Coronary Microcirculatory Function Indicated by Coronary Angiography-Derived Index of Microvascular Resistance in Patients Undergoing Rotational Atherectomy

Abstract

Background: There are scarce published data reporting the effect of rotational atherectomy (RA) on coronary microcirculation function. Objectives: We aimed to evaluate coronary microcirculation function indicated by the coronary angiography-derived index of microvascular resistance (caIMR) in patients undergoing RA. Methods: RA procedures between January 2013 and December 2021 were retrospectively analyzed. We investigated coronary microcirculation function indicated by caIMR as well as peri-procedural adverse events among the study population. All caIMR measurements were performed using a FlashAngio system. The primary outcome was a composite of post-RA thrombolysis in myocardial infarction (TIMI) flow grade <3 in the target vessel, myocardial injury, procedure-related myocardial infarction, and cardiac death during hospitalization. Results: A total of 155 RA procedures were analyzed. The post-RA caIMRs were significantly higher than pre-RA caIMRs in the target vessels (16.0 ± 7.0 vs. 14.5 ± 7.5, p = 0.029). Patients with post-RA caIMR ≥25 accounted for nearly 12% of those with pre-RA caIMR <25. Patients with post-RA thrombolysis in myocardial infarction (TIMI) flow grade <3 had a significantly higher pre-RA caIMR (23.5 ± 10.2 vs. 13.7 ± 6.6, p = 0.005), and the proportion of patients with pre-RA caIMR ≥25 in the group with TIMI flow grade <3 was greater (61.5% vs. 38.5%, p < 0.001) than that in the group with TIMI flow grade of 3. Maximum RA time of each pass (odds ratio: 1.127, 95% confidence interval: 1.025–1.239, p = 0.014) and pre-RA caIMR ≥25 (odds ratio: 3.254, 95% confidence interval: 1.054–10.048, p = 0.040) were identified to be the independent predictors of the primary outcome for patients who underwent RA. Conclusions: There were significant changes in the coronary microcirculation function of the target vessels after receiving RA as indicated by increased post-RA caIMR compared to pre-RA caIMR. Patients with baseline coronary microcirculatory dysfunction were more likely to have post-RA TIMI flow grade <3, whereas those with pre-RA caIMR ≥25 experienced worse outcomes.