Stroke protection effects like night and day

Scientists at Massachusetts General Hospital have suggested the different circadian cycles of humans and rodents as an explanation for the clinical failure of stroke medications that have been successful in animal studies. Multiple stroke drugs have failed in clinical trials, including normobaric hyperoxia (NBO), after showing neuroprotective effects in rodents. The authors tested NBO, as well as the free radical scavenger aPBN and the NMDA receptor antagonist ketamine, during both the active and the inactive phases of rodents. In each case, the drugs were successful at reducing the amount of brain damage after an experimentally induced stroke if treatment was given during the waking part of the animals’ daily cycle, but ineffective if given during their sleep cycle. Clinical trials typically recruit patients who have had strokes while awake, as it allows them to precisely establish the time of onset. “Our findings suggest that, in order to move forward, stroke mechanisms and targets should be re-assessed in rodent models with the appropriate circadian context,” the authors concluded. Their work appeared in the June 4, 2020, issue of Nature.

Blood pressure meds help range of patients when taken as prescribed

A new study has found that taking blood pressure medication as prescribed helped even the frailest, older patients live longer. That’s according to findings published June 8, 2020, in Hypertension. “We knew that high blood pressure medication was protective in general among older people; however, we focused on whether it is also protective in frail patients with many other medical conditions who are usually excluded from randomized trials,” said Giuseppe Mancia, lead study author and professor emeritus at the University of Milano-Bicocca in Milan, Italy. To that end, the researchers reviewed data on almost 1.3 million people ages 65 and older in the Lombardy region of northern Italy who had three or more high blood pressure medication prescriptions in 2011-2012. Researchers compared roughly 255,000 people who died during the seven-year follow-up with age-, gender- and health-status-matched controls who survived and divided them into four groups of health status: good, medium, poor or very poor. The probability of death over that time frame was 16% for people rated in good health at the beginning of the study. Mortality probability rose to 64% for those rated in very poor health. In addition, people with high adherence to blood pressure medications were 44% less likely to die if they started in good health and 33% less likely to die if they started in very poor health. A similar pattern was seen with cardiovascular deaths.

Test IDs undetected blood clots in COVID-19 patients

Baylor College of Medicine researchers say that all COVID-19 patients admitted to the intensive care unit (ICU) should undergo a thromboelastography (TEG) to test for the risk of forming blood clots. That comes after they found that more than half of the patients tested under these same conditions developed clinically significant blood clots that went undetected using routine screenings. The findings appeared June 5, 2020, in JAMA Network Open. “As the surgical critical care team at Baylor St. Luke’s Medical Center was discussing their work in the ICU a few weeks ago, I was amazed to hear them express that one of their greatest challenges was that the central intravenous and arterial lines and the dialysis catheters kept unexpectedly clotting in COVID-19 patients in the ICU,” said Todd Rosengart, chair and professor of the Michael E. DeBakey Department of Surgery at Baylor and senior author of the paper. “I’d never seen or heard anything like this in my 30 years as a surgeon, even in our sickest patients.” He and his colleagues subsequently reviewed the types of tests that could help identify these undetected clots. Eventually, they evaluated the TEG test, which looks at how quickly a clot forms, its strength and stability. Typically, it is used in open heart surgery patients who often have abnormal clot function, as well as trauma patients. Of note, they determined that the patients who they found were clotting their central intravenous and arterial lines and dialysis catheters had abnormally high clotting function vs. those who did not have clotting issues. Further, of the 21 patients studied, 62% developed 46 blood clots that could only be detected through the TEG test. “The TEG test should be performed on all COVID-19 ICU patients immediately to find those who are at a higher risk of clotting,” Rosengart said. “At the point where physicians discover that their central line and catheter is clotting, the horse is out of the barn.”

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