Session 2: Impact of thrombus on neointima, restenosis and flow – Patrick Serruys

Impact of Thrombus on Neointimal Hyperplasia

Overview of Thrombus Issues

• The discussion centers around the impact of thrombus on neointimal hyperplasia, emphasizing that while acute thrombotic occlusion is no longer a primary concern, chronic issues such as late luminal loss persist.

• The session aims to resolve questions regarding these chronic issues and explore OCT visualization in vitro for assessing drug transfer with DCB (drug-coated balloons) in humans.

Findings from the Transform Trial

• In 2022, during the Transform trial, significant discrepancies were noted between angiography and OCT findings; angiography suggested minimal dissection (11.4%), while OCT revealed a much higher rate (97.2%).

Mechanisms of Balloon Angioplasty and DCB

• The mechanism behind balloon angioplasty and DCB involves structural fractures; quantifying these fractures is crucial for understanding their implications.

• Manual contouring for analysis takes approximately 60 minutes due to lack of advanced software, contrasting sharply with AI-assisted methods that can achieve similar results in just one minute.

AI Application in Quantification

• The use of AI significantly enhances the accuracy and efficiency of lumen quantification post-dilation and pre-drug coating balloon application, demonstrating high-quality contouring capabilities.

• A statistical measure known as the Dice coefficient was employed to assess similarity between data sets; a median value of 0.990 indicates excellent overlap after three iterations with AI assistance.

Thrombus Observations in DCB Procedures

Insights from Post-Dilation Assessments

• In the Transform trial involving 97 patients with 104 lesions, it was observed that thrombus presence was noted in 41% of vessels assessed post-dilation before DCB application—an important finding for clinical practice.

Visual Evidence of Thrombus Formation

• Specific images from the trial illustrate thrombus formation associated with dissections; notable examples include small thrombi attached at dissection flaps and erosions within luminal structures highlighted by arrows in provided visuals.

Mechanism Behind Thrombus Development