Intravenous Nicorandil in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary PCI

BACKGROUND: Nicorandil, an adenosine triphosphate-sensitive potassium-channel opener with nitrate-like properties, may reduce reperfusion injury and microvascular obstruction in ST-segment elevation myocardial infarction (STEMI), but large-scale randomized evidence on long-term clinical outcomes is inconclusive. OBJECTIVES: The CLEAN trial aimed to assess whether adjunctive intravenous nicorandil improves 12-month clinical outcomes in patients with STEMI undergoing primary percutaneous coronary intervention. METHODS: In this multicenter, randomized, double-blind, placebo-controlled trial conducted at 49 hospitals in China, patients aged 18 to 80 years with STEMI within 12 hours of symptom onset were randomly assigned (1:1) to receive intravenous nicorandil (6 mg bolus before reperfusion followed by 6 mg/h infusion for 48 h) or matching placebo. Oral nicorandil was prohibited during follow-up. The primary outcome was a composite of cardiovascular death, nonfatal myocardial infarction, target vessel revascularization, or unplanned hospitalization for heart failure within 12 months. RESULTS: Between January 2021 and December 2023, 1,503 patients were enrolled and randomly assigned to nicorandil (n = 748) or placebo (n = 755). The primary composite outcome occurred in 98 patients (13.1%) in the nicorandil group (113 events over 717.2 person-years) and 99 (13.1%) in the placebo group (136 events over 710.3 person-years), with no significant difference between groups (rate ratio: 0.869; 95% CI: 0.650-1.162; P = 0.3429). Among secondary outcomes, nominal reductions were observed in cardiovascular death (1.9% vs 3.6%; HR: 0.515; 95% CI: 0.269-0.983) and target-vessel revascularization (1.1% vs 3.0%; HR: 0.322; 95% CI: 0.143-0.727), whereas rates of nonfatal myocardial infarction and unplanned hospitalization for heart failure were similar between groups. Adverse events did not differ between groups. CONCLUSIONS: In patients with STEMI undergoing primary percutaneous coronary intervention, adjunctive intravenous nicorandil did not significantly reduce the 12-month primary composite outcome. These findings do not support routine use of intravenous nicorandil in unselected patients with STEMI. (Clinical Efficacy and sAfety of Intravenous Nicorandil; NCT04665648).