. Male sex (HR = 1.77, 95% CI: 1.08-2.89) and younger AAI (HR = 1.15, 95% CI: 1.06-1.25) were associated with increased NCD risk. CONCLUSION: Increased surgical complexity, male sex and younger AAI were associated with increased risk of NCDs in pediatric CHD patients. Surveillance protocols should be considered to identify NCDs in CHD patients after cardiac intervention.

Risk prediction models for heart failure admissions in adults with congenital heart disease.

BACKGROUND: Heart failure (HF) is the leading cause of death in adult patients with congenital heart disease (ACHD). No risk prediction model exists for HF hospitalization (HFH) for ACHD patients. We aimed to develop a clinically relevant one-year risk prediction system to identify ACHD patients at high risk for HFH. METHODS: Data source was the Quebec CHD Database. A retrospective cohort including all ACHD patients aged 18-64 (1995-2010) was constructed for assessing the cumulative risk of HFH adjusting for competing risk of death. To identify one-year predictors of incident HFH, multivariable logistic regressions were employed to a nested case-control sample of all ACHD patients aged 18-64 in 2009. The final model was used to create a risk score system based on adjusted odds ratios. RESULTS: The cohort included 29,991 ACHD patients followed for 648,457 person-years. The cumulative HFH risk by age 65 was 12.58%. The case-control sample comprised 26,420 subjects, of whom 189 had HFHs. Significant one-year predictors were age ≥ 50, male sex, CHD lesion severity, recent 12-month HFH history, pulmonary arterial hypertension, chronic kidney disease, coronary artery disease, systemic arterial hypertension, and diabetes mellitus. The created risk score ranged from 0 to 19. The corresponding HFH risk rose rapidly beyond a score of 8. The risk scoring system demonstrated excellent prediction performance. CONCLUSIONS: One eighth of ACHD population experienced HFH before age 65. Age, sex, CHD lesion severity, recent 12-month HFH history, and comorbidities constructed a risk prediction model that successfully identified patients at high risk for HFH.

Children and adults with congenital heart disease lost to follow-up: who and when?

BACKGROUND: Many patients with congenital heart disease (CHD) require lifelong care. However, the duration of cardiology follow-up in children and adults with CHD is unknown. We sought to determine the proportion of children and young adults with CHD receiving outpatient cardiology care and to identify predictors of lack of follow-up. METHODS AND RESULTS: The study population consisted of individuals born in 1983 and alive at age 22 years who were diagnosed with CHD in Quebec, Canada, before 6 years of age (n=643). Patients and outpatient visits were identified with the use of the provincial physician's claims database. Three age groups were examined for the presence of outpatient cardiology follow-up: 6 to 12, 13 to 17, and 18 to 22 years. CHD lesions were classified as severe (n=84; 13%), simple shunts (n=390; 61%), and "other" lesions (n=169; 26%). Failure to receive cardiac follow-up after the 6th, 13th, and 18th birthday occurred in 28%, 47%, and 61%, respectively. Among those with severe lesions, only 79% were seen after the 18th birthday. However, the majority of subjects visited primary care physicians in all age groups, and 93% remained in contact with the healthcare system into early adulthood. Predictors of lack of cardiology follow-up in adulthood included male sex, a nonsevere lesion, and a history of follow-up outside a university hospital setting. CONCLUSIONS: Lack of cardiology follow-up begins during childhood, even among those with severe lesions. This occurs despite patients being in contact with other healthcare providers. Improved communication with primary care physicians may reduce the proportion of patients lost to cardiac follow-up.

Atrial arrhythmias in adults with congenital heart disease.

