Impact of COVID-19 Pandemic on TAVR Activity: A Worldwide Registry

Background: The COVID-19 pandemic had a considerable impact on the provision of structural heart intervention worldwide. Our objectives were: 1) to assess the impact of the COVID-19 pandemic on transcatheter aortic valve replacement (TAVR) activity globally; and 2) to determine the differences in the impact according to geographic region and the demographic, development, and economic status of diverse international health care systems. Methods: We developed a multinational registry of global TAVR activity and invited individual TAVR sites to submit TAVR implant data before and during the COVID-19 pandemic. Specifically, the number of TAVR procedures performed monthly from January 2019 to December 2021 was collected. The adaptive measures to maintain TAVR activity by each site were recorded, as was a variety of indices relating to type of health care system and national economic indices. The primary subject of interest was the impact on TAVR activity during each of the pandemic waves (2020 and 2021) compared with the same period pre–COVID-19 (2019). Results: Data were received from 130 centers from 61 countries, with 14 subcontinents and 5 continents participating in the study. Overall, TAVR activity increased by 16.7% (2,337 procedures) between 2018 and 2019 (ie, before the pandemic), but between 2019 and 2020 (ie, first year of the pandemic), there was no significant growth (–0.1%; –10 procedures). In contrast, activity again increased by 18.9% (3,085 procedures) between 2020 and 2021 (ie, second year of the pandemic). During the first pandemic wave, there was a reduction of 18.9% (945 procedures) in TAVR activity among participating sites, while during the second and third waves, there was an increase of 6.7% (489 procedures) and 15.9% (1,042 procedures), respectively. Further analysis and results of this study are ongoing and will be available at the time of the congress. Conclusion: The COVID-19 pandemic initially led to a reduction in the number of patients undergoing TAVR worldwide, although health care systems subsequently adapted, and the number of TAVR recipients continued to grow in subsequent COVID-19 pandemic waves. Categories: STRUCTURAL: Valvular Disease: Aorti

Transport and Secretion of the Wnt3 Ligand by Motor Neuron-like Cells and Developing Motor Neurons

The vertebrate neuromuscular junction (NMJ) is formed by a presynaptic motor nerve terminal and a postsynaptic muscle specialization. Cumulative evidence reveals that Wnt ligands secreted by the nerve terminal control crucial steps of NMJ synaptogenesis. For instance, the Wnt3 ligand is expressed by motor neurons at the time of NMJ formation and induces postsynaptic differentiation in recently formed muscle fibers. However, the behavior of presynaptic-derived Wnt ligands at the vertebrate NMJ has not been deeply analyzed. Here, we conducted overexpression experiments to study the expression, distribution, secretion, and function of Wnt3 by transfection of the motor neuron-like NSC-34 cell line and by in ovo electroporation of chick motor neurons. Our findings reveal that Wnt3 is transported along motor axons in vivo following a vesicular-like pattern and reaches the NMJ area. In vitro, we found that endogenous Wnt3 expression increases as the differentiation of NSC-34 cells proceeds. Although NSC-34 cells overexpressing Wnt3 do not modify their morphological differentiation towards a neuronal phenotype, they effectively induce acetylcholine receptor clustering on co-cultured myotubes. These findings support the notion that presynaptic Wnt3 is transported and secreted by motor neurons to induce postsynaptic differentiation in nascent NMJs

Evolution of the interaction between Runx2 and VDR, two transcription factors involved in osteoblastogenesis

