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Background The Danish cardiovascular screening (DANCAVAS) trial, a nationwide trial designed to investigate the impact of cardiovascular screening in men, did not decrease all-cause mortality, an outcome decided by the investigators. However, the target group may have varied preferences. In this study, we aimed to evaluate whether men aged 65 to 74 years requested a CT-based cardiovascular screening examination and to assess its impact on outcomes determined by their preferences. Methods and findings This is a post hoc study of the randomised DANCAVAS trial. All men 65 to 74 years of age residing in specific areas of Denmark were randomised (1:2) to invitation-to-screening (16,736 men, of which 10,471 underwent screening) or usual-care (29,790 men). The examination included among others a non-contrast CT scan (to assess the coronary artery calcium score and aortic aneurysms). Positive findings prompted preventive treatment with atorvastatin, aspirin, and surveillance/surgical evaluation. The usual-care group remained unaware of the trial and the assignments. The user-defined outcome was based on patient preferences and determined through a survey sent in January 2023 to a random sample of 9,095 men from the target group, with a 68.0% response rate (6,182 respondents). Safety outcomes included severe bleeding and mortality within 30 days after cardiovascular surgery. Analyses were performed on an intention-to-screen basis. Prevention of stroke and myocardial infarction was the primary motivation for participating in the screening examination. After a median follow-up of 6.4 years, 1,800 of 16,736 men (10.8%) in the invited-to-screening group and 3,420 of 29,790 (11.5%) in the usual-care group experienced an event (hazard ratio (HR), 0.93 (95% confidence interval (CI), 0.88 to 0.98; p = 0.010); number needed to invite at 6 years, 148 (95% CI, 80 to 986)). A total of 324 men (1.9%) in the invited-to-screening group and 491 (1.7%) in the usual-care group had an intracranial bleeding (HR, 1.17; 95% CI, 1.02 to 1.35; p = 0.029). Additionally, 994 (5.9%) in the invited-to-screening group and 1,722 (5.8%) in the usual-care group experienced severe gastrointestinal bleeding (HR, 1.02; 95% CI, 0.95 to 1.11; p = 0.583). No differences were found in mortality after cardiovascular surgery. The primary limitation of the study is that exclusive enrolment of men aged 65 to 74 renders the findings non-generalisable to women or men of other age groups. Conclusion In this comprehensive population-based cardiovascular screening and intervention program, we observed a reduction in the user-defined outcome, stroke and myocardial infarction, but entail a small increased risk of intracranial bleeding. Trial registration ISRCTN Registry number, ISRCTN12157806 https://www.isrctn.com/ISRCTN12157806., Author(s): Axel Cosmus Pyndt Diederichsen 1,*, Anna Mejldal 2, Rikke Søgaard 3, Jesper Hallas 4, Jess Lambrechtsen 5, Flemming Hald Steffensen 6, Lars Frost 7, Kenneth Egstrup 5, Martin Busk [...]

This study examined the effects of polyethylene oxide (PEO) on the survival rate, hemodynamics, blood gas indexes, lactic acid levels, microcirculation, and inflammatory cytokine levels in rats subjected to severe hemorrhagic shock. The shocked rats were resuscitated with either Ringer's lactate solution or 20 ppm of PEO in Ringer's lactate solution for 1 h. It was found that infusion of PEO effectively improved the survival, metabolic acidosis, oxygen delivery, hyperlactacidemia, tissue perfusion, and inflammatory responses of rats subjected to hemorrhagic shock. In addition, we found, for the first time, that PEO showed protective effects on hepatic and renal injury, as evidenced by the significant decreases in the elevated levels of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine caused by shock induction after infusion of PEO (p < 0.05, 60 min post-resuscitation by comparison with pre-resuscitation). All of these findings indicate that PEO exhibits strong therapeutic effects under conditions of severe hemorrhagic shock, which also provides theoretical and experimental bases for the clinical use of PEO. Key words: drag-reducing polymers, polyethylene oxide, hemorrhagic shock, survival rate, microcirculation, organ damage. Les presents travaux vise a etudier les effets du polyethylene glycol (PEG) sur le taux de survie, les parametres hemodynamiques, les gaz sanguins, les taux d'acide lactique, la microcirculation et les taux de cytokines inflammatoires chez des rats soumis a un choc hemorragique grave. Les rats soumis au choc etaient reanimes au moyen de solution Ringer ou de 20 ppm de PEG dans une solution Ringer pendant une heure. Nous avons observe que la perfusion de PEG ameliorait l'etat des rats soumis a un choc hemorragique sur les plans de la mortalite, de l'acidose metabolique, de l'apport en oxygene, de l'hyperlactacidemie, de la perfusion tissulaire et de la reaction inflammatoire. De plus, nous avons montre pour la premiere fois que le PEG a des effets protecteurs flagrants sur les lesions hepatiques et renales, comme l'indiquent les chutes importantes des taux d'ALT, d'AST, d'azote ureique sanguin et de creatinine dont les elevations ont ete causees par le choc, apres la perfusion de PEG (p < 0,05, 60 min apres reanimation p/r a avant reanimation). Tous ces resultats indiquent que le PEG a des effets therapeutiques marques sur le choc hemorragique grave et fournissent une base theorique et experimentale pour l'utilisation du PEG en clinique. [Traduit par la Redaction] Mots-cles: polymeres reducteurs de frottement, polyethylene glycol, choc hemorragique, taux de survie, microcirculation, lesion organique., Introduction Trauma is the leading cause of death among North Americans between the ages of 1 and 44 years (Brasel et al. 2008). Each year, approximately 100 000 people die [...]

