Cardiac Magnetic Resonance to Predict Coronary Artery Compression in Transcatheter Pulmonary Valve Implantation Into Conduits.

OBJECTIVES: The aim of this study was to evaluate the accuracy of cardiac magnetic resonance (CMR) in predicting coronary artery (CA) compression during transcatheter pulmonary valve implantation (TPVi). BACKGROUND: TPVi is a widely available option to treat dysfunctional right ventricle (RV)-to-pulmonary artery (PA) conduits, but CA compression is an absolute contraindication. CMR can evaluate coronary anatomy, but its utility in predicting CA compression is not well established. METHODS: After Institutional Review Board approval was obtained, all patients at 9 centers with attempted TPVi in RV-PA conduits and recent CMR (≤12 months) were analyzed. A core laboratory reviewed all CMR studies for the shortest orthogonal distance from a CA to the conduit, the shortest distance from a CA to the most stenotic area of the conduit, and subjective assessment of CA compression risk. RESULTS: Among 231 patients, TPVi was successful in 198 (86%); in 24 (10%), balloon testing precluded implantation (documented CA compression or high risk). Distance to the RV-PA conduit ≤2.1 mm (area under the curve [AUC]: 0.70) and distance to most stenotic area ≤13.1 mm (AUC: 0.69) predicted CA compression. Subjective assessment had the highest AUC (0.78), with 96% negative predictive value. Both distances and qualitative assessment remained independently associated with CA compression when controlling for abnormal coronary anatomy or degree of conduit calcification. CONCLUSIONS: CMR can help predict the risk for CA compression during TPVi in RV-PA conduits but cannot completely exclude CA compression. CMR may assist in patient selection and counseling families prior to TPVi, although balloon testing remains essential.

Health Care Disparities in Congenital Cardiology: Considerations Through the Lens of an Interventional Cardiologist.

When resources in a society are dispersed unevenly, generally through allocation standards, distinct patterns emerge along lines of socially defined categories of people. Power, religion, kinship, prestige, race, ethnicity, gender, age, sexual orientation, and class all play a role in determining who has access to social goods in society. In most cases, social inequality refers to a lack of equality of outcome, but it can also refer to a lack of equality of access to opportunity. Unfortunately, health care is not immune to these social disparities and/or inequalities. These health care disparities in interventional cardiology were recently brought to the forefront by the Society for Cardiovascular Angiography and Interventions (SCAI) as a major focus of 2020-2021. In a recent publication, unique factors leading to disparities were reported to exist among the subsections of interventional cardiology. The congenital heart disease council of SCAI created a task force to further investigate the unique challenges and disparities impacting the practice of congenital heart disease and pediatric cardiology.

Racial and ethnic disparities in coronary, vascular, structural, and congenital heart disease.

Cardiovascular disease (CVD) remains the leading cause of death in the United States. However, percutaneous interventional cardiovascular therapies are often underutilized in Blacks, Hispanics, and women and may contribute to excess morbidity and mortality in these vulnerable populations. The Society for Cardiovascular Angiography and Interventions (SCAI) is committed to reducing racial, ethnic, and sex-based treatment disparities in interventional cardiology patients. Accordingly, each of the SCAI Clinical Interest Councils (coronary, peripheral, structural, and congenital heart disease [CHD]) participated in the development of this whitepaper addressing disparities in diagnosis, treatment, and outcomes in underserved populations. The councils were charged with summarizing the available data on prevalence, treatment, and outcomes and elucidating potential reasons for any disparities. Given the huge changes in racial and ethnic composition by age in the United States (Figure 1), it was difficult to determine disparities in rates of diagnosis and we expected to find some racial differences in prevalence of disease. For example, since the average age of patients undergoing transcatheter aortic valve replacement (TAVR) is 80 years, one may expect 80% of TAVR patients to be non-Hispanic White. Conversely, only 50% of congenital heart interventions would be expected to be performed in non-Hispanic Whites. Finally, we identified opportunities for SCAI to advance clinical care and equity for our patients, regardless of sex, ethnicity, or race.

The Role of Novel Transcatheter Procedures in Patients With Congenital Heart Disease.

The development of percutaneous structural interventions in patients with acquired heart disease is happening at an exponential rate, and some of this technology is being used to treat patients with congenital heart disease. This review describes the pathophysiology of valvular abnormalities specific to congenital heart disease and discusses the application of structural procedures in this population. Although the overall experience has been encouraging, especially in high-risk patients, this article will highlight the reasons that a cautious approach to adoption of this technology is necessary in these patients.

