MixEHR-SurG: A joint proportional hazard and guided topic model for inferring mortality-associated topics from electronic health records.

Survival models can help medical practitioners to evaluate the prognostic importance of clinical variables to patient outcomes such as mortality or hospital readmission and subsequently design personalized treatment regimes. Electronic Health Records (EHRs) hold the promise for large-scale survival analysis based on systematically recorded clinical features for each patient. However, existing survival models either do not scale to high dimensional and multi-modal EHR data or are difficult to interpret. In this study, we present a supervised topic model called MixEHR-SurG to simultaneously integrate heterogeneous EHR data and model survival hazard. Our contributions are three-folds: (1) integrating EHR topic inference with Cox proportional hazards likelihood; (2) integrating patient-specific topic hyperparameters using the PheCode concepts such that each topic can be identified with exactly one PheCode-associated phenotype; (3) multi-modal survival topic inference. This leads to a highly interpretable survival topic model that can infer PheCode-specific phenotype topics associated with patient mortality. We evaluated MixEHR-SurG using a simulated dataset and two real-world EHR datasets: the Quebec Congenital Heart Disease (CHD) data consisting of 8211 subjects with 75,187 outpatient claim records of 1767 unique ICD codes; the MIMIC-III consisting of 1458 subjects with multi-modal EHR records. Compared to the baselines, MixEHR-SurG achieved a superior dynamic AUROC for mortality prediction, with a mean AUROC score of 0.89 in the simulation dataset and a mean AUROC of 0.645 on the CHD dataset. Qualitatively, MixEHR-SurG associates severe cardiac conditions with high mortality risk among the CHD patients after the first heart failure hospitalization and critical brain injuries with increased mortality among the MIMIC-III patients after their ICU discharge. Together, the integration of the Cox proportional hazards model and EHR topic inference in MixEHR-SurG not only leads to competitive mortality prediction but also meaningful phenotype topics for in-depth survival analysis. The software is available at GitHub: https://github.com/li-lab-mcgill/MixEHR-SurG.

Hypertensive disorders of pregnant women with heart disease: the ESC EORP ROPAC Registry.

AIMS: Hypertensive disorders of pregnancy (HDP) occur in 10% of pregnancies in the general population, pre-eclampsia specifically in 3-5%. Hypertensive disorders of pregnancy may have a high prevalence in, and be poorly tolerated by, women with heart disease. METHODS AND RESULTS: The prevalence and outcomes of HDP (chronic hypertension, gestational hypertension or pre-eclampsia) were assessed in the ESC EORP ROPAC (n = 5739), a worldwide prospective registry of pregnancies in women with heart disease.The overall prevalence of HDP was 10.3%, made up of chronic hypertension (5.9%), gestational hypertension (1.3%), and pre-eclampsia (3%), with significant differences between the types of underlying heart disease (P < 0.05). Pre-eclampsia rates were highest in women with pulmonary arterial hypertension (PAH) (11.1%), cardiomyopathy (CMP) (7.1%), and ischaemic heart disease (IHD) (6.3%). Maternal mortality was 1.4 and 0.6% in women with vs. without HDP (P = 0.04), and even 3.5% in those with pre-eclampsia. All pre-eclampsia-related deaths were post-partum and 50% were due to heart failure. Heart failure occurred in 18.5 vs. 10.6% of women with vs. without HDP (P < 0.001) and in 29.1% of those with pre-eclampsia. Perinatal mortality was 3.1 vs. 1.7% in women with vs. without HDP (P = 0.019) and 4.7% in those with pre-eclampsia. CONCLUSION: Hypertensive disorders of pregnancy and pre-eclampsia rates were higher in women with CMP, IHD, and PAH than in the general population. Adverse outcomes were increased in women with HDP, and maternal mortality was strikingly high in women with pre-eclampsia. The combination of HDP and heart disease should prompt close surveillance in a multidisciplinary context and the diagnosis of pre-eclampsia requires hospital admission and continued monitoring during the post-partum period.

