The findings of a transformative research presented in the Annual American College of Cardiology Congress (ACC.25) demonstrate for the first time that a heart procedure ultrasound AI-based imaging technique guided with the same AI imaging non-invasive ultrasound works equally well as an AI imaging technique as ultrasound works in guiding heart procedures. These findings could change AI imaging.
AI Imaging: A New Tool for Heart Procedures
Subjects who had at least 50% stenosis of the three main coronary arteries were similarly treated with stent placement, each having been guided around with the ultrasound-propelled new AI imaging system.
“In patients with angiographically significant lesions, this is the first such study,” said Jian’an Wang, MD, Heart Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China, Senior Author of the Work.
Fewer Procedures with AI Guidance
Of note, the techniques used to evaluate patients who had their evaluation performed by the AI system yielded about 10% fewer procedures, which may point to less healthcare spending.
The FLAVOUR II Study: Key Findings
Wang reported that the study known as FLAVOUR II achieved its primary endpoint, which was a composite measure of death, heart attack, or need for repeat procedure at one year.
Patients enrolled in the study had angiographically significant coronary artery disease. This is the narrowing of three primary arteries that hinder the supply of blood to the heart due to further inflammation or blockage from cholesterol deposits, causing angina, dyspnea, and fatigue.
Understanding PCI
The procedure done on these patients is called percutaneous coronary intervention (PCI), or more commonly known as coronary angioplasty. This is a type of surgery done through small cuts on the body. It involves the placing of small metal tubes, known as ‘stents,’ in the clogged arteries to ensure proper blood flow.
In order to know which patients would benefit from PCI the most, doctors use a method called fractional flow reserve (FFR) assessment. This technique measures blood pressure and flow within the arteries’ blood vessels, which are narrowed. Generally, patients having an FFR score of 0.80 or lower are subjected to PCI, while those having higher scores are treated with drugs.
The Innovation: AngioFFR
The standard practice of FFR assessment requires a wire or catheter to be advanced to the obstructed coronary arteries. While it is effective, Wang noted that “technical and logistical challenges have limited its use.”
In FLAVOUR II, researchers applied a novel, AI-powered method dubbed AngioFFR. This technique derives FFR from a single-view angiogram (x-ray) of the coronary arteries. As per Wang, “non-invasive, simpler, and less time-consuming to perform” defines AngioFFR in comparison to the traditional method.
Comparing AngioFFR and IVUS
The study’s primary focus was to analyze the effectiveness of PCI performed with AngioFFR versus PCI performed with intravascular ultrasound (IVUS) guidance. In IVUS, sound waves are used to visualize the degree of narrowing of the artery, and it is the most common imaging technique used to guide PCI.
Study Details and Patient Population
The FLAVOUR II study recruited 1,872 patients (mean age 65 years, 68% male) across 22 medical centers in China. Patients were required to have at least a 50% narrowing of the three major arteries but were not allowed significant narrowing of the left main coronary artery.
The collection of study patients had multiple comorbidities, including the following:
– 67.6% Hypertension
– 31% Diabetes
– 66.9% Hyperlipidemia
– 24.3% Chronic Kidney Disease
– 25% Active Smokers
– 13.9% History of Myocardial Infarction
Study Outcomes: AngioFFR and IVUS-Guided PCI—Similar Results
All participants were blinded to the method of PCI—patients assigned to AngioFFR-guided PCI and IVUS-guided PCI were subjected to the procedure if AngioFFR ≤ 0.80. In the IVUS group, procedures were done for a narrowing of the distal vessel between 3-4mm with a plaque burden greater than 70% with plaque in <>70% of the vessel diameter.
At 1 year, the first composite endpoint (all-cause mortality, myocardial infarction, or necessitating re-intervention) was reached by 6.3% of patients in the AngioFFR group and 6.0% of patients in the IVUS group. Despite passive observation of ultrasound-guided PCI, it was demonstrated that the difference within groups was not statistically significant, underpinning that both approaches achieved comparable success rates.
Similar trends were seen across subgroups with diabetes as well as other constituents of the primary endpoint (mortality, myocardial infarction, or repeat procedure).
Future Considerations of Wu et al.’s Work and its Constraints
Wang et al. have set out to observe the patients for a minimum of five years to look for differences in effectiveness over time between the two guidance methods.
Wang acknowledged the study does have some limitations. The patients recruited had angiographically significant lesions but did not have complex lesions, which are more difficult to manage with PCI. Furthermore, the study was conducted in China, which meant the patient population was not very heterogeneous.
