Correlation between endothelial dysfunction and occurrence of no-reflow in patients undergoing post-thrombolysis early invasive percutaneous intervention for ST-elevation myocardial infarction.

backgroundEndothelial dysfunction and no-reflow share microcirculatory obstruction as a common pathophysiological mechanism. This study evaluated the relationship between systemic peripheral endothelial dysfunction assessed by flow-mediated dilatation (FMD) of the brachial artery and no-reflow in patients with ST-segment elevation myocardial infarction (STEMI) who received successful fibrinolysis.

resultsThis study included 150 patients managed by the percutaneous coronary intervention (PCI) after successful fibrinolysis. Patients were divided according to coronary angiographic success into normal flow versus no-reflow groups. According to FMD measured through brachial artery ultrasound, patients were divided based on their endothelial function into endothelial dysfunction versus normal endothelial function. No-reflow occurred in 44 patients (29.3%). No-reflow patients had longer pain to door time (6.52 ± 1.82 vs 5.19 ± 1.85 h), more Killip class II (36.4% vs 16%, p = 0.006), and lower FMD (7.26 ± 1.92 vs 8.23 ± 2.76%, p = 0.036). Also, they showed more endothelial dysfunction; however, this difference was statistically nonsignificant (97.7% vs 87.7%, p = 0.055). One hundred and thirty-six patients (90.7%) had endothelial dysfunction. They were older (57.51 ± 5.92 vs 50.86 ± 4.55 years, p value ≤ 0.001), more smokers (41.2% vs 14.3%, p = 0.04). Patients with normal endothelial function had a more myocardial blush grade (MBG) 3 (78.6% vs 26.5%, p value = 0.001) in comparison with more MBG 2 in those with endothelial dysfunction (41.9% vs 14.3%, p value = 0.001). Endothelial dysfunction patients had nonsignificant more no-reflow (31.6% vs 7.1%, p-value: 0.06). There was a significant weak positive correlation between thrombolysis in myocardial infarction (TIMI) flow and FMD (r = 0.174, p = 0.033) and a significant moderate positive correlation between MBG and FMD (r = 0.366, p < 0.001). Patients with TIMI I flow had significantly lower FMD compared with patients with TIMI II and TIMI III flow post-PCI. FMD ≤ 6% could predict post-procedural TIMI I flow.

conclusionsIn STEMI patients who underwent PCI within 24 h after successful fibrinolysis, those who had no-reflow showed worse peripheral systemic endothelial function as they had lower brachial artery FMD. Also, FMD showed a significant positive correlation with the post-procedural angiographic flow (TIMI flow and MBG). FMD ≤ 6% could predict TIMI I flow.