Cardiac magnetic resonance parameters associated with successful conversion from a single ventricular to a one-and-a-half or biventricular circulation in patients with a hypoplastic right ventricle.

BACKGROUND: Some patients with pulmonary atresia with an intact ventricular septum (PA/IVS) or a left ventricle dominant atrioventricular canal defect (LDAVC) with a hypoplastic right ventricle (RV) and univentricular (1 V) circulation may be candidates for conversion to either a complete biventricular (2 V) repair or a one-and-a-half ventricle repair (1.5 V). We sought to identify pre-operative cardiovascular magnetic resonance (CMR) findings associated with successful conversion from 1V to 1.5V or 2V circulation. METHODS: In this single center retrospective study, subjects with PA/IVS or LDAVC and no conotruncal abnormalities were included if they had a 1 V circulation at the time of CMR followed by a surgical intervention intended to convert them to a 1.5 V or 2 V circulation. Conversion failure was defined as any of the following: (1) oxygen saturation < 90% at the most recent follow-up, (2) conversion back to a 1.5 V or 1 V circulation, or (3) death. RESULTS: In the PA/IVS cohort (n = 15, median age 1.32 years), 10 patients underwent surgical conversion to a 1.5 V circulation and 5 to a 2 V circulation. In the attempted 1.5 V group, there were 2 failures, and these cases had a lower RV mass (p = 0.04). In the attempted 2 V group, there was 1 failure, and no CMR parameters were significantly different compared to the successes. Among the successful 2 V group patients, the minimum RV end-diastolic volume (EDV) was 27 ml/m2. In the LDAVC cohort (n = 15, median age 1.0 years), 1 patient underwent surgical conversion to a 1.5 V circulation and 14 patients to a 2 V circulation. In the attempted 1.5 V group, the 1 conversion was a failure and had an RV EDV of 15 ml/m2. In the attempted 2 V group, there were 2 failures, and these cases had a smaller RV:LV stroke volume ratio (p = 0.05) and a lower RV ejection fraction (p = 0.05) compared to the successes. Among the successful 2 V group patients, the minimum RV EDV was 22 ml/m2. CONCLUSIONS: We identified multiple CMR parameters associated with successful conversion from 1 V circulation to 1.5 V or 2 V circulation in patients with PA/IVS and LDAVC. This information may improve patient selection for conversion procedures and encourage larger studies to better define the role of CMR.

Orally Bioavailable Macrocyclic Peptide That Inhibits Binding of PCSK9 to the Low Density Lipoprotein Receptor.

BACKGROUND: Inhibition of PCSK9 (proprotein convertase subtilisin/kexin type 9)-low density lipoprotein receptor interaction with injectable monoclonal antibodies or small interfering RNA lowers plasma low density lipoprotein-cholesterol, but despite nearly 2 decades of effort, an oral inhibitor of PCSK9 is not available. Macrocyclic peptides represent a novel approach to target proteins traditionally considered intractable to small-molecule drug design. METHODS: Novel mRNA display screening technology was used to identify lead chemical matter, which was then optimized by applying structure-based drug design enabled by novel synthetic chemistry to identify macrocyclic peptide (MK-0616) with exquisite potency and selectivity for PCSK9. Following completion of nonclinical safety studies, MK-0616 was administered to healthy adult participants in a single rising-dose Phase 1 clinical trial designed to evaluate its safety, pharmacokinetics, and pharmacodynamics. In a multiple-dose trial in participants taking statins, MK-0616 was administered once daily for 14 days to characterize the safety, pharmacokinetics, and pharmacodynamics (change in low density lipoprotein cholesterol). RESULTS: MK-0616 displayed high affinity (Ki = 5pM) for PCSK9 in vitro and sufficient safety and oral bioavailability preclinically to enable advancement into the clinic. In Phase 1 clinical studies in healthy adults, single oral doses of MK-0616 were associated with >93% geometric mean reduction (95% CI, 84-103) of free, unbound plasma PCSK9; in participants on statin therapy, multiple-oral-dose regimens provided a maximum 61% geometric mean reduction (95% CI, 43-85) in low density lipoprotein cholesterol from baseline after 14 days of once-daily dosing of 20 mg MK-0616. CONCLUSIONS: This work validates the use of mRNA display technology for identification of novel oral therapeutic agents, exemplified by the identification of an oral PCSK9 inhibitor, which has the potential to be a highly effective cholesterol lowering therapy for patients in need.

