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Landmark Study of HeartFlow’s New Non-Invasive Diagnostic Test Demonstrates High
Diagnostic Performance in Patients with Suspected Coronary Artery Disease
Computed FFR CT Identifies Flow-Restricting Arterial Blockages with High Accuracy
REDWOOD CITY AND SAN FRANCISCO, Calif., October 30, 2013 - HeartFlow, Inc. today
announced positive data from a study of the company’s newest-generation non-invasive
computed fractional flow reserve FFR CT technology. Results from the HeartFlowNXT study
demonstrate that, when compared to standard coronary CT angiography (CT) or invasive
coronary angiography (ICA), FFR CT provides a more accurate determination of which arterial
blockages are associated with coronary ischemia and which are not, suggesting that FFR CT may
aid physicians in making decisions regarding further invasive testing or treatment.
The study’s findings were presented today in a First Report Investigation session at the 25 th
Annual Transcatheter Cardiovascular Therapeutics (TCT) meeting in San Francisco.
HeartFlow’s patient-specific coronary blood flow modeling technology is a new non-invasive test
that uses proprietary algorithms based on computational fluid dynamics and data from a
patient’s coronary CT scan to assist physicians in the diagnosis of coronary artery disease and
identification of specific flow-restricting blockages in the coronary arteries.
The prospective international HeartFlow NXT study enrolled 254 stable patients with suspected
coronary artery disease (CAD) at 10 centers in seven countries. The objective of the study was
to compare diagnostic performance of FFR CT , coronary CT, and ICA, to invasive FFR
measurement (the current gold standard for determining flow-restricting arterial blockages). All
patients underwent coronary CT, invasive coronary angiography (ICA), and invasive FFR, and
then had FFR CT analysis performed using the latest generation of HeartFlow’s software
The findings of the study suggest the potential to eliminate the need for risky and expensive
invasive evaluation and treatment in some patients. FFR CT demonstrated superior ability to
correctly identify those patients without coronary ischemia compared to coronary CT (specificity
79% vs. 34%). The study also showed a specificity of 79% compared to invasive angiography of
51%. FFR CT correctly identified patients who had coronary ischemia with a high sensitivity (86%)
and high negative predictive value (92%). There was also a striking improvement in the ability
of FFR CT to discriminate patients with and without flow-restricting arterial blockages compared to
CT alone (area under the curve [AUC] on receiver operating characteristics analysis 0.82 vs.
0.63, p<0.0001). AUC is a robust measure of diagnostic test reliability and accuracy.
“Proper selection of patients for invasive diagnosis and treatment is a crucial element of taking
care of people who may have coronary artery disease. These procedures entail risk and
expense. This new tool will be an exciting step forward for cardiology and may significantly
improve how we guide coronary artery disease patients towards effective and efficient care,”
said principal investigator Bjarne Norgaard, M.D., Ph.D., department of Cardiology, Aarhus
University Hospital Skejby, Aarhus, Denmark. Dr. Norgaard presented the data today at TCT.
Studies have shown that treatment guided by invasive FFR results in better clinical outcomes,
including a 34% reduced risk of death or major cardiac event, and significantly lower healthcare
costs. 1-3 Currently available noninvasive diagnostic tests do not provide stenosis-specific
functional data, and therefore have limited diagnostic accuracy compared to invasive FFR. 4-6
HeartFlow’s noninvasive technology is designed to provide physicians with FFR CT values at
every point along the coronary tree. 7 Traditional FFR measurements can only be obtained
invasively during coronary angiography with a pressure-sensing guidewire.
“The results of HeartFlowNXT allow us to consider for the first time the real possibility of a single
non-invasive standardized test which can help physicians determine the impact of patients’
coronary artery disease, offering the promise of a new standard for diagnosis of coronary artery
disease,” said John H. Stevens, M.D., chairman and CEO of HeartFlow. “This technology will
substantially improve the ability of physicians to accurately determine which patients need or do
not need coronary angiography, potentially resulting in better patient outcomes and reduced
An analysis of the potential positive impact of FFR CT on healthcare costs and on patient
outcomes was recently published by Mark A. Hlatky, M.D., professor of Health Policy and
Research at Stanford University. In his analysis, Dr. Hlatky noted that using FFR CT to guide
selection of patients for invasive evaluation and PCI might “reduce costs and improve clinical
outcomes compared to current treatment pathways.” The model showed potential savings of
more than $3,000 per-patient when compared to the conventional angiography-based treatment
strategy. 8
About HeartFlow, Inc.
Founded in 2007, HeartFlow, Inc., is a cardiovascular company based in Redwood City, Calif. A
pioneer in the field of non-invasive coronary artery disease diagnosis, HeartFlow is committed to
developing technology designed to help physicians noninvasively diagnose coronary artery
disease and improve patient outcomes while reducing health care costs. For more information
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