Original Manuscript Nicorandil Versus Nitroglycerin for Symptomatic Relief of Angina in Patients With Slow Coronary Flow Phenomenon: A Randomized Clinical

Objective: Patients with the coronary slow flow phenomenon frequently experience angina episodes. The present study aimed to compare the efficacy of nicorandil versus nitroglycerin for alleviation of angina symptoms in slow flow patients.Methods: In a single-center, single-blind, parallel-design, comparator-controlled, randomized clinical trial (NCT02254252), 54 patients with slow flow and normal or near-normal coronary angiography who presented with frequent angina episodes were randomly assigned to 1-month treatment with nicorandil 10 mg, 2 times a day (n 27) or sustained-release glyceryltrinitrate 6.4 mg 2 times a day (n 27). Frequency of angina episodes, pain intensity, and the Canadian Cardiovascular Society (CCS) grading of angina pectoris were assessed at baseline and after 1 month of treatment.Results: In all, 25 patients in the nicorandil arm and 24 patients in the nitroglycerin arm were analyzed. After 1 month, patients treated with nicorandil had fewer angina episodes (adjusted mean number of episodes per week, nicorandil versus nitroglycerin; 1.68+ 0.15 vs 2.29+ 0.15, P .007, effect size 14.6%). Patients also reported greater reductions in pain intensity with nicorandil versus nitroglycerin (adjusted mean of self-reported pain score; 3.03+ 0.29 vs 3.89+ 0.30, P .046, effect size 8.4%). A significantly higher proportion of patients in the nicorandil arm were categorized in CCS class I (76 % vs 33.3%, P .004) or class II (16.0 % vs 45.8%, P .032). Conclusion: In slow flow patients, nicorandil provides better symptomatic relief of angina than nitroglycerin. Keywords angina pectoris/drug therapy, nicorandil/administration and dosage, nitroglycerin/administration and dosage, treatment outcome, blood flow velocity/drug effects, randomized controlled tria