Rotational Artherectomy (RA) a high speed rotating diamond-coated burr for percutaneous coronary intervention (PCI) of heavily calcified lesions. Atheroablative procedure increases the risk of complications including slow flow,no reflow, bradycardia, atrioventricular block, dissection, perforation, myocardial infarction, stroke, and death compared to conventional procedure.      Bradycardia and heart block are most commonly occured when performing RAin right coronary artery (RCA), Dominant left circumflex artery (LCx) or in a left anterior descending artery (LAD) that gives collateral artery to RCA.The mechanism of bradycardia is unclear but may be result from embolized RA debris disturb the AV nodal perfusion, reflex bradycardia from the burr vibration or intracoronary heat generation.    Bradycardia can occur at any time of the RA procedure. Sometimes  it occurs immediately after the burr activation, but more usually the heart rate gradually drops during burring and recovers when the RA is stopped.Temporary pacemaker insertion is oftened used during these RA procedures. It is not clearly knowwhether temporary pacing should be routinely used.    A previous retrospective cohort showed that bradycardia or temporary pacing was more commonly associated with right coronary artery and left-dominant circumflex lesions . Current expert consensus on RA from clinical expert consensus document on RA  from the Japanese association of cardiovascular intervention 2021 and European expert consensus on RA from Eurointervention 2015 provide no standard of care with regard to the use of temporary pacing during these procedures. Prophylactic pacemaker insertion is used arbitrarily based on personal experience.  

Materials and Methods     This study was an observational retrospective cohort recruiting patients who underwent rotational atherectomy at Central Chest Institute of Thailand between 1 June 2020 to 31 June 2022 were included in analysis. The inclusion criteria were Patient age 18 or greater, Heavy calcified coronary lesions (Fluoroscope involving both sides of the arterial wall, Intravascular imaging revealing >= 270 degree calcium), Reference vessel diameter >= 2.5 mm and <= 5.0 mm and stenosis >= 70%. The exclusion criteria were Thrombus contained lesion, Degenerated SVGs, Lesions with extensive dissection, Last remaining vessel with compromised Left ventricular function.    Data was collected from medical records. Baseline Demographic, Age, Sex, Body weight, BMI, Underlying disease, NYHA, Medication, Electrocardiography (EKG), LV ejection fraction (LVEF). Procedural characteristic were collected including Rotational atherectomy technique, Maximum burr size, Number of burrs used, Maximum rotations per minute, Runs per single burr, Total runs, Total duration, Max run duration, Stent per case, Drug Coat Balloon (DCB), Vessel treated (LM trunk, LAD, LCx, RCA), IVUS, IABP, Bail-out use of Glycoprotein IIb/IIIa inhibitors, Final TIMI flow, pacemaker activation, atropine, periprocedural complications were obtained and analyzed.     The primary outcomes were bradycardia (HR <50 bpm) requiring emergent temporary pacemaker placement, secondary outcomes were Major adverse cardiac events (composite of death, MI, target vessel revascularization, stent thrombosis, major bleeding).  

      A total of 128 patients who underwent were enrolled in this study. The average was 70.27 ± 9.52 years. 63.3% of these patients were male. The average BMI was 24.3 ± 4.12 Kg/m²_. Most of the patients had hypertension, diabetes mellitus and dyslipidemia. 78.9% of the patients had triple vessel disease. 73.4% of the patients were chronic coronary syndrome. 87.5% of the patients received clopidogrel. The average heart rate was 71.84 ± 13.31 bpm and was sinus rhythm. The average left ventricular ejection fraction was 56.25 ± 11.84%.     The average hemoglobin and platelet were 12.11 ± 1.77 g/dl and 252,648.44 ± 81,089.68/uL respectively. The average Creatinine and eGFR were 1.08 ± 0.68 mg/dl and 69.8 ± 20.48 ml/min respectively.    The cardiac medication profiles were similar between the 2 groups and mainly were clopidogrel. There were no  differences in the anticoagulation between the 2 groups and mainly were warfarin.    There were no differences between the groups in the indication for the procedure. Most of the procedures were performed for chronic coronary syndrome.     All of RA procedure were femoral approach. There were no significant differences between the groups in any of the RA characteristics including number of burr used, burr size, maximum rotations per minute, total runs, total duration and max run duration. Initial burr size varied from 1.25 to 2.25 mm, 81.3% used single burr.       The incidence of bradycardia that required atropine or pacemaker activation were 13.3% (17/128). All of these patients had right dominant system. 2 cases of temporary pacemaker lead were inserted when RA was performed to the right coronary artery (RCA).      The incidence of death and target lesion revascularization were 0.8% and 2.3% respectively.

The incidence of bradycardia and temporary pacing during rotational atherectomy was very low. Bradycardia is most common with RCA lesions. The role of prophylactic temporary pacemaker should be considered with RA to the RCA and left dominant LCx artery to prevent conduction abnormalities but it is not necessary to use in the case of right dominant LCA.