The researchers from Germany investigated whether noninvasive testing (i.e., CCTA plus FFR-CT) would lead to different treatment choices for patients with multiple-vessel coronary artery disease compared with conventional angiography. They found that the noninvasive and invasive evaluation methods resulted in nearly identical treatment selections.
"Treatment decision-making based on CCTA showed high agreement with decisions derived from conventional coronary angiography, suggesting that treatment decision-making and planning based solely on this noninvasive imaging modality and clinical information is the best way to do it," presenter Dr. Ulf Teichgräber told session attendees. Teichgräber is chairman of diagnostic and interventional radiology at Jena University Hospital.
Determining the best course of treatment for patients classified as having high-risk coronary artery disease currently relies on anatomical information drawn from an invasive coronary angiography exam. In most cases, a team of cardiologists and cardiac surgeons use grading tools such as the SYNTAX scoring algorithm to quantify the complexity of a patient's coronary disease and then recommend either percutaneous coronary intervention or coronary artery bypass surgery (CABG) based on the score.
Recent advancements in CT technology may now enable physicians to determine the best way to manage these patients using noninvasive imaging techniques, potentially removing the need for patients to undergo invasive coronary angiography, Teichgräber noted. This proposal was put forth in a study led by Dr. Patrick Serruys, PhD, inventor of the SYNTAX score, in the SYNTAX Extended Survival (SYNTAX III) trial published earlier this year in Lancet.
To validate this idea, Teichgräber and colleagues established two distinct "heart teams" made up of a cardiologist, cardiac surgeon, and radiologist. The teams examined data from 223 patients with coronary artery disease who underwent both CCTA and conventional invasive angiography in order to determine the best course of treatment for each case.
Comparing the treatment decisions from both teams, the researchers found that there was high agreement between the teams' treatment decisions (Cohen's kappa coefficient was 0.82). The conventional angiography team recommended CABG for 28% of the patients, compared with 26% by the CCTA team -- meaning that they recommended the same treatment nearly 93% of the time. The teams also flagged the exact same coronary artery segments for revascularization in 80% of the cases.
For the CCTA group, approximately 88% of the patients also received FFR-CT analysis. And FFR-CT analysis led to changes in the treatment decision in 7% of the patients.
New role for radiologists
By incorporating CCTA and FFR-CT into risk assessment for heart disease, the SYNTAX III scoring technique has "the potential to be a game changer," Teichgräber said. Several clinical guidelines in Europe already recommend CCTA as the initial test for diagnosing CAD in patients suspected of having chronic coronary syndrome, so using the imaging modality for treatment decision-making could remove the need for patients to receive an additional invasive procedure.
Furthermore, implementation of the SYNTAX III scoring method would mean that radiologists would play a new role in the treatment phase of the heart team's decision-making process, Teichgräber noted.
"From the SYNTAX III trial, we as radiologists learned that it's very important not to simply define the lesion by giving just the SYNTAX score [to cardiologists] but also to provide information on the composition of the plaque and, from there, to make recommendations on stent planning," he said.