NIAMI: Nitrites in AMI

In patients with acute ST-elevation myocardial infarction (STEMI), sodium nitrite administered intravenously (iv) prior to reperfusion, "did not reduce infarct size," according to results of the Nitrites In Acute Myocardial Infarction (NIAMI) Trial presented Nov. 17 as part of AHA 2013.

The trial looked at 220 patients with first acute STEMI and TIMI 0 or 1 flow, who were randomized to either 70micromol of sodium nitrite administered iv or placebo, "more than five minutes before the opening of the infarct-related artery." Results showed six to eight days following the procedure, the infarct size shown by cardiovascular magnetic resonance imaging (CMR) did not differ between the nitrite and placebo groups (effect size -0.7 percent 95 percent CI -2.2,+0.7; p=0.34).

Further, there were "no significant differences" in the secondary endpoints of "infarct size shown by CMR at six months; plasma CK and Troponin I measured over 72 hours after injection of the study medication; infarct size corrected for area at risk measured using T2 weighted CMR; and left ventricular (LV) ejection fraction and LV end systolic volume index measured by CMR at six to eight days and at six months."

The authors add that although non-diabetics did not have any effects, the sodium nitrite reduced infarct size by 4.5 percent in diabetics (95 percent CI -8.8,-0.2; p=0.041), but was not significant (p=0.067). "This study provides no evidence for benefit in the general population using this specific strategy," said Nishat Siddiqi, MBBCh, lead author of the study and a cardiology clinical research fellow at the University of Aberdeen in Scotland. "Higher doses of sodium nitrite delivered over a longer period might have brought us different results, but at this dose it doesn't work," he adds.

However, the authors conclude that moving forward, the "potential benefit in diabetics warrants further study."

Source: www.cardiosource.org