Background: Intracoronary nitroprusside and thrombus aspiration have been demonstrated to improve myocardial perfusion during percutaneous coronary interventions (PCI) for ST-segment elevation acute myocardial infarction (STEMI) However, no long-term clinical studies have been performed comparing these approaches.
Methods: A single medical center retrospective study was conducted to evaluate the effects of intracoronary nitroprusside administration before slow/no-reflow phenomena versus thrombus aspiration during primary PCI. Forty-three consecutive patients with STEMI were enrolled in the intracoronary nitroprusside treatment group. One hundred twenty-four consecutive STEMI patients who received thrombus aspiration were enrolled; ninety-seven consecutive STEMI patients who did not receive either thrombus aspiration or intracoronary nitroprusside treatment were enrolled and served as control subjects. Patients with cardiogenic shock, who had received platelet glycoprotein IIb/IIIa inhibitor, or intra-aortic balloon pump insertion were excluded. Thrombolysis in Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count and TIMI myocardial perfusion grade (TMPG) were assessed prior to and following PCI by two independent cardiologists blinded to the procedures. The rate of major adverse cardiac events (MACE) at 30 days, 1 year, and 3 years after study enrollment as a composite of recurrent myocardial infarction, target-vessel revascularization, and cardiac death were recorded.
Results: The control group had a significantly lower pre-PCI TIMI flow (≤ 1; 49.5% vs. 69.8% vs. 77.4%; p = < 0.001) compared with the nitroprusside and thrombus aspiration groups. The thrombus aspiration group had a significantly higher pre-PCI thrombus score (> 4; 98.4% vs. 88.4% vs. 74.3%; p = < 0.001) and post-PCI TMPG (3; 39.5% vs. 16.3% vs. 20.6%; p = 0.001) compared with the nitroprusside and control groups. No significant differences were noted in the post-PCI thrombus score, 30-day, 1-year and 3-year MACE rate, and Kaplan-Meier curve among 3 groups of patients.
Conclusions: Although thrombus aspiration provided improved TMPG compared with early administration of intracoronary nitroprusside and neither of both during primary PCI, it did not have a significant impact on 30-day, 1-year and 3-year MACE rate.
Key words: Acute myocardial infarction; Intracoronary nitroprusside; Thrombus aspiration.