Six months for a cardiac patient could be one-tenth of their life.
Until now, that was how long it took just to determine whether one of the most commonly prescribed medications is having any positive effect.
“It?s not a big window of opportunity we?re working with here,” said Dr. Stephen Liggett, director of the Cardiopulmonary Genomics Program at the University of Maryland School of Medicine. Onein five new patients dies of the disease within the first year after diagnosis.
The results of genetic testing, announced Monday, promises to improve the survival rate and reduce side effects in cardiac patients by identifying which ones will respond positively to beta blockers, the second in a series of medications all heart patients are prescribed. Beta blockers reduce the strain on the heart by lowering heart rate and blood pressure ? allowing the heart to begin healing.
Identifying which people respond to the drugs, then aggressively pursuing the appropriate treatment could cut deaths by 38 percent in the five years following diagnosis, Liggett said.
“Our results really pave the way for what we call personalized medicine,” Liggett said, “being able to tailor the treatment for a person?s DNA.”
More than 500,000 people are diagnosed with heart disease in this country every year, and that trend is increasing, Liggett said. Treatment of the disease and related illnesses costs the country $28 billion annually.
Studying outcomes of more than 1,000 patients over five years, researchers tested for the presence of two genetic markers. Patients with a marker called arginine responded exceptionally well to beta blockers, with nearly 80 percent surviving the time period. People with an alternate marker called glycine showed no reaction or worse outcomes than those taking a placebo.
That doesn?t mean people with the glycine marker are out of luck, said Dr. Mandeep Mehra, chief of cardiology for the University of Maryland Medical Center. “It would really help our patients if we could refine predicting who will respond to a drug.”
Previously all new heart patients began aggressive treatment with medications called ace inhibitors, followed immediately by beta blockers and as many as 13 other medications layered one after another, Mehra said.
With no known explanation, some patients did not respond at all to the beta blockers, and as many as 30 percent of cardiac patients cannot tolerate the doses required to be effective, he said. Side effects include low heart rate, low blood pressure and depression.
Testing would allow doctors to explore other treatments more quickly in patients who won?t respond to beta blockers, Mehra said.
The genetic test could be available nationwide by the end of the year, and the combination of testing and the beta blocker called bucindolol will be submitted for FDA approval by the end of the year. Currently, the genetic test is only performed at the University of Maryland and two other institutions.
