LidocAine Versus Opioids In MyocarDial infarction: The AVOID-2 randomised controlled trial.

BACKGROUND: Opioid analgesia has been shown to interfere with the bioavailability of oral P2Y12 inhibitors prompting the search for safe and effective non-opioid analgesics to treat ischemic chest pain.

METHODS: The AVOID-2 trial was a prospective, phase II, prehospital, open-label, non-inferiority, randomized controlled trial enrolling patients with suspected STEACS with moderate to severe pain (numerical rating scale (NRS) at least 5/10). Intravenous lidocaine (maximum dose 300 mg) or intravenous fentanyl (up to 50 µg every 5 min) were administered as prehospital analgesia. The co-primary endpoints were prehospital pain reduction and adverse events requiring intervention. Secondary endpoints included peak cardiac troponin I, cardiac MRI (cMRI) assessed myocardial infarct size and clinical outcomes to 30 days.

RESULTS: A total of 308 patients were enrolled. The median reduction in pain score (NRS) was 4 versus. 3 in the fentanyl and lidocaine arms respectively for the primary efficacy endpoint (estimated median difference -1 (95% confidence interval -1.58, -0.42, p = 0.5 for non-inferiority, p = 0.001 for inferiority of lidocaine). Adverse events requiring intervention occurred in 49% vs. 36% in the fentanyl and lidocaine arms which met non-inferiority and superiority favouring lidocaine (p = 0.016 for superiority). No significant differences in myocardial infarct size and clinical outcomes at 30 days were seen.

CONCLUSIONS: IV Lidocaine did not meet criteria for non-inferiority with lower prehospital pain reduction than fentanyl but was safe and better tolerated as analgesia in STEMI. Future trials testing non-opioid analgesics in STEMI and whether opioid avoidance improves clinical outcomes are needed.