Pathology of explanted pediatric hearts: An 11-year study. Population characteristics and implications for outcomes.

BACKGROUND: As more pediatric patients become candidates for heart transplantation (HT), understanding pathological predictors of outcome and the accuracy of the pretransplantation evaluation are important to optimize utilization of scarce donor organs and improve outcomes. The authors aimed to investigate explanted heart specimens to identify pathologic predictors that may affect cardiac allograft survival after HT. METHODS: Explanted pediatric hearts obtained over an 11-year period were analyzed to understand the patient demographics, indications for transplant, and the clinical-pathological factors. RESULTS: In this study, 149 explanted hearts, 46% congenital heart defects (CHD), were studied. CHD patients were younger and mean pulmonary artery pressure and resistance were significantly lower than in cardiomyopathy patients. Twenty-one died or underwent retransplantation (14.1%). Survival was significantly higher in the cardiomyopathy group at all follow-up intervals. There were more deaths and the 1-, 5- and 7-year survival was lower in patients ≤10 years of age at HT. Early rejection was significantly higher in CHD patients exposed to homograft tissue, but not late rejection. Mortality/retransplantation rate was significantly higher and allograft survival lower in CHD hearts with excessive fibrosis of one or both ventricles. Anatomic diagnosis at pathologic examination differed from the clinical diagnosis in eight cases. CONCLUSIONS: Survival was better for the cardiomyopathy group and patients >10 years at HT. Prior homograft use was associated with a higher prevalence of early rejection. Ventricular fibrosis (of explant) was a strong predictor of outcome in the CHD group. We presented several pathologic findings in explanted pediatric hearts.

Burden with No Benefit: Prior Authorization in Congenital Cardiology.

Prior authorization is a process that health insurance companies use to determine if a patient's health insurance will cover certain medical treatments, procedures, or medications. Prior authorization requests are common in adult congenital and pediatric cardiology (ACPC) due to need for advanced diagnostics, complex procedures, disease-specific medications, and the heterogeneity of the ACPC population. Prior authorizations in ACPC are rarely denied, but nonetheless, they are often accompanied by significant administrative burden on clinical care teams and delays in patient care. Prior authorizations have been implicated in worsening care inequities. The prior authorization process is insurer specific with differences between commercial and public insurers. Prior authorization rejections were previously found to be more common for women, racial minorities, those with low education, and in low-income groups. Prior authorization unduly burdens routine diagnostics, routine interventional and surgical procedures, and routine cardiac specific medication use in the ACPC population. This manuscript highlights the burdens of prior authorization and advocates for the elimination of prior authorization for ACPC patients.

National Variation in Congenital Heart Surgery Outcomes.

BACKGROUND: Optimal strategies to improve national congenital heart surgery outcomes and reduce variability across hospitals remain unclear. Many policy and quality improvement efforts have focused primarily on higher-risk patients and mortality alone. Improving our understanding of both morbidity and mortality and current variation across the spectrum of complexity would better inform future efforts. METHODS: Hospitals participating in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2014-2017) were included. Case mix-adjusted operative mortality, major complications, and postoperative length of stay were evaluated using Bayesian models. Hospital variation was quantified by the interdecile ratio (IDR, upper versus lower 10%) and 95% credible intervals (CrIs). Stratified analyses were performed by risk group (Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery [STAT] category) and simulations evaluated the potential impact of reductions in variation. RESULTS: A total of 102 hospitals (n=84 407) were included, representing ≈85% of US congenital heart programs. STAT category 1 to 3 (lower risk) operations comprised 74% of cases. All outcomes varied significantly across hospitals: adjusted mortality by 3-fold (upper versus lower decile 5.0% versus 1.6%, IDR 3.1 [95% CrI 2.5-3.7]), mean length of stay by 1.8-fold (19.2 versus 10.5 days, IDR 1.8 [95% CrI 1.8-1.9]), and major complications by >3-fold (23.5% versus 7.0%, IDR 3.4 [95% CrI 3.0-3.8]). The degree of variation was similar or greater for low- versus high-risk cases across outcomes, eg, ≈3-fold mortality variation across hospitals for STAT 1 to 3 (IDR 3.0 [95% CrI 2.1-4.2]) and STAT 4 or 5 (IDR 3.1 [95% CrI 2.4-3.9]) cases. High-volume hospitals had less variability across outcomes and risk categories. Simulations suggested potential reductions in deaths (n=282), major complications (n=1539), and length of stay (101 183 days) over the 4-year study period if all hospitals were to perform at the current median or better, with 37% to 60% of the improvement related to the STAT 1 to 3 (lower risk) group across outcomes. CONCLUSIONS: We demonstrate significant hospital variation in morbidity and mortality after congenital heart surgery. Contrary to traditional thinking, a substantial portion of potential improvements that could be realized on a national scale were related to variability among lower-risk cases. These findings suggest modifications to our current approaches to optimize care and outcomes in this population are needed.

