Improvement of Postoperative Immunosuppression in Patients Receiving Coronary Artery Bypass Grafting by Transcutaneous Electrical Acupoint Stimulation: Study Protocol for a Double-blind Randomized Controlled Trial

This clinical study was a single-center clinical trial. The 88 patients scheduled to receive CABG under CPB were randomized into 2 groups: the group of TEAS, and the group of transcutaneous acupoint pseudo - electric stimulation (Sham TEAS). Monocytic HLA-DR expression serves as a primary endpoint, and other laboratory parameters (e.g. IL-6, IL-10) and clinical outcomes (e.g. postoperative infectious complications, ICU stay time, and mortality) as the secondary endpoints. In addition, some immune indicators, such as high mobility group protein 1 (HMGB1) and regulatory T cell (Treg), possibly related to the mechanism of TEAS, will also be measured.

This study is a preliminary, mono-center, double-blind, randomized and controlled clinical trial (number of sample, n=88) to explore the effects of TEAS therapy on improvement of postoperative immunosuppression indicated by diminished HLA-DR expression of patients receiving CABG (Fig. 1). The trial will be commenced after ethical approval has been obtained from the Ethics Committee of Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. All study-related procedures will be performed only after subjects have given their written informed consent. The trial is designed following the Consolidated Standards of Reporting Trials (CONSORT) guidelines, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) Checklist (Additional file 1), and Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) recommendations.

We calculate the sample size from the pilot study in our hospital based on the primary outcome Human leukocyte antigen of monocyte (mHLA-DR). In the study, the expression of mHLA-DR three days after surgery was (36.17±5.42) % in the TEAS group and (27.33±3.50) % in the Sham TEAS group, with a power of 80% and 5% Type I error rate. Assuming that the dropout rate to be 10%, 88 patients (n=44 for each group) are needed.

Patients will be recruited from the department of Thoracic and Cardiovascular surgery, at Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. Potentially eligible subjects who have scheduled for CABG under CPB for coronary diseases will be invited to participate. Patients will be referred from a cardiothoracic surgeon, and then a research assistant will approach the subjects in the general ward pre operation. Patients will be screened and consented for the study. Following the consent, eligible participants will be block randomized into two groups: ⑴ TEAS group (n=44) and ⑵ sham TEAS group (n=44). All patients will conduct a standard operative procedure and postoperative analgesia management. The patients of TEAS group will receive TEAS therapy in perioperative period, and the Sham TEAS will not be performed to receive electrical stimulation sensation in perioperative period. Assessments will be conducted during the perioperative period until 30 days after surgery.