Drugs Reduce Heart Surgery Risks

Within six months of heart disease surgery, up to 60 percent of patients suffer from their arteries reblocking.

Dr Anita Thomas and her colleagues at The University of Queensland have discovered a way to precisely deliver drugs to blockage sites in the arteries – preventing complications after surgery to treat heart disease. The technique uses antibodies linked to the drugs to ensure they are deposited in the arteries where doctors want them, rather than in other places in the body where they can lead have unacceptable side effects. Cardiovascular diseases – which can lead to heart attack, angina and stroke – are the biggest single preventable killer in the developed world, and result in the deaths of at least 17 million people each year. Most of these diseases are due to a single cause, the blockage of arteries by cholesterol-rich thickenings. “Surgical techniques have been developed to remove these blockages, but in up to 60 percent of patients they re-occur within six months,” says Dr Thomas, a post-doctoral fellow at the Australian Institute of Bioengineering and Nanotechnology. “We thought we could use drugs to prevent this from happening, but they have to be carefully targeted.” Dr Thomas and Professor Julie Campbell observed that the protein fibrin, which is found in blood clots, is deposited in arteries within 10 minutes of surgery to remove the original blockage. They then confirmed that fibrin could be used to attract antibodies, which they linked to drugs to prevent the artery from becoming re-blocked. The targeted delivery of these drugs was effective in preventing re-blocking, and also stopped the drug being dispersed within the blood stream. Dr Thomas found. Because the drug is concentrated where it is of most value, it can be used in low doses with minimal side effects. It also promotes rapid healing of the lining of the blood vessel, a significant benefit. Dr Thomas said various parts of the treatment were already being tested. “With a little bit more tweaking, we should see the treatment in hospitals within five years,” she said. Dr Thomas is one of 16 early-career scientists presenting their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Federal and Victorian Governments. (Source: University of Queensland : November 2007)