Management of Complex Left Ventricular Outflow Tract Obstruction: A Comparison of Konno and Modified Konno Techniques.

Management of complex left ventricular outflow tract obstruction (LVOTO) can be achieved with a Konno or Modified Konno procedure to enlarge the LVOT. We hypothesized that patients who undergo a Modified Konno procedure would have a higher rate of LVOT re-intervention compared to the Konno procedure. Patients who underwent a Konno or Modified Konno procedure for LVOTO at a single tertiary care center between 1990 and 2014 were retrospectively reviewed. The primary outcome was LVOT re-intervention post-discharge from index Konno or Modified Konno procedure. Cox regression and Kaplan-Meier estimates were used for time-to-event analysis of LVOT re-interventions, any unplanned re-interventions, and transplant-free survival. The study included 122 patients: 51 (41.8%) in the Konno group and 71 (58.2%) in the Modified Konno group. Median age at surgery was 8.2 (IQR 3-16) years in the Konno group and 3.9 (IQR 1.5-11) years in the Modified Konno group. Multiple left heart lesions were less prevalent in Modified Konno patients. There were 36 (29.5%) patients with LVOT re-interventions: 8 (16%) in the Konno group and 28 (39.4%) in the Modified Konno group (p = 0.01). Transplant-free survival at five years was 87.2% for the Konno group and 93.5% for the Modified Konno group. A higher rate of LVOT re-intervention was found in the Modified Konno group although the Konno and Modified Konno techniques were applied to different patient populations. This finding suggests that careful preoperative decision-making can direct therapy appropriately and that fundamental diagnosis affects procedure choice.

Accurate Prediction of Congenital Heart Surgical Length of Stay Incorporating a Procedure-Based Categorical Variable.

OBJECTIVES: There is increasing demand for the limited resource of Cardiac ICU care. In this setting, there is an expectation to optimize hospital resource use without restricting care delivery. We developed methodology to predict extended cardiac ICU length of stay following surgery for congenital heart disease. DESIGN: Retrospective analysis by multivariable logistic regression of important predictive factors for outcome of postoperative ICU length of stay greater than 7 days. SETTING: Cardiac ICU at Boston Children's Hospital, a large, pediatric cardiac surgical referral center. PATIENTS: All patients undergoing congenital heart surgery at Boston Children's Hospital from January 1, 2010, to December 31, 2015. INTERVENTIONS: No study interventions. MEASUREMENTS AND MAIN RESULTS: The patient population was identified. Clinical variables and Congenital Heart Surgical Stay categories were recorded based on surgical intervention performed. A model was built to predict the outcome postoperative ICU length of stay greater than 7 days at the time of surgical intervention. The development cohort included 4,029 cases categorized into five Congenital Heart Surgical Stay categories with a C statistic of 0.78 for the outcome ICU length of stay greater than 7 days. Explanatory value increased with inclusion of patient preoperative status as determined by age, ventilator dependence, and admission status (C statistic = 0.84). A second model was optimized with inclusion of intraoperative factors available at the time of postoperative ICU admission, including cardiopulmonary bypass time and chest left open (C statistic 0.87). Each model was tested in a validation cohort (n = 1,008) with equivalent C statistics. CONCLUSIONS: Using a model comprised of basic patient characteristics, we developed a robust prediction tool for patients who will remain in the ICU longer than 7 days after cardiac surgery, at the time of postoperative ICU admission. This model may assist in patient counseling, case scheduling, and capacity management. Further examination in external settings is needed to establish generalizability.

Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals: collateral vessel disease burden and unifocalisation strategies.