BACKGROUND: Atrial arrhythmias increase disease burden in the general adult population. Adults with congenital heart lesions constitute a rapidly growing group of patients with cardiovascular disease. We hypothesized that atrial arrhythmias increase with age and impair health outcomes in this population. METHODS AND RESULTS: We conducted a population-based analysis of prevalence, lifetime risk, mortality, and morbidity associated with atrial arrhythmias in adults with congenital heart disease from l983 to 2005. In 38 428 adults with congenital heart disease in 2005, 5812 had atrial arrhythmias. Overall, the 20-year risk of developing atrial arrhythmia was 7% in a 20-year-old subject and 38% in a 50-year-old subject. More than 50% of patients with severe congenital heart disease reaching age 18 years developed atrial arrhythmias by age 65 years. In patients with congenital heart disease, the hazard ratio of any adverse event in those with atrial arrhythmias compared with those without was 2.50 (95% confidence interval, 2.38 to 2.62; P<0.0001), with a near 50% increase in mortality (hazard ratio, 1.47; 95% confidence interval, 1.37 to 1.58; P<0.001), more than double the risk of morbidity (stroke or heart failure) (hazard ratio, 2.21; 95% confidence interval, 2.07 to 2.36; P<0.001), and 3 times the risk of cardiac interventions (hazard ratio, 3.00; 95% confidence interval, 2.81 to 3.20; P<0.001). CONCLUSIONS: Atrial arrhythmias occurred in 15% of adults with congenital heart disease. The lifetime incidence increased steadily with age and was associated with a doubling of the risk of adverse events. An increase in resource allocation should be anticipated to deal with this increasing burden.

Planning the specialized care of adult congenital heart disease patients: from numbers to guidelines; an epidemiologic approach.

Guidelines published in 2001 recommended 1 regional adult congenital heart disease (ACHD) center per 3 to 10 million population. Our objective was to determine if published guidelines on the numbers of regional ACHD centers are sufficient to meet the needs of adults with congenital heart disease in the general population. Population data were examined to evaluate the recommendations for the number of regional centers. We extrapolated a population prevalence of 4.09 per 1,000 adults corresponding to 847,896 and 87,375 patients with ACHD in the United States and Canada, respectively. We reviewed the information currently available on the numbers of ACHD facilities of any kind indexed to continental populations. We examined the distribution of disease and health services in pediatric and adult populations and examined the evidence for pressure points during the transition process. Published data on 6 of the largest regional ACHD centers were used to model regional center care. We reviewed determinants and recommendations for follow-up in regional centers. We explore 3 scenarios of referral patterns to regional centers, examining their impact of the number of centers required per country population. In conclusion, we demonstrate that 1 regional ACHD center for a population of 2.0 million adults appears to be closer to what is required for improving access to specialized care for patients with ACHD in the United States and Canada.

Transition and Transfer From Pediatric to Adult Congenital Heart Disease Care in Canada: Call For Strategic Implementation.

Dramatic increases in survival to adulthood for persons born with congenital heart disease (CHD) have led rise to a corresponding need to provide age-appropriate and developmentally appropriate care across the lifespan. Health care transition is a multidimensional process that ideally begins in early adolescence in the pediatric setting and continues through young adulthood with input from both pediatric and adult CHD providers. Preparation for transition includes the fostering of adolescents' knowledge of their CHD and of self-management and self-advocacy skills needed for lifelong management of chronic disease. Transfer is the event in time when a patient's care and ownership of health records is taken over by the adult health care team; this is just one element of the broader transition process. Transfer typically occurs by age 18 throughout much of Canada. Successful transition is a shared responsibility, requiring engaged pediatric and adult providers and partnership with both young adults and their parents, all of whom may struggle with this process. An interdisciplinary approach to transition is recommended, given that health care transition is a complex process that occurs within the broader context of young adults' lives. This review summarizes existing evidence regarding transition and transfer, offers perspectives from multiple stakeholders, and proposes a transition curriculum of development of CHD education and self-management and self-advocacy skills. Specific recommendations to improve implementation of transition and transfer care within the Canadian context are provided. This review sheds light on the current capacity and challenges of adult CHD providers and proposes directions to move this field forward.