Much of the current knowledge of human cardiovascular pathologies and treatment strategies has been gained from understanding the cardiac physioiogies and functions in small animal models, such as mice, rats, and zebrafish. In this paper, we present the development of a high-frame-rate duplex ultrasound biomicroscopy (UBM) capable of B-mode imaging and pulsed-wave (PW) Doppler measurement for in vivo cardiovascular investigation in small animals. A frame rate of 200 frames per second (fps) was accomplished at a view of 5 mm x 8 mm, using a novel high-speed sector probe and specially designed lightweight transducers. In a reduced lateral view of 1.2 mm, a frame rate of 400 fps was achieved to examine more detailed cardiac motion. The UBM utilized transducers with different center frequencies (40-75 MHz) and geometries, which made it useful for various applications in small animal cardiac imaging. The highest spatial resolution the UBM achieved was 25 [micro]m x 56 [micro]m. In addition, the image-guided PW Doppler implemented in the UBM demonstrated the detection of the velocity of a moving wire as low as 0.1 mm/s, and flow in a polyimide tube as small as 200 [micro]m in diameter. Furthermore, the UBM achieved a 15-[micro]V minimal detectable signal and a 60-dB dynamic range using a low-cost PCB-based design. Finally, sample in vivo cardiac images of mouse and zebrafish hearts were given. These results showed that the UBM integrated with B-mode and PW Doppler is useful to investigate the pathophysiological mechanism in the cardiovascular studies.

A percutaneous ventricular assist device (pVAD) is an extracorporeal cardiac assist system that supports the failing ventricle in advanced stage heart failure by bypassing blood from the venous to the arterial circulation through a blood pump. The system can be implanted in a Cath lab using standard interventional techniques, and typically consists of a venous or atrial drainage cannula, the VAD (or blood pump), and an arterial perfusion cannula. Because the device allows clinicians the freedom of choosing the configuration and size of the cannulae based on the patient's body size and the size of the artery, it is extremely difficult but important to be able to predict the amount of blood flow that the device can provide before it is implanted to support the patient. In this paper, we develop a novel method that can be used to accurately predict the mean flow rate that the device can provide to the patient based on the size and configuration of the arterial cannula, the pump speed, and the patient's left atrial and mean arterial pressures. To do this, we first develop a nonlinear electric circuit model for the pVAD. This model includes a speed dependent voltage source and flow dependent resistors to simulate the pressure-flow relationship in the various cannulae in the device. We show that the flow rate through the device can be determined by solving a quadratic equation whose coefficients are scaled depending on the size and configuration of the arterial cannula. The model and prediction method were tested experimentally on a test loop supported by the TandemHeart pVAD (Cardiacassist, Inc., Pittsburgh, PA). A comparison of the predicted flow rates obtained from our method with experimental data shows that our method can predict the flow rates accurately with error indices less than 6 % for all test conditions over the entire range of intended use of the device. Computer simulations of the pVAD model coupled to a cardiovascular model showed that the accuracy of the method in estimating the mean flow rate is consistent over the normal range of operation of the device regardless of the pulsatility introduced by the cardiovascular system. This method can be used as an additional too to assist cardiologists in choosing a proper arterial cannulae configurations and sizes for pVAD patients. It can also be used as a tool to train clinical personnel to operate the device under different physiological conditions. Index Terms--Blood pump modeling, cardiovascular system, nonlinear circuit analysis, performance prediction, ventricular assist device (VAD).

A four-dimensional mapping (three spatial dimensions + time) of myocardial strain-rate would help to describe the mechanical properties of the myocardium, which affect important physiological factors such as the pumping performance of the ventricles. Strain-rate represents the local instantaneous deformation of the myocardium and can be calculated from the spatial gradients of the velocity field. Strain-rate has previously been calculated using one-dimensional (ultrasound) or two-dimensional (2-D) magnetic resonance imaging) techniques. However, this assumes that myocardial motion only occurs in one direction or in one plane, respectively. This paper presents a method for calculation of the time-resolved three-dimensional (3-D) strain-rate tensor using velocity vector information in a 3-D spatial grid during the whole cardiac cycle. The strain-rate tensor provides full information of both magnitude and direction of the instantaneous deformation of the myocardium. A method for visualization of the full 3-D tensor is also suggested. The tensors are visualized using ellipsoids, which display the principal directions of strain-rate and the ratio between strain-rate magnitude in each direction. The presented method reveals the principal strain-rate directions without a priori knowledge of myocardial motion directions. Index Terms--Cardiovascular system, kinematics, magnetic resonance imaging.