IntroductionThe optimal approach to unifocalisation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (pulmonary artery/ventricular septal defect/major aortopulmonary collaterals) remains controversial. Moreover, the impact of collateral vessel disease burden on surgical decision-making and late outcomes remains poorly defined. We investigated our centre's experience in the surgical management of pulmonary artery/ventricular septal defect/major aortopulmonary collaterals.Materials and methodsBetween 1996 and 2015, 84 consecutive patients with pulmonary artery/ventricular septal defect/major aortopulmonary collaterals underwent unifocalisation. In all, 41 patients received single-stage unifocalisation (Group 1) and 43 patients underwent multi-stage repair (Group 2). Preoperative collateral vessel anatomy, branch pulmonary artery reinterventions, ventricular septal defect status, and late right ventricle/left ventricle pressure ratio were evaluated. RESULTS: Median follow-up was 4.8 compared with 5.7 years for Groups 1 and 2, respectively, p = 0.65. Median number of major aortopulmonary collaterals/patient was 3, ranging from 1 to 8, in Group 1 compared with 4, ranging from 1 to 8, in Group 2, p = 0.09. Group 2 had a higher number of lobar/segmental stenoses within collateral vessels (p = 0.02). Group 1 had fewer catheter-based branch pulmonary artery reinterventions, with 5 (inter-quartile range from 1 to 7) per patient, compared with 9 (inter-quartile range from 4 to 14) in Group 2, p = 0.009. Among patients who achieved ventricular septal defect closure, median right ventricle/left ventricle pressure was 0.48 in Group 1 compared with 0.78 in Group 2, p = 0.03. Overall mortality was 6 (17%) in Group 1 compared with 9 (21%) in Group 2.DiscussionSingle-stage unifocalisation is a promising repair strategy in select patients, achieving low rates of reintervention for branch pulmonary artery restenosis and excellent mid-term haemodynamic outcomes. However, specific anatomic substrates of pulmonary artery/ventricular septal defect/major aortopulmonary collaterals may be better suited to multi-stage repair. Preoperative evaluation of collateral vessel calibre and function may help inform more patient-specific surgical management.

Advances in MALDI imaging mass spectrometry of proteins in cardiac tissue, including the heart valve.

Significant progress has been made for tissue imaging of proteins using matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI IMS). These advancements now facilitate mapping of a wide range of proteins, peptides, and post-translational modifications in a wide variety of tissues; however, the use of MALDI IMS to detect proteins from cardiac tissue is limited. This review discusses the most recent advances in protein imaging and demonstrates application to cardiac tissue, including the heart valve. Protein imaging by MALDI IMS allows multiplexed histological mapping of proteins and protein components that are inaccessible by antibodies and should be considered an important tool for basic and clinical cardiovascular research. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.

A Method to Account for Variation in Congenital Heart Surgery Length of Stay.

OBJECTIVES: We sought to develop a risk-adjustment methodology for length of stay in congenital heart surgery, as none exist. DESIGN: Prospective cohort analysis combined with previously obtained retrospective cohort analysis of a Department of Cardiovascular Surgery clinical database. PATIENTS: Patients discharged from Boston Children's Hospital between October 1, 2006, and May 31, 2014, that underwent a congenital heart surgery procedure(s) linked to one of 103 surgical procedure types. MEASUREMENTS AND MAIN RESULTS: Six thousand two hundred nine discharges during the reporting period at Boston Children's Hospital comprised the cohort. Seven Surgical Length Categories were developed to group surgical procedure types. A multivariable model for outcome length of stay was built using a derivation cohort consisting of a 75% random sample, starting with Surgical Length Categories and considering additional a priori factors. Postoperative factors were then added to improve predictive performance. The remaining 25% of the cohort was used to validate the multivariable models. The coefficient of determination (R) was used to estimate the variability in length of stay explained by each factor. The Surgical Length Categories yielded an R of 42%. Model performance increased when the a priori factors preoperative status, noncardiac abnormality, genetic anomaly, preoperative catheterization during episode of care, weight less than 3 kg, and preoperative vasoactive support medication were introduced to the model (R = 60.8%). Model performance further improved when postoperative ventilation greater than 7 days, operating room time, postoperative catheterization during episode of care, postoperative reintubation, number of postoperative vasoactive support medications, postoperative ICU infection, and greater than or equal to one secondary surgical procedure were added (R = 76.7%). The validation cohort yielded an R of 76.5%. CONCLUSIONS: We developed a statistically valid procedure-based categorical variable and multivariable model for length of stay of congenital heart surgeries. The Surgical Length Categories and important a priori and postoperative factors may be used to pursue a predictive tool for length of stay to inform scheduling and bed management practices.

