Selective intracoronary administration of nitroprusside before balloon dilatation prevents slow reflow during percutaneous coronary intervention in patients with acute myocardial infarction

Background: Previous studies have shown that intracoronary nitroprusside injection is safe and effective after slow reflow complicates percutancous coronary intervention (PCI). Objectives: We sought to determine the safety and efficacy of selective intracoronary administration of nitroprusside through the drug delivery catheter before balloon dilatation to prevent no or slow reflow during PCI for acute myocardial infarction (AMI). Methods: We studied 120 consecutive patients with AMI treated by PCI. In 60 patients (nitroprusside group), nitroprusside (120 mu g) was selectively administered through the drug delivery catheter into the distal coronary artery to reach the target lesion before balloon dilatation. Clinical and angiographic data, as well as in-hospital outcomes, of the nitroprusside group were retrospectively compared with 60 patients who had conventional PCI without nitroprusside (control group). Results: There were no significant differences in the baseline clinical and angiographic characteristics between the 2 groups. Compared to the control group, the nitroprusside group had 1) less slow reflow during the procedure (12% versus 35%, P = 0.0025), 2) a shorter fluoroscopic time (14.4 +/- 7.9 versus 18.7 +/- 9.1 minutes, P = 0.0093), 3) a shorter procedure time (57.6 +/- 20.6 versus 78.1 +/- 26.4, P < minutes, P < 0.0001), 4) a better final TIMI flow grade (III:II:I:0 = 59:1:0:0 versus 53:6:1:0, P = 0.0284), 5) a betterblush grade (III:II:I:0 = 49:10:1:0 versus 33:15:8:4, P = 0.0006), and 6) a better corrected TIMI coronary flame count (30.8 +/- 13.7 versus 46.5 +/- 44.7, P = 0.0102). There were no particular complications with nitroprusside use. Conclusions: The selective intracoronary administration of nitroprusside prior to PCI is safe and well tolerated, prevents no or slow reflows, and improves reperfusion of the infarcted myocardium.