A randomized controlled trial of renin-angiotensin-aldosterone system inhibitor management in patients admitted in hospital with COVID-19.

BACKGROUND: Renin-angiotensin aldosterone system inhibitors (RAASi) are commonly used among patients hospitalized with a severe acute respiratory syndrome coronavirus 2 infection coronavirus disease 2019 (COVID-19). We evaluated whether continuation versus discontinuation of RAASi were associated with short term clinical or biochemical outcomes. METHODS: The RAAS-COVID-19 trial was a randomized, open label study in adult patients previously treated with RAASi who are hospitalized with COVID-19 (NCT04508985). Participants were randomized 1:1 to discontinue or continue RAASi. The primary outcome was a global rank score calculated from baseline to day 7 (or discharge) incorporating clinical events and biomarker changes. Global rank scores were compared between groups using the Wilcoxon test statistic and the negative binomial test (using incident rate ratio [IRR]) and the intention-to-treat principle. RESULTS: Overall, 46 participants were enrolled; 21 participants were randomized to discontinue RAASi and 25 to continue. Patients' mean age was 71.5 years and 43.5% were female. Discontinuation of RAASi, versus continuation, resulted in a non-statistically different mean global rank score (discontinuation 6 [standard deviation [SD] 6.3] vs continuation 3.8 (SD 2.5); P = .60). The negative binomial analysis identified that discontinuation increased the risk of adverse outcomes (IRR 1.67 [95% CI 1.06-2.62]; P = .027); RAASi discontinuation increased brain natriuretic peptide levels (% change from baseline: +16.7% vs -27.5%; P = .024) and the incidence of acute heart failure (33% vs 4.2%, P = .016). CONCLUSION: RAASi continuation in participants hospitalized with COVID-19 appears safe; discontinuation increased brain natriuretic peptide levels and may increase risk of acute heart failure; where possible, RAASi should be continued.

Interventional Therapy Versus Medical Therapy for Secundum Atrial Septal Defect: A Systematic Review (Part 2) for the 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.

Secundum atrial septal defect (ASD) is the most common adult congenital heart defect and can present with wide variation in clinical findings. With the intention of preventing morbidity and mortality associated with late presentation of ASD, consensus guidelines have recommended surgical or percutaneous ASD closure in adults with right heart enlargement, with or without symptoms. The aim of the present analysis was to determine if the protective effect of secundum ASD closure in adults could be qualified by pooling data from published studies. A systematic review and meta-analysis were performed by using EMBASE, MEDLINE (through PubMed), and the Cochrane Library databases to assess the effect of secundum ASD percutaneous or surgical closure in unoperated adults ≥18 years of age. Data were pooled across studies with the DerSimonian-Laird random-effects model or a Bayesian meta-analysis model. Between-study heterogeneity was assessed with Cochran's Q test. Bias assessment was performed with the Newcastle-Ottawa Scale and the Cochrane Risk of Bias Tool, and statistical risk of bias was assessed with Begg and Mazumdar's test and Egger's test. A total of 11 nonrandomized studies met the inclusion criteria, contributing 603 patients. Pooled analysis showed a protective effect of ASD closure on New York Heart Association functional class and on right ventricular systolic pressure, volumes, and dimensions. Two additional studies comprising 652 patients were reviewed separately for mortality outcome and primary outcome of interest because they did not meet the inclusion criteria. Those studies showed that ASD closure was associated with a weak protective effect on adjusted mortality rate but no significant impact on atrial arrhythmias in patients >50 years of age. Across all studies, there was significant heterogeneity between studies for nearly all clinical outcomes. The overall body of evidence was limited to observational cohort studies, the limitations of which make for low-strength evidence. Even within the parameters of the included studies, quality of evidence was further diminished by the lack of well-defined clinical outcomes. In conclusion, pooled data analysis on the impact of secundum ASD closure in adults was notably limited because of the lack of randomized controlled trials in patients with only secundum ASD. The few cohort studies in this population demonstrated improvement in functional status and right ventricular size and function as shown by echocardiogram. However, our findings suggest that at the time of this publication, insufficient data are available to determine the impact of ASD repair on mortality rate in adults.

