Despite underlying pathologies leading to ICU admittance are heterogeneous, many patients develop a systemic inflammatory response syndrome often in the absence of microbial pathogens. Mitochondrial DNA that shows similarities to bacterial DNA may be released after tissue damage and activates the innate immune system by binding to toll-like receptor-9 on immune cells. The aim of this study was to analyze whether levels of mitochondrial DNA are associated with 30-day survival and whether this predictive value is modified by the expression of its receptor toll-like receptor-9. Single-center, prospective, observational study. A tertiary ICU in a university hospital. Two hundred twenty-eight consecutive patients admitted to a medical ICU between August 2012 and August 2013. None. Blood was taken within 24 hours after ICU admission, and the levels of circulating mitochondrial DNA were quantified by real-time polymerase chain reaction. Toll-like receptor-9 expression in monocytes was measured by flow cytometry. Median acute physiology and chronic health evaluation II score was 20, and 30-day mortality was 25%. Median mitochondrial DNA levels at admission were significantly higher in nonsurvivors when compared with survivors (26.9, interquartile range = 11.2-60.6 ng/mL vs 19.7, interquartile range = 9.5-34.8 ng/mL; p < 0.05). Patients with plasma levels of mitochondrial DNA in the highest quartile (mitochondrial DNA > 38.2 ng/mL) had a 2.6-fold higher risk (p < 0.001) of dying, independently of age, gender, diagnosis, and acute physiology and chronic health evaluation II score. Mitochondrial DNA improved the c-statistic of acute physiology and chronic health evaluation II score (p < 0.05) and showed enhancement in individual risk prediction indicated by a net reclassification improvement of 32.3% (p < 0.05). Stratification of patients according to toll-like receptor-9 expression above/below median demonstrated that only patients with high expression of toll-like receptor-9 showed an increased risk associated with increased mitochondrial DNA levels (odds ratio, 2.7; p < 0.01), whereas circulating mitochondrial DNA was not associated with mortality in patients with low toll-like receptor-9 expression (odds ratio, 1.1; p = 0.98). Circulating levels of mitochondrial DNA at ICU admission predict mortality in critically ill patients. This association was in particular present in patients with elevated toll-like receptor-9 expression.

Atherosclerosis is considered to be an inflammatory disease in which monocytes and monocyte-derived macrophages play a key role. Circulating monocytes can be divided into three distinct subtypes, namely in classical monocytes (CM; CD14++CD16-), intermediate monocytes (IM; CD14++CD16+) and non-classical monocytes (NCM; CD14+CD16++). Low density lipoprotein particles are heterogeneous in size and density, with small, dense LDL (sdLDL) crucially implicated in atherogenesis. The aim of this study was to examine whether monocyte subsets are associated with sdLDL serum levels. We included 90 patients with angiographically documented stable coronary artery disease and determined monocyte subtypes by flow cytometry. sdLDL was measured by an electrophoresis method on polyacrylamide gel. Patients with sdLDL levels in the highest tertile (sdLDL≥4mg/dL;T3) showed the highest levels of pro-inflammatory NCM (15.2±7% vs. 11.4±6% and 10.9±4%, respectively; p<0.01) when compared with patients in the middle (sdLDL=2-3mg/dL;T2) and lowest tertile (sdLDL=0-1mg/dL;T1). Furthermore, patients in the highest sdLDL tertile showed lower CM levels than patients in the middle and lowest tertile (79.2±8% vs. 83.9±7% and 82.7±5%; p<0.01 for T3 vs. T2+T1). Levels of IM were not related to sdLDL levels (5.6±4% vs. 4.6±3% vs. 6.4±3% for T3, T2 and T1, respectively). In contrast to monocyte subset distribution, levels of circulating pro- and anti-inflammatory markers were not associated with sdLDL levels. The atherogenic lipoprotein fraction sdLDL is associated with an increase of NCM and a decrease of CM. This could be a new link between lipid metabolism dysregulation, innate immunity and atherosclerosis.