MALDI Imaging Mass Spectrometry as a Lipidomic Approach to Heart Valve Research.

BACKGROUND: Valvular disease is characterized in part by lipid deposition, but systematic analysis of the patterns of global lipid expression in healthy and diseased valve tissues are unknown. This is due in part to tissue limitations for lipidomic preparations and technologies for evaluating lipid distribution in tissues. The study aim was to examine the application of matrixassisted laser desorption ionization imaging mass spectrometry (MALDI IMS) to the aortic valve during development and disease, as an approach to detect and map lipids and ultimately better understand valve structure and function. METHODS: Established MALDI IMS strategies were applied to thin tissue sections of heart valves to map lipids to corresponding morphological features. Healthy prenatal and adult ovine aortic valve tissues were evaluated using the developed techniques. Lipid expression levels were compared between prenatal and adult valves using Wilcoxon rank sum testing and area under the receiver operating curves. A classification algorithm was used to determine distinct lipid signatures in adult extracellular matrix (ECM) substructures, including fibrosa and spongiosa layers. Lipid patterns were examined in heart valve tissue from pediatric patients with congenital aortic valve stenosis (CAVS). RESULTS: Lipid levels were decreased in adult ovine aortic valves when compared with prenatal valves. Classification algorithms applied to lipid signatures reported distinct lipid signatures mapping to ECM substructures in the adult aortic valve, but could not distinguish amorphous structures at pre-natal day 5. In CAVS, the in-situ lipid aggregation of distinct lipid species showed unique patterning both concurrent and divergent with ECM disarray. Fatty acid content varied between normal and diseased human aortic valves. CONCLUSIONS: MALDI IMS provides a new and useful approach to evaluate lipid biology in heart valve tissue. These findings define a role for lipid regulation in aortic valve development and demonstrate patterns of lipid deregulation in congenital disease.

Reciprocal interactions between mitral valve endothelial and interstitial cells reduce endothelial-to-mesenchymal transition and myofibroblastic activation.

Thickening of mitral leaflets, endothelial-to-mesenchymal transition (EndMT), and activated myofibroblast-like interstitial cells have been observed in ischemic mitral valve regurgitation. We set out to determine if interactions between mitral valve endothelial cells (VECs) and interstitial cells (VICs) might affect these alterations. We used in vitro co-culture in Transwell™ inserts to test the hypothesis that VICs secrete factors that inhibit EndMT and conversely, that VECs secrete factors that mitigate the activation of VICs to a myofibroblast-like, activated phenotype. Primary cultures and clonal populations of ovine mitral VICs and VECs were used. Western blot, quantitative reverse transcriptase PCR (qPCR) and functional assays were used to assess changes in cell phenotype and behavior. VICs or conditioned media from VICs inhibited transforming growth factor ß (TGFß)-induced EndMT in VECs, as indicated by reduced expression of EndMT markers α-smooth muscle actin (α-SMA), Slug, Snai1 and MMP-2 and maintained the ability of VECs to mediate leukocyte adhesion, an important endothelial function. VECs or conditioned media from VECs reversed the spontaneous cell culture-induced change in VICs to an activated phenotype, as indicated by reduced expression of α-SMA and type I collagen, increased expression chondromodulin-1 (Chm1), and reduced contractile activity. These results demonstrate that mitral VECs and VICs secrete soluble factors that can reduce VIC activation and inhibit TGFß-driven EndMT, respectively. These findings suggest that the endothelium of the mitral valve is critical for the maintenance of a quiescent VIC phenotype and that, in turn, VICs prevent EndMT. We speculate that the disturbance of the ongoing reciprocal interactions between VECs and VICs in vivo may contribute to the thickened and fibrotic leaflets observed in ischemic mitral regurgitation, and in other types of valve disease.

Accelerated degeneration of a bovine pericardial bioprosthetic aortic valve in children and young adults.

