This is a single-center, randomized controlled study focusing on patients with CHD who have significant CAC and are candidates for RA. The objective of the study is to examine differences in perioperative complications and long-term prognosis among various rotational speed protocols in these patients. We plan to continuously recruit participants at a tertiary A-grade hospital in Anhui, China, which is renowned for its large patient population with cardiovascular diseases and advanced medical technology. Patients who require RA treatment and meet the specific inclusion criteria (Table 1) will be enrolled in the study. Prior to undergoing RA, the principal investigator (PI) will verify patient eligibility and obtain written informed consent.

Lesions with acute angulation (≤ 90°) were excluded as studies have identified severe angulation as an independent predictor of procedural and clinical failure in RA [21]. Immediate RA following stent placement was excluded due to the high risk of burr entrapment and suboptimal long-term outcomes reported in previous studies [22,23,24,25]. CAC, coronary artery calcification; OCT, optical coherence tomography; IVUS, intravascular ultrasound; LVEF, left ventricular ejection fraction.

It is anticipated that 210 patients who meet the inclusion and exclusion criteria will be randomly assigned in a 1:1:1 ratio to three different rotational speed groups: a continuous low-speed rotation (LSRA) group (140,000 rpm), a continuous high-speed rotation (HSRA) group (180,000 rpm), and a high-speed to low-speed rotation (HSRA + LSRA) group (initially 180,000 rpm, followed by 100,000 rpm). The study includes a 12-month follow-up period. Research protocols and documents have been distributed to relevant researchers. Recruitment began on October 1, 2023, and will continue until the estimated number of patients is reached, with the study expected to be completed within 3 years.

This study protocol has been approved by the Medical Research Ethics Committee of the First Affiliated Hospital of the University of Science and Technology of China (Anhui Provincial Hospital) under approval number 2023-KY- 076.

Eligible patients who provide informed consent will be randomly assigned in a 1:1:1 ratio to one of three rotational speed groups for RA treatment (Fig. 1). To ensure unbiased random allocation, a computer-generated random number table was created prior to the commencement of the study. Patients will be assigned sequentially based on this table to one of three groups: LSRA, HSRA, or HSRA + LSRA, maintaining a 1:1:1 distribution to ensure group balance. Once a patient meets the inclusion criteria, the assigned study personnel will disclose the randomization result but will not be involved in data collection or follow-up. To minimize bias, outcome assessors will remain blinded to the treatment allocation. These assessors, responsible for evaluating primary and secondary endpoints, will not be aware of the specific intervention each patient receives. Randomization data will be securely stored and managed by an independent data management team, ensuring blinding until the completion of data analysis. This methodology ensures an objective assessment of the safety and efficacy of different RA rotational speed protocols, offering valuable insights for optimizing treatment strategies in coronary heart disease.

LSRA, low-speed rotation; HSRA, high-speed rotation; HSRA + LSRA, a high-speed to low-speed rotation; OCT, optical coherence tomography; IVUS, intravascular ultrasound; PCI, percutaneous

Our center utilizes the Siemens DTC (or PHILIPS FD1010) angiography system for coronary angiography and interventional therapy. The Rotablator System (Boston Scientific Corporation, Natick, MA, USA) was used for all the RA procedures. Prior to the procedure, patients were treated with aspirin (100 mg per day) and thienopyridine (clopidogrel 75 mg daily or ticagrelor 100 mg twice daily). In addition, normal heparin (70–100 units/kg) was administered intravenously during the procedure to achieve an appropriate activated clotting time (250 s). Percutaneous coronary intervention was performed at the operator’s discretion. In previous studies [26], we observed that higher experience in RA might be linked to worse outcome in PCI via femoral approach in both stable angina and acute coronary syndrome settings. However, the specific approach should still be determined based on the characteristics of the patient’s specific lesions and the conditions of the peripheral vascular pathways. Catheters up to 7 F in diameter were used to exchange a 0.009-inch (1 inch = 2.54 cm) rotating wire flexible disk to the distal end of the target lesion with the help of a Finecross or Crossair microcatheter. Each RA session lasted less than 30 s, with a 60-s interval between each RA. During the RA procedure, a continuous pressurized drip of plain heparin nitroglycerin flushing solution was administered. Noncompliant balloon dilation and stent placement were performed following the RA procedure, depending on the lesion characteristics. Patients who developed bradyarrhythmias after RA received both a strong cough and intravenous atropine. Atropine and a temporary pacemaker were prepared for patients with right coronary artery or systolic branch predominance. Implantation of intra-aortic balloon counter pulsation (IABP) depends on the judgment and guidance of the supervising cardiologist. Following the completion of rotational atherectomy, a follow-up coronary angiography was performed. In cases of vascular spasm, intracoronary nitroglycerin or sodium nitroprusside was administered via the catheter to relieve the spasm.