Phase 2b Randomized Trial of the Oral PCSK9 Inhibitor MK-0616.

BACKGROUND: MK-0616 is an oral macrocyclic peptide inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9) in development for the treatment of hypercholesterolemia. OBJECTIVES: This Phase 2b, randomized, double-blind, placebo-controlled, multicenter trial aimed to evaluate the efficacy and safety of MK-0616 in participants with hypercholesterolemia. METHODS: This trial was planned to include 375 adult participants with a wide range of atherosclerotic cardiovascular disease risk. Participants were assigned randomly (1:1:1:1:1 ratio) to MK-0616 (6, 12, 18, or 30 mg once daily) or matching placebo. The primary endpoints included percentage change from baseline in low-density lipoprotein cholesterol (LDL-C) at Week 8 and the proportion of participants with adverse events (AEs) and study intervention discontinuations due to AEs; participants were monitored for AEs for an additional 8 weeks after the 8-week treatment period. RESULTS: Of the 381 participants randomized, 49% were female, and the median age was 62 years. Among 380 treated participants, all doses of MK-0616 demonstrated statistically significant (P < 0.001) differences in least squares mean percentage change in LDL-C from baseline to Week 8 vs placebo: -41.2% (6 mg), -55.7% (12 mg), -59.1% (18 mg), and -60.9% (30 mg). AEs occurred in a similar proportion of participants in the MK-0616 arms (39.5% to 43.4%) as placebo (44.0%). Discontinuations due to AEs occurred in 2 or fewer participants in any treatment group. CONCLUSIONS: MK-0616 demonstrated statistically significant and robust, dose-dependent placebo-adjusted reductions in LDL-C at Week 8 of up to 60.9% from baseline and was well tolerated during 8 weeks of treatment and an additional 8 weeks of follow-up. (A Study of the Efficacy and Safety of MK-0616 [Oral PCSK9 Inhibitor] in Adults With Hypercholesterolemia [MK-0616-008]; NCT05261126).

Factors associated with morbidity, mortality, and hemodynamic failure after biventricular conversion in borderline hypoplastic left hearts.

OBJECTIVE: A subset of patients with borderline hypoplastic left heart may be candidates for single to biventricular conversion, but long-term morbidity and mortality persist. Prior studies have shown conflicting results regarding the association of preoperative diastolic dysfunction and outcome, and patient selection remains challenging. METHODS: Patients with borderline hypoplastic left heart undergoing biventricular conversion from 2005 to 2017 were included. Cox regression identified preoperative factors associated with a composite outcome of time to mortality, heart transplant, takedown to single ventricle circulation, or hemodynamic failure (defined as left ventricular end-diastolic pressure >20 mm Hg, mean pulmonary artery pressure >35 mm Hg, or pulmonary vascular resistance >6 international Woods units). RESULTS: Among 43 patients, 20 (46%) met the outcome, with a median time to outcome of 5.2 years. On univariate analysis, endocardial fibroelastosis, lower left ventricular end-diastolic volume/body surface area (when <50 mL/m2), lower left ventricular stroke volume/body surface area (when <32 mL/m2), and lower left:right ventricular stroke volume ratio (when <0.7) were associated with outcome; higher preoperative left ventricular end-diastolic pressure was not. Multivariable analysis demonstrated that endocardial fibroelastosis (hazard ratio, 5.1, 95% confidence interval, 1.5-22.7, P = .033) and left ventricular stroke volume/body surface area 28 mL/m2 or less (hazard ratio, 4.3, 95% confidence interval, 1.5-12.3, P = .006) were independently associated with a higher hazard of the outcome. Approximately all patients (86%) with endocardial fibroelastosis and left ventricular stroke volume/body surface area 28 mL/m2 or less met the outcome compared with 10% of those without endocardial fibroelastosis and with higher stroke volume/body surface area. CONCLUSIONS: History of endocardial fibroelastosis and smaller left ventricular stroke volume/body surface area are independent factors associated with adverse outcomes among patients with borderline hypoplastic left heart undergoing biventricular conversion. Normal preoperative left ventricular end-diastolic pressure is insufficient to reassure against diastolic dysfunction after biventricular conversion.

N-terminal pro-B-type natriuretic peptide testing patterns in patients with heart failure with reduced ejection fraction.