(1) Background: An unhealthy lifestyle is a significant contributor to the development of chronic diseases. Physical activity can benefit primary and secondary prevention. Higher DNase activity is associated with favourable outcomes after cardiovascular (CV) events. In this study, we aimed to investigate the influence of consequent endurance exercise on DNase activity. (2) Methods: 98 subjects with at least one CV risk factor but the physical ability to perform endurance training were included. Individuals performed a bicycle stress test at the beginning and after 8 months to assess physical performance. In between, all participants were instructed to engage in guideline-directed physical activity. Blood samples were drawn in two-month intervals to assess routine laboratory parameters, cell-free DNA (cfDNA), and DNase activity. (3) Results: Prevailing CV risk factors were overweight (65.9%), a positive family history (44.9%), hypertension (32.7%) and smoking (20.4%). Performance changed by 7.8 ± 9.1% after 8 months. Comparison of baseline to 8 months revealed a decrease in cfDNA and an increase in DNase activity. This effect was driven by participants who achieved a performance gain. (4) Conclusions: Regular physical activity might improve CV health by increasing DNase activity and thereby, the capacity to lower pro-inflammatory signalling, complementing measures of primary and secondary prevention.

Background: Acute heart failure and cardiogenic shock are associated with an impaired intestinal perfusion, which may lead to a release of cytoplasmatic proteins by hypoxic epithelial injury. Intestinal fatty acid binding protein (iFABP), highly specific for the small bowel enterocyte, may pose a useful novel and very sensitive biomarker for predicting outcome of these patients. The aim of this study was to investigate whether circulating levels of iFABP are associated with mortality in patients with acute heart failure or cardiogenic shock requiring intensive care unit (ICU) admission. Methods: We included 90 consecutive patients with cardiogenic shock (74.4%) or severe acute heart failure (25.6%) admitted to a cardiac ICU. Blood samples were taken at day 0 and day 3. Median age was 64.7 (49.4–74.3), 76.7% of patients were male and median NT-proBNP levels were 4,986 (1,525–23,842) pg/mL. 30-day survival was 64.4%. Results: Patients with serum levels of iFABP at day 0 in the highest quartile (iFABP ≥ 588.4 pg/mL) had a 2.5-fold risk (P = 0.02) of dying independent of demographics, NT-proBNP levels, and vasopressor use. Extensively elevated admission levels of iFABP above the 90th percentile (iFABP ≥ 10208.4 pg/mL) were associated with an excessive mortality rate of 88.9%. In contrast, iFABP levels at day 3 were not associated with outcome. Conclusion: Circulating levels of iFABP at admission predict mortality. This suggests that early inadequate perfusion of the small intestine may be associated with a dramatically decreased survival in patients with cardiogenic shock or severe acute heart failure.

Inflammation is regarded as an important trigger for disease progression in heart failure. Particularly in severe acute heart failure, tissue hypoxia may lead to cellular damage and the release of intracellular mitochondrial DNA, which acts as an activator of the immune system due to its resemblance to bacterial DNA. It may therefore serve as a mediator of disease progression. The aim of this study was to determine circulating levels of mitochondrial DNA and its association with mortality in patients with heart failure in different presentations. Plasma levels of circulating mitochondrial DNA were measured in 90 consecutive patients with severe acute heart failure admitted to our medical intensive care unit as well as 109 consecutive chronic heart failure patients. In patients admitted to our medical intensive care unit (median age 64 (49–74) years, median NT-pro-brain natriuretic peptide 4986 (1525–23,842) pg/mL, 30-day survival 64.4%), mitochondrial DNA levels were significantly higher in patients who died within 30 days after intensive care unit admission, and patients with plasma levels of mitochondrial DNA in the highest quartile had a 3.4-fold increased risk (P=0.002) of dying independent of renal function, vasopressor use and NT-pro-brain natriuretic peptide, troponin T, lactate levels or CardShock and acute physiology and chronic health evaluation II score. However, mitochondrial DNA did not provide incremental prognostic accuracy on top of the current gold standard acute physiology and chronic health evaluation II. Patients with severe acute heart failure showed significantly higher mitochondrial DNA levels (P<0.005) as compared to patients with chronic heart failure. In these patients, mitochondrial DNA levels were associated with the New York Heart Association functional class but were not associated with outcome. The release of mitochondrial DNA into the circulation is associated with mortality in patients with severe acute heart failure but not in patients with chronic heart failure. The release of mitochondrial DNA may therefore play a role within the pathophysiology of acute heart failure, which warrants further research. However, the use of mitochondrial DNA as a biomarker for risk stratification in these patients is of limited utility.