Optical coherence tomography-versus intravascular ultrasound-guided stent expansion in calcified lesions

Optical coherence tomography (OCT) has a higher resolution than intravascular ultrasound (IVUS) and enables a more precise evaluation of calcium severity. We investigated the impact of the imaging method (OCT versus IVUS) on stent expansion during intravascular imaging-guided percutaneous coronary intervention (PCI) in calcified lesions. In this single-center, retrospective, observational study, 145 lesions with moderate to severe calcification were divided into four groups: 40 IVUS-guided rotational atherectomy (RA), 38 IVUS-guided non-RA, 35 OCT-guided RA, and 32 OCT-guided non-RA. Lesions without pre-procedural intravascular imaging were excluded. OCT-guided RA was associated with greater stent expansion at the target calcium compared with IVUS-guided RA (median 88.0%, interquartile range [78.0-96.0] vs. 76.5% [71.0-84.3], P = 0.008). Furthermore, stent expansion in OCT-guided non-RA was similar to OCT-guided RA. OCT-guided RA used a larger burr compared to IVUS-guided RA (1.75 mm [1.50-2.0] vs. 1.50 mm [1.50-1.75], P = 0.004). In OCT-guided RA, the median minimum calcium thickness was significantly reduced from 800 (640-980) µm to 550 (350-680) µm (P < 0.001). There was no significant difference in the incidence of ischemia driven target lesion revascularization between the four groups (P = 0.37). By determining the indication and endpoint of lesion modification by RA based on the thickness of calcium, OCT-guided PCI was associated with significantly greater stent expansion compared with IVUS-guided PCI.