The Preventive Value of Acupoint Sensitization for Patients with Stable Angina Pectoris: A Randomized, Double-Blind, Positive-Controlled, Multicentre Trial

Abstract

Background: Acupoint sensitization is considered an important factor in the efficacy of acupoint therapy. This study aimed to evaluate the efficacy of acupressure in the prevention of stable angina pectoris using acupoints with different pressure-pain sensitivities.

Methods: A total of 202 patients were enrolled and randomly assigned to a high-sensitivity group (HSG) (n = 109) in which patients received acupressure at the five acupoints with the highest sensitivity to pain and a low-sensitivity group (LSG) (n = 93) in which patients received acupressure at the five acupoints with the lowest sensitivity to pain. The duration of acupressure treatment was 4 weeks, and the patients were evaluated at baseline, week 4, and week 8. The primary outcome was a change in the frequency of angina attacks from baseline. The secondary outcomes included nitroglycerin consumption, the Canadian Cardiovascular Society classification, and the Seattle Angina Questionnaire score. Adverse events such as bleeding and subcutaneous haemorrhage were recorded in both groups.

Results: The effect of acupressure compared with baseline on the prevention of angina pectoris in HSG was better than that in LSG at week 4 (incidence rate ratio (IRR): 0.691 and 95% confidence interval (CI): [0.569, 0.839]) and week 8 (IRR: 0.692 and 95% CI: [0.569, 0.839]). No significant difference between groups was found in the frequency of nitroglycerin consumption at week 4 (odds ratio (OR) = 0.863 and 95% CI: [0.147, 5.077]) or week 8 (OR = 1.426 and 95% CI: [0.211, 9.661]). Two themes in the questionnaire showed significantly different changes from baseline between the two groups. Scores on the angina frequency (AF) subscale had changed more from the baseline in the HSG at week 8 than in the LSG (mean difference (MD) = 3.807 and 95% CI: [0.673, 6.942]). Scores on the treatment satisfaction (TS) subscale had also changed more in the HSG than in the LSG at week 4 (MD = 3.651 and 95% CI: [0.327, 7.327]) and week 8 (MD = 4.220 and 95% CI: [0.347, 7.346]). One patient in the LSG reported bruising at the acupoint. No unexpected safety problems arose.

Conclusions: This study showed that acupressure at acupoints with high sensitivity to pain may effectively reduce the frequency of stable angina pectoris episodes. This trial is registered with NCT03975140.

Conflict of interest statement

The authors declare that there are no conflicts of interest associated with this manuscript.

Copyright © 2021 Shourui Huang et al.

Figures

Figure 1

Flowchart of enrolment, randomization, and follow-up. HSG: high-sensitivity group; LSG: low-sensitivity group.

Figure 2

Change in the frequency of angina attacks during the study. HSG: high-sensitivity group; LSG: low-sensitivity group; ΔHSG: changes of the number of angina attacks from baseline to week 4 in the high-sensitivity group; and ΔLSG: changes of the number of angina attacks from baseline to week 4 in the low-sensitivity group.

Figure 3

Subgroup analysis of associations between angina attack and intervention. IRR: incidence rate ratio; CI: confidence interval; BMI: body mass index; and CHD: coronary heart disease.

Figure 4

Change of PPT between groups from baseline to week 4. HSG: high-sensitivity group; LSG: low-sensitivity group; PPT: pressure-pain threshold; and error bars indicate the standard error of the mean.