AIMS: The N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a commonly used biomarker in heart failure for diagnosis and prognostication. We aimed to determine the prevalence of NT-proBNP testing, distribution of NT-proBNP concentrations, and factors associated with receiving an NT-proBNP test in patients with heart failure with reduced ejection fraction (HFrEF), including the subset with a worsening heart failure event (WHFE). METHODS AND RESULTS: This was a retrospective cohort study using two US databases: (i) the de-identified Humana Research Database between January 2015 and December 2018 and (ii) the Veradigm PINNACLE Registry® between July 2013 and September 2017. We included adult patients with a confirmed diagnosis of HFrEF. In each data source, a subgroup of patients with a WHFE was identified, where a WHFE was defined as a heart failure-related hospitalization or receipt of intravenous diuretics. Bivariate and multivariate analyses were conducted to assess factors associated with receiving NT-proBNP testing. In Cohort 1 (n = 249 238), 9.2% of patients with HFrEF and 10.8% of patients with a WHFE received NT-proBNP testing. When restricted to patients with at least one laboratory claim, 11.3% of patients with HFrEF and 13.2% of those with a WHFE received NT-proBNP testing. In Cohort 2 (n = 91 444), 2.3% of patients with HFrEF were tested. Median (inter-quartile range) NT-proBNP concentrations among patients with HFrEF were 1399 (423-4087) pg/mL in Cohort 1 and 394 (142-688) pg/mL in Cohort 2. Median (inter-quartile range) NT-proBNP concentrations in the subset of patients with a WHFE in each cohort were 2209 (740-5894) and 464 (174-783) pg/mL, respectively. In Cohort 1, 13.4% of all HFrEF patients receiving NT-proBNP testing and 18.9% of patients with a WHFE had NT-proBNP values >8000 pg/mL; in Cohort 2, these percentages were 1.0% and 2.5%, respectively. CONCLUSIONS: In US clinical practice, NT-proBNP testing was not frequently performed in patients with HFrEF. NT-proBNP concentrations varied across data sources and subpopulations within HFrEF.

ACC/AHA/ASE/HRS/ISACHD/SCAI/SCCT/SCMR/SOPE 2020 Appropriate Use Criteria for Multimodality Imaging During the Follow-Up Care of Patients With Congenital Heart Disease: A Report of the American College of Cardiology Solution Set Oversight Committee and Appropriate Use Criteria Task Force, American Heart Association, American Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Pediatric Echocardiography.

The American College of Cardiology (ACC) collaborated with the American Heart Association, American Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and the Society of Pediatric Echocardiography to develop Appropriate Use Criteria (AUC) for multimodality imaging during the follow-up care of patients with congenital heart disease (CHD). This is the first AUC to address cardiac imaging in adult and pediatric patients with established CHD. A number of common patient scenarios (also termed "indications") and associated assumptions and definitions were developed using guidelines, clinical trial data, and expert opinion in the field of CHD.1 The indications relate primarily to evaluation before and after cardiac surgery or catheter-based intervention, and they address routine surveillance as well as evaluation of new-onset signs or symptoms. The writing group developed 324 clinical indications, which they separated into 19 tables according to the type of cardiac lesion. Noninvasive cardiac imaging modalities that could potentially be used for these indications were incorporated into the tables, resulting in a total of 1,035 unique scenarios. These scenarios were presented to a separate, independent panel for rating, with each being scored on a scale of 1 to 9, with 1 to 3 categorized as "Rarely Appropriate," 4 to 6 as "May Be Appropriate," and 7 to 9 as "Appropriate." Forty-four percent of the scenarios were rated as Appropriate, 39% as May Be Appropriate, and 17% as Rarely Appropriate. This AUC document will provide guidance to clinicians in the care of patients with established CHD by identifying the reasonable imaging modality options available for evaluation and surveillance of such patients. It will also serve as an educational and quality improvement tool to identify patterns of care and reduce the number of Rarely Appropriate tests in clinical practice.

Changes in Prognosis of Heterotaxy Syndrome Over Time.

