Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blood transfusions increase mortality of hospitalized heart patients

06.10.2004


Heart patients are more than twice as likely to die during their first 30 days of hospitalization if they receive a blood transfusion to treat blood loss or anemia, according to a new analysis by cardiologists at the Duke Clinical Research Institute (DCRI).

Additionally, such patients are more than three times as likely to suffer a heart attack within 30 days, when compared to those who did not receive a transfusion.

These findings -- which emerged after a retrospective analysis of the treatments received by more than 24,000 patients hospitalized with an acute coronary syndrome -- run counter to earlier and smaller observational studies. For this reason, the researchers believe that a large randomized clinical trial needs to be initiated to resolve the issue and provide clear evidence-based guidance on how best to treat these patients. "Until such a trial can be conducted to resolve the differences between our study and past studies, we suggest caution in the routine use of blood transfusion for heart patients who are stable," said Duke cardiologist Sunil Rao, M.D., lead author of a study. For example, Rao said that cardiologists should not automatically order blood transfusions for anemic patients. The study results will be published Oct. 6, 2004, in the Journal of the American Medical Association. "The risks of transfusion remained even after we statistically controlled for other factors, such age, other illnesses and timing of the transfusions."



This issue is an important one, the researchers said, since cardiologists are now more aggressive in the treatment of patients who come to the hospital with symptoms of a heart attack. Physicians will often use clot-busting drugs or angioplasty procedures in an attempt to quickly re-open clogged arteries and save at-risk heart muscle. These treatments, as well as the routine drawing of blood for laboratory tests during hospitalization, can often leave patients with blood loss or anemia, a condition marked by decreased levels of oxygen-carrying red blood cells. "Many physicians, upon learning that their heart patients are anemic, will reflexively order a blood transfusion, believing that the additional red blood cells will deliver more oxygen to the heart and other tissues," Rao said. "However, there is data to suggest that oxygenation of the tissues do not necessarily increase as a result of blood transfusion."

The better understand the effects of transfusion on patient outcomes, the research team pooled the medical data from three large randomized clinical trials involving patients with acute coronary symdromes. Of the combined 24,111 patients, 10 percent (2,401) received at least one blood transfusion during the first 30 days of their hospitalization. The researchers found that in general, the patients receiving transfusions were older and had more additional medical problems.

Since the original clinical trials were not specifically designed to study the effect of transfusion, the researchers used three different statistical approaches in analyzing any associations between transfusions and adverse outcomes. All came to the same conclusions.

Specifically, the researchers found that 8 percent of transfused patients had died after 30 days, compared to 3.08 percent for those who did not receive a transfusion. Heart attacks occurred in 25.16 percent of those receiving additional blood, compared to 8.16 percent for those who did not. "The results of our analysis suggest that physicians should look at the whole patient, and not just the blood count number, when considering whether or not to transfuse someone," Rao said. "If patients appear to be fine, except for an abnormal blood number, it is probably best to hold off on transfusion. The body is constantly replenishing its blood supply, so in these patients it may be best to follow them to see if they can raise their blood counts on their own. If they don’t, then the physician should investigate potential underlying causes why the patient’s body isn’t responding."

According to Rao, the causes underlying the increased incidence of adverse events after transfusion are unclear. Previous studies have shown that transfused blood increases oxygen delivery only in the most severely anemic patients. Also, nitric oxide is essential for delivery of oxygen from the hemoglobin in red blood cells to tissues. However, according to Rao, nitric oxide has a short half-life, so by the time stored blood has been transfused, the essential nitric oxide may have been depleted.

It is also possible, Rao continued, that the transfused blood may stimulate an immune response that can exacerbate already existing coronary artery disease. "All of these factors, taken together, may act to promote ischemia in the heart rather than mitigate it,’ he said.
Rao’s analysis was funded by the DCRI. The three trials from which data was collected were GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) IIb, PURSUIT (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy) and PARAGON (Platelet IIb/IIIa Antagonism for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network) B.

Additional Duke members of the team were: James Jollis, M.D., Robert Harrington, M.D., Christopher Granger, M.D., Kristin Newby, M.D., Lauren Linblad, Karen Piper, Jonathan Stamler, M.D. (also a Howard Hughes Medical Institute investigator) and Robert Califf, M.D. Other members of the team were Eric Topol, M.D., Cleveland Clinic; Paul Armstrong, M.D., University of Alberta; and David Moliterno, M.D., University of Kentucky.

Richard Merritt | EurekAlert!
Further information:
http://www.mc.duke.edu

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>