Comparison of complications with a 1.25-mm versus a 1.5-mm burr for severely calcified lesions that could not be crossed by an intravascular ultrasound catheter

Since intravascular imaging such as intravascular ultrasound (IVUS) can provide useful information for rotational atherectomy (RA), intravascular imaging should be attempted before RA. However, some calcified lesions do not allow imaging catheters to cross before RA. Although small burrs (1.25 mm or 1.5 mm) should be selected for such tight lesions, it is unknown whether a 1.25-mm burr or 1.5-mm burr is safer as the initial burr. The aim of this study was to compare the incidence of complications with a 1.25-mm versus a 1.5-mm burr as the initial burr for IVUS-uncrossable lesions. This was a retrospective, single-center study. A total of 109 IVUS-uncrossable lesions were included, and were divided into a 1.25-mm group (n =52) and a 1.5-mm group (n =57). The incidence of slow flow just after RA was not different between the 2 groups (1.25-mm group: 25%, 1.5-mm group: 31.6%, P =0.45). The incidence of peri-procedural MI with slow flow was not different and equally low in the 2 groups (1.25-mm group: 1.9%, 1.5-mm group: 3.5%, P =0.61). The use of the 1.5-mm burr as the initial burr was not significantly associated with slow flow after controlling for chronic renal failure on hemodialysis and reference diameter (vs. 1.25-mm: OR 2.34, 95% CI 0.89–6.19, P =0.09). In conclusion, the incidence of complications following RA was comparable between the 1.25-mm and the 1.5-mm burrs as the initial burr for IVUS-uncrossable lesions. The present study provides insights into the selection of an appropriate burr for IVUS-uncrossable lesions.