Lesion-specific coronary artery calcium score to predict stent underexpansion

TL;DR

This study shows that high lesion-specific coronary calcium scores predict stent underexpansion, using noninvasive imaging methods.

Contribution

The study introduces lesion-specific CAC scores as a noninvasive predictor of stent underexpansion.

Findings

Stent underexpansion occurred in 34.6% of 416 lesions.

CAC scores >200 were strongly linked to stent underexpansion in both NCCT and CCTA groups.

High CAC scores independently predicted stent underexpansion risk.

Abstract

Previous intracoronary imaging studies have shown that coronary artery calcium (CAC) is an independent risk factor of stent underexpansion; however, limited preintervention assessments of CAC have been performed using noninvasive methods. We aimed to determine the association between lesion-specific CAC score and stent underexpansion.

In this retrospective observational study, we included 416 lesions from 359 patients who underwent intravascular ultrasound (IVUS)-guided stent implantation. CAC of each lesion was quantified using the Agatston method derived from either nongated noncontrast chest CT (NCCT) or electrocardiogram-gated coronary CT angiography (CCTA). The primary endpoint was stent underexpansion defined as minimum stent area of <80% of the average reference lumen area.

Overall, stent underexpansion occurred in 144 (34.6%) of 416 lesions. Lesion-specific CAC score was significantly negatively correlated with the stent expansion rate (in NCCT cohort, r = 0.8113, P < 0.05; in CCTA cohort, r = 0.8024, P < 0.05). The optimal cutoff values of lesion-specific CAC score to predict stent underexpansion were >200 in both NCCT (sensitivity, 91.4%; specificity, 66.8%) and CCTA (sensitivity, 84.6%; specificity, 64.3%) cohort, which were associated with 24.94-fold increased risk of stent underexpansion in NCCT cohort and 13.56-fold increased risk of stent underexpansion in CCTA cohort.

In this study, we found that lesion-specific CAC scores in both NCCT and CCTA cohorts were significantly independently associated with an increased risk of stent underexpansion, and the cutoff value to predict stent underexpansion was >200.

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