A new optical coherence tomography-based calcium scoring system to predict stent underexpansion

Area of Science:

• Cardiovascular Imaging
• Interventional Cardiology
• Medical Device Technology

Background:

• Stent underexpansion remains a significant complication in percutaneous coronary interventions.
• Accurate assessment of coronary calcification is crucial for optimizing stent deployment.
• Optical coherence tomography (OCT) provides high-resolution imaging of coronary anatomy.

Purpose of the Study:

• To develop and validate an OCT-based calcium scoring system to predict stent underexpansion.
• To identify specific OCT-derived calcium characteristics associated with poor stent expansion.
• To guide pre-stent plaque modification strategies.

Main Methods:

• Retrospective development and external validation of an OCT-based calcium scoring system.
• Analysis of pre- and post-stent OCT imaging in 261 patients (128 test, 133 validation).
• Multivariable modeling to identify predictors of stent expansion and define the calcium score (angle, thickness, length).

Main Results:

• Maximum calcium angle (>180°), thickness (>0.5 mm), and length (>5 mm) were independent predictors of stent expansion.
• A calcium score of 0-3 indicated excellent stent expansion, while a score of 4 indicated poor expansion (96% vs. 78%, p<0.01) in the validation cohort.
• The OCT-based calcium score was an independent predictor of stent underexpansion.

Conclusions:

• An OCT-based calcium scoring system can reliably predict stent underexpansion.
• This scoring system aids in identifying lesions requiring plaque modification before stenting.
• Lesions with significant calcification (angle >180°, thickness >0.5 mm, length >5 mm) are at higher risk for underexpansion.