BACKGROUND: Experience with aortic valve replacement (AVR) with current-generation pericardial bioprostheses in young patients is limited. The death of a child with accelerated bioprosthetic aortic stenosis prompted enhanced surveillance of all such patients at our institution. METHODS AND RESULTS: We reviewed records of 27 patients who had undergone AVR (median follow-up, 13.7 months) with a bovine pericardial bioprosthesis at ≤30 years of age. In the Mitroflow LXA valve group (n=15), freedom from valve failure was 100% at 1 year, 53% (95% confidence interval, 12-82) at 2 years, and 18% (95% confidence interval, 1-53) at 3 years. No Magna/Magna Ease valves (n=12) failed by 3 years. Among valve failure patients, median age at AVR was 12 years (range, 10-21 years). Life-threatening prosthetic aortic stenosis was detected at a median of 6 months after prior echocardiograms showing mild or less gradients. Patients with Mitroflow LXA compared with Magna/Magna Ease valves were smaller (median body surface area, 1.42 versus 1.93 m(2); P=0.002) and younger (median age, 13.0 versus 20.9 years; P=0.02) at AVR. Pathology demonstrated diffuse intrinsic leaflet calcification, not associated with inflammation or infection, and virtually immobile leaflets in closed position. CONCLUSIONS: Young patients undergoing AVR with Mitroflow LXA pericardial valves are at high risk for rapid progression from mild or less to severe aortic stenosis over months, highlighting their need for heightened echocardiographic surveillance and suggesting that this aortic bioprosthesis should not be implanted in the young. Current data are insufficient to assess the safety of AVR with other pericardial bioprostheses in children and the youngest adults.

Comparative effectiveness of revascularization strategies.

BACKGROUND: Questions persist concerning the comparative effectiveness of percutaneous coronary intervention (PCI) and coronary-artery bypass grafting (CABG). The American College of Cardiology Foundation (ACCF) and the Society of Thoracic Surgeons (STS) collaborated to compare the rates of long-term survival after PCI and CABG. METHODS: We linked the ACCF National Cardiovascular Data Registry and the STS Adult Cardiac Surgery Database to claims data from the Centers for Medicare and Medicaid Services for the years 2004 through 2008. Outcomes were compared with the use of propensity scores and inverse-probability-weighting adjustment to reduce treatment-selection bias. RESULTS: Among patients 65 years of age or older who had two-vessel or three-vessel coronary artery disease without acute myocardial infarction, 86,244 underwent CABG and 103,549 underwent PCI. The median follow-up period was 2.67 years. At 1 year, there was no significant difference in adjusted mortality between the groups (6.24% in the CABG group as compared with 6.55% in the PCI group; risk ratio, 0.95; 95% confidence interval [CI], 0.90 to 1.00). At 4 years, there was lower mortality with CABG than with PCI (16.4% vs. 20.8%; risk ratio, 0.79; 95% CI, 0.76 to 0.82). Similar results were noted in multiple subgroups and with the use of several different analytic methods. Residual confounding was assessed by means of a sensitivity analysis. CONCLUSIONS: In this observational study, we found that, among older patients with multivessel coronary disease that did not require emergency treatment, there was a long-term survival advantage among patients who underwent CABG as compared with patients who underwent PCI. (Funded by the National Heart, Lung, and Blood Institute.).

Development of a charge adjustment model for cardiac catheterization.

A methodology that would allow for comparison of charges across institutions has not been developed for catheterization in congenital heart disease. A single institution catheterization database with prospectively collected case characteristics was linked to hospital charges related and limited to an episode of care in the catheterization laboratory for fiscal years 2008-2010. Catheterization charge categories (CCC) were developed to group types of catheterization procedures using a combination of empiric data and expert consensus. A multivariable model with outcome charges was created using CCC and additional patient and procedural characteristics. In 3 fiscal years, 3,839 cases were available for analysis. Forty catheterization procedure types were categorized into 7 CCC yielding a grouper variable with an R (2) explanatory value of 72.6%. In the final CCC, the largest proportion of cases was in CCC 2 (34%), which included diagnostic cases without intervention. Biopsy cases were isolated in CCC 1 (12%), and percutaneous pulmonary valve placement alone made up CCC 7 (2%). The final model included CCC, number of interventions, and cardiac diagnosis (R (2) = 74.2%). Additionally, current financial metrics such as APR-DRG severity of illness and case mix index demonstrated a lack of correlation with CCC. We have developed a catheterization procedure type financial grouper that accounts for the diverse case population encountered in catheterization for congenital heart disease. CCC and our multivariable model could be used to understand financial characteristics of a population at a single point in time, longitudinally, and to compare populations.

Cardiovascular outcomes after the arterial switch operation for D-transposition of the great arteries.

