Cardiac Damage Staging Predicts Outcomes in Aortic Valve Stenosis After Aortic Valve Replacement: Meta-Analysis.

Background: The prognostic value of cardiac damage staging classification based on the extent of extravalvular damage has been proposed in moderate/severe aortic stenosis (AS). Objectives: The purpose of this study was to assess the association of cardiac damage staging with mortality across the spectrum of patients with AS following aortic surgical or transcatheter aortic valve replacement (AVR). Methods: We conducted a pooled meta-analysis of Kaplan-Meier-derived reconstructed time-to-event data from studies published through February 2023. Results: In total, 16 studies (n = 14,499) met our eligibility criteria and included 12,282 patients with symptomatic severe AS and 2,217 patients with asymptomatic severe/moderate AS. For patients with symptomatic severe AS, all-cause mortality was 24.0%, 27.7%, 38.0%, 56.3%, and 57.3% at 5 years in patients with cardiac damage stage 0, 1, 2, 3, and 4, respectively (stage 0 as reference; HR in stage 1: 1.30 [95% CI: 1.03-1.64]; P = 0.029; stage 2: 1.74 [95% CI: 1.41-2.16]; P < 0.001; stage 3: 2.92 [95% CI: 2.35-3.64]; P < 0.001, and stage 4: 3.51 [95% CI: 2.79-4.41]; P < 0.001). For patients with asymptomatic moderate/severe AS, all-cause mortality was 19.3%, 36.9%, 51.7%, and 67.8% at 8 years in patients with cardiac damage stage 0, 1, 2, and 3 to 4, respectively (HR in stage 1: 1.70 [95% CI: 1.21-2.38]; P = 0.002; stage 2: 2.20 [95% CI: 1.60-3.02]; P < 0.001; and stage 3 to 4: 3.90 [95% CI: 2.79-5.47]; P < 0.001). Conclusions: In patients undergoing AVR across the symptomatic and severity spectrum of AS, cardiac damage staging at baseline has important prognostic implications. This pooled meta-analysis in patients undergoing AVR suggests that staging of baseline cardiac damage could be considered for timing and selection of therapy in patients with moderate or severe AS to determine the need for earlier AVR or adjunctive pharmacotherapy to prevent irreversible cardiac damage and improve the long-term prognosis.

Impact of Cerebral Embolic Protection Devices on Disabling Stroke after Transcatheter Aortic Valve Replacement: Updated Results from the STS/ACC TVT Registry.

Background: Cerebral embolic protection devices (EPDs) were developed to mitigate the risk of stroke during transcatheter aortic valve replacement (TAVR), but their benefit remains unproven. In the PROTECTED-TAVR trial, EPD use did not reduce periprocedural stroke (primary study outcome) but led to a 62% reduction in the secondary endpoint of disabling stroke. Given these results, the impact of EPDs during TAVR remains unclear. Methods: We used STS/ACC TVT registry data to examine the association between EPD use and a proxy for disabling stroke among transfemoral TAVR patients between 1/2018-6/2023. The primary outcome was in-hospital disabling stroke-defined as stroke associated with either in-hospital death or discharge to a non-home location. We evaluated the association between EPD use and disabling stroke using instrumental variable (IV) analysis with site-level preference for EPD use as the instrument-a quasi-experimental approach that can support causal inference. In addition, we performed a propensity-score based comparison using overlap weighting as a secondary analysis. Results: The study population consisted of 414,649 patients of whom 53,389 (12.9%) received an EPD. The unadjusted rate of in-hospital disabling stroke was 0.7% among the EPD group and 0.9% in the no EPD group. EPD use was associated with a reduction in disabling stroke in both IV analysis (RR 0.87; 95% CI: 0.73-1.00) and propensity-weighted (PW) analysis (OR 0.79; 95% CI: 0.70-0.90) but was not associated with a reduction in non-disabling stroke. In subgroup analyses, the benefit of EPD was greater among those with versus without prior stroke (interaction p<0.05 for IV and PW). Conclusions: In the largest study to date, among patients undergoing TAVR, EPD use was associated with a small, borderline significant reduction in stroke associated with death or a discharge to a non-home location (a proxy for disabling stroke) that is likely to be causal in nature. Taken together with previous mechanistic and clinical studies, these findings provide credible evidence that EPDs benefit patients undergoing TAVR.

