Imaging Technologies Provide More Precise Predictions for MI Patients

Viet Le, PA-C, physician assistant and cardiovascular researchers, Intermountain Medical Center Heart Institute

Viet Le, PA-C

Researchers at the Intermountain Medical Center Heart Institute found that incorporating underused, but available, imaging technologies more precisely predicts those at risk for myocardial infarctions and similar threats, with enough time to prevent them.

In the research presented at the 67th American College of Cardiology Scientific Session, investigators measured the level of calcium in the coronary arteries during stress testing using 2 common diagnostic tests to determine a patient's risk of heart disease: a positron emission tomography (PET), and computer tomography (CT).

"Conducting a PET/CT test to measure coronary artery calcium means clinicians can tell the difference between the potential risk of heart disease and actually having a disease," lead author, Viet Le, PA-C, physician assistant and cardiovascular researchers, Intermountain Medical Center Heart Institute, said in a statement. "High blood pressure, diabetes, high cholesterol and smoking are all risks of heart disease, yet many people who have those risks never have the disease or suffer an event. Coronary artery calcium is the disease — and to an extent, it shows just how much of the disease is present."

Researchers studied more than 8000 patients at Intermountain Medical Center without a history of coronary artery disease, myocardial infarction (MI) or known restricted blood flow to the heart who visited a physician clinic or hospital with symptoms of suspected heart disease and received a PET/CT imaging exam between 2013-2016.

Of the patients examined, researchers found that 53.2% had no calcium in the coronary arteries, while 46.8% did.

Within 60 days of the study, 6% of patients with no calcium underwent coronary angiography, compared to 10.8% who had calcium; 8% of patients with no calcium went on to receive revascularization to restore blood flow to the heart, versus 6.5% of patients with calcium; 9% of patients with no calcium had a major adverse coronary artery event like a MI, compared to 6% of patients with calcium; and 4% of patients with no calcium died, versus 4.2% of patients with calcium.

"The coronary artery calcium PET/CT test allows us to recommend therapy sooner, if necessary," Le adds. "We can say, 'Well, the ball may have made it all the way down the hallway, but there's an obstruction lying in wait there, which means you've got heart disease. This isn't theoretical; you're at risk. You need to be more vigilant about exercise, diet and your symptoms. We may need to initiate medical therapy.' We then can monitor those patients more aggressively to reduce their risk."

The result of assessing calcium during a PET/CT stress tests allows care to be more precise in providing patients more motivation to improve lifestyles.

The imaging technologies have the potential to proactively reduce healthcare costs since prevention is the and most cost-effective way to treat it.

"Avoiding a heart attack is a huge economic benefit," Le concluded. "A similar benefit comes as clinicians prescribe medications more efficiently by identifying precisely who needs them."