This study will assess the effectiveness of coronary RA using IVUS and OCT, which provide detailed imaging of lesion structure and treatment outcomes. IVUS is a technique that uses high-frequency sound waves to visualize the inner walls of blood vessels [27]. IVUS utilizes high-frequency sound waves to visualize the inner walls of blood vessels, allowing us to accurately measure the degree of stenosis and the composition of the plaque. In this study, IVUS will assess intimal lumen diameter and plaque morphology before and after RA. This will help clarify how different rotational speeds affect the vessel wall and plaques. On the other hand, OCT uses near-infrared light to capture high-resolution images of the vessel lining [28]. OCT can provide higher resolution images than IVUS, especially in assessing intima and plaque surface characteristics. In this study, OCT will be used to assess endovascular surface features after RA treatment, including plaque tears, stenting effects, and possible vessel damage. By combining IVUS and OCT, we will be able to comprehensively evaluate the effects of RA treatment at both macroscopic and microscopic levels. This information will provide important clinical data for evaluating the safety and efficacy of different rotational speeds, thus contributing to optimize the use of RA in the treatment of coronary artery disease (CAD).

The primary focus of this study is to investigate the safety and efficacy of using different rotational speeds in coronary rotational atherectomy. The main endpoint is the incidence of complications during the atherectomy procedure. Secondary endpoints include assessments through intravascular imaging, in-hospital adverse cardiovascular events, and adverse cardiovascular events during the 1-year follow-up period (Table 2).

In IVUS, calcific ring disruption is defined as a loss of continuity in the calcified plaque, presenting as fissures, defects, or fractures along the plaque margins. In OCT, it is identified by cracks, defects, or fractures within the calcified region, resulting in surface irregularities or cavitations. RA, rotational atherectomy; MLA, minimum lumen area of target lesion; MLD, minimum lumen diameter of target lesion; TIA, transient ischemic attack; MACCE, major adverse cardiovascular and cerebrovascular events; IVUS, intravascular ultrasound; OCT, optical coherence tomography.

The follow-up plan includes both perioperative and long-term clinical outcomes (see Table 3). The clinical data to be collected will include preoperative baseline information, including demographic information, imaging studies (electrocardiogram, echocardiography), laboratory tests (including total platelet count, cardiac troponin I, and N-terminal pro-brain natriuretic peptide (NT-proBNP)), medication history, as well as primary and secondary endpoint data. Follow-ups for all participants are scheduled at 12 months, during which both primary and secondary outcomes, as well as safety, will be assessed.

According to the literature, the probability of complications occurring during RA is 4%, 14% in the HSRA + LSRA group [18], and 24% at higher rotational speeds. A sample size of 175 achieves 80% power to detect an effect size (W) of 0.2353 using a 2-degree-of-freedom chi-square test with a significance level of α = 0.05 [29]. Considering a 15% dropout rate, the total required sample size is 210, with 70 participants per group.

All data will be statistically analyzed using SPSS version 22.0. Quantitative data will be presented as mean ± standard deviation (± s), with intergroup comparisons made using independent sample t-tests. Categorical data will be presented as number (percentage) [n (%)], with intergroup comparisons using the χ2 test. Logistic regression analysis will be applied to ascertain the correlation between coronary rotational speed and perioperative complications, as well as 1-year MACCE. Considering potential data missing and loss to follow-up, we will mainly use intention-to-treat (ITT) analysis and apply per-protocol (PP) dataset for sensitivity analysis. Besides, we will preset some subgroup analyses (e.g., based on patient age groups or lesion complexity) to verify results’ stability and explore special effect participants. To account for multiple comparisons, family-wise error rate (FWER) control methods will be applied where appropriate. Specifically, Bonferroni correction (adjusting the significance threshold to α′ = 0.025) and the Holm-Bonferroni procedure (a stepwise approach that improves statistical power while maintaining FWER control) will be used for primary analyses. To minimize unnecessary tests, only key comparisons (HSRA vs. LSRA; HSRA + LSRA vs. LSRA) will be included. When the sample size is limited, Holm’s method will be preferred over Bonferroni to optimize the balance between statistical power and error control. A P value of < 0.05 will be considered statistically significant. All statistical tests will be two-sided.

This study is conducted without patient or public involvement in its design, execution, or analysis. Physicians will communicate the results to participants.