Suppressive effect of nicorandil in ventricular arrhythmias after reperfusion therapy in patients with acute myocardial infarction

BACKGROUND: Nicorandil is reported to inhibit reperfusion arrhythmias in patients with acute myocardial infarction (AMI), but few studies have counted ventricular arrhythmias with Holter electrocardiograms in patients treated with nicorandil following AMI reperfusion. OBJECTIVES: In the present study, we examined the effects of nicorandil by investigating the occurrence of ventricular arrhythmia with Holter electrocardiogram monitoring after percutaneous coronary intervention with acute myocardial infarction. METHODS: Forty patients with AMI who underwent successful percutaneous coronary intervention (PCI) were enrolled and randomly assigned to nicorandil or placebo groups. Following PCI, nicorandil was infused intravenously at 6 mg/hr for 24 hr, with Holter electrocardiogram monitoring. Patients with 100 or more premature ventricular contractions (PVCs) over the 24-hour period were studied. The total number of PVCs, frequency of occurrence of ventricular tachycardia, and clinical characteristics were compared between the two groups. RESULTS: Fourteen patients in the nicorandil group and 12 patients in the placebo group exhibited 100 or more PVCs over the 24-hour period. Lesion characteristics and procedural factors did not differ between the two groups. Fewer PVCs were counted in the nicorandil group than in the placebo group(144.6 +/- 106.5 vs 286.8 +/- 159.1 beats/day, p = 0.012). The frequency of coupled PVCs was lower in the nicorandil group (6.9 +/- 6.9 vs 16.3 +/- 12.8 beats/day, p = 0.025). Although the frequency of ventricular tachycardia did not differ between the two groups, ventricular tachycardia duration was significantly shorter in the nicorandil group (3.73 +/- 2.30 vs 8.34 +/- 7.45 sec, p = 0.03). CONCLUSIONS: Our study indicates nicorandil inhibits ventricular arrhythmias following PCI for patients with AMI. Nicorandil treatment following PCI for AMI is convenient and may reduce the rate of cardiac events by inhibiting ventricular arrhythmias, thereby potentially improving the prognosis.