Medical Therapy for Systemic Right Ventricles: A Systematic Review (Part 1) for the 2018 AHA/ACC Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.

Patients with systemic morphological right ventricles (RVs), including congenitally corrected transposition of the great arteries and dextro-transposition of the great arteries with a Mustard or Senning atrial baffle repair, have a high likelihood of developing systemic ventricular dysfunction. Unfortunately, there are a limited number of clinical studies on the efficacy of medical therapy for systemic RV dysfunction. We performed a systematic review and meta-analysis to assess the effect of angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers (ARBs), beta blockers, and aldosterone antagonists in adults with systemic RVs. The inclusion criteria included age ≥18 years, systemic RVs, and at least 3 months of treatment with ACE inhibitor, ARB, beta blocker, or aldosterone antagonist. The outcomes included RV end-diastolic and end-systolic dimensions, RV ejection fraction, functional class, and exercise capacity. EMBASE, PubMed, and Cochrane databases were searched. The selected data were pooled and analyzed with the DerSimonian-Laird random-effects meta-analysis model. Between-study heterogeneity was assessed with Cochran's Q test. A Bayesian meta-analysis model was also used in the event that heterogeneity was low. Bias assessment was performed with the Newcastle-Ottawa Scale and Cochrane Risk of Bias Tool, and statistical risk of bias was assessed with Begg and Mazumdar's test and Egger's test. Six studies met the inclusion criteria, contributing a total of 187 patients; treatment with beta blocker was the intervention that could not be analyzed because of the small number of patients and diversity of outcomes reported. After at least 3 months of treatment with ACE inhibitors, ARBs, or aldosterone antagonists, there was no statistically significant change in mean ejection fraction, ventricular dimensions, or peak ventilatory equivalent of oxygen. The methodological quality of the majority of included studies was low, mainly because of a lack of a randomized and controlled design, small sample size, and incomplete follow-up. In conclusion, pooled results across the limited available studies did not provide conclusive evidence with regard to a beneficial effect of medical therapy in adults with systemic RV dysfunction. Randomized controlled trials or comparative-effectiveness studies that are sufficiently powered to demonstrate effect are needed to elucidate the efficacy of ACE inhibitors, ARBs, beta blockers, and aldosterone antagonists in patients with systemic RVs.

Quantification of apparent axon density and orientation dispersion in the white matter of youth born with congenital heart disease.

BACKGROUND: White matter alterations have previously been demonstrated in adolescents born with congenital heart disease (CHD) using diffusion tensor imaging (DTI). However, due to the non-specific nature of DTI metrics, it is difficult to interpret these findings in terms of their microstructural implications. This study investigated the use of neurite orientation dispersion and density imaging (NODDI), which involves the acquisition of advanced multiple b-value data over two shells and provides proxy measures of apparent axon density and orientation dispersion within white matter, as a complement to classic DTI measures. STUDY DESIGN: Youth aged 16 to 24 years born with complex CHD and healthy peers underwent brain magnetic resonance imaging. White matter tract volumes and tract-average values of DTI and NODDI metrics were compared between groups. Tract-average DTI and NODDI results were spatially confirmed using tract-based spatial statistics. RESULTS: There were widespread regions of lower tract-average neurite density index (NDI) in the CHD group as compared to the control group, particularly within long association tracts and in regions of the corpus callosum, accompanied by smaller white matter tract volumes and isolated clusters of lower fractional anisotropy (FA). There were no significant differences in orientation dispersion index (ODI) between groups. CONCLUSION: Lower apparent density of axonal packing, but not altered axonal orientation, is a key microstructural factor in the white matter abnormalities observed in youth born with CHD. These impairments in axonal packing may be an enduring consequence of early life brain injury and dysmaturation and may explain some of the long-term neuropsychological difficulties experienced by this at-risk group.

