Effects of Aromatherapy on Anxiety and Blood Pressure in Patients with Acute Coronary Syndrome: A Meta-Analysis of Randomized Controlled Trials

Introduction: Patients with acute coronary syndrome (ACS) often experience high levels of anxiety, which can significantly impact their prognosis. However, evidence regarding anxiety reduction by aromatherapy in patients with ACS is lacking. This study aimed to investigate the effects of aromatherapy on anxiety in patients with ACS.Methods: The literature search was conducted using PubMed, CINAHL, Embase, Web of Science, Cochrane Library, and PsycINFO from their inception until February 21, 2024. Based on inclusion criteria, randomized controlled trials (RCTs) on aromatherapy in patients with ACS aged >= 18 years were included. The risk of bias in the included studies was assessed using the revised Cochrane risk-of-bias tool for RCTs.Results: A total of 14 studies were included in the final analysis. Aromatherapy significantly reduced anxiety among patients with ACS, with a large effect size (standardized mean difference [SMD] = -1.66, 95% confidence interval [CI]: -2.47 to -0.85). The effect on systolic blood pressure (SBP) was -0.65 (95% CI: -1.15 to -0.15), indicating a moderate effect size, whereas there was no significant effect on diastolic blood pressure. Inhalation therapy demonstrated a large effect size (SMD = -1.70, 95% CI: -2.33 to -1.08), whereas massage therapy did not show a significant effect on reducing anxiety.Discussion/Conclusions: The findings show that aromatherapy can effectively reduce anxiety and SBP in patients with ACS. In particular, inhalation therapy showed a significant effect on reducing anxiety levels. Applying aromatherapy in clinical settings to reduce anxiety among patients with ACS should be considered. However, the limited number of studies analyzed hinders a comprehensive evaluation of the effectiveness of massage therapy. Hence, further research is necessary to elucidate its potential role in reducing anxiety among patients with ACS.