Halftime rotational atherectomy: a unique concept for diffuse long severely calcified lesions.

Rotational atherectomy (RA) is technically more difficult in a diffuse calcified lesion than in a focal calcified lesion. We hypothesized that taking a halftime can be another option for RA to the diffuse calcified lesions. Halftime was defined as at least one long break during RA, in which an operator pulled out the Rotablator system from the guide catheter before crossing the lesion. This study aimed to compare the complications between RA with and without halftime. We included 177 diffuse long severely calcified lesions (lesion lengths ≥ 30 mm) that required RA, and divided those lesions into a halftime group (n = 29) and a no-halftime group (n = 148). The primary outcome was periprocedural myocardial infarction (MI). The reference diameter was smaller in the halftime group than in the no-halftime group [1.82 (1.70-2.06) mm versus 2.17 (1.89-2.59) mm, p = 0.002]. The total run time was longer in the halftime group than in the non-halftime group [133.0 (102.0-223.0) seconds versus 71.5 (42.0-108.0) seconds, p < 0.001]. Although creatinine kinase (CK) and CK-myocardial band (MB) was significantly higher in the halftime group than in the no-halftime group [CK: 156 (97-308) U/L versus 99 (59-216) U/L, p = 0.021; CK-MB: 15 (8-24) U/L versus 5 (3-15) U/L, p < 0.001], periprocedural MI was not observed in the halftime group. In conclusion, periprocedural MI was not observed in RA with halftime. This preliminary study suggests that halftime RA may be a safe option for diffuse severely calcified lesions.