Impact of quercetin in patients with myocardial infarction. A multicenter, randomized, and open-label pilot study

Myocardial infarction (MI) is one of the leading causes of death in the world. Early myocardial reperfusion improves acute MI survival. Bioflavonoid quercetin is known to have antioxidant, anti-inflammatory, and anti-proliferative properties. The presented pilot study aims to investigate the cardioprotective effect of quercetin on infarct size limiting in patients with ST-segment elevation myocardial infarction (STEMI).

Patients (n = 143) with first anterior STEMI within 6 hours from symptoms onset were included in this open-label multicenter pilot study. Patients were randomized either into quercetin group (n = 70) in addition to standard treatment or recommended therapy alone group (control group, n = 73). Quercetin infusions were initiated before reperfusion and repeated during the next 5 days. The infarct size assessed using creatine kinase-myocardial band area under curve (CK-MB AUC) was the primary study outcome.

The study arms did not differ in demographics, time to admission, and main clinical data. The median early CK-MB AUC was significantly lower in quercetin group than in controls (8036 ± 7594 vs 11219 ± 8146 U × 1 h/L, p = 0.015). Intravenous quercetin administration was associated with less reperfusion-induced intramyocardial hemorrhage by Cardiac Magnetic Resonance on Day 3 (11.1% of patients in quercetin group vs 53.3% of patients in control group, p < 0.024). There were no significant differences in left ventricle ejection fraction and LV remodeling indicators.

Our pilot study is the first to demonstrate novel insight into ischemia/reperfusion damage in STEMI patients. The addition of quercetin to standard STEMI therapy limits infarct size and prevents intramyocardial hemorrhage after the first anterior STEMI. Further research will be necessary to both validate and expand upon these findings.