A novel, minimally invasive computer software-based method that uses artificial intelligence to determine whether plaques in a coronary artery are restricting blood flow to the patient's heart performed similarly to the standard, more invasive wire-based procedure, according to a large international randomized trial presented at the American College of Cardiology's Annual Scientific Session (ACC.26).
"We have shown that using this (FFRangio) software-based tool in the cath lab results in similar clinical outcomes at one year compared with the current gold standard of invasive wire-based assessment," said Ajay J. Kirtane, MD, professor of medicine at Columbia University Vagelos College of Physicians and Surgeons, an interventional cardiologist at NewYork-Presbyterian/Columbia University Irving Medical Center and director of Columbia Interventional Cardiovascular Care, and the study's senior author. "Our hope is that these findings--with a technology that does not require further coronary manipulation beyond a routine angiogram--will lead to increased adoption of coronary physiologic testing as recommended by current guidelines."
Coronary artery disease (CAD) occurs when fatty plaques build up in the walls of the arteries that supply the heart, causing them to narrow. Traditionally, cardiologists use a coronary angiogram (heart X-ray) to visually estimate how severe these blockages are and decide if percutaneous coronary intervention (PCI) or angioplasty is needed. PCI, or angioplasty, opens blocked arteries using a small balloon and wire-mesh stent. Previous studies have shown that adding wire-based tests that directly measure pressure beyond the blockage can more accurately determine how much blood flow is reduced and whether PCI will benefit the patient.
To perform wire-based testing, doctors first thread a wire or catheter into the blocked artery and then give the patient a drug that increases blood flow to the heart. This strategy allows them to calculate how well blood is flowing through the artery beyond the blockage. Although research has shown that the use of these tests improve patient outcomes and treatment guidelines recommend it, use of the technique still remains low. Researchers have suggested that this may be due to the added steps and additional procedural time needed to place the wire and make these measurements.
Several less invasive methods of deriving the pressures and flow within coronary arteries are being tested in clinical trials. In general, these new methods use sophisticated computer software modeling of images generated during a coronary angiogram to evaluate whether a blockage in a coronary artery is restricting blood flow to a patient's heart. These new methods eliminate the need to medicate the patient or insert a wire or catheter into the artery. However, a randomized trial of one such method, known as quantitative flow ratio (QFR), published in 2024 was unable to demonstrate that this technique performed similarly to wire-based testing.
FFRangio is a novel technique that combines computer software and artificial intelligence to create a three-dimensional model from coronary angiograms and calculates and quantifies if the blood flow to the heart is being restricted in narrowed arteries, Kirtane said. The ALL-RISE trial was designed to assess whether FFRangio could produce similar results to conventional wire-based testing in patients with CAD who were undergoing evaluation for PCI.
The trial enrolled 1,930 patients (average age 68, 75% men, 60% white) in the United States and four other countries (Israel, Japan, Switzerland and the U.K). Patients were randomly assigned to receive either FFRangio or conventional wire-based pressure measurements to guide the decision to perform PCI. About 17% of the patients had a previous heart attack and about 40% had prior PCI. Around 80% had high blood pressure, 80% had high cholesterol, and around 40% had diabetes, 12% treated with insulin. The trial's primary endpoint was a composite of death from any cause, a heart attack or any other unplanned procedure to restore blood flow to the heart, at one year.
The two approaches showed comparable results, with 6.9% of patients in the FFRangio group experiencing a primary endpoint event, compared with 7.1% in the conventional wire-based assessment group. The new computer software-based technique was also faster to perform, and unlike wire-based assessment, did not require additional procedural steps such as the introduction of additional catheters and wires or administration of medication, Kirtane said.
A limitation of the study is that it was not blinded, meaning patients, doctors and independent assessors all knew whether patients had received FFRangio or wire-based assessments. In addition, because the study excluded patients who had prior coronary artery bypass surgery or those who might have required it, use of this approach in these patients needs further study, he said.
As a next step, Kirtane and colleagues plan to analyze whether FFRangio generates cost savings compared with conventional wire-based assessments, especially based upon these trial results.
The study was funded by CathWorks, Ltd., the developer of FFRangio. Dr. Kirtane reports Institutional funding to Columbia University and Cardiovascular Research Foundation from CathWorks and Medtronic.
This study was simultaneously published online in the New England Journal of Medicine at the time of presentation.
Results from a study of another novel, minimally invasive approach to estimating coronary pressure and flow known as vesselFFR, will be presented in the same session and press conference.
Kirtane will present the study, "A Large-scale, Global Randomized Trial of Coronary Physiology Derived from Conventional Angiography Compared with an Invasive Pressure Wire-based Approach To Guide Percutaneous Coronary Intervention," on Sunday, March 29, at 8:30 a.m. CT / 13:30 UTC in the Main Tent, Great Hall.
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