C3 Glomerulopathy Recurs Early after Kidney Transplantation in Serial Biopsies Performed within the First Two Years Post-Transplantation.

BACKGROUND: C3 glomerulopathy (C3G), which encompasses C3 glomerulonephritis (C3GN) and dense deposit disease (DDD), results from dysregulation of the alternative complement pathway. Data on disease recurrence after kidney transplantation is limited, and details on histologic features of recurrent C3G are scarce. We aimed to evaluate C3G recurrence in the allograft, with a focus on histologic presentation and progression. METHODS: We retrospectively analyzed 18 patients with native kidney failure attributed to C3G (12 C3GN and six DDD) who received a kidney transplant from January 2016 to January 2023. Demographic, genetic, clinical, and histologic data were studied. The Nanostring 770 genes immune profiling panel was used for transcriptomic analysis. Disease recurrence was the primary outcome. RESULTS: During a median (IQR) follow-up period of 37 (18, 56) months, C3G recurrence occurred in 16 (89%) of patients (11 with C3GN and five with DDD), at a median (IQR) of 33 (13, 141) days post-transplantation. Over a third (38%) of recurrent cases were detected in protocol biopsies, and only 31% of patients presented with >300 mg/g of proteinuria. Recurrence in index biopsies was mainly established through a combination of immunofluorescence and electron microscopy findings, while it showed only subtle histologic alterations and no characteristic transcriptomic signals. Over time, histologic chronicity indices increased, but all allografts were functioning at the end of follow-up. Patients with recurrence of C3GN and DDD showed overlapping immunofluorescence and electron microscopy findings and had similar recurrence rate and time to recurrence. CONCLUSIONS: The majority of patients with native kidney failure attributed to C3G developed disease recurrence very early after kidney transplantation, usually with minimal proteinuria, mild histologic alterations, and favorable short-term allograft survival. Immunofluorescence and electron microscopy played a crucial role in detecting early, sub-clinical recurrence of C3GN and DDD, which showed significant overlapping features.

Muscle fibrosis, NF-κB, and TGF-ß are differentially altered in two models of paralysis (Botox vs. Neurectomy).

OBJECTIVE: Volumetric muscle loss (VML) results in intramuscular axotomy, denervating muscle and leading to paralysis and loss of muscle function. Once the nerve is damaged, paralyzed skeletal muscle will atrophy and accumulate non-contractile connective tissue. The objective of this study was to determine differences in connective tissue, atrophy, and inflammatory signaling between two paralysis models, botulinum toxin (Botox), which blocks acetylcholine transmission while keeping nerves intact, and neurectomy, which eliminates all nerve to muscle signaling. APPROACH: Twenty-eight male Sprague Dawley rats were randomized and received either a sciatic-femoral neurectomy (SFN), Botox-induced muscle paralysis of the proximal femur muscles, quadriceps femoris, hamstrings, and calf muscles (BTX), or sham. Muscle force was measured 52 days post-surgery, and samples were collected for histology, protein, and mRNA assays. RESULTS: SNF and BTX decreased twitch and tetanic force, decreased fiber size by two-fold, and increased myogenic expression compared to controls. SFN increased levels of all major ECM proteins correlating with fibrosis (e.g. laminin, fibronectin, and collagen type(s) I, III, VI). SFN also increased pro-fibrotic and pro-inflammatory mRNA compared to BTX and controls. INNOVATION: SFN and BTX were similar in gross morphology and functional deficiencies. However, SFN exhibited a higher amount of fibrosis in histological sections and immunoblotting. The present study shows evidence that nerve signaling changes NF-κB and TGF-ß signaling, warranting future studies to determine the mechanisms involved. CONCLUSION: These data indicate that nerve signaling may influence fibrogenesis following denervation, but the mechanisms involved may differ as a function of the method of paralysis.

Outcomes of Atrial Fibrillation Ablation Among Older Adults in the United States: A Nationwide Study.