Transcatheter Pulmonary Valve Replacement With the Sapien Prosthesis.

BACKGROUND: There are limited published data focused on outcomes of transcatheter pulmonary valve replacement (TPVR) with either a Sapien XT or Sapien 3 (S3) valve. OBJECTIVES: This study sought to report short-term outcomes in a large cohort of patients who underwent TPVR with either a Sapien XT or S3 valve. METHODS: Data were entered retrospectively into a multicenter registry for patients who underwent attempted TPVR with a Sapien XT or S3 valve. Patient-related, procedural, and short-term outcomes data were characterized overall and according to type of right ventricular outflow tract (RVOT) anatomy. RESULTS: Twenty-three centers enrolled a total of 774 patients: 397 (51%) with a native/patched RVOT; 183 (24%) with a conduit; and 194 (25%) with a bioprosthetic valve. The S3 was used in 78% of patients, and the XT was used in 22%, with most patients receiving a 29-mm (39%) or 26-mm (34%) valve. The implant was technically successful in 754 (97.4%) patients. Serious adverse events were reported in 67 patients (10%), with no difference between RVOT anatomy groups. Fourteen patients underwent urgent surgery. Nine patients had a second valve implanted. Among patients with available data, tricuspid valve injury was documented in 11 (1.7%), and 9 others (1.3%) had new moderate or severe regurgitation 2 grades higher than pre-implantation, for 20 (3.0%) total patients with tricuspid valve complications. Valve function at discharge was excellent in most patients, but 58 (8.5%) had moderate or greater pulmonary regurgitation or maximum Doppler gradients >40 mm Hg. During limited follow-up (n = 349; median: 12 months), 9 patients were diagnosed with endocarditis, and 17 additional patients underwent surgical valve replacement or valve-in-valve TPVR. CONCLUSIONS: Acute outcomes after TPVR with balloon-expandable valves were generally excellent in all types of RVOT. Additional data and longer follow-up will be necessary to gain insight into these issues.

Outcomes of Adults with Congenital Heart Disease Supported with Extracorporeal Life Support After Cardiac Surgery.

Patients with adult congenital heart disease (ACHD) who undergo cardiac surgery may require extracorporeal life support (ECLS) for cardiopulmonary support, but outcomes after ECLS support have not been well described. This study aimed to identify risk factors for ECLS mortality in this population. We identified 368 ACHD patients who received ECLS after cardiac surgery between 1994 and 2016 in the Extracorporeal Life Support Organization (ELSO) database, a multicenter international registry of ECLS centers. Risk factors for mortality were assessed using multivariate logistic regression. Overall mortality was 61%. In a multivariate model using precannulation characteristics, Fontan physiology (odds ratio [OR]: 5.7; 95% CI: 1.6-20.0), weight over 100 kg (OR: 2.6; 95% CI: 1.3-5.4), female gender (OR: 1.6; 95% CI: 1.001-2.6), delayed ECLS cannulation (OR: 2.0; 95% CI: 1.2-3.2), and neuromuscular blockade (OR: 1.9; 95% CI: 1.1-3.3) were associated with increased mortality. Adding postcannulation characteristics to the model, renal complications (OR: 3.0; 95% CI: 1.7-5.2), neurologic complications (OR, 4.7; 95% CI: 1.5-15.2), and pulmonary hemorrhage (OR: 6.4; 95% CI: 1.3-33.2) were associated with increased mortality, whereas Fontan physiology was no longer associated, suggesting the association of Fontan physiology with mortality may be mediated by complications. Fontan physiology was also a risk factor for neurologic complications (OR: 8.2; 95% CI: 3.3-20.9). Given the rapid increase in ECLS use, understanding risk factors for ACHD patients receiving ECLS after cardiac surgery will aid clinicians in decision-making and preoperative planning.

Transcatheter Pulmonary Valve Replacement With the Melody Valve in Small Diameter Expandable Right Ventricular Outflow Tract Conduits.

