Improved CT Scan Helps Screen For Heart Disease

Before the heart attack or initial “event” that alerts the unsuspecting to life-threatening illness, cardiovascular disease often stalks its victims with the stealth of a silent killer. The plaque that fills and clogs the arteries, cutting off the flow of blood through the body and to the heart, accumulates without notice or warning.

Until now, the only tools to predict a cataclysmic, possibly fatal event have been the stress test and the angiogram. The prescribing of a stress test without symptoms or other indications doesn’t make sense for most people. And the invasive angiogram, which requires the threading of a catheter in through the groin, isn’t useful as an early detection screening tool.

“It’s tough to study a beating heart,” explained Dr Robert Russo, chairperson of radiology at St Vincent’s Medical Center in Bridgeport. But now, according to Dr Russo, advances in CT scan technology are making it possible to get an image of plaque in the arteries that may help predict the likelihood that a person will suffer a heart attack.

“The new equipment is faster and has software that can calculate the amount of calcification found in the plaque,” Dr Russo continued. “We can compare those numbers to charts that show us where the person may fall within the spectrum, and we can give them a pretty good idea about where they stand in regards to heart disease.”

Dr Kathleen Harper, a cardiologist at St Vincent’s Medical Center, noted, “Plaque is a complex substance. It’s made up of two components: fat, or lipids, and calcifications.” Soft plaque, the kind made of just lipids, accounts for 50 percent of heart attacks, she said.

“Not all plaque has calcifications, but the presence of calcification is an indicator that there are also lipids in the arteries,” Dr Harper said. The American College of Cardiology, she went on to explain, reports that a CT scan that shows no calcification makes the presence of lipids, and therefore heart disease, unlikely. “It is consistent with a low risk for the occurrence of a heart attack or anginal event in the following two to five years.”

The coronary artery calcification chart that radiologists like Dr Russo use to gauge the density of the calcification, and therefore probability of cardiovascular diseases, ranges from zero to 400. “A score of one to 10 suggests a low risk of disease,” Dr Russo explained. “Eleven to 100 indicates a moderate risk. Any score between 101 and 400 we consider moderately high, and beyond 400, there’s a high likelihood of significant blockage.”

A moderate to high score, according to Dr Harper, would call for further evaluation of a patient’s cholesterol levels. “A high score should definitely be a wake-up call,” emphasized the cardiologist.

According to both St Vincent’s doctors, the advances in CT scan equipment, with improved resolution of the scanner and the ability to image thinner and thinner “slices” of tissue, make this a cost-effective screening tool for those with risk factors but who have had no symptoms. Those risk factors include a family history of coronary artery disease, cigarette smoking, high blood pressure, high cholesterol levels, and diabetes.

“This is a cutting edge tool for early screening for cardiovascular disease,” Dr Harper continued. “St Vincent’s is among only a handful of places where this is now an option.” 

Because most insurance plans do not cover this preventive test, the cost is an out of pocket expense, running around $300.