BACKGROUND: Pulmonary vein isolation (PVI) is increasingly recommended as first-line therapy for atrial fibrillation. Recent data suggest growing PVI volumes but rising complication rates, although comprehensive real-world outcomes including both inpatient and outpatient encounters remain unclear. OBJECTIVES: The purpose of this study was to evaluate patient characteristics, population rates, and 30-day outcomes of PVI in a nationwide sample of U.S. adults aged >65 years. METHODS: First-time PVIs were identified among U.S. Medicare fee-for-service beneficiaries using Current Procedural Terminology procedural codes. Comorbidities were ascertained using International Classification of Diseases-10th Revision diagnosis codes associated with each procedural claim. Outcomes included periprocedural complications, all-cause hospitalizations, and mortality at 30 days. RESULTS: From January 2017 through December 2021, a total of 227,133 patients underwent PVI (mean age 72.5 years, 42% women, 92.7% White) with an increasing comorbidity burden over time. PVI volume increased from 83.8 (2017) to 111.6 per 100,000 patient-years (2021), which was driven by outpatient procedures (87.8% of all PVIs). Concurrently, there was a significant decrease in complication rates (3.9% in 2017 vs 3.1% in 2021; P < 0.001) and hospitalizations (8.8% vs 7.0%; P < 0.001), with no significant change in mortality (0.4%; P = 0.08). The most common periprocedural complications were bleeding (1.8%), pericardial effusion (1.4%), and vascular access damage (0.8%). CONCLUSIONS: The use of PVI has steadily increased among older patients in contemporary U.S. clinical practice; yet, cumulative complication and hospitalization rates at 30 days have decreased over time, with stably low rates of short-term mortality despite rising comorbidity burden among treated patients. These data may reassure patients and providers on the safety of PVI as an increasingly common first-line procedure for atrial fibrillation.

Laryngeal Cancer Cells Metabolize 25-Hydroxyvitamin D3 and Respond to 24R,25-dihydroxyvitamin D3 via a Mechanism Dependent on Estrogen Receptor Levels.

Studies have evaluated vitamin D3's therapeutic potential in estrogen-responsive cancers, with conflicting findings. We have shown that the proliferation of breast cancer cells is regulated by 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) depending on estrogen receptor alpha 66 (ERα66) expression, suggesting that this could also be the case for estrogen-sensitive laryngeal cancer cells. Accordingly, we examined levels of ERα isoforms in ERα66-positive UM-SCC-12 and ERα66-negative UM-SCC-11A cells and their response to 24R,25(OH)2D3. 24R,25(OH)2D3 stimulated proliferation, increased the expression of metastatic markers, and inhibited apoptosis in UM-SCC-12 cells while having the opposite effect in UM-SCC-11A cells. To evaluate if vitamin metabolites could act via autocrine/paracrine mechanisms, we assessed the expression, protein levels, and activity of vitamin D3 hydroxylases CYP24A1 and CYP27B1. Both cell types expressed both mRNAs; but the levels of the enzymes and their activities were differentially regulated by estrogen. ERα66-negative UM-SCC-11A cells produced more 24,25(OH)2D3 than UM-SCC-12 cells, but comparable levels of 1,25(OH)2D3 when treated with 25(OH)D3 These results suggest that the regulation of vitamin D3 metabolism in laryngeal cancer cells is modulated by ERα66 expression, and support a role for 24R,25(OH)2D3 as an autocrine/paracrine regulator of laryngeal cancer. The local metabolism of 25(OH)D3 should be considered when determining the potential of vitamin D3 in laryngeal cancer.

Repeat Mitral Valve Interventions After Transcatheter Edge-to-Edge Repair: The COAPT Trial.

