- N-Acetylcysteine (NAC) is an anti-oxidant which potentiates the action of nitroglycerine
- When used with nitrates in the context of acute myocardial infarction, it may reduce infarct size by minimising reperfusion injury as well as potentiating nitroglycerine’s vasodilating and anti-platelet effects
- The NACIAM trial – The early use of N-Acetyl Cysteine In Acute Myocardial Infarction to assess the impact of early NAC therapy in reducing myocardial infarct size as determined by Cardiac Magnetic Resonance Imaging (CMRI).
- It is a randomised, double-blind, placebo-controlled study assessing the impact of early NAC therapy in reducing infarct size (as assessed by cardiac MRI) in patients with acute ST elevation myocardial infarction (STEMI) receiving intravenous nitrate therapy and undergoing primary percutaneous coronary intervention
- STEMI patients (mean age 64 years) within 12 hours of symptom onset from three Australian hospitals all received IV glyceryl trinitrate (GTN) and were randomized to receive either high-dose (15 g/24 hours) NAC or placebo, both drugs delivered intravenously over 48 hours and started in the emergency department
- Intravenous NAC 15g or saline placebo in 500 ml 5% Dextrose delivered at 20 mg/min for 1st hour then 10 mg/min for next 47 hours
- Cardiac magnetic resonance (CMR) imaging performed within 1 week and again 3 months post-MI showed that patients who received NAC had reductions in infarct size of 33% and 50%, respectively, compared with placebo (p=0.02 for both)
- There was a similar but not significant trend toward reduction in creatine kinase (CK) release
- In addition, myocardial salvage, measured at 1 week, was approximately doubled in patients who received NAC (60% vs 27%, p<0.001), and there was also evidence of accelerated tissue reperfusion and hypochlorous acid “scavenging” in these patients
- Most benefit occurred in patients treated early—within 3 hours of symptom onset
- Over 2 years of follow-up, the combination of cardiac readmissions and deaths was less frequent in NAC-treated (three vs 16 patients, p<0.01).
- Safety end points, including hypotension, bleeding, and contrast-induced nephropathy, were similar in both groups.
“Intravenous NAC administration was associated with more rapid chest-pain resolution, improved myocardial salvage, a favorable in-hospital safety profile, sustained infarct size reduction at 3 months post-STEMI, and promising clinical outcomes at 2 years,” concluded Dr. Sivabaskari Pasupathy (University of Adelaide, Australia). “While the results of this study are encouraging, we would prefer to regard NACIAM as the precursor of a follow-up study, sized for clinical end points,” she concluded.
The update can be accessed from the below mentioned link.
The trial is registered on the Australian New Zealand Clinical Trial Registry (ANCTR) and can be accessed from the below mentioned link.