Objective To investigate the clinical efficacy of nicorandil and diltiazem in the recurrence of unstable angina pectoris (UAP) patients following postoperative percutaneous coronary intervention (PCI). Methods A total of 72 UAP patients who underwent PCI due to coronary heart disease in our hospital from January 2015 to August 2016 were enrolled in this study. They were randomly and equally divided into nicorandil (24 males and 12 females, at an age of 62.61±9.26 years, ranging from 48 to 80) and diltiazem groups (21 males and 15 females, at an age of 61.72±8.18 years, ranging from 48 to 79). The patients of the former group were given oral administration of 5 mg nicorandil, 3 times per day besides routine treatment, and those from the latter group received oral administration of 90 mg diltiazem, twice per day. During 60 days’ treatments, the frequency and duration of angina, nitroglycerin dosage, electrocardiographic changes, and adverse reactions every week were observed and compared between the 2 groups. ResultsThere were no significant differences in the age, gender, duration of disease, smoking history, comorbidity and score of Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) between the 2 groups (P>0.05). After 60 days’ treatment, the frequency and duration of weekly angina attack and nitroglycerin dosage were reduced, and the nicorandil group had obviously better outcomes than the diltiazem group (P<0.05). The total effective rate was 88.9%(32/36) in the nicorandil group, and 75.0%(27/36) in the diltiazem group, with no statistical difference between them (Chi square=2.347, P=0.126). Compared with the patients of nicorandil group, those of the diltiazem group were prone to headache (P<0.05). ConclusionNicorandil and diltiazem have curative efficacy in postoperative recurrence of UAP after PCI. Nicorandil is more significant in the treatment, with obvious improvement of angina symptoms and less adverse reactions.