Pregnancy outcomes in women with cardiovascular disease: evolving trends over 10 years in the ESC Registry Of Pregnancy And Cardiac disease (ROPAC).

AIMS: Reducing maternal mortality is a World Health Organization (WHO) global health goal. Although maternal deaths due to haemorrhage and infection are declining, those related to heart disease are increasing and are now the most important cause in western countries. The aim is to define contemporary diagnosis-specific outcomes in pregnant women with heart disease. METHODS AND RESULTS: From 2007 to 2018, pregnant women with heart disease were prospectively enrolled in the Registry Of Pregnancy And Cardiac disease (ROPAC). Primary outcome was maternal mortality or heart failure, secondary outcomes were other cardiac, obstetric, and foetal complications. We enrolled 5739 pregnancies; the mean age was 29.5. Prevalent diagnoses were congenital (57%) and valvular heart disease (29%). Mortality (overall 0.6%) was highest in the pulmonary arterial hypertension (PAH) group (9%). Heart failure occurred in 11%, arrhythmias in 2%. Delivery was by Caesarean section in 44%. Obstetric and foetal complications occurred in 17% and 21%, respectively. The number of high-risk pregnancies (mWHO Class IV) increased from 0.7% in 2007-2010 to 10.9% in 2015-2018. Determinants for maternal complications were pre-pregnancy heart failure or New York Heart Association >II, systemic ejection fraction <40%, mWHO Class 4, and anticoagulants use. After an increase from 2007 to 2009, complication rates fell from 13.2% in 2010 to 9.3% in 2017. CONCLUSION: Rates of maternal mortality or heart failure were high in women with heart disease. However, from 2010, these rates declined despite the inclusion of more high-risk pregnancies. Highest complication rates occurred in women with PAH.

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.

Hippocampal alterations and functional correlates in adolescents and young adults with congenital heart disease.

There is a high prevalence of neurodevelopmental impairments in individuals living with congenital heart disease (CHD) and the neural correlates of these impairments are not yet fully understood. Recent studies have shown that hippocampal volume and shape differences may provide unique biomarkers for neurodevelopmental disorders. The hippocampus is vulnerable to early life injury, especially in populations at risk for hypoxemia or hemodynamic instability such as in neonates with CHD. We compared hippocampal gray and white matter volume and morphometry between youth born with CHD (n = 50) aged 16-24 years and healthy peers (n = 48). We also explored whether hippocampal gray and white matter volume and morphometry are associated with executive function and self-regulation deficits. To do so, participants underwent 3T brain magnetic resonance imaging and completed the self-reported Behavior Rating Inventory of Executive Function-Adult version. We found that youth with CHD had smaller hippocampal volumes (all statistics corrected for false discovery rate; q < 0.05) as compared to controls. We also observed significant smaller surface area bilaterally and inward displacement on the left hippocampus predominantly on the ventral side (q < 0.10) in the CHD group that were not present in the controls. Left CA1 and CA2/3 were negatively associated with working memory (p < .05). Here, we report, for the first-time, hippocampal morphometric alterations in youth born with CHD when compared to healthy peers, as well as, structure-function relationships between hippocampal volumes and executive function. These differences may reflect long lasting alterations in brain development specific to individual with CHD.

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.

Brain in Congenital Heart Disease Across the Lifespan: The Cumulative Burden of Injury.

