Dengzhan Shengmai Capsule Versus Aspirin in the Treatment of Carotid Atherosclerotic Plaque: A Single-Centre, Non-Inferiority, Prospective, Randomised Controlled Trial

Background: Aspirin is an effective antiplatelet agent for the treatment of carotid atherosclerosis. However, the high risk of bleeding events associated with the drug makes it necessary to seek a safer alternative, with similar or more efficacy than aspirin. Dengzhan Shengmai (DZSM) capsules have been widely used to treat carotid atherosclerosis, and if proven to be non-inferior to aspirin, it may be preferable over the latter for carotid atherosclerosis treatment due to its numerous advantages. We conducted a randomised trial to test the non-inferiority of DZSM to aspirin for the treatment of carotid atherosclerotic plaques. Methods: We performed a single-centre, prospective, open-label, randomised non-inferiority trial. Patients with carotid atherosclerotic plaques were enrolled and randomly assigned (1:1) to receive either DZSM capsules or aspirin. The follow-up period was 12 months. The primary outcome was the mean change in carotid intima-media thickness (IMT). Secondary outcomes included ischaemic events, rate of lumen stenosis, lipid levels, and plaque scores, length, counts, and vulnerability. Adverse events and laboratory test results were recorded as safety outcomes. The non-inferiority of DZSM was demonstrated when the lower limit of the one-sided 97.5% confidence interval (CI) of the difference in IMT between groups was more than -0.06 mm (margin of noninferiority). This trial has been registered at ClinicalTrials.gov (CHiCTR1900021365). Results: From 1 April 2019 to 30 September 2019, 150 patients were enrolled, and there was no statistical difference in demographics between the groups. Intention-to-treat analysis showed that the decrease in IMT(Delta IMT) was 0.216 +/- 0.160 and 0.225 +/- 0.149 mm in the DZSM and aspirin groups, respectively. The one-sided 97.5% CI for the difference between Delta IMTs was (-0.0593, +infinity). The non-inferiority of DZSM was demonstrated (Pnon-inferiority = 0.0234). There was no significant difference in the incidence of ischaemic events between the groups (P = 1.0). The DZSM group had significantly reduced plaque scores (P < 0.0001), length (P < 0.0001), and counts (P < 0.0001), and improved plaque vulnerability (P < 0.0001). The DZSM group also had reduced levels of low-density lipoprotein cholesterol (LDL-C) (P < 0.0001). Finally, the DZSM group had a lower incidence of total adverse events (14.7% vs. 28%, P = 0.046), especially gastrointestinal discomfort (5.3% vs. 16%, P = 0.034). Although there was no significant difference in bleeding events (0 vs. 5.3%, P = 0.120), the DZSM group tended to have a lower incidence. Conclusion: This trial demonstrated that DZSM was not inferior, in efficacy, to aspirin in treating carotid atherosclerotic plaques, and was found to be superior to aspirin in terms of safety. This study provides a new approach for treating carotid plaques, especially in aspirin-intolerant patients.