BACKGROUND: Long-term outcomes in heterotaxy syndrome (HS) are poorly described. Some reports suggest improved survival in the recent era, whereas others do not. We sought to describe long-term outcomes and assess whether outcomes have changed over time. METHODS: Patients with HS born between 1985 and 2014 who had cardiac care (except initial palliation) at our institution were divided into 4 birth eras and survival over time was compared. Independent risk factors for mortality were identified by using Cox proportional hazards regression. In patients who underwent surgery, association between surgical pathway (univentricular versus biventricular repair) and mortality after adjusting for baseline confounders was evaluated. A risk stratification model was created by using classification and regression analysis. RESULTS: Among 264 patients, 118 (44.7%) had asplenia and 146 (55.3%) had polysplenia syndrome. Overall mortality was 40.2% (n = 106), with median follow-up of 10.2 years (longest 31.5 years). In multivariable analysis, pulmonary vein stenosis, coarctation, univentricular circulation, asplenia phenotype, and at least mild atrioventricular valve regurgitation at presentation were associated with mortality, whereas birth era was not. Among patients who underwent surgery, univentricular repair remained associated with mortality after adjustment. In classification and regression analysis, patients with biventricular circulation (especially those with polysplenia) had lower mortality than those with univentricular circulation. CONCLUSIONS: In this large retrospective study of HS, outcomes remain poor and have not improved since the early 1990s. We identified risks factors associated with earlier mortality and found that those with univentricular circulation and totally anomalous pulmonary venous connection had the worst prognosis. Survival was higher in those with biventricular circulation.

Repair of double outlet right ventricle: Midterm outcomes.

OBJECTIVE: Double outlet right ventricle (DORV) is a complex cardiac malformation with many anatomic variations and various approaches for surgical repair. This study aimed to describe the clinical outcomes of biventricular (BiV) repair for DORV. METHODS: Patients with DORV, who underwent BiV repair between January 2000 and December 2017 were retrospectively reviewed. Group 1 underwent primary BiV repair, whereas group 2 underwent staged BiV repair over a series of operations. The decision to pursue staged approach included complexity of intracardiac anatomy, age of the patient, and the size and function of the ventricles and the atrioventricular valves. Time-dependent surgical reintervention for LVOTO and mortality were evaluated using Kaplan-Meier survival analysis. RESULTS: A total of 238 patients with DORV underwent BiV repair at a median age of 6.2 months (range, 1.1 month-27.5 years) (158 in group 1, 80 in group 2). Twenty-two patients (7.8%) required surgical reintervention within 30 days of BiV repair. Overall survival at 5 years was 89.0%. Freedom from LVOTO reoperation at 5 years was 84%. Primary outcomes were not significantly different between groups. CAVC repair and right ventricle to pulmonary artery conduit at BiV repair were associated with higher surgical reintervention (hazard ratio, 2.9 and 1.75, respectively). CONCLUSIONS: Patients with DORV and complex anatomy may undergo staged BiV repair with acceptable outcomes. Although LVOTO is a potential complication in these patients, the rate of surgical reintervention for LVOTO does not differ significantly from patients undergoing primary BiV repair.

Normal Values for Left Ventricular Strain and Synchrony in Children Based on Speckle Tracking Echocardiography.

Strain and synchrony are associated with clinical outcomes in children with heart diseases. Robust normative data for these values, measured by 2-dimensional speckle tracking echocardiography (2DSTE), are limited. Therefore, we aimed to derive normal ranges and z-scores of 2DSTE strain and synchrony parameters in children. Subjects were <21 years old with structurally and functionally normal hearts. High frame-rate 2-dimensional echocardiographic images were retrospectively analyzed to measure longitudinal (LS) and circumferential (CS) strain and synchrony; views used were apical 4, 2, and 3-chamber (AP 4, 2, 3) and mid-papillary short-axis (SAX-M). Synchrony measures included standard deviation of time to peak strain, maximal wall delay, and cross-correlation mean segmental delay; these were calculated without and with heart rate (HR) correction (divided by √RR). Z-score equations were created for AP4 and SAX-M strain components. n = 312 subjects (40% female) were included (age 3 days to 20.5 years). Mean strain values (%) were: AP4 -24.4 ± 3.2, AP2 -24.2 ± 3.3, AP3 -24.6 ± 3.4, SAX-M -25.8 ± 3.4. Significant differences between ages were present for all strain components (AP4 p < 0.001; AP2 p = 0.003; AP3 p = 0.014; SAX-M p = 0.01). LS components decreased with increasing age and body surface area (p < 0.001 for all); CS did not. Longitudinal, but not circumferential, synchrony parameters decreased with age; however, these were nonsignificant after HR correction. In conclusion, normal pediatric 2DSTE strain and synchrony parameters and z-scores are reported to provide a foundation for incorporation into clinical practice. LS decline with age whereas CS does not. Age-related decreases in LS synchrony were mostly nonsignificant when corrected for HR.

