Abstract 4469: Reversal of No-Reflow/Slow-Flow during Percutaneous Coronary Intervention in Patients with Acute Myocardial Infarction–A Prospective Randomized Study Comparing Intracoronary Infusion of Diltiazem, Verapamil and Nitroglycerin
No-reflow/slow-flow is a frequent observation during direct PCI for AMI and associated with a poor clinical outcome. The present pharmacological management involves the use of different vasodilators including nitrates, verapamil, adenosine and nicorandil. But no randomized trial has been conducted to assess any of these agents, or to determine the appropriate dosage. In a consecutive series of 236 direct PCI for AMI, no-reflow/slow-flow phenomenon [TIMI flow grade (TFG) <3] was observed in 30 patients (12.7%). All lesions in the infarction-related-coronary (IRC) were treated by stents. The 30 patients were randomised to one of three groups: intracoronary infusion of diltiazem (n=10), verapamil (n=10) and nitroglycerin (n=10). All the drugs were given via an infusion catheter distal to the angioplasty site. Pre-PCI, post-PCI and after drugs were given, IRC flow was assessed using TFG and TIMI frame count (TFC) by blinded angiographic readers. LVEF through echocardiography and NT-proBNP levels were measured at days 1 and 30 post-PCI. Patient, procedural characteristics and the baseline IRC flow post-PCI in the three groups were similar. The average intracoronary infusion drug dose was diltiazem 0.8mg, verapamil 0.4mg and nitroglycerin 0.4mg. All the three drugs could improve the IRC flow measured by TFG and TFC significantly (p<0.05). Compared with nitroglycerin, diltiazem and verapamil could improve the IRC flow more significantly (p<0.05). The improvements in TFG and TFC did not differ significantly between the diltiazem and verapamil groups (p>0.05). Five patients in the verapamil group developed transient heart block, not seen with diltiazem (p<0.01). During 30 days follow-up, the LVEF improved insignificantly in the three groups. The NT-proBNP levels in the diltiazem and verapamil groups were lower than nitroglycerin group (p<0.05). There is no significant difference in the NT-proBNP levels between the diltiazem and verapamil groups. The intracoronary infusion of diltiazem or verapamil can reverse no-reflow/slow flow phenomenon more effectively than infusion of nitroglycerin during direct PCI for AMI. The efficacy of diltiazem and verapamil is similar but diltiazem seems safer.