Timing of PCI in Patients Undergoing Transcatheter Aortic-Valve Implantation.

August 30, 2026| Source: The New England journal of medicine

Approximately one half of patients undergoing transcatheter aortic-valve implantation (TAVI) have concomitant coronary artery disease. Although percutaneous coronary intervention (PCI) is often performed before TAVI, the preferred treatment strategy has not been established. We conducted an international, open-label, randomized, noninferiority trial at 48 centers in Europe. Patients with severe aortic stenosis and coronary artery disease were randomly assigned in a 1:1 ratio to a strategy of either TAVI before PCI (TAVI-first group) or PCI before TAVI (PCI-first group). The primary end point was a composite of death from any cause; nonfatal myocardial infarction; ischemia-driven revascularization; rehospitalization related to the valve, procedure, or heart failure; or life-threatening, disabling, or major bleeding at 1 year after randomization. The noninferiority margin was 6.6 percentage points, with testing for noninferiority of TAVI first as compared with PCI first. A total of 986 patients underwent randomization: 498 were assigned to the TAVI-first group and 488 to the PCI-first group. A primary end-point event occurred in 105 patients (22.2%) in the TAVI-first group and in 112 patients (24.2%) in the PCI-first group (risk difference, -2.0 percentage points; 95% confidence interval, -7.4 to 3.4; P<0.001 for noninferiority). Serious adverse events occurred in 264 patients in the TAVI-first group and in 273 patients in the PCI-first group. Among patients with severe aortic stenosis and coronary artery disease, a strategy of TAVI before PCI was noninferior to a strategy of PCI before TAVI with respect to the primary end point at 1 year. (Funded by University Hospital Zurich and others; TAVI PCI ClinicalTrials.gov number, NCT04310046.).

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Extensive glacier loss in the coterminous United States.

Glaciers populate the mountain ranges of the western conterminous United States and despite their importance to alpine hydrology, their area and volume change have never been comprehensively evaluated. Our study shows that since the mid-twentieth century about one-quarter of the glaciers have disappeared and the overall area and volume are reduced by one-third. The pattern of glacier shrinkage suggests most glaciers in the conterminous United States are largely maintained by local topographic in

Physical/TechOctober 20, 2026

Reaction-based cryo-EM resolves the continuous conformational spectrum of CTP synthase catalysis.

Capturing enzymes under native turnover conditions remains a grand challenge in structural biology. Here, we develop a reaction-based cryo-electron microscopy (cryo-EM) strategy that directly samples Drosophila melanogaster cytidine triphosphate synthase (CTPS) from actively catalyzing mixtures containing only natural substrates and allosteric effectors. By integrating reaction-based sampling with three-dimensional variability analysis, we resolve a continuous conformational spectrum of CTPS dur

Physical/TechOctober 20, 2026

GTP orchestrates CTP synthase via an allosteric effector-cycling mechanism.

Cytidine triphosphate (CTP), a fundamental building block of RNA, plays vital roles in diverse biological processes. CTP synthase (CTPS) is the only known enzyme for de novo synthesis of CTP. Efficient CTPS catalysis requires guanosine triphosphate (GTP) in a dose-dependent, nonconsumptive manner; however, the precise mechanism by which GTP drives CTP formation remains unclear. Here, we integrate a series of cryo-EM structures of Drosophila melanogaster CTPS captured from actively catalyzing sam

Physical/TechOctober 20, 2026

Antiferromagnetism and tightly bound Cooper pairs induced by kinetic frustration.

Antiferromagnetism and superconductivity are often viewed as competing orders in correlated electron systems. Here, we demonstrate that kinetic frustration in hole motion facilitates their coexistence within the square-lattice repulsive Hubbard model. Combining exact analytical solutions on tailored geometries with large-scale numerical simulations, we reveal a robust pairing mechanism: Holes on opposite sublattices behave as if they carry opposite effective charges due to spin singlet formation

Physical/TechOctober 20, 2026

Coordinated transformations of the labyrinth and occiput during the dinosaur-bird transition.

Evolutionary shape changes of the vertebrate semicircular canals (SCCs) are often ascribed to evolutionary transitions in locomotion, including the origin of flight during the dinosaur-bird transition. However, the potential for transformations of braincase architecture to influence SCC shape independent of sensory-functional adaptation has generally been overlooked. We evaluate the influence of both factors using a large dataset of 146 living and recently extinct crown birds, including taxa rep