Aspirin May Not Protect Heart After Non-Cardiac Surgeries: Study

Giving aspirin to patients around the time of surgery may do them more harm than good, a large new study finds. Surgery of any kind -- not just heart surgery -- may raise a person's risk for having a heart attack, research has shown. Doctors often start patients on a low dose of aspirin shortly before and after their procedures to help prevent those events. But the new study, which pitted aspirin against a dummy pill ("placebo") in over 10,000 patients who were having major surgeries that didn't involve their hearts, found that not only did aspirin fail to prevent heart attacks, it also significantly increased the risk of major bleeding. The authors pointed out that many patients were already taking other drugs meant to prevent blood clots. The most common surgeries in the study were orthopedic procedures like joint replacements. For the study, researchers recruited patients from 135 hospitals in 23 countries. Half were randomly assigned to take 200 milligrams of aspirin just before surgery and then to continue on 100 milligrams for up to a month after surgery. The other half took a placebo pill. Half of the patients were already taking a low-dose aspirin every day when they entered the study. Those patients were told to stop their daily aspirin at least three days before surgery and pick it up again seven days after. The average age of patients who participated in the study was 68, almost evenly divided between women and men. About a third of patients in both groups had a history of blood clots that had caused heart attacks, strokes, or peripheral vascular disease. And nearly two-thirds also got some kind of additional blood thinner, typically Enoxaparin or Rivaroxaban, to prevent clots. Nearly the same number of patients, about 7 percent, died or had a heart attack within 30 days of their surgeries, whether they took aspirin or the placebo -- 351 of 4,998 patients in the aspirin group compared with 355 of 5,012 patients who took the placebo. That was true even for patients who were already on a daily aspirin regimen before their operations. But significantly more patients in the aspirin group experienced major bleeding than those who took the placebo -- 230 patients versus 188 in the placebo group. The findings contradict previous studies that found that aspirin could help prevent heart attacks after surgery. But those studies were smaller, the researchers noted, or looked at surgical outcomes after treatments had already been assigned, making their results less definitive. Researchers say it could be that aspirin does prevent heart attacks caused by blood clots, but when it's given to patients in addition to other blood thinners, as is often the case, the bleeding risk cancels any benefit. Bleeding can also cause heart attacks, explained study author. A sharp drop in blood pressure can seriously stress the heart, sending it into cardiac arrest. "The perioperative period is a tricky period in terms of balancing these competing physical effects that are going on," he said. "We should stop aspirin during the perioperative period, because we're only putting patients at risk without an apparent benefit," he added. For patients who take a low dose of aspirin each day to prevent either first or second heart attacks, he said the study found that it's safest to resume that regimen eight to 10 days after surgery, since that's when bleeding risk subsides. 

Return to top

More Signs Autism May Originate During Pregnancy

Children with autism show key "patches of disorganization" in the outer layers of the brain, according to a new study said to offer more evidence that the developmental disorder begins in the womb. Experts have long believed autism involves disruptions in typical brain development, going back to pregnancy. For the study, researchers examined samples of brain tissue from 22 children after death -- 11 with autism and 11 without. They were able to spot tiny patches of disrupted development dotting the outer layers of the brain in the children with autism. Differences like that would take shape during prenatal development, lead researcher said. "This is pretty direct evidence of a prenatal origin," he added. In general, however, experts believe autism arises from genetic susceptibility and yet unknown environmental factors. "Ultimately, it's an interplay between genes and environment," researcher said. In the United States, an estimated one in 88 children has an autism spectrum disorder, which affects the ability to communicate and interact with others. Some kids are profoundly affected, speaking very little or not at all and focusing obsessively on just a few interests. Others have milder problems communicating and reading social cues, such as other people's gestures and facial expressions. Researchers have managed to find a few hundred genes that are linked to autism risk. And although there is no definite environmental culprit, studies have tied certain factors during pregnancy to an increased risk, including exposure to high levels of air pollution, low intake of the B vitamin folate and viral infections. For the new study, lead researcher and his colleagues examined small samples of the neocortex -- the outer surface of the brain. During fetal development, the neocortex forms six layers, each with its own specialized brain cells. As those cells develop, they take on a "genetic signature" that can be visualized in tissue samples, using sophisticated techniques. Overall, the study found, brain tissue from children with autism showed tiny patches where certain genetic signatures were absent from brain cells. What's more, those patches were concentrated in areas associated with higher order brain functions, such as understanding language and social cues. Lead researcher said the fact that the brain tissue showed small patches of disruption, rather than pervasive abnormalities, is "potentially good news." It suggests that much of the neocortex is actually typical in children with autism, he said. That might help explain why autistic toddlers who get early behavioral therapy often show significant improvements, he said. It's possible the brain is able to "rewire," to an extent, to get around some of the trouble spots seen in this study.

SOURCE: HealthDay News, March 2014

Return to top

Anti-Seizure Drug May Guard Against Some Cancers

A drug used to treat seizures may reduce the risk of head and neck cancers, a new study suggests. Valproic acid is prescribed to prevent seizures and also to control mood, but it is also being investigated for cancer prevention because it inhibits genetic changes that can lead to cancer. The new study included nearly 440,000 U.S. veterans, including about 27,000 who were taking valproic acid for bipolar disorder, post-traumatic stress disorder (PTSD), migraines and seizures. Overall, veterans who took the drug for at least one year were 34 percent less likely to develop head and neck cancers than those who didn't take the drug, the investigators found. The risk appeared to be even lower in those who took it in higher doses or for longer periods of time, according to the study. Veterans who took valproic acid did not have a reduced risk for lung, bladder, colon or prostate cancers, said team leader. "A 34 percent risk reduction for the development of head and neck cancer with [valproic acid] use could result in the prevention of up to approximately 16,000 new cases and 3,000 to 4,000 annual deaths in the U.S. alone," lead authorsaid. "Head and neck cancer is an important global health crisis, and low cost and low toxicity prevention strategies like [valproic acid] use have a high potential impact on pain, suffering, costs, and [death] associated with this disease," he added. Although the study found an association between valproic acid use and reduced risk of certain cancers, it did not prove cause-and-effect.  

Return to top