Courtesy: Intermountain Medical
Center Heart Institute
Cardiac PET/CT catches heart attack, stroke candidates that stress tests miss
November 17, 2016
by John W. Mitchell
, Senior Correspondent
Findings from a study presented this week at the American Heart Association Scientific Association in New Orleans concluded that doctors can further assess a patient's future heart risk by also checking calcium buildup caused by plaque via a PET/CT scan.
This extra measure can mean the difference between life and death for some patients.
"Many patients may mistakenly understand or interpret a "negative" stress test to mean, "you don't have any coronary disease at all"," Viet T. Le, MPAS, PA-C, lead author and cardiology research physician assistant at Intermountain Medical Center Heart Institute told HCB News. The study team also included physicians. "Some clinicians may also interpret a negative test to mean the same. This simply is not true."
Le explained that traditional stress tests - whether chemical or exertion-based - only indicate a moment in time. The stress test indicates that blood flow appeared to pass through the coronary artery well enough not to raise any concerns.
Cardiac experts have known for years that calcium left by plaque is a good marker of heart disease. But there was not good imaging technology to measure it without exposing the patient to too much radiation. Le said that changed about five years ago with PET/CT scan applications. PET/CT scanning can measure calcium build-up, which is a predictor of future cardiac events.
"PET/CT allows clinicians to answer both the immediate question of whether a patient's current symptoms could be related to a coronary obstruction and whether they need to be more vigilant," said Le.
The research team studied 658 men and women between the ages of 57 and 77 who passed a stress test for blocked arteries, but were later found to have plaque buildup, indicated by the calcium in their arteries through PET/CT studies. For five percent of these patients, the calcium was a predictor, within a year, of serious cardiac events, such as heart attack or stroke. In some cases, such events resulted in sudden death.
Calcification cannot be reversed. However, the condition can be managed with lifestyle changes, managing high blood pressure, high cholesterol or diabetes and with the use of risk-reducing medications.
Le stressed that the team's findings are not intended to replace clinical thinking or assessment of the patient when they present with symptoms of suspicious active coronary disease.
"We can provide both patients and clinicians a better assessment of that patient's coronary health beyond assessing blood flow on the day they present to the ER," Le explained. "PET/CT screening will allow both patients and clinicians to have a more informed decision process for treatment and risk reduction."