OBJECTIVES: This study sought to evaluate the safety, feasibility, and outcomes of transcatheter pulmonary valve replacement (TPVR) in conduits ≤16 mm in diameter. BACKGROUND: The Melody valve (Medtronic, Minneapolis, Minnesota) is approved for the treatment of dysfunctional right ventricular outflow tract (RVOT) conduits ≥16 mm in diameter at the time of implant. Limited data are available regarding the use of this device in smaller conduits. METHODS: The study retrospectively evaluated patients from 9 centers who underwent percutaneous TPVR into a conduit that was ≤16 mm in diameter at the time of implant, and reported procedural characteristics and outcomes. RESULTS: A total of 140 patients were included and 117 patients (78%; median age and weight 11 years of age and 35 kg, respectively) underwent successful TPVR. The median original conduit diameter was 15 (range: 9 to 16) mm, and the median narrowest conduit diameter was 11 (range: 4 to 23) mm. Conduits were enlarged to a median diameter of 19 mm (29% larger than the implanted diameter), with no difference between conduits. There was significant hemodynamic improvement post-implant, with a residual peak RVOT pressure gradient of 7 mm Hg (p < 0.001) and no significant pulmonary regurgitation. During a median follow-up of 2.0 years, freedom from RVOT reintervention was 97% and 89% at 2 and 4 years, respectively, and there were no deaths and 5 cases of endocarditis (incidence rate 2.0% per patient-year). CONCLUSIONS: In this preliminary experience, TPVR with the Melody valve into expandable small diameter conduits was feasible and safe, with favorable early and long-term procedural and hemodynamic outcomes.

Value of a flow cytometry cross-match in the setting of a negative complement-dependent cytotoxicity cross-match in heart transplant recipients.

Complement-dependent cytotoxicity cross-match (CDCXM) is used for evaluation of preformed HLA-specific antibodies in patients undergoing heart transplantation. Flow cytometry cross-match (FCXM) is a more sensitive assay and used with increasing frequency. To determine the clinical relevance of a positive FCXM in the context of negative CDCXM in heart transplantation, the United Network for Organ Sharing (UNOS) database was analyzed. Kaplan-Meier analysis and Cox proportional hazard modeling were used to assess graft survival for three different patient cohorts defined by cross-match results: T-cell and B-cell CDCXM+ ("CDCXM+" cohort), CDCXM- but T-cell and/or B-cell FCXM+ ("FCXM+" cohort), and T-cell/B-cell CDCXM- and FCXM- ("XM-" cohort). During the study period, 2558 patients met inclusion criteria (10.7% CDCXM+, 18.8% FCXM+, 65.5% XM-). CDCXM+ patients had significantly decreased graft survival compared to FCXM+ and XM- cohorts (P = .003 and <.001, respectively). CDCXM- and FCXM+ patients did not have decreased graft survival compared to XM- patients (P = .09). In multivariate analysis, only CDCXM+ was associated with decreased graft survival (HR 1.22, 95% CI 1.01-1.49). In conclusion, positive FCXM in the context of negative CDCXM does not confer increased risk of graft failure. Further study is needed to understand implications of CDCXM and FCXM testing in heart transplant recipients.

Changes in the methodology of pre-heart transplant human leukocyte antibody assessment: an analysis of the United Network for Organ Sharing database.

BACKGROUND: We sought to investigate temporal trends in the methodology of human leukocyte antibody assessment in heart transplantation. METHODS: The United Network for Organ Sharing database was queried from June 2004 to March 2013 to obtain pre-heart transplantation human leukocyte antibody results. The % panel reactive antibody for class I and II antibodies was recorded along with the methodology of assessment. Allosensitization was defined as class I and/or II panel reactive antibody of ≥ 10%. The primary outcome measure was graft survival. RESULTS: During the study period, 12,858 patients with available data underwent heart transplantation. The prevalence of allosensitization increased, with 16.8% in 2005-2006 sensitized at the time of transplantation compared to 23.1% in 2010-2011 (p < 0.001); this occurred in conjunction with an increase in the utilization of flow cytometry (77.2% in 2005-2006; 97.0% in 2010-2011, p < 0.001). Using multivariable analysis, a positive pre-heart transplantation panel reactive antibody by flow cytometry independently predicted graft loss. CONCLUSIONS: There has been a recent increase in flow cytometric assessment of human leukocyte antibodies prior to heart transplantation, which may be associated with an increase in the prevalence of pre-transplant patients being characterized as allosensitized. Flow cytometry may identify patients with the highest likelihood of graft loss.

Lung transplant waitlist mortality: height as a predictor of poor outcomes.

