Long-term outcome of rotational atherectomy according to burr-to-artery ratio and changes in coronary artery blood flow: Observational analysis

BACKGROUND: Rotational atherectomy (RA) has been proven to be efficient for the treatment of calcified and diffuse coronary artery lesions. However, the optimal burr-to-artery ratio (BtAR) remains unidentified as well as an influence of change in blood flow on long-term outcome. Aim of our study was to examine the association between long-term outcome, and both BtAR and change in coronary flow during RA. METHODS: We conducted a retrospective study including patients who underwent RA. Two independent observers calculated BtAR, pre- and postprocedural corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (cTFC) for artery treated with RA. The long-term outcome was defined as all-cause mortality. RESULTS: Receiver operating characteristic curve analysis of BtAR determined threshold of 0.6106 for all-cause mortality detection with sensitivity 50.0%, specificity 90.8%, and area under the curve 0.730 (p < 0.001). Kaplan-Meier survival analysis showed that the all-cause mortality rate in the group with the BtAR > 0.6106 is significantly higher compared to the patients with lower BtAR (hazard ratio [HR] 3.76, 95% confidence interval [CI] 1.51–9.32; p < 0.001). Kaplan-Meier survival analysis revealed that the all-cause mortality rate in the group with impairment in coronary flow was significantly higher compared to group with cTFC difference ≤ 0 after RA (HR 3.28, 95% CI 1.56–9.31; p = 0.02). CONCLUSIONS: Burr-to-artery ratio > 0.6106 is associated with worse prognosis of patients treated with RA. Patients showing post-RA impairment in blood flow in the target artery have worse prognosis.