BACKGROUND: Data regarding long-term outcomes after the arterial switch operation for D-transposition of the great arteries are scarce. METHODS AND RESULTS: A single-institution retrospective cohort study was conducted to assess cardiovascular outcomes after an arterial switch operation between 1983 and 1999. Patients without follow-up visits within 3 years were contacted and secondary sources of information obtained. Overall, 400 patients, 154 (38.3%) with a ventricular septal defect, 238 (59.5%) with an intact septum, and 9 (2.3%) with a Taussig-Bing anomaly, were followed for a median of 18.7 years. In perioperative survivors, overall and arrhythmia-free survival rates at 25 years were 96.7±1.8% and 96.6±0.1%, respectively. Late mortality was predominantly a result of sudden deaths and myocardial infarction. At 25 years, 75.5±2.5% remained free from surgical or catheter-based reintervention. Freedom from an adverse cardiovascular event was 92.9±1.9% at 25 years. Independent predictors were a single right coronary artery (hazard ratio, 4.58; 95% confidence interval, 1.32-15.90), P=0.0166) and postoperative heart failure (hazard ratio, 6.93; 95% confidence interval, 1.57-30.62; P=0.0107). At last follow-up, the left ventricular ejection fraction was 60.3±8.9%, 97.3% had class I symptoms, and 5.2% obstructive coronary artery disease. Peak oxygen uptake was 35.1±7.6 mL/kg/min (86.1±15.1% predicted), with a chronotropic index <80% in 34.2%. At least moderate neoaortic and pulmonary regurgitation were present in 3.4% and 6.6%, respectively, and more than mild neoaortic and pulmonary stenosis in 3.2% and 10.3%. CONCLUSIONS: Long-term and arrhythmia-free survival is excellent after arterial switch operation. Although sequelae include chronotropic incompetence and neoaortic, pulmonary, and coronary artery complications, most patients maintain normal systolic function and exercise capacity.

Heart transplantation in adults with congenital heart disease.

Heart transplantation has become an increasingly common and effective therapy for adults with end-stage congenital heart disease (CHD) because of advances in patient selection and surgical technique. Indications for transplantation in CHD are similar to other forms of heart failure. Pretransplant assessment of CHD patients emphasizes evaluation of cardiac anatomy, pulmonary vascular disease, allosensitization, hepatic dysfunction, and neuropsychiatric status. CHD patients experience longer waitlist times and higher waitlist mortality than other transplant candidates. Adult CHD patients undergoing transplantation carry an early hazard for mortality compared with non-CHD recipients, but by 10 years posttransplant, CHD patients have a slight actuarial survival advantage.

Prognostic utility of a novel risk prediction model of 1-year mortality in patients surviving to discharge after surgery for congenital or acquired heart disease.

OBJECTIVE: We sought to develop a novel risk prediction model of 1-year mortality after congenital heart surgery that accounts for clinical, anatomic, echocardiographic, and socioeconomic factors. METHODS: This was a single-center, retrospective review of consecutive index operations for congenital or acquired heart disease, from January 2011 to January 2021, among patients with known survival status at 1 year after discharge from the index hospitalization. The primary outcome was postdischarge mortality at 1 year. Variables of interest included age, prematurity, noncardiac anomalies or syndromes, the Childhood Opportunity Index, primary procedure, major adverse postoperative complications, and the Residual Lesion Score. Logistic regression was used to develop a weighted risk score for the primary outcome. Internal validation using a bootstrap-resampling approach was performed. RESULTS: Of 10,412 consecutive operations for congenital or acquired heart disease, 8808 (84.6%) cases met entry criteria, including survival to discharge. There were 190 (2.2%) deaths at 1 year postdischarge. A weighted risk score was formulated on the basis of the variables in the final risk prediction model, which included all aforementioned risk factors of interest. This model had a C-statistic of 0.82 (95% confidence interval, 0.80-0.85). The median risk score was 6 (interquartile range, 4-8) points. Patients were categorized as low (score 0-5), medium (score 6-10), high (score 11-15), or very high (score 16-20) risk. The expected probability of mortality was 0.4% ± 0.2%, 2.0% ± 1.1%, 10.1% ± 5.0%, and 36.6% ± 9.6% for low-risk, medium-risk, high-risk, and very high-risk patients, respectively. CONCLUSIONS: A risk prediction model of 1-year mortality may guide prognostication and follow-up of patients after discharge after surgery for congenital or acquired heart disease.