Original title: Open Label, Randomized, Placebo-Controlled Evaluation of Intracoronary Adenosine or Nitroprusside Alter Thrombus Aspiration During Primary Percutaneous Coronary Intervention for the Prevention of Microvascular Obstruction in Acute Myocardial Infartion . The Reopen-AMI Study Reference: Giampaolo Niccoli, et al. J Am Coll Cardiol Intv 2013. Article in Press

One of the challenges of PCI is to achieve the correct myocardial reperfusion. Numerous studies and treatments have been carried out to achieve this goal. This multicenter, randomized, controlled, blind study, assessed the effect of adenosine (120 µg bolus followed by 2 mg in 2 minutes) nitroprusside (60 µg bolus followed by100 µg in 2 minutes) or placebo (saline) on micro circulation after thrombus aspiration in the context of primary or rescue PCI. All patients received Abciximab and thrombus aspiration. Patients admitted for rescue PCI had received Tenecteplase.

240 STEMI patients with Thrombolysis In Myocardial Infarction (TIMI) flow grade 0/1 were randomly allocated 1:1:1 to receive adenosine, nitroprusside or placebo after thrombus aspiration. The primary endpoint was ST-segment resolution >70% at 90 min. Secondary endpoints were angiographic microvascular obstruction incidence (TIMI flow grade ≤2 or 3 with a myocardial blush grade <2) and MACE rate at 30 days. Infarct size was defined by CK, CK-MB and TnT enzyme peak.

In most patients, the drug was infused via the TA catheter. The incidence of AV block with no transitory pacing was greater in the adenosine group and the hypotension rate was similar in NPS and placebo groups. Adenosine presented a significative higher STEMI resolution rate compared to nitroprusside and placebo (71% vs 54% vs 51% respectively, p=0.009 and p=0.75 vs placebo) and a lower MVO (18% vs 24% vs 30% respectively, p= 0.06 y p=0.37 vs placebo). Infarct size was also lower in the adenosine group. MACE rate at 30 days was lower for adenosine, without any significant statistical value (10% vs 14% vs 20%, p=0.08 and p=0.29 vs placebo). 

Conclusion: 

In STEMI patients treated with PCI and TA, adenosine administration, but not nitroprusside, improves STEMI resolution and MVO. 

Comment: 

This analysis shows that high intracoronary adenosine administration through the TA catheter proved beneficial at MVO level with no clear clinical translation at 30 days. In a sub study of AMISTAD II, adenosine at high doses did reduce mortality and infarct area within 3 hours. 

Courtesy of Dr Carlos Fava.
Interventional Cardiologist,
Favaloro Foundation, Buenos Aires Argentina

Dr. Carlos Fava.