The frequency and effectiveness of repeat mitral valve interventions (RMVI) after transcatheter edge-to-edge repair (TEER) for secondary mitral regurgitation (MR) are unknown. We aimed to examine the rate of and outcomes after RMVI after TEER in the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial. Only 3.9% of COAPT trial patients required a repeat mitral valve intervention during 4-year follow-up which was successful in 90% of cases but was associated with an increased rate of heart failure (HF) hospitalizations (HFH). The COAPT trial randomized HF patients with severe secondary MR to TEER with the MitraClip device plus guideline-directed medical therapy (GDMT) versus GDMT alone. We evaluated the characteristics and outcomes of patients who had an RMVI during 4-year follow-up. A MitraClip implant was attempted in 293 patients randomized to TEER+GDMT, 10 of whom underwent an RMVI procedure (9 repeat TEER and 1 surgical mitral valve replacement) after 4 years of follow-up (cumulative incidence 3.90%, 95% confidence interval [CI] 2.08 to 7.08; median 182 days after the initial procedure). Patients with RMVI had larger mitral annular diameters, fewer clips implanted, and were more likely to have ≥3+MR at discharge compared with those without RMVI. Reasons for RMVI included failed index procedure because of difficult transseptal puncture (n = 2) or tamponade (n = 1); residual or recurrent severe MR after an initially successful procedure (n = 5); partial clip detachment (n = 1); and site-assessed mitral stenosis (n = 1). RMVI was successful in 8/10 (80%) patients. Patients who underwent RMVI had higher 4-year rates of HFH but similar mortality compared with those without RMVI. The annualized incidence rates of all HFH in patients who underwent RMVI were 234 events per 100 person-years (95% CI 139 to 395) pre-RMVI and 46 per 100 person-years (95% CI 25 to 86) post-RMVI as compared with 32 events per 100 patient-years (95% CI 28 to 36) in patients without RMVI. The rate ratio of HFH was reduced after RMVI in patients who underwent RMVI (0.20, 95% CI 0.09 to 0.45). In conclusion, the cumulative incidence of RMVI after 4 years was 3.9% in patients who underwent TEER for severe secondary MR in the COAPT trial. Patients who underwent RMVI were at increased risk of HFH which was reduced after the RMVI procedure. Clinical Trial Registration: Clinical Trial Name: Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (The COAPT Trial) (COAPT) ClinicalTrial.gov Identifier: NCT01626079 URL:https://clinicaltrials.gov/ct2/show/NCT01626079.

Variation in Health Status With Invasive vs Conservative Management of Chronic Coronary Disease.

BACKGROUND: The ISCHEMIA trial found that patients with chronic coronary disease randomized to invasive strategy had better health status than those randomized to conservative strategy. It is unclear how best to translate these population-level results to individual patients. OBJECTIVES: The authors sought to identify patient characteristics associated with health status from invasive and conservative strategies, and develop a prediction algorithm for shared decision-making. METHODS: One-year disease-specific health status was assessed in ISCHEMIA with the Seattle Angina Questionnaire (SAQ) Summary Score (SAQ SS) and Angina Frequency, Physical Limitations (PL), and Quality of Life (QL) domains (range 0-100, higher = less angina/better health status). RESULTS: Among 4,617 patients from 320 sites in 37 countries, mean SAQ SS was 74.1 ± 18.9 at baseline and 85.7 ± 15.6 at 1 year. Lower baseline SAQ SS and younger age were associated with better 1-year health status with invasive strategy (P interaction = 0.009 and P interaction = 0.004, respectively). For the individual domains, there were significant treatment interactions for baseline SAQ score (Angina Frequency, PL), age (PL, QL), anterior ischemia (PL), and number of baseline antianginal medications (QL), with more benefit of invasive in patients with worse baseline health status, younger age, anterior ischemia, and on more antianginal medications. Parsimonious prediction models were developed for 1-year SAQ domains with invasive or conservative strategies to support shared decision-making. CONCLUSIONS: In the management of chronic coronary disease, individual patient characteristics are associated with 1-year health status, with younger age and poorer angina-related health status showing greater benefit from invasive management. This prediction algorithm can support the translation of the ISCHEMIA trial results to individual patients. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Different Methods to Modify the Hydrophilicity of Titanium Implants with Biomimetic Surface Topography to Induce Variable Responses in Bone Marrow Stromal Cells.

The osteoblastic differentiation of bone marrow stromal cells (bMSCs), critical to the osseointegration of titanium implants, is enhanced on titanium surfaces with biomimetic topography, and this is further enhanced when the surfaces are hydrophilic. This is a result of changing the surface free energy to change protein adsorption, improving cell attachment and differentiation, and improving bone-to-implant contact in patients. In this study, we examined different methods of plasma treatment, a well-accepted method of increasing hydrophilicity, and evaluated changes in surface properties as well as the response of bMSCs in vitro. Commercially pure Ti and titanium-aluminum-vanadium (Ti6Al4V) disks were sand-blasted and acid-etched to impart microscale and nanoscale roughness, followed by treatment with various post-processing surface modification methods, including ultraviolet light (UV), dielectric barrier discharge (DBD)-generated plasma, and plasma treatment under an argon or oxygen atmosphere. Surface wettability was based on a sessile water drop measurement of contact angle; the elemental composition was analyzed using XPS, and changes in topography were characterized using scanning electron microscopy (SEM) and confocal imaging. The cell response was evaluated using bMSCs; outcome measures included the production of osteogenic markers, paracrine signaling factors, and immunomodulatory cytokines. All plasma treatments were effective in inducing superhydrophilic surfaces. Small but significant increases in surface roughness were observed following UV, DBD and argon plasma treatment. No other modifications to surface topography were noted. However, the relative composition of Ti, O, and C varied with the treatment method. The cell response to these hydrophilic surfaces depended on the plasma treatment method used. DBD plasma treatment significantly enhanced the osteogenic response of the bMSCs. In contrast, the bMSC response to argon plasma-treated surfaces was varied, with an increase in OPG production but a decrease in OCN production. These results indicate that post-packaging methods that increased hydrophilicity as measured by contact angle did not change the surface free energy in the same way, and accordingly, cells responded differently. Wettability and surface chemistry alone are not enough to declare whether an implant has an improved osteogenic effect and do not fully explain how surface free energy affects cell response.

