New research has found that adding Heartflow’s fractional flow reserve (FFR) analysis to the diagnostic pathway in patients with stable coronary artery disease (CAD) reduced the rate of unnecessary invasive coronary angiography (ICA) procedures by almost half at one year.
The FUSION trial, funded by the Dutch National Health Care Institute and set to be presented at the 2026 European Society of Cardiology (ESC) congress, taking place 28-31 August in Munich, Germany, randomised 528 patients with 50%-90% stenosis in the coronary arteries to receive FFR CT-guided or the usual care of coronary computed tomography angiography (CCTA).
CCTA is recognised as the primary first-line test for evaluating patients with suspected CAD. However, the visual assessment of CCTAs is limited to assessing anatomy and whether plaque is present, and it cannot determine lesion-specific physiology or whether a blockage significantly restricts blood flow to the heart – a reality that commonly leads physicians to refer patients for ICA.
With the addition of Heartflow’s FFR technology, a 44% relative reduction in unnecessary ICA in the FUSION study was achieved at one year, versus 22% in the CCTA-only group. Meanwhile, overall rates of ICA were 18% lower at one year in the Heartflow pathway compared to the CCTA-only group.
Heartflow’s FFR is an artificial intelligence (AI)-based test applied to standard CT scans to calculate changes in blood pressure and blood flow across any blockages or plaque buildups.
The one year findings were consistent with FUSION’s primary endpoint for unnecessary ICA at 90 days, which was 18% in the FRR group versus 33% with CCTA alone.
Ahead of its presentation at ESC, the data has also been published in the Journal of the American College of Cardiology (JACC).
“CCTA is established as the optimal first-line diagnostic test for coronary artery disease as it is non-invasive, but when anatomical scans show intermediate stenosis, determining whether that blockage is clinically significant remains a critical challenge,” said Alexander Hirsch, associate professor of cardiology at Erasmus MC in Rotterdam, Netherlands and principal investigator of the FUSION trial.
“The FUSION trial shows that adding Heartflow lesion-specific physiology makes CCTA even more powerful and improves diagnostic efficiency. It gives clinicians the clarity to know which patients require further invasive testing, safely avoiding unnecessary invasive catheterisations while maintaining excellent patient outcomes,” Hirsch continued.
