Cell-free DNA and Microvascular Damage in ST-segment Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

Abstract Introduction and objectives Cell-free DNA (cfDNA) in ST-segment elevation myocardial infarction might originate from hyperactivated leukocytes at the coronary lesion. Our aim was to investigate the relationship between cfDNA and coronary reperfusion. Methods We studied 116 patients treated with primary angioplasty using thrombus aspiration. Coronary (during aspiration) and peripheral (at the end of the procedure) blood samples were drawn for cfDNA, as well as high-sensitivity troponin T and myeloperoxidase quantification. The primary endpoint was no ST-segment resolution (STR) (≥ 70%) and the secondary endpoint was lack of final Thrombolysis In Myocardial Infarction flow 3 (TIMI 3). Results ST-segment resolution was achieved in 51 (44%) patients and TIMI 3 flow in 97 (84%). Patients without STR and TIMI 3 flow had a smaller peripheral-coronary cfDNA gradient ( P = .02 and P = .04 respectively). A small cfDNA gradient (< 1.82 ng/mL) was associated with a higher rate of no STR (65% vs 30%; P = .001) and lack of TIMI 3 flow (21% vs 3%; P = .05). After multivariable adjustment, the small cfDNA gradient was predictive of no STR (OR, 4.50; 95%CI, 1.60-12.62; P = .004), while there was a nonsignificant trend for final TIMI 3 flow ( P = .14). Cell-free DNA levels did not correlate with troponin T or myeloperoxidase. Conclusions A small peripheral-coronary cfDNA gradient, as an expression of high coronary cfDNA burden, is associated with no STR in acute myocardial infarction. Intracoronary cfDNA might reflect neutrophil activation. Whether this phenomenon contributes to thrombus aspiration failure requires further study.