The effect of aromatherapy on patients with acute coronary syndrome: A systematic review and meta-analysis

Objective: To systematically investigate the efficacy of aromatherapy in patients with acute coronary syndrome (ACS). Methods: We conducted a comprehensive search for papers published until November 2023 using the following databases: PubMed, Embase, and Cochrane Library. This study was conducted following the PRISMA and Cochrane Guidelines. The inclusion criteria were randomized controlled trials (RCTs) performed to assess the comparative effectiveness of inhalation aromatherapy versus controls in individuals diagnosed with ACS. The Jadad rating method was used to assess the quality of the included studies, and a meta-analysis was performed using the RevMan 5.4 software. Heterogeneity was quantified using the Higgins I2 (%) test. Results: A total of 12 RCTs with 476 patients with ACS were included. Aromatherapy has been shown to reduce anxiety scores significantly (standard mean difference [SMD]: -1.18, 95 % confidence interval [CI]: -1.33 to -1.03; P < 0.00001) along with reduction in systolic blood pressure (MD = -8.78, 95 % CI [-13.92, -3.65], P = 0.008); diastolic blood pressure (MD = -7.76, 95 % CI [-11.39, -4.12], P < 0.001); mean artery pressure MD = -9.68, 95 % CI [-13.93.-5.44]; P < 0.0001). However, no significant effects were reported on the heart rate (MD = -6.98, 95 % CI [-15.46, 1.50], P = 0.11) and respiratory rate (MD = -0.67, 95 % CI [-2.52, 1.19], P = 0.48). A greater frequency of aromatherapy was associated greater anxiety -1.80 incidence, with 95 % CI [-2.04, -1.56]. Citrus essential oils exhibited the strongest effect (SMD = -1.97, 95 % CI [-3.34, -0.60], P = 0.005) in reducing anxiety levels. Conclusion: Aromatherapy appears to be an effective non-pharmacological intervention for reducing blood pressure and anxiety in individuals with ACS. This suggests that aromatherapy more than twice a day is effective in reducing anxiety levels. However, aromatherapy had no statistically significant impact on the heart or respiratory rates. Moreover, additional high-quality RCTs should be conducted to verify these results and explore the efficacy and mechanism of aromatherapy in patients with ACS.