Prevalence and anatomical factors associated with stent under-expansion in non-severely calcified lesions.

BACKGROUND: Stent underexpansion, typically related to lesion calcification, is the strongest predictor of adverse events after percutaneous coronary intervention (PCI). Although uncommon, underexpansion may also occur in non-severely calcified lesions. AIM: We sought to identify the prevalence and anatomical characteristics of underexpansion in non-severely calcified lesions. METHODS: We included 993 patients who underwent optical coherence tomography-guided PCI of 1051 de novo lesions with maximum calcium arc <180°. Negative remodeling (NR) was the smallest lesion site external elastic lamina diameter that was also smaller than the distal reference. Stent expansion was evaluated using a linear regression model accounting for vessel tapering; underexpansion required both stent expansion <70% and stent area <4.5mm2. RESULTS: Underexpansion was observed in 3.6% of non-heavily calcified lesions (38/1051). Pre-stent maximum calcium arc and thickness were greater in lesions with versus without underexpansion (median 119° vs. 85°, p = 0.002; median 0.95 mm vs. 0.78 mm, p = 0.008). NR was also more common in lesions with underexpansion (44.7% vs. 24.5%, p = 0.007). In the multivariable logistic regression model, larger and thicker eccentric calcium, mid left anterior descending artery (LAD) location, and NR were associated with underexpansion in non-severely calcified lesions. The rate of underexpansion was especially high (30.7%) in lesions exhibiting all three morphologies. Two-year TLF tended to be higher in underexpanded versus non-underexpanded stents (9.7% vs. 3.7%, unadjusted hazard ratio [95% confidence interval] = 3.02 [0.92, 9.58], p = 0.06). CONCLUSION: Although underexpansion in the absence of severe calcium (<180°) is uncommon, mid-LAD lesions with NR and large and thick eccentric calcium were associated with underexpansion.

Etiologies and Impact of Exclusion Rates for Transcatheter Mitral and Tricuspid Valve Structural Heart Clinical Trials at a High-Volume Quaternary Care Hospital.

There are various devices under clinical investigation for transcatheter mitral valve intervention and transcatheter tricuspid valve intervention (TTVI); however, the exclusion rates remain high. We aimed to investigate the exclusion rates for transcatheter mitral valve repair (TMVr), transcatheter mitral valve replacement (TMVR), transcatheter tricuspid valve repair (TTVr), and transcatheter tricuspid valve replacement (TTVR). There were 129 patients who were referred to St. Francis Hospital & Heart Center valve clinic and completed screening between January 2021 and July 2022. The causes for exclusion were classified into 4 categories: patient withdrawal, anatomic unsuitability, clinical criteria, and medical futility. In 129 patients, the exclusion rates for TMVr, TMVR, TTVr, and TTVR were 81%, 85%, 91%, and 87%, respectively. Patient withdrawal and medical futility were leading etiologies for exclusion, followed by anatomic unsuitability. TMVr had the highest rate of patient withdrawal (64%) and the lowest anatomic unsuitability (5%) because of short posterior leaflet length. Replacement interventions have a higher anatomic unsuitability (33%) than repair interventions (17%) (p = 0.04). Most exclusions of anatomic unsuitability were because of mitral stenosis or small annulus size for TMVR and large annulus size for TTVR. A total of 50% of exclusions from TTVr were because of the presence of pacemaker/defibrillator leads. In patients excluded from their respective trials, patients being referred for TMVr had the highest recurrent hospitalization and repair group had a higher mortality (p <0.01 and p = 0.01, respectively). In conclusion, the exclusion rates for transcatheter mitral valve intervention and TTVI trials remain high because of various reasons, limiting patient enrollment and treatment. This supports the need for further device improvement or exploring alternative means of therapy.