Dual-Site Ventricular Pacing in Patients With Fontan Physiology and Heart Block: Does it Mitigate the Detrimental Effects of Single-Site Ventricular Pacing?

OBJECTIVES: This study sought to determine the long-term effect of dual-site ventricular pacing (i.e., cardiac resynchronization therapy [CRT]) versus single-site pacing in patients with Fontan physiology and high-grade atrioventricular block (AVB). BACKGROUND: Chronic single-site ventricular pacing in Fontan patients is associated with significant morbidity and mortality. METHODS: The study conducted a retrospective review of all Fontan patients with high-grade AVB who received pacemakers at a single institution between 1990 and 2016 with follow-up of 12 months or greater. The primary study outcome was a composite of death or heart transplantation. RESULTS: Nineteen patients received CRT devices and 43 patients received single-site ventricular pacemakers (SVPMs), with a median follow-up of 4.9 years (range 1.1 to 11.3 years) and 10.4 years (range 1.1 to 26.8 years), respectively. One (5.3%) CRT patient and 11 (25.6%) SVPM patients reached the composite endpoint of death or transplant (odds ratio: 0.16; 95% confidence interval: 0.02 to 1.36; p = 0.09). Kaplan-Meier analysis showed similar rates of freedom from death or transplant between the 2 study groups over a 5-year follow-up period (p = 0.08). The proportion of SVPM patients with abnormal ventricular systolic function before device implantation (9.5%) and at follow-up (33.3%) significantly increased (p=0.009). The CRT cohort had less change in their ventricular function (42.1% before device implant, 36.8% at follow-up; p = 1.00); however, a Kaplan-Meier analysis over a 5-year follow-up period found no difference in the presence of abnormal ventricular systolic function between groups (p = 0.27). CONCLUSIONS: There was no significant difference in long-term outcomes between Fontan patients who were single- or dual-site paced for high-grade AVB.

Coronary artery compression from epicardial leads: More common than we think.

BACKGROUND: A child with an epicardial pacemaker presented with sudden death at our institution, secondary to coronary artery compression. This case prompted enhanced surveillance of all patients with epicardial pacing or defibrillation systems. OBJECTIVE: The purpose of this study was to determine the incidence of coronary artery compression and the diagnostic yield of catheter angiography (CA) and computed tomography (CT). METHODS: All patients with epicardial leads who underwent CA or cine CT were retrospectively reviewed. A patient with postmortem diagnosis of coronary compression was also included. RESULTS: Coronary compression was noted in 8 of 145 patients (5.5%) with epicardial leads. Median age at diagnosis was 11.4 years (range 3.0-29.6 years). Six patients had compression noted by CA, 6 by CT, and 1 by postmortem analysis. Chest radiography had sensitivity and specificity of 57% and 96%, respectively; CT 100% and 93%, respectively; and CA 86% and 100%, respectively. There was no difference in age or weight at the time of lead implant between those who did and those who did not have compression (age: median 1.3 vs 2.4 years; P = .36; weight: 9.5 vs 11.8 kg; P = .46). Among those with coronary compression, 6 of 8 (75%) had symptoms (1 sudden death, 3 chest pain [2 with associated troponin leak]), 2 unexplained fatigue). Seven patients had surgical repositioning of their lead. CONCLUSION: We found a higher incidence of coronary artery compression by epicardial leads (5.5%) than previously reported in the literature. Chest radiography can serve as a good surveillance tool, with cine CT scans considered in those with concerning radiographs or with symptoms. Confirmatory CA can be performed before surgical intervention.

Effects of Dose Reduction on Diagnostic Image Quality of Coronary Computed Tomography Angiography in Children Using a Third-Generation Dual-Source Computed Tomography Scanner.

