February 21, 2013
Noninvasive Scan May Help Determine Heart Attack Risk
Jason Pierce, MSN, MBA, RN for redOrbit.com — Your Universe Online
A study recently published in the journal“¯Radiology reports that coronary computerized tomography angiography (CCTA) may be used as a reliable, noninvasive alternative to traditional coronary angiography for assessing risk of heart attack in patients with no medically modifiable risk factors.“CCTA should be considered as an appropriate first-line test for patients with atypical chest pain and suspected but not confirmed coronary artery disease,” said lead author Jonathon Leipsic, M.D., FRCPC, from the University of British Columbia in Vancouver.
The Centers for Disease Control and Prevention (CDC) lists heart disease as the leading cause of death for men and women in the US. Modifiable risk factors are those risks that can be reduced by changes to the patient´s lifestyle or medical treatment. Modifiable risk factors include smoking, high blood pressure, high cholesterol, obesity and physical inactivity. Non-modifiable risk factors include the patient´s age, sex and family history.
The study involved data provided by the Coronary CT Angiography Evaluation For Clinical Outcomes: An International Multicenter (CONFIRM) registry. The registry includes nearly 30,000 patients from North America, Europe and Asia with suspected coronary artery disease (CAD), known CAD, or asymptomatic persons undergoing CAD evaluation.
Dr Leipsic and his colleagues looked at CCTA findings of 5,262 patients with suspected CAD and no medically modifiable risk factors. "We found that patients with narrowing of the coronary arteries on CT had a much higher risk of an adverse cardiac event," Dr. Leipsic said. "This was true even for those without a family history of heart disease."
According to Dr Leipsic, there is currently no adequate guide for determining risk of future heart attacks in patients who have cardiac-like symptoms, such as chest pain or shortness of breath, but do not have cardiac risk factors or known coronary artery disease. CCTA could provide a means to determine which patients would benefit from more invasive treatments.
"If a patient shows up with vague symptoms and no medically modifiable risk factors, doctors often dismiss them or do a treadmill test, which won't identify atherosclerosis and only has a modest sensitivity for detecting obstructive disease," said Dr. Leipsic. In fact, a previous study published in the Journal of American College of Cardiology found CCTA to be more effective at identifying obstructive heart disease than the treadmill test.
A CCTA is a radiology test that provides an X-ray of the arteries that supply the heart muscle with blood. By contrast, a traditional coronary angiogram involves the injection of dye into the blood vessels that feed the heart. The dye is injected during cardiac catheterization, a process involving threading a long catheter into the heart vessels. The catheter is inserted through a vein in the arm, upper thigh, or neck. Although more invasive, the process of cardiac catheterization allows the physician to perform interventions, such as cardiac stent placement, to correct inadequate blood flow. This ability to immediately intervene makes traditional coronary angiogram the preferred choice for patients with known coronary artery disease (CAD).