Long-acting cilostazol versus isosorbide mononitrate for patients with vasospastic angina: a randomized controlled trial

Background Cilostazol has a vasodilatory function that may be beneficial for patients with vasospastic angina (VSA). We conducted a randomized, open-label, controlled trial to compare the efficacy and safety of long-acting cilostazol and isosorbide mononitrate (ISMN) for VSA. Methods The study included patients with confirmed VSA between September 2019 and May 2021. Participants were randomly assigned to receive long-acting cilostazol (test group, 200 mg once daily) or conventional ISMN therapy (control group, 20 mg twice daily) for 4 weeks. The clinical efficacy and safety were evaluated using weekly questionnaires. Results Forty patients were enrolled in the study (long-acting cilostazol, n = 20; ISMN, n = 20). Baseline characteristics were balanced between the two groups. Long acting cilostazol showed better angina symptom control within the first week compared to ISMN reduction of pain intensity score, 6.0 (4.0–8.0) vs. 4.0 (1.0–5.0), P = 0.005; frequency of angina symptom, 0 (0–2.0) vs. 2.0 (0–3.0), P = 0.027, respectively. The rate of neurological adverse reactions was lower in the cilostazol group than in the ISMN group (headache or dizziness, 40 vs. 85%, P = 0.009; headache, 30 vs. 70%, P = 0.027). Conclusion Long-acting cilostazol provided comparable control of angina and fewer adverse neurologic reactions within 4 weeks compared to ISMN. Long-acting cilostazol provides more intensive control of angina within 1 week, suggesting that it may be an initial choice for the treatment of VSA.