The C-CAT sign may predict coronary artery perforation in severe calcified lesions during coronary intervention: a case series

Background Coronary artery rupture is a rare but fatal complication of percutaneous coronary intervention (PCI). The mortality rate reaches 19% in patients with the Ellis type III classification. The predictors of coronary artery rupture were reported in previous studies. However, there are few reports showing the risk factors of this threatening complication in terms of intravascular image such as optical coherence tomography and intravascular ultrasound (IVUS). Case summary We report the case of three patients with coronary artery rupture, who underwent IVUS-guided PCI for severe calcified lesions. All three patients developed the Ellis grade III rupture, which was successfully managed with the use of a perfusion balloon and covered stents. In these patients, the common characteristics were observed in pre-procedural IVUS images. Specifically, a C-type CAlcified and residual Thin plaque sign (C-CAT sign) was seen in all three patients. Discussion These patient cases provide an insight into the coronary artery rupture in severe calcified lesions. The C-CAT sign in the pre-IVUS image may predict coronary artery rupture. If we obtain such a unique IVUS image before intervention, we have to consider using a smaller balloon size, for example a half size down, judging from the vessel diameter of the reference site or using ablation devices such as orbital atherectomy and rotational atherectomy to prevent coronary artery rupture. Conclusion The C-CAT sign may predict coronary artery perforation in severe calcified lesions during PCI, although larger registries of such intracoronary pre-perforation imaging are required in order to correlate different signs with outcomes.