Cognitive dysfunction associated with CABG surgery generally gone within eight weeks . . . The cognitive dysfunction observed in patients who undergo coronary artery bypass grafting (CABG) surgery usually disappears within eight weeks following surgery, according to a study published in the April issue of The Annals of Thoracic Surgery. Previously published estimates of the incidence of post-operative cognitive dysfunction vary widely, with some studies reporting lasting impairment in as many as 50% of patients. Researchers from Monash University and RMIT University (both Victoria, Australia), periodically tested cognitive function in three sets of patients: 16 patients who underwent elective CABG surgery, 15 patients who underwent elective chest surgery for lung biopsies or lobectomies, and 15 non-surgical patients. "Our study carefully controlled for a wide range of factors that can influence cognition, such as the residual effect of general anesthesia, familiarity with testing procedures during retesting (practice effects), general intelligence, age, education levels, emotional state, and levels of pre-existing impairment," said Kathryn Bruce, the primary author of the study. The researchers found that CABG patients performed worse on every subtest prior to surgery, and these disparities continued following surgery. Anxiety, depression, and stress were associated with impaired cognitive performance in patients in the two surgical groups one week after surgery. At one-week post-operation, 44% of CABG patients and 33% of surgical control patients were significantly impaired; however, by eight-weeks post-operation nearly all patients had recovered to pre-operation levels with 25% of CABG patients and 13% of surgical control patients improving beyond their pre-operative performance. The researchers also found that even though the surgical groups showed impairment, when individual performance within these groups was examined, more than half of the patients were unaffected by the surgery. The results also showed that the strongest predictor of worse cognitive performance after surgery was the emotional state of the patient, and patients who were anxious or stressed prior to undergoing surgery generally performed worse afterwards. In an invited commentary appearing in the same issue, Ola Selnes, PhD, from The Johns Hopkins University (Baltimore), noted that patients who are worried about adverse neurological outcomes, such as cognitive decline, can be reassured that post-operative cognitive decline is significantly less common than was reported in the past.

New imaging technology may benefit heart procedure patients . . . Patients undergoing angioplasty or other heart-related medical procedures could benefit from a new technology being developed with funding from the National Science Foundation. Optical imaging technology from Wasatch Photonics (Logan, Utah) is designed to create images of coronary artery walls in vivo to show where lesions and plaques have formed. Physicians can use the images to determine the best course of action, including where a stent might be placed, the company noted. William Brown, VP of business development at Wasatch Photonics, said the outcome of developing the technology will be the availability of a new tool to identify and treat coronary artery disease. "Our technology, called intravascular optical coherence tomography, provides detailed imaging information for physicians to use in plaque assessment and stent implantation and monitoring. Our system, with its increased image resolution capability and competitive cost, will provide a significant improvement over the current systems," Brown said. Wasatch Photonics received a two-year Small Business Innovation Research Phase II grant for $498,325 from the NSF. The grant provides funding to continue developing the intravascular optical coherence tomography system. Brown said the grant also validates the company's approach.

STS releases guidelines for aortic valve disease . . . The Society of Thoracic Surgeons (STS; Chicago) has released a set of clinical practice guidelines to address major advances in the evaluation and management of patients with aortic valve disease. An executive summary of the clinical practice guidelines on aortic valve and ascending aorta procedures appears in the April issue of The Annals of Thoracic Surgery. The full guidelines will be published as a supplement in an upcoming issue of the journal. The guideline writing committee included surgeons and cardiologists who expanded on previous guidelines and concentrated on surgical aspects, such as the evolving technology of percutaneous valves, to help increase the quality of care for patients undergoing aortic valve replacement (AVR) or thoracic aorta surgery. "For cardiac surgeons and cardiologists, there have been few options and no guidelines on how to manage high-risk, previously inoperable patients," said Lars Svensson, MD, from the Cleveland Clinic and chair of the guideline task force. "In creating these new guidelines, we wanted to outline the pros and cons of treatment options for repairing the aortic valve, replacing the valve, and using transcatheter approaches. We also wanted to outline areas where more research is needed and incorporate quality metrics." The new aortic valve and ascending aorta clinical practice guidelines make recommendations in 26 areas, including mechanical aortic valves, biological valves, and transcatheter aortic valve replacement (TAVR). "We expect that these new guidelines will raise questions, and that with new information and literature, the guidelines will need to be updated and new iterations will evolve as we gain knowledge of this patient population," Svensson said. "We trust this will continue to raise the level of already excellent care and outcomes for patients with aortic valve disease."

