White thrombi on optical coherence tomography after rotational atherectomy of severely calcified coronary lesions

Purpose Rotational atherectomy (RA) has improved percutaneous treatment of severely calcified coronary lesions, but the “no-reflow” phenomenon remains a serious complication. Platelet activation by RA may contribute to no-reflow, and the use of optical coherence tomography (OCT) to test the effect of RA on white thrombus could confirm platelet activation indirectly. Methods We analyzed 53 consecutive patients with severely calcified lesions on coronary angiography. All patients were examined with OCT. In total, 20 patients who received RA and for whom OCT imaging was performed before and after RA and stent implantation comprised the RA group. The remaining 33 patients formed the control group, for whom OCT imaging was performed before balloon dilatation and after stent implantation. Results The patients in the RA group were older and had a higher incidence of diabetes mellitus. In the control group, there was no thrombogenesis during the procedure, whereas in the RA group, all the target vessels had white thrombi on OCT after RA. The average number of white thrombi per lesion after RA was 7.23 ± 4.4, and the average length of white thrombus was 0.51 ± 0.33 mm. Statistical analysis with Pearson’s correlation coefficient showed that thrombus load was related to burr size ( r = 0.575, p = 0.040) and number of rotations ( r = 0.599, p = 0.031). Conclusion White thrombi during RA can be verified by performing OCT. Treating calcified lesions with RA may enhance thrombogenesis. These data suggest using appropriate therapy to avoid no-reflow during RA.