Abstract 4547: Intracoronary Administration of Nicorandil Augments the Beneficial Effect of Intravenous Usage on Improvement of Deteriorated Microcirculation in Patients With Acute Myocaridal Infarction
Background: Abnormal coronary microcirculation closely related with long-term outcome persists in patients (pts) with ST-segment elevation myocardial infarction (STEMI) in whom reperfusion is achieved by primary percutaneous coronary intervention (PCI). Little is known the effect of intracoronary Nicorandil (Nic) on coronary circulation in pts with STEMI, although intravenous administration of Nic, a potassium channel opener, improves microvascular dysfunction.
Objectives: To investigate whether intracoronary Nic augments the beneficial effect of intravenous Nic, we compared the index of microcirculatory resistance (IMR) measured after intracoronary Nic with that after intracoronary saline in pts with STEMI.
Methods: In 38 patients, Nic (0.067mg/kg bolus and 1.67μg/kg/min) were started intravenously and baseline IMR was measured immediately after successful PCI. Following measurement of baseline IMR, 20 pts (Group N) were administrated Nic (2mg/10ml) with intracoronary injection, and 18 pts (Control) were given intracoronary saline (10ml). Then, IMR was measured again in both groups. IMR, the most valuable method to evaluate microvascular dysfunction, was measured by a coronary pressure sensor/thermistor-tipped guidewire (Radi Medical Systems, Sweden).
Results: There were not significant differences in pts and lesion characteristics between two groups. In both group, Baseline IMR after PCI were very high (average: 35.5U). In Group N, IMR decreased after Nic significantly by 30.5±20.0% (p<0.0001). In Control, IMR did not change after saline administration (p=0.9069). IMR after PCI in Group N was substantially low comparing with that of Control and percent change of IMR in Group N was significantly low (table⇓).
Conclusion: Intracoronary Nicorandil added on intravenous infusion improved abnormal coronary microcirculation more than intravenous administration alone in pts with STEMI treated with PCI.