Saliva test may revolutionize pre-hospital care of heart attacks
SAN ANTONIO (Dec. 7, 2009) — Could a swab of saliva help paramedics confirm a heart attack sooner and give the patient a better shot at survival? A team from The University of Texas Health Science Center at San Antonio thinks it’s possible.
The Health Science Center enlisted San Antonio paramedics to collect saliva samples with patients’ consent at the site of ambulance calls. The samples are being analyzed for levels of several biological markers. If it turns out saliva can be used to diagnose heart attacks, paramedics will be able to alert hospitals sooner so patients can bypass emergency rooms and head straight to cardiac intensive care.
Emergency health professionals face a tall order when a person is having chest pains or shortness of breath. The patient’s symptoms, risk factors, medical history and electrocardiogram (EKG) accurately reveal a heart attack up to half of the time at the scene, but in the rest of cases the diagnosis is unclear until confirmed in the hospital using blood tests.
“Studies have shown that the shorter amount of time the patient gets to cardiac care, the lower the incidence of complications and death,” said paramedic and study collaborator Geoffrey Smith, instructor of emergency health sciences in the Health Science Center’s School of Health Professions. “If we take the next step to giving cardiologists and emergency room doctors more confidence in a scientific test versus our clinical interpretation, it will revolutionize care across the United States.”
Collaborator David Wampler, Ph.D., assistant professor of emergency health sciences, said: “If a patient is having chest pain, there is a cause for it, myocardial infarction (MI) or otherwise. Esophageal spasms and gastric reflux disease can mimic heart attacks. A good test could rule out MI’s and eliminate unnecessary hospital admissions. This point-of-care diagnostic tool should improve patient outcomes while saving money.”
Twenty San Antonio paramedics are using a mouth swab to obtain the saliva samples, with no need for a blood draw that could add to patients’ anxiety. In eight months they have swabbed 30 patients for the research database. They will test an additional 100 patients over the next year.
“We are looking for the same enzyme markers that they try to detect in the emergency room,” said collaborator Terry Bauch, M.D., assistant professor in the Janey and Dolph Briscoe Division of Cardiology at the Health Science Center School of Medicine. “If we move confirmation of markers to the emergency level, this would be useful in triaging patients. It would be one of those blockbuster technologies, potentially.”
One analysis performed in medical centers is for levels of troponin, a complex of three proteins that the heart releases during stress, Dr. Bauch said.
Chih-Ko Yeh, B.D.S., Ph.D., professor of dental diagnostic science in the Health Science Center Dental School, is a salivary gland expert and the lead investigator of the saliva biomarkers study. “We want to analyze multiple factors in saliva that are associated with heart attack,” Dr. Yeh said. “Before we were thinking of only one magic biomarker, but now we are looking for a combination to put together, analyze and make the diagnosis of heart attack.”
Four salivary markers are promising candidates, including three shown to be elevated in patients studied 48 hours after an MI. “What we don’t know is what the markers look like immediately after an event,” Dr. Yeh said. “There are also different markers that occur in the blood later.”
The paramedics soon will utilize portable technology developed at UT Austin and Rice University, said collaborator Spencer Redding, D.D.S., M.Ed., professor and chairman of dental diagnostic science in the Dental School. “The technology to do the testing is very small,” Dr. Redding said. “The UT Austin/Rice group is developing a portable box that will perform the saliva analysis and is small enough to be carried on the ambulance.”
The study is supported by a $470,000 grant from the National Institute for Dental and Craniofacial Research.
The University of Texas Health Science Center at San Antonio is the leading research institution in South Texas and one of the major health sciences universities in the world. With an operating budget of $668 million, the Health Science Center is the chief catalyst for the $16.3 billion biosciences and health care sector in San Antonio’s economy. The Health Science Center has had an estimated $36 billion impact on the region since inception and has expanded to six campuses in San Antonio, Laredo, Harlingen and Edinburg. More than 25,600 graduates (physicians, dentists, nurses, scientists and other health professionals) serve in their fields, including many in Texas. Health Science Center faculty are international leaders in cancer, cardiovascular disease, diabetes, aging, stroke prevention, kidney disease, orthopaedics, research imaging, transplant surgery, psychiatry and clinical neurosciences, pain management, genetics, nursing, dentistry and many other fields. For more information, visit www.uthscsa.edu.