Dipyridamole versus verapamil for treatment of no-reflow during primary angioplasty

Background: No previous study has assessed the possible role of dipyridamole for treatment of no-reflow during acute myocardial infarction (AMI). Methods and Results: Forty-six consecutive patients (age 64 ± 13 years, 37 men) with no reflow during primary percutaneous coronary intervention were randomized to initial treatment with either dipyridamole (0.56 mg/kg i.c.) or verapamil (1 mg i.c.). Patients with unsuccessful response to the first drug were then switched to the second one (from dipyridamole to verapamil and vice versa). Angiographic end-points were similar in the two groups: TIMI flow was 2.9 ± 0.3 versus 2.8 ± 0.4 (P = 0.28), corrected TIMI frame count (cTFC) 26.4 ± 8.8 versus 31.6 ± 11.4 (P = 0.14) and TIMI myocardial perfusion grade (TMPG) 2.1 ± 1.2 versus 1.7 ± 1.2 (P = 0.12) in dipydidamole and verapamil group, respectively. Optimal myocardial perfusion (TMPG-3) was achieved by 56% of patients with dipyridamole and 39% with verapamil (P = 0.38). In patients with persistent no-reflow administration of dipyridamole on top of verapamil resulted in a significant further improvement of cTFC (from 31.6 ± 11.4 to 24.6 ±5.7 P = 0.009) and of TMPG (from 1.7 ± 1.2 to 2.6 ± 0.7, P = 0.007). Conversely, verapamil did not induce a significant improvement in coronary flow (cTFC changed from 26.4 ± 8.8 to 24.5 ± 8.5, P = 0.28 and TMPG from 2.1 ± 1.2 to 2.4 ± 1.2, P = 0.13). There were no significant side effects induced by dipyridamole, while verapamil caused AV block in 9% of cases. Conclusions: Dipyridamole is a safe and effective first-line drug for treatment of no-reflow. Dipyridamole can also be successfully used in patients with incomplete response to verapamil. © 2010 Wiley-Liss, Inc.