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.

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.

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.

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.

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.