103Maximum calcium thickness is a useful predictor for under expansion after post dilatation in calcified lesions: optical coherence tomographic study

Abstract

Abstract Background Several reports have revealed that stent under expansion is associated with target lesion failure and calcified lesions usually induced inadequate stent expansion. Contemporary debulking devices such as rotational/orbital atherectomy can modify severe calcified lesions before stenting. However, it is uclear which calcium parameter is most useful predictor for stent expansion in the calcified lesions. Thus, we investigated useful calcium parameters correlating with stent expansion in the calcified lesions. Methods We enrolled 43 consecutive calcified lesions (43 patients) who underwent optical coherence tomography (OCT) guided percutaneous coronary intervention (PCI) between September 2016 and January 2019. We evaluated the lesions treated with post dilatation by non-compliant balloon due to stent under expansion after stenting. Exclusion criteria included acute coronary syndrome, in-stent restenosis and lesions without any calcium or treated with rotational atherectomy. If there were several calcium lesions in one patient, we selected maximum calcium angle lesion. Stent expansion defined as post-PCI lumen area divided by the values predicted by the manufactures compliance charts. We compared mean reference area, pre lesion area stenosis, calcium parameters including calcium arc, maximum thickness, area and longitudinal length in pre-PCI OCT evaluations with post-PCI stent expansion at that site. Results Maximum calcium thickness showed significant correlation with stent expansion, while the others did not show a significant correlation with stent expansion (table). The optimal thresholds of maximum calcium thickness for the prediction of acceptable stent expansion defined by 80% of the values predicted by the manufactures compliance charts was 870mm (area under curve (AUC): 0.65) (figure). Results of OCT parameters Univariate analysis P value Mean reference area 0.41 Pre % area stenosis 0.16 Calcium parameters Calcium arc 0.37 Calcium maximum thickness 0.04 Calcium area 0.20 Calcium longitudinal length 0.43 Conclusion A maximum calcium thickness<870mm is a useful predictor for acceptable stent expansion after post dilatation in calcified lesions.