The LAS was designed to minimize pretransplant mortality while maximizing post-transplant outcome. Recipients <12 are not allocated lungs based on LAS. Waitlist mortality has decreased for those >12, but not <12, suggesting this population may be disadvantaged. To identify predictors of waitlist mortality, a retrospective analysis of the UNOS database was performed since implementation of the LAS. There were 16,973 patients listed for lung transplant in the United States; 12,070 (71.1%) were transplanted, and 2498 (14.7%) patients died or were removed from the wait list. Significantly more pediatric patients died or were removed compared with adults (22.0% vs. 14.4%, p < 0.01). In multivariate analysis, in addition to higher LAS at time of listing (adj. HR1.058, 1.055-1.060), shorter height (1.008, 1.006-1.010), male gender (1.210, 1.110-1.319), and requiring ECMO (1.613, 1.202-2.163) were associated with pretransplant mortality. Post-transplant survival was not affected by height. The current age cutoff may impose limitations within the current lung allocation system in the United States. Height is an independent predictor of waitlist mortality and may be a valuable factor for the development of a comprehensive lung allocation system.

Impact of congenital heart disease on outcomes of pediatric heart-lung transplantation.

HLT is reserved for children with cardiopulmonary disease not amendable to alternative therapies. Children with CHD with or without ES may be considered for HLT. Outcomes of HLT in this population are not well described. To test the hypothesis that CHD without ES is associated with worse graft survival and identify factors associated with poor outcome, a retrospective analysis of the UNOS database was performed. One hundred and seventy-eight pediatric HLTs were performed between 1987 and 2011. CHD was the diagnosis in 65 patients, of which 34 had CHD without ES. Patients with CHD without ES had decreased patient survival (median 1.31 yr) compared with CHD with ES (4.80 yr, p = 0.05). On multivariable analysis, the following were associated with graft failure: CHD without ES (adjusted HR 1.69, 95% CI 1.09-2.62), younger age (1.04, 1.01-1.08), pretransplant mechanical ventilation (1.75, 1.01-3.06), pretransplant ECMO (3.07, 1.32-7.12), pretransplant PRAs (1.53, 1.06-2.20), and transplant era (1.85, 1.16-2.94). In children with CHD who require HLT, underlying physiology influences outcomes. Those without ES have a worse prognosis. The diagnosis of CHD without ES and preoperative factors may inform decisions in a complex patient population.

Barriers to pediatric lead screening: implications from a web-based survey of Vermont pediatricians.

The pernicious effects of lead on child health are well documented. The Vermont Department of Health (VDH) recommends screening all 12- and 24-month-old children for elevated blood lead levels (BLL). In 2006, only 41.4% of 24-month-old Vermont children were screened. To identify barriers preventing pediatricians from performing blood lead screening, a survey was distributed to Vermont primary care pediatricians-divided in higher and lower screening groups. Vermont pediatricians were more likely to be lower screeners if they reported negative health outcomes began at BLL >" xbd="641" xhg="618" ybd="1456" yhg="1421"/> 10 microg/dL (odds ratio [OR] = 3.64, 95% confidence interval [CI] = 1.12-11.99), practiced in Chittenden County (OR = 3.34, 95% CI = 1.14-9.78), or disagreed with the VDH's recommendation (OR = 4.90, 95% CI = 1.66-15.50). Adjusted analysis indicated the most significant determinants of lower screening rates were male gender, a perceived dangerous BLL as >10 microg/dL and low self-reported Medicaid population. The VDH may have an opportunity to increase BLL screening emphasizing the significant health risks associated with BLL < or = 10 microg/dL.

The SloR/Dlg metalloregulator modulates Streptococcus mutans virulence gene expression.

Metal ion availability in the human oral cavity plays a putative role in Streptococcus mutans virulence gene expression and in appropriate formation of the plaque biofilm. In this report, we present evidence that supports such a role for the DtxR-like SloR metalloregulator (called Dlg in our previous publications) in this oral pathogen. Specifically, the results of gel mobility shift assays revealed the sloABC, sloR, comDE, ropA, sod, and spaP promoters as targets of SloR binding. We confirmed differential expression of these genes in a GMS584 SloR-deficient mutant versus the UA159 wild-type progenitor by real-time semiquantitative reverse transcriptase PCR experiments. The results of additional expression studies support a role for SloR in S. mutans control of glucosyltransferases, glucan binding proteins, and genes relevant to antibiotic resistance. Phenotypic analysis of GMS584 revealed that it forms aberrant biofilms on an abiotic surface, is compromised for genetic competence, and demonstrates heightened incorporation of iron and manganese as well as resistance to oxidative stress compared to the wild type. Taken together, these findings support a role for SloR in S. mutans adherence, biofilm formation, genetic competence, metal ion homeostasis, oxidative stress tolerance, and antibiotic gene regulation, all of which contribute to S. mutans-induced disease.