Objectives: Early and successful myocardial reperfusion by either thrombolysis or primary percutaneous coronary intervention improve survival in ST-segment elevation myocardial infarction (STEMI) patients. Several strategies, including administration of cardioprotective agents, were tested to prevent microvascular obstruction and myocardial injury after reperfusion. There is some experimental data of anti-ischemic properties of bioflavonoid quercetin (Q) and its capability to limit myocardial injury and prevent left ventricular (LV) remodeling. We have hypothesized that addition of intravenous Q to standard therapy would limit infarct size in patients with STEMI.
Design and methods: 143 patients admitted for the first anterior STEMI within 6 hrs from symptoms onset were included in open-label multicenter (15 sites involved) clinical trial. They were randomized either to Q (n=70) in addition to standard treatment or recommended therapy alone (controls, n=73). Q infusions were started before reperfusion and repeated during the next 5 days. The primary trial outcome was the infarct size assessed by CK-MB AUC. LV ejection fraction (EF) and LV remodeling were assessed at day 10 and after 3 months. Cardiac MRI with gadolinium enhancement was done in 32 patients with evaluation of intramyocardial hemorrhage (IMH) and area at risk (AAR) on the 3d day and after 3 months. Statistical analysis was performed using SPSS 16.0 program.
Results: The study groups did not differ in terms of demographic characteristics, time to admission and main clinical data. Q treatment was safe and well tolerated. The median 48-h CK-MB AUC was significantly lower in Q group than in controls (8036±7594 vs 11219±8146 U×1h/L, p<0.021), fig. 1. There were no significant differences in LVEF and number of patients with LV remodeling between groups at day 10 and after 3 months. Q treatment was associated with significantly lower rate of reperfusion-induced IMH according to MRI data on day 3 after STEMI onset (11.1% of patients in Q group vs 57.1% of patients in control group, p=0.016). There were no differences between groups in MRI assessed infarct size after 3 months, though patients from Q group tended to have larger AAR at initial MRI.
Figure 1
Conclusion: Our results show that using of intravenous Q additionally to standard therapy prevents reperfusion-induced IMH and limits infarct size in reperfused patients with first anterior STEMI.
