The level of free circulating mitochondrial DNA in blood as predictor of death in case of acute coronary syndrome

BACKGROUND: The efficacy of treating acute myocardial ischemic damages depends, to a large extent, on the development of technologies for predicting their course and outcome. The aim of this paper was to explore whether it would be possible to consider the content of free circulating mitochondrial DNA as a danger-associated molecular pattern for assessing the probability of death from myocardial infarction. METHODS: We have analyzed the clinical outcomes based on discharge summaries and autopsy reports obtained in the course of the PROTOCOL observational trial. This study was approved by the Irkutsk Scientific Center of Surgery and Traumatology ethics committee (protocol No. 3, 10.08.2015). To examine whether the assessment of the level of free circulating mtDNA in acute coronary syndrome can help predicting clinical outcomes, all patients were divided into two groups: group 1, involving those who survived during 30 days after hospitalization, and group 2, involving those who died during this time. A quantitative analysis of the free circulating mtDNA was conducted using the PCR method in situ. RESULTS: The analysis showed that in patients who survived the level of freely circulating mtDNA (36.0 copies/ml) was 164 times lower than in those who died (5900 copies/ml, p = 0.049). It should be mentioned that according to the logistic regression analysis, the probability of death of patients with the increased level of blood plasma mtDNA (more than 4000 copies/ml) is 50%. CONCLUSIONS: Thus, the PROTOCOL observational trial proved that the increase in the content of free circulating mtDNA in blood is a predictor of lethal outcome in patients with acute coronary syndrome. Trial registration The observational studies (those in which the assignment of the medical intervention is not at the discretion of the investigator) do not require registration.