The number of patients surviving with congenital heart disease (CHD) has soared over the last 3 decades. Adults constitute the fastest-growing segment of the CHD population, now outnumbering children. Research to date on the heart-brain intersection in this population has been focused largely on neurodevelopmental outcomes in childhood and adolescence. Mutations in genes that are highly expressed in heart and brain may cause cerebral dysgenesis. Together with altered cerebral perfusion in utero, these factors are associated with abnormalities of brain structure and brain immaturity in a significant portion of neonates with critical CHD even before they undergo cardiac surgery. In infancy and childhood, the brain may be affected by risk factors related to heart disease itself or to its interventional treatments. As children with CHD become adults, they increasingly develop heart failure, atrial fibrillation, hypertension, diabetes mellitus, and coronary disease. These acquired cardiovascular comorbidities can be expected to have effects similar to those in the general population on cerebral blood flow, brain volumes, and dementia. In both children and adults, cardiovascular disease may have adverse effects on achievement, executive function, memory, language, social interactions, and quality of life. Against the backdrop of shifting demographics, risk factors for brain injury in the CHD population are cumulative and synergistic. As neurodevelopmental sequelae in children with CHD evolve to cognitive decline or dementia during adulthood, a growing population of CHD can be expected to require support services. We highlight evidence gaps and future research directions.

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.

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.

The Role of Cardiopulmonary Exercise Testing for Decision Making in Patients with Repaired Tetralogy of Fallot.

Tetralogy of Fallot is the most common form of cyanotic congenital heart disease. As a result of the surgical strategies employed at the time of initial repair, chronic pulmonary regurgitation (PR) is prevalent in this population. Despite sustained research efforts, patient selection and timing of pulmonary valve replacement (PVR) to address PR in young asymptomatic patients with repaired tetralogy of Fallot (rToF) remain a fundamental but as yet unanswered question in the field of congenital heart disease. The ability of the heart to compensate for the chronic volume overload imposed by PR is critical in the evaluation of the risks and benefits of PVR. The difficulty in clarifying the functional impact of PR on the cardiovascular capacity may be in part responsible for the uncertainty surrounding the timing of PVR. Cardiopulmonary exercise testing (CPET) may be used to assess abnormal cardiovascular response to increased physiologic demands. However, its use as a tool for risk stratification in asymptomatic adolescents and young adults with rToF is still ill-defined. In this paper, we review the role of CPET as a potentially valuable adjunct to current risk stratification strategies with a focus on asymptomatic rToF adolescents and young adults being considered for PVR. The role of maximal and submaximal exercise measurements to identify young patients with a decreased or borderline low peak VO2 resulting from impaired ventricular function is explored. Current knowledge gaps and research perspectives are highlighted.

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.

Specialized adult congenital heart disease care: the impact of policy on mortality.

BACKGROUND: Clinical guidelines recommend specialized care for adult congenital heart disease (ACHD) patients. In reality, few patients receive such dedicated care. We sought to examine the impact of specialized care on ACHD patient mortality. METHODS AND RESULTS: We examined referral rates to specialized ACHD centers and ACHD patient mortality rates between 1990 and 2005 in the population-based Quebec Congenital Heart Disease database (n=71 467). This period covers several years before and after the publication of guidelines endorsing specialized care for ACHD patients. A time-series design, based on Joinpoint and Poisson regression analyses, was used to assess the changes in annual referral and patient mortality rates. The association between specialized ACHD care and all-cause mortality was assessed in both case-control and cohort studies. The time-series analysis demonstrated a significant increase in referral rates to specialized ACHD centers in 1997 (rate ratio, +7.4%; 95% confidence interval [CI], +6.6% to +8.2%). In parallel, a significant reduction in expected ACHD patient mortality was observed after year 2000 (rate ratio, -5.0%;95% CI, -10.8% to -0.8%). In exploratory post hoc cohort and case-control analyses, specialized ACHD care was independently associated with reduced mortality (hazard ratio, 0.78; 95% CI, 0.65-0.94) and a reduced odds of death (adjusted odds ratio, 0.82; 95% CI, 0.08-0.97), respectively. This effect was predominantly driven by patients with severe congenital heart disease (hazard ratio, 0.38; 95% CI, 0.22-0.67). CONCLUSIONS: A significant increase in referrals to specialized ACHD centers followed the introduction of the clinical guidelines. Moreover, referral to specialized ACHD care was independently associated with a significant mortality reduction. Our findings support a model of specialized care for all ACHD patients.

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.