Ticagrelor with or without aspirin following percutaneous coronary intervention in high-risk patients with concomitant peripheral artery disease: A subgroup analysis of the TWILIGHT randomized clinical trial.

BACKGROUND: The optimal antiplatelet regimen after percutaneous coronary intervention (PCI) in patients with peripheral artery disease (PAD) is still debated. This analysis aimed to compare the effect of ticagrelor monotherapy versus ticagrelor plus aspirin in patients with PAD undergoing PCI. METHODS: In the TWILIGHT trial, patients at high ischemic or bleeding risk that underwent PCI were randomized after 3 months of dual antiplatelet therapy (DAPT) to aspirin or matching placebo in addition to open-label ticagrelor for 12 additional months. In this post-hoc analysis, patient cohorts were examined according to the presence or absence of PAD. The primary endpoint was Bleeding Academic Research Consortium (BARC) 2, 3, or 5 bleeding. The key secondary endpoint was a composite of all-cause death, myocardial infarction (MI), or stroke. Endpoints were assessed at 12 months after randomization. RESULTS: Among 7,119 patients, 489 (7%) had PAD and were older, more likely to have comorbidities, and multivessel disease. PAD patients had more bleeding or ischemic complications than no-PAD patients. Ticagrelor monotherapy compared to ticagrelor plus aspirin was associated with less BARC 2, 3, or 5 bleeding in PAD (4.6% vs 8.7%; HR 0.52; 95%CI 0.25-1.07) and no-PAD patients (4.0% vs 7.0%; HR 0.56; 95%CI 0.45-0.69; interaction P-value .830) and a similar risk of death, MI, or stroke in these 2 groups (interaction P-value .446). CONCLUSIONS: Despite their higher ischemic and bleeding risk, patients with PAD undergoing PCI derived a consistent benefit from ticagrelor monotherapy after 3 months of DAPT in terms of bleeding reduction without any relevant increase in ischemic events. CLINICAL TRIAL REGISTRY INFORMATION:: https://www. CLINICALTRIALS: gov/study/NCT02270242.

Regulatory Pathways in Growth Plate Chondrocytes that Are Impacted by Matrix Vesicle microRNA Identified by Targeted RISC Pulldown and Sequencing of the Resulting Transcriptome.

During endochondral bone formation, growth plate chondrocytes are differentially regulated by various factors and hormones. As the cellular phenotype changes, the composition of the extracellular matrix is altered, including the production and composition of matrix vesicles (MV) and their cargo of microRNA. The regulatory functions of these MV microRNA in the growth plate are still largely unknown. To address this question, we undertook a targeted bioinformatics approach. A subset of five MV microRNA was selected for analysis based on their specific enrichment in these extracellular vesicles compared to the parent cells (miR-1-3p, miR-22-3p, miR-30c-5p, miR-122-5p, and miR-133a-3p). Synthetic biotinylated versions of the microRNA were produced using locked nucleic acid (LNA) and were transfected into rat growth plate chondrocytes. The resulting LNA to mRNA complexes were pulled down and sequenced, and the transcriptomic data were used to run pathway analysis pipelines. Bone and musculoskeletal pathways were discovered to be regulated by the specific microRNA, notably those associated with transforming growth factor beta (TGFß) and Wnt pathways, cell differentiation and proliferation, and regulation of vesicles and calcium transport. These results can help with understanding the maturation of the growth plate and the regulatory role of microRNA in MV.

A multicenter prospective study to define the natural history of BK viral infections in kidney transplantation.

