Lorenz Koller

A multi-biomarker risk score improves prediction of long-term mortality in patients with advanced heart failure

BACKGROUND Accurate risk prediction is important for an adequate management of heart failure (HF) patients. We assessed the incremental prognostic ability of a multi-biomarker approach in advanced HF. METHODS In 349 patients with advanced HF (median 75 years, 66% male) we investigated the incremental prognostic value of 12 novel biomarkers involved in different pathophysiological pathways including inflammation, immunological activation, oxidative stress, cell growth, remodeling, angiogenesis and apoptosis. RESULTS During a median follow-up of 4.9 years 55.9% of patients died. Using multivariable Cox regression and bootstrap variable-selection age, chronic obstructive pulmonary disease, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and the following 5 novel biomarkers were retained in the best mortality prediction model: the chemokine fractalkine, the angiogenic and mitogenic hepatocyte growth factor (HGF), the growth differentiation factor 15 (GDF-15) influencing cardiac remodeling and apoptosis, and the 2 pro-apoptotic molecules soluble apoptosis-stimulating fragment (sFAS) and soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL). This multi-biomarker score had strong discriminatory power for 5-year mortality (area under the Receiver Operating Characteristic curve [AUC]=0.81) and improved risk prediction beyond the prognostic power of a comprehensive conventional risk score including known clinical predictors and NT-proBNP (AUC=0.77). Net reclassification confirmed a significant improvement of individual risk prediction (p=0.003). CONCLUSIONS Risk prediction by a multi-biomarker score is superior to a conventional risk score including clinical parameters and NT-proBNP. Additional predictive information from different biological pathways reflects the multisystemic character of HF.

Fractalkine is an independent predictor of mortality in patients with advanced heart failure

Immunological processes are implicated in the multifactorial pathophysiology of heart failure (HF). The multifunctional chemokine fractalkine (CX3CL1) promotes the extravasation of cytotoxic lymphocytes into tissues. We aimed to assess the prognostic value of fractalkine in HF. Fractalkine plasma levels were determined in 349 patients with advanced systolic HF (median 75 years, 66% male). During a median follow-up of 4.9 years (interquartile range: 4.6-5.2), 55.9% of patients died. Fractalkine was a significant predictor of all-cause mortality (p<0.001) with a hazard ratio of 2.78 (95% confidence interval: 1.95-3.95) for the third compared to the first tertile. This association remained significant after multivariable adjustment for demographics, clinical predictive variables and N-terminal pro-B-type natriuretic peptide (NT-proBNP, p=0.008). The predictive value of fractalkine did not significantly differ between patients with ischaemic and non-ischaemic HF aetiology (p=0.79). The predictive value of fractalkine tertiles was not significantly modified by tertiles of NT-proBNP (p=0.18) but was more pronounced in the first and third tertile of NT-proBNP. Fractalkine was also an independent predictor of cardiovascular mortality (p=0.015). Fractalkine levels were significantly lower in patients on angiotensin-converting enzyme inhibitor therapy (p<0.001). In conclusion, circulating fractalkine with its pro-inflammatory and immunomodulatory effects is an independent predictor of mortality in advanced HF patients. Fractalkine improves risk prediction beyond NT-proBNP and might therefore help to identify high risk patients who need special care. Our data indicate the implication of immune modulation in HF pathology.

Differential in vivo activation of monocyte subsets during low-grade inflammation through experimental endotoxemia in humans

Human monocytes are a heterogeneous cell population, which can be divided into a classical (CD14++CD16−), a non-classical (CD14+CD16+), and an intermediate (CD14++CD16+) subset. We hypothesized that low-grade inflammation may differentially affect monocyte subsets. We used a human lipopolysaccharide (LPS) infusion model to mimic low-grade inflammation to identify, which monocyte subsets are preferentially activated under these conditions. Monocyte subsets were identified by staining for CD14 and CD16, activation status of monocytes was analyzed by staining for CD11b and a novel in situ mRNA hybridization approach to detect IL-6 and IL-8 specific mRNA at the single-cell level by flow cytometry. After LPS challenge, cell numbers of monocyte subsets dropped after 2 h with cell numbers recovering after 6 h. Distribution of monocyte subsets was skewed dramatically towards the intermediate subset after 24 h. Furthermore, intermediate monocytes displayed the largest increase of CD11b expression after 2 h. Finally, IL-6 and IL-8 mRNA levels increased in intermediate and non-classical monocytes after 6 h whereas these mRNA levels in classical monocytes changed only marginally. In conclusion, our data indicates that the main responding subset of monocytes to standardized low-grade inflammation induced by LPS in humans is the CD14++CD16+ intermediate subset followed by the CD14+CD16+ non-classical monocyte subset. Circulating classical monocytes showed comparably less reaction to LPS challenge in vivo.