Performing coronary computed tomography angiography (CCTA) using third-generation dual source computed tomography (3G-DSCT) scanners results in radiation dose reduction without sacrificing image quality in adults. The largest dose reductions have been reported with prospectively gated, high-pitch imaging. However, there are limited data to determine if these benefits extend to pediatric patients. We evaluated image quality and radiation dose range of CCTA performed in children using a 3G-DSCT scanner. A retrospective review of 44 children (median age 10years, range 0.6 to 17) who underwent imaging to evaluate coronary artery origins (n = 27), Kawasaki disease (n = 12) or other coronary abnormalities (n = 5) were performed. General anesthesia was used in 9/44 (20%) patients and a ß blocker was administered in 19/44 (43%). Prospectively gated high-pitch scanning was most frequently used (n = 24). Other techniques used included prospectively-gated "step and shoot" (n = 14), retrospectively gated (n = 2) and nongated high-pitch scan (n = 4). Median effective radiation doses were lowest for prospectively gated high-pitch scans (0.5mSv, range 0.4 to 0.7). Overall coronary artery image quality grade (1-excellent and 4-nondiagnostic) was acceptable for all electrocardiography-gated techniques, with no significant differences between high-pitch and "step-and-shoot" scan types (median 1, range 1 to 3 vs median 1, range 1 to 4, p = 0.22). Image quality grade was diagnostic (1 to 3) for all proximal coronary segments but rare distal segments were nondiagnostic (0.8% segments for gated high-pitch scan). In conclusion, CCTA can be performed in children using 3G-DSCT scanners withacceptable image quality. Prospectively gated high-pitch scans deliver the lowest radiation dose without reduction in image quality compared with conventional scan techniques.

Delayed Presentation of Traumatic Pericardial Rupture: Diagnostic and Surgical Considerations for Treatment.

Traumatic pericardial rupture is a rare event with high mortality. We present the case of a 15-year-old boy who sustained thoracic and abdominal trauma secondary to motor vehicle collision, with a delayed diagnosis of traumatic pericardial rupture with cardiac herniation. Out of concern for torsion and hemodynamic collapse, surgical repair was advised. We have developed a novel surgical approach to this rare condition, utilizing a combination of thoracoscopic and open surgical techniques. The guiding principles of our repair include the utilization of fenestrated pieces of bovine pericardium to create a tension free repair, minimizing the likelihood of pericardial effusion, and returning the cardiac mass to normal anatomic position.

Staged ventricular recruitment in patients with borderline ventricles and large ventricular septal defects.

OBJECTIVES: Patients with borderline ventricles and ventricular septal defects (VSDs) who have previously undergone single ventricle palliation might be candidates for staged ventricular recruitment with the ultimate goal of biventricular conversion. This study aimed to determine the effect of atrial septal defect (ASD) restriction without VSD closure on ventricular growth in patients with borderline right or left ventricles and VSDs. METHODS: Patients with borderline ventricles and VSD who underwent a staged ventricular recruitment procedure with strategies to increase blood flow through hypoplastic ventricle via ASD restriction without VSD closure after single ventricle palliation were retrospectively reviewed. Pre- and postrecruitment ventricular volumes were compared using Wilcoxon signed rank test. RESULTS: A total of 21 patients underwent staged ventricular recruitment via ASD restriction without VSD closure at median age of 20.0 months (interquartile range [IQR], 8.0-52.5 months). At a median of 9.0 months (IQR, 8.0-11.8 months) after the recruitment procedure, there were increases in the median indexed ventricular diastolic volume (31.7 mL/m2 [IQR, 24.5-37.1] to 48.5 mL/m2 [IQR, 38.4-58.0; P < .01]), median indexed systolic volume (13.3 mL/m2 [IQR, 9.7-18.7] to 19.5 mL/m2 [IQR, 16.8-29.7]; P < .01), and the median indexed stroke volume (18.4 mL/m2 [IQR, 14.8-21.1] to 28.1 mL/m2 [IQR, 21.3-31.8]; P < .01). Biventricular conversion was ultimately performed in 14 (67%). Two patients died after biventricular conversion. CONCLUSIONS: Staged ventricular recruitment via ASD restriction without VSD closure is associated with growth of the hypoplastic ventricle. In patients who are deemed high-risk for single ventricle, this approach might facilitate eventual biventricular conversion. Further studies are needed to identify optimal candidates for this approach.

Development of a congenital cardiovascular computed tomography imaging registry: Rationale and implementation.