Heart disease increases with BMI . . . Coronary heart disease (CHD) increases with BMI, as well as with age, finds an article published in BioMed Central's open access journal BMC Medicine. The research from the Million Women Study indicates that increased weight increases risk of CHD equivalent to that caused by getting older. Researchers from the University of Oxford followed the health of 1.2 million women from England and Scotland for (on average) almost a decade. Analysis of the data showed that the occurrence of CHD increases with BMI so that every 5 unit increase in BMI, calculated as weight/height, increases incidence by 23%, which is equivalent to the risk conferred by getting older by 2.5 years. The results showed that one in eleven lean middle aged women (with an average BMI of 21) will be admitted to hospital or will have died from CHD between the ages of 55 to 74. This risk progressively increases with BMI, and it reaches one in six, for obese women (with an average BMI of 34).

Scientists analyze stem cells to shed light on common bleeding disorder . . . Scientists have shed light on a common bleeding disorder by growing and analyzing stem cells from patients' blood to discover the cause of the disease in individual patients. The technique may enable doctors to prescribe more effective treatments according to the defects identified in patients' cells. In future, this approach could go much further: these same cells could be grown, manipulated, and applied as treatments for diseases of the heart, blood and circulation, including heart attacks and haemophilia. The study focused on von Willebrand disease (vWD), which is estimated to affect 1 in 100 people and can cause excessive, sometimes life-threatening bleeding. vWD is caused by a deficiency of von Willebrand factor (vWF), a blood component involved in making blood clot. vWF is produced by endothelial cells, which line the inside of every blood vessel in our body. Unfortunately, they are difficult to study because taking biopsies from patients is invasive and unpleasant. A group led by Anna Randi, PhD, at the National Heart and Lung Institute, Imperial College London used a new approach to investigate the disease. Richard Starke, PhD, a British Heart Foundation Intermediate Fellow and lead author of the study, took routine blood samples from eight patients with vWD, extracted stem cells called endothelial progenitor cells, and grew them in the lab to yield large numbers of endothelial cells. By testing these cells, they were able to analyze each patient's disease in unprecedented detail. In some patients, the scientists found new types of defect, which may enable them to recommend improved treatments. Professor Mike Laffan, a collaborator in the study and in charge of patients with VWD at Hammersmith Hospital (West London), is looking to apply these findings to reduce severe bleeding in these patients. Randi believes that endothelial progenitor cells could become an invaluable resource for testing new drugs for vWD and other diseases. "We will be able to test the effects of a range of compounds in the patients' own cells, before giving the drugs to the patients themselves," she said. This approach could have impact far beyond vWD. Endothelial cells derived from blood could also be isolated and reinjected into someone recovering from a heart attack, to help them grow new blood vessels and repair the injured heart tissue. Starke says this approach avoids the main problem with transplant therapies, in which the immune system tries to destroy the foreign material. Work is well underway towards achieving this goal, but blood-derived endothelial cells are only now being explored. The group's previous research has already thrown up pointers for potential new treatments. Aside from producing vWF to form clots, endothelial cells are responsible for forming new blood vessels. In their last paper, the group showed that vWF is actually needed to build healthy blood vessels.

— Compiled by Amanda Pedersen, MDD Senior Staff Writer

amanda.pedersen@ahcmedia.com

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