CT scans may detect heart disease more clearly in patients with chest pain
A new study has found that CT scans may help doctors better diagnose heart disease in patients with chest pain.
Scottish researchers found that CT scans seemed to detect more heart problems than standardized tests, allowing doctors to minimize the risk of a heart attack. The patients suffered from chest pain and suspected heart disease which, in most cases, is caused by clogged arteries that disrupt the flow of blood in the body.
"A CT scan clarifies the diagnosis, changes treatments and may reduce the risk of a heart attack," said lead investigator Dr. David Newby, a professor at the University of Edinburgh.
"The chest pain, or angina, is a tightness in the chest which comes on when they exert themselves. Patients are usually seen in the clinic and can undergo a range of potential tests that could include a myocardial perfusion scan, which measures blood flow to the heart with a radioactive tracer, and ultrasound 'echo' scan, an MRI or a coronary angiogram."
Standard tests for patients with chest pain include an electrocardiogram and a stress test. An electrocardiogram (EKG or ECG) records the electrical activity of the heart, which is then translated into line tracings on a sheet of paper. A stress test usually involves walking on a treadmill or pedaling a stationary bike at increasing levels of difficulty while heart rate, blood pressure and an ECG are being monitored.
A CT scan combines a series of X-ray views taken from several different angles and computer processing to create cross-sectional images of the soft tissues and bones inside the body. A CT scan changed the initial diagnosis in 25 percent of cases, while standard care resulted in different diagnoses in only 1 percent of patients. CT scans also led to changes in treatment in 23 percent of cases versus 5 percent in patients who received standard care.
During a 20-month follow-up period, the number of heart attacks was 38 percent lower in patients who received a CT scan.
The findings were presented at the American College of Cardiology conference in San Diego on March 15 and published online in the The Lancet.
However, a federal study involving more than 10,000 patients in the United States and Canada found that people checked with a CT scan after seeing a doctor for chest pain had no less risk of heart attack or dying than those who take a treadmill test. The study also exposed the amount of radiation that patients who undergo CT scans get. Although radiation can increase the risk of developing cancer, few doctors are choosing tests that do not require radiation. The results of that study were also presented at the American College of Cardiology conference and published online in the New England Journal of Medicine.
A 2012 study published in JAMA Internal Medicine found that most individuals are unaware of the health risks involved with getting a CT scan. They expose patients to between 10 to 100 times more radiation than a normal head or chest X-ray. Of 235 patients, 81 (34 percent) were unaware that a CT scan would expose them to radiation. Only 3 percent said that they thought about radiation exposure before undergoing the scan.