Efficacy and safety of intracoronary epinephrine for the management of the no-reflow phenomenon following percutaneous coronary interventions: a systematic-review study

Background: Currently, no pharmacological or device-based intervention has been fully proven to reverse the no-reflow phenomenon. Objectives: To assess the efficacy and safety of intracoronary (IC) epinephrine in the management of no-reflow phenomenon following percutaneous coronary intervention (PCI), either as first-line treatment or after the failure of conventional agents. Design: Systematic review. Data sources and methods: PubMed and Scopus databases were systematically searched up to 28 May 2022, with additional manual search on the Google Scholar and review of the reference lists of the relevant studies to identify all published studies. Cohort studies, case series, and interventional studies written in English which evaluated the efficacy and safety of IC epinephrine in patients with no-flow phenomenon were included in our review. Results: Six of the 646 articles identified in the initial search met our inclusion criteria. IC epinephrine was used either as a first-line treatment [two randomized clinical trials (RCTs)] or after the failure of conventional agents (two cohort studies and two case series) for restoring the coronary flow, mainly after primary PCI. As first-line therapy, IC epinephrine successfully restored coronary flow in over 90% of patients in both RCTs, which significantly outperformed IC adenosine (78%) but lagged behind combination of verapamil and tirofiban (100%) in this regard. In the refractory no-flow phenomenon, successful reperfusion [thrombolysis in myocardial infarction (TIMI) flow grade = 3] was achieved in three out of four patients after the administration of IC epinephrine based on the results from both case series. Their findings were confirmed by a recent cohort study that further compared IC epinephrine with IC adenosine and found significant differences between them in terms of efficacy [% TIMI flow grade 3: (69.1% versus 52.7%, respectively; p value = 0.04)] and 1-year major adverse cardiac event (MACE) outcomes (11.3% versus 26.7%, respectively; p value ⩽ 0.01). Overall, malignant ventricular arrhythmias were reported in none of the patients treated with IC epinephrine. Conclusion: Results from available evidence suggest that IC epinephrine might be an effective and safe agent in managing the no-reflow phenomenon.