Imaging Artery Calcification Reveals Predictors of Stent Expansion
Findings from optical frequency-domain imaging show potential for improving clinical outcomes.
Drug-eluting stents are tiny tubes coated with medicine that helps prevent coronary arteries from closing again after angioplasty. But severe calcification in coronary arteries can prevent these stents from expanding enough to work properly, increasing the risk of life-threatening complications. A technique called rotational atherectomy can remove calcified plaques in arteries, facilitating stent deployment. However, little is known about the factors that predict good stent expansion after rotational atherectomy for severely calcified coronary arteries.
In a study published Jan. 9 in the International Journal of Cardiovascular Imaging, researchers addressed this question using a technique called optical frequency-domain imaging (OFDI). Unlike a frequently used imaging tool called intravascular ultrasound, OFDI has a spatial resolution high enough to evaluate the extent of coronary artery calcification. The researchers performed OFDI to examine 50 severely calcified coronary artery lesions in 44 patients, both after rotational atherectomy and after stenting.
The most important predictor of stent expansion was minimum thickness of calcium in the intima -- the innermost layer of the blood vessel wall -- after rotational atherectomy. Another predictor of good stent expansion was disruption of the surface of the artery wall after rotational atherectomy. According to the authors, achieving these two endpoints should be the aim of rotational atherectomy to ensure good stent expansion.