Abstract P146: Circulating Cell-Free DNA Level Associates with Postresuscitation Survival in Out-Of-Hospital Cardiac Arrest Patients
Introduction: Cell-free DNA level, which increases in circulation as a result of tissue injuries, is a novel biomarker for prognosis of clinical diseases. Early biomarker would be helpful for evaluating the outcome of cardiac arrest patients, who sustain global organ injuries and cell damage.
Hypothesis: Tissue damage and cell death in out-of-hospital cardiac arrest (OHCA) patients may lead to the release of free DNA into peripheral blood, which may have prognostic significance.
Method: There were 40 non-traumatic adult OHCA patients who were successfully resuscitated and included. Blood samples were took at the time point of at ROSC, 1st and 3rd days after cardiac arrest. After the plasma separated from the cellular components of blood samples, DNA in the plasma fraction was extracted by a QIAamp DNA isolation Kit. DNA copy numbers were measured by quantitative real-time polymerase chain reactions. Baseline clinical characteristics, CPR process, biochemical measurements and outcomes of studied patients were collected and analyzed.
Result: The cell free DNA level at ROSC was significantly lower in patients who survived up to 7 days than those who were death within 7 days following cardiac arrest (5.6±10.7 g.e./mL vs. 24.8±25.9 g.e./mL, P=0.003 by t-test). Using 5 g.e./mL as cutoff point, more patients surviving up to 7 days has the DNA level at ROSC below the cutoff value (79 % vs. 33%, p=0.039 by Fisher’s exact test). While evaluating the correlation between the survival duration and cell-free DNA levels at ROSC, the survivors who survived longer had lower cell free DNA level (P=0.016, r2=0.144). The cell free DNA level was also associated with troponin-I level sampled at ROSC (P=0.043, r2=0.129). For overall patients, cell-free DNA level decreased from 8.5±15.2 g.e./mL at ROSC to 2.1±4.8 g.e./mL on 3rd day following cardiac arrest without difference of cell-free DNA levels at 3rd day between the survival and non-survival groups.
Conclusion: Circulating cell-free DNA level, an indicator of cell damage, is significantly associated with postresuscitation survival in OHCA patients.