<p>Abstract</p> <p>Background</p> <p>The mineralized skeleton is a major evolutionary novelty that has contributed to the impressive morphological diversifications of the vertebrates. Essential to bone biology is the solidified extracellular matrix secreted by highly specialized cells, the osteoblasts. We now have a rather complete view of the events underlying osteogenesis, from a cellular, molecular, genetic, and epigenetic perspective. Because this knowledge is still largely restricted to mammals, it is difficult, if not impossible, to deduce the evolutionary history of the regulatory network involved in osteoblasts specification and differentiation. In this study, we focused on the transcriptional regulators Runx2 and VDR (the Vitamin D Receptor) that, in mammals, directly interact together and stabilize complexes of co-activators and chromatin remodellers, thereby allowing the transcriptional activation of target genes involved in extracellular matrix mineralization. Using a combination of functional, biochemical, and histological approaches, we have asked if the interaction observed between Runx2 and VDR represents a recent mammalian innovation, or if it results from more ancient changes that have occurred deep in the vertebrate lineage.</p> <p>Results</p> <p>Using immunohistochemistry and <it>in situ </it>hybridization in developing embryos of chick, frog and teleost fishes, we have revealed that the co-expression of Runx2 and VDR in skeletal elements has been particularly strengthened in the lineage leading to amniotes. We show that the teleost Runx2 orthologue as well as the three mammalian Runx1, Runx2 and Runx3 paralogues are able to co-immunoprecipitate with the VDR protein present in nuclear extracts of rat osteoblasts stimulated with 1α,25-dihydroxyvitamin D₃. In addition, the teleost Runx2 can activate the transcription of the mammalian <it>osteocalcin </it>promoter in transfection experiments, and this response can be further enhanced by 1α,25-dihydroxyvitamin D₃. Finally, using pull-down experiments between recombinant proteins, we show that the VDR homologue from teleosts, but not from ascidians, is able to directly interact with the mammalian Runx2 homologue.</p> <p>Conclusions</p> <p>We propose an evolutionary scenario for the assembly of the molecular machinery involving Runx2 and VDR in vertebrates. In the last common ancestor of actinopterygians and sacropterygians, the three Runx paralogues possessed the potential to physically and functionally interact with the VDR protein. Therefore, 1α,25-dihydroxyvitamin D₃might have been able to modulate the transcriptional activity of Runx1, Runx2 or Runx3 in the tissues expressing VDR. After the split from amphibians, in the lineage leading to amniotes, Runx2 and VDR became robustly co-expressed in developing skeletal elements, and their regulatory interaction was incorporated in the genetic program involved in the specification and differentiation of osteoblasts.</p

Coronary artery aneurysms, insights from the international coronary artery aneurysm registry (CAAR).

Coronary Aneurysms are a focal dilatation of an artery segment >1.5-fold the normal size of adjacent segments. Although some series have suggested a prevalence of 0.3-12%, data are lacking. In addition, they are not mentioned in practice guidelines. Our aim was investigate its prevalence, management and long-term outcomes. The coronary artery aneurysm registry (CAAR) involved 32 hospitals across 9 countries in America and Europe. We reviewed 436,467 consecutive angiograms performed over the period 2004-2016. Finally, 1565 patients were recruited. Aneurysm global prevalence was 0.35%. Most patients were male (78.5%) with a mean age of 65 years and frequent cardiovascular risk factors. The main indication for angiogram was an acute coronary syndrome, 966 cases. The number of aneurisms was ≤2 per patient in 95.8% of the cases, mostly saccular, most frequently found in the left anterior descending and with numbers proportional with coronary stenosis. Aortopathies were related with more aneurysms too. Most patients received any revascularization procedure (69%), commonly percutaneous (53%). After a median follow-up of 37.2 months, 485 suffered a combined event (MACE) and 240 died. Without major differences comparing CABG vs PCI, MACE and death were more frequent in patients who received bare metal stents. Coronary artery aneurysms are not uncommon. Usually, they are associated with coronary stenosis and high cardiovascular risk. Antiplatelet therapy seems reasonable and a percutaneous approach is safe and effective

Impact of the COVID-19 Pandemic on Global TAVR Activity:The COVID-TAVI Study

Background: The COVID-19 pandemic adversely affected health care systems. Patients in need of transcatheter aortic valve replacement (TAVR) are especially susceptible to treatment delays. Objectives: This study sought to evaluate the impact of the COVID-19 pandemic on global TAVR activity. Methods: This international registry reported monthly TAVR case volume in participating institutions prior to and during the COVID-19 pandemic (January 2018 to December 2021). Hospital-level information on public vs private, urban vs rural, and TAVR volume was collected, as was country-level information on socioeconomic status, COVID-19 incidence, and governmental public health responses. Results: We included 130 centers from 61 countries, including 65,980 TAVR procedures. The first and second pandemic waves were associated with a significant reduction of 15% (P &lt; 0.001) and 7% (P &lt; 0.001) in monthly TAVR case volume, respectively, compared with the prepandemic period. The third pandemic wave was not associated with reduced TAVR activity. A greater reduction in TAVR activity was observed in Africa (−52%; P = 0.001), Central-South America (−33%; P &lt; 0.001), and Asia (−29%; P &lt; 0.001). Private hospitals (P = 0.005), urban areas (P = 0.011), low-volume centers (P = 0.002), countries with lower development (P &lt; 0.001) and economic status (P &lt; 0.001), higher COVID-19 incidence (P &lt; 0.001), and more stringent public health restrictions (P &lt; 0.001) experienced a greater reduction in TAVR activity. Conclusions: TAVR procedural volume declined substantially during the first and second waves of the COVID-19 pandemic, especially in Africa, Central-South America, and Asia. National socioeconomic status, COVID-19 incidence, and public health responses were associated with treatment delays. This information should inform public health policy in case of future global health crises.</p