BACKGROUND: The cumulative exposure and risk of anesthesia, vascular access, contrast agents and radiation is emerging as a significant lifelong burden in patients with congenital heart disease (CHD). Latest generation computerized tomographic (CT) scanners are increasingly used for high resolution cardiovascular imaging and have both hardware and post processing radiation dose reduction strategies that can be implemented. Currently, these dose reduction strategies are not uniformly applied and there is a large variability in radiation dose used for the performance of CT in CHD. METHODS: We propose the development and implementation of a prospective, multi-center and multi-specialty consortium to measure the variability of use, risk and image quality of CT scans in patients of all ages with CHD. The primary goals of this collaboration are 1) define variability of use, diagnostic quality, and risk of cardiac CT 2) establish best practice guidelines designed to optimize diagnostic image quality with appropriate use of radiation and anesthesia exposure 3) provide institution specific feedback compared with the group norm across participating centers 4) improve the level of evidence for the use of CT in CHD through the collection of prospective and multi-institutional data. CONCLUSIONS: Prospective multi-institutional data is needed to inform risk estimates of CT in CHD using current generation scanners and aggressive dose optimization techniques. This registry will provide a platform for future collaboration establishing a multi-modality risk assessment tool specific to patients with CHD.

Hemodynamic parameters predict adverse outcomes following biventricular conversion with single-ventricle palliation takedown.

OBJECTIVE: Patients with a borderline left ventricular hypoplasia in the hypoplastic left heart syndrome variant or an unbalanced atrioventricular canal who undergo initial single-ventricle palliation may be candidates for biventricular (BiV) conversion following left ventricle (LV) recruitment procedures. We investigated associations among preoperative parameters and postoperative outcomes in patients undergoing BiV conversion. METHODS: We performed a retrospective review of patients who underwent BiV conversion to determine variables associated with clinical outcomes. Predictor variables included cardiac diagnosis, age and weight, LV dimension, LV end diastolic volume, LV mass, preoperative LV end diastolic pressure (LVEDP), and preoperative left atrial pressure. Primary outcome was a composite of death, heart transplant, or BiV takedown. RESULTS: Of 51 patients, 11 experienced primary outcome (22%). Patients with hypoplastic left heart syndrome variant were more likely to experience primary outcome than those with an unbalanced atrioventricular canal (30% vs 6%; P = .03). Receiver operating characteristic analysis demonstrated that preoperative LVEDP had good predictive accuracy in classifying patients with and without the primary outcome (area under the curve, 0.757; 95% confidence interval, 0.594-0.919; P = .012). The Youden J-index indicated a cutoff of LVEDP ≥ 13 mm Hg as optimal for predicting the primary outcome. Multivariable Cox regression demonstrated that LVEDP ≥ 13 mm Hg (adjusted hazard ratio, 4.00; P = .037) and postoperative right ventricle pressure > 3/4 (adjusted hazard ratio, 21.75; P < .001) were significantly associated with primary outcome, independent of age, weight, and diagnosis. CONCLUSIONS: Elevated preoperative LVEDP is a risk factor for suboptimal postoperative hemodynamic parameters and adverse outcome following BiV conversion from single-ventricle palliation.

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.

Anomalous Pulmonary Venous Connection With an Intraparenchymal Course.

An intraparenchymal course of the pulmonary venous pathway within one lung in anomalous pulmonary venous connection is a rare and poorly recognized variation. We report three new cases and summarize the remaining 19 known cases of this infrequent anomaly. We expect that this review will call attention to this unusual pattern of pulmonary venous drainage and enhance prospective diagnosis.

Advances in pediatric cardiac MRI.

PURPOSE OF REVIEW: Spurred by numerous recent technological advances, cardiac MRI (CMR) is now the gold standard for anatomic evaluation, quantitative assessment of chamber size and function, flow quantification, and tissue characterization. This review focuses on recent advances in pediatric and congenital CMR, highlighting recent safety data, and discussing future directions. RECENT FINDINGS: CMR has become an important component of risk stratification and procedural planning in numerous congenital and pediatric heart diseases. Innovative approaches to image acquisition and reconstruction are leading the way toward fast, high-resolution, three- and four-dimensional datasets for delineation of cardiac anatomy, function, and flow. In addition, techniques for assessing the composition of the myocardium may help elucidate the pathophysiology of late complications, identify patients at risk for heart failure, and assist in the evaluation of therapeutic strategies. SUMMARY: CMR provides invaluable morphologic, hemodynamic, and functional data that help guide diagnosis, assessment, and management of pediatric and adult congenital heart disease. As imaging techniques advance and data accumulate on the relative and additive value of CMR in patient care, its role in a multimodality approach to the care of this population of patients is becoming clear and is likely to continue to evolve.