BACKGROUND: BK polyomavirus (BKV) can cause permanent loss of allograft function due to BKV-associated nephropathy (BKVN) in kidney transplant recipients. Besides immunosuppression reduction, there are no consistently effective interventions for BKV infection. Study purpose was to define natural history of BKV infection, identify risk factors for BKV reactivation and BKVN in kidney transplant recipients, and inform the design/conduct of future clinical trials of BKV-targeted therapeutics. METHODS: We conducted a multicenter prospective observational study of incident kidney transplant recipients at six U.S. transplant centers. Participants were monitored every 4 weeks for BKV reactivation and followed for up to 24 months post-transplant. We used regression models (logistic, survival, mixed models) to study relationships between BK viremia/BKVN, clinical characteristics, and allograft function. RESULTS: We enrolled 335 participants. Fifty-eight (17%) developed BK viremia, 6 (2%) developed biopsy-proven BKVN, and 29 (9%) developed suspected/presumed BKVN (defined as BKV viral load > 10,000 copies/mL without biopsy). Male donor sex was associated with lower odds for BK viremia, whereas recipient Black race was associated with two-fold increased odds for BK viremia. Recipient female sex was associated with more rapid clearance of BK viremia. Persistent BK viremia/BKVN was associated with poorer allograft function by 24 months post-transplant. CONCLUSIONS: We identified multiple donor and recipient demographic factors associated with risk for BKV infection and poorer allograft function by 24 months post-transplant. This may help design future clinical trials of therapies to prevent or mitigate the deleterious impact of BKV reactivation on kidney transplant outcomes.

Genetic versus self-reported African ancestry of the recipient and neighborhood predictors of kidney transplantation outcomes in 2 multiethnic urban cohorts.

African American (AA) kidney recipients have a higher risk of allograft rejection and failure compared to non-AAs, but to what extent these outcomes are due to genetic versus environmental effects is currently unknown. Herein, we tested the effects of recipient self-reported race versus genetic proportion of African ancestry (pAFR), and neighborhood socioeconomic status (SES) on kidney allograft outcomes in multiethnic kidney transplant recipients from Columbia University (N = 1083) and the University of Pennsylvania (N = 738). All participants were genotyped with SNP arrays to estimate genetic admixture proportions. US census tract variables were used to analyze the effect of neighborhood factors. In both cohorts, self-reported recipient AA race and pAFR were individually associated with increased risk of rejection and failure after adjustment for known clinical risk factors and neighborhood SES factors. Joint analysis confirmed that self-reported recipient AA race and pAFR were both associated with a higher risk of allograft rejection (AA: HR 1.61 (1.31-1.96), P = 4.05E-06; pAFR: HR 1.90 (1.46-2.48), P = 2.40E-06) and allograft failure (AA: HR 1.52 (1.18-1.97), P = .001; pAFR: HR 1.70 (1.22-2.35), P = .002). Further research is needed to disentangle the role of genetics versus environmental, social, and structural factors contributing to poor transplantation outcomes in kidney recipients of African ancestry.

National Variability in Pacemaker Implantation Rate Following TAVR: Insights From the STS/ACC TVT Registry.

BACKGROUND: Although permanent pacemaker (PPM) implantation is a common complication of transcatheter aortic valve replacement (TAVR), hospital variation and change in PPM implantation rates are ill defined. OBJECTIVES: The aim of this study was to determine hospital-level variation and temporal trends in the rate of PPM implantation following TAVR. METHODS: Using the American College of Cardiology/Society of Thoracic Surgeons TVT (Transcatheter Valve Therapy) Registry, temporal changes in variation of in-hospital and 30-day PPM implantation were determined among 184,452 TAVR procedures across 653 sites performed from 2016 to 2020. The variation in PPM implantation adjusted for valve type by annualized TAVR volume was determined, and characteristics of sites below, within, and above the 95% boundary were identified. A series of stepwise multivariable hierarchical models were then fit, and the median OR was used to measure variation in pacemaker rates among sites. RESULTS: From 2016 to 2020, the overall rate of PPM implantation was 11.3%, with wide variation across sites (range: 0%-36.4%); rates trended lower over time. Adjusted for annualized volume, there were 34 sites with PPM implantation rates above the 95th percentile CI and 28 with rates below, with wide variation among the remaining sites. After adjusting for patient-level covariates, there was variation among sites in the probability of PPM implantation (median OR: 1.39; 95% CI: 1.35-1.43, P < 0.001); although some of the variation was explained by the addition of valve type, residual variation in PPM implantation rates persisted in additional models incorporating site-level covariates (annualized volume, region, teaching status, hospital beds, etc). CONCLUSIONS: Although PPM implantation rates have decreased over time, substantial site-level variation remains even after accounting for observed patient characteristics and site-level factors. As there are numerous outlier sites both above and below the 95% confidence limit, dissemination of best practices from high-performing sites to low-performing sites and guideline-based education may be important quality improvement initiatives to reduce rates of this common complication.