C‐reactive protein predicts mortality in patients referred for coronary angiography and symptoms of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) has a different pathophysiological background compared to heart failure with reduced ejection fraction (HFrEF). Tailored risk prediction in this separate heart failure group with a high mortality rate is of major importance. Inflammation may play an important role in the pathogenesis of HFpEF because of its significant contribution to myocardial fibrosis. We therefore aimed to assess the predictive value of C‐reactive protein (CRP) in patients with HFpEF.

Mitochondrial DNA and Toll-Like Receptor-9 Are Associated With Mortality in Critically Ill Patients.

Objectives: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. Design:Single-center, prospective, observational study. Setting:A tertiary ICU in a university hospital. Patients:Two hundred twenty-eight consecutive patients admitted to a medical ICU between August 2012 and August 2013. Interventions:None. Measurements and Main Results: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). Conclusions: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.

Association of small dense LDL serum levels and circulating monocyte subsets in stable coronary artery disease.

Objective 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. Methods 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. Results 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. Conclusion 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.

Fibroblast Growth Factor 23 Is an Independent and Specific Predictor of Mortality in Patients With Heart Failure and Reduced Ejection Fraction

Background—Strategies to improve risk prediction are of major importance in patients with heart failure (HF). Fibroblast growth factor 23 (FGF-23) is an endocrine regulator of phosphate and vitamin D homeostasis associated with an increased cardiovascular risk. We aimed to assess the prognostic effect of FGF-23 on mortality in HF patients with a particular focus on differences between patients with HF with preserved ejection fraction and patients with HF with reduced ejection fraction (HFrEF). Methods and Results—FGF-23 levels were measured in 980 patients with HF enrolled in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study including 511 patients with HFrEF and 469 patients with HF with preserved ejection fraction and a median follow-up time of 8.6 years. FGF-23 was additionally measured in a second cohort comprising 320 patients with advanced HFrEF. FGF-23 was independently associated with mortality with an adjusted hazard ratio per 1-SD increase of 1.30 (95% confidence interval, 1.14–1.48; P<0.001) in patients with HFrEF, whereas no such association was found in patients with HF with preserved ejection fraction (for interaction, P=0.043). External validation confirmed the significant association with mortality with an adjusted hazard ratio per 1 SD of 1.23 (95% confidence interval, 1.02–1.60; P=0.027). FGF-23 demonstrated an increased discriminatory power for mortality in addition to N-terminal pro–B-type natriuretic peptide (C-statistic: 0.59 versus 0.63) and an improvement in net reclassification index (39.6%; P<0.001). Conclusions—FGF-23 is independently associated with an increased risk of mortality in patients with HFrEF but not in those with HF with preserved ejection fraction, suggesting a different pathophysiologic role for both entities.

Von Willebrand Factor Improves Risk Prediction in Addition to N-Terminal Pro–B-type Natriuretic Peptide in Patients Referred to Coronary Angiography and Signs and Symptoms of Heart Failure and Preserved Ejection Fraction

Background—Heart failure with preserved ejection fraction (HFpEF) represents a growing health burden associated with substantial mortality and morbidity. Consequently, risk prediction is of highest importance. Endothelial dysfunction has been recently shown to play an important role in the complex pathophysiology of HFpEF. We therefore aimed to assess von Willebrand factor (vWF), a marker of endothelial damage, as potential biomarker for risk assessment in patients with HFpEF. Methods and Results—Concentrations of vWF were assessed in 457 patients with HFpEF enrolled as part of the LUdwigshafen Risk and Cardiovascular Health (LURIC) study. All-cause mortality was observed in 40% of patients during a median follow-up time of 9.7 years. vWF significantly predicted mortality with a hazard ratio (HR) per increase of 1 SD of 1.45 (95% confidence interval, 1.26–1.68; P<0.001) and remained a significant predictor after adjustment for age, sex, body mass index, N-terminal pro–B-type natriuretic peptide (NT-proBNP), renal function, and frequent HFpEF-related comorbidities (adjusted HR per 1 SD, 1.22; 95% confidence interval, 1.05–1.42; P=0.001). Most notably, vWF showed additional prognostic value beyond that achievable with NT-proBNP indicated by improvements in C-Statistic (vWF×NT-proBNP: 0.65 versus NT-proBNP: 0.63; P for comparison, 0.004) and category-free net reclassification index (37.6%; P<0.001). Conclusions—vWF is an independent predictor of long-term outcome in patients with HFpEF, which is in line with endothelial dysfunction as potential mediator in the pathophysiology of HFpEF. In particular, combined assessment of vWF and NT-proBNP improved risk prediction in this vulnerable group of patients.

Prognostic relevance of circulating endothelial progenitor cells in patients with chronic heart failure

Novel strategies for a tailored risk prediction in chronic heart failure (CHF) are crucial to identify patients at very high risk for an improved patient management and to specify treatment regimens. Endothelial progenitor cells (EPCs) are an important endogenous repair mechanism with the ability to counteract endothelial injury and the possibility of new vessel formation. We hypothesised that exhaustion of circulating EPCs may be a suitable prognostic biomarker in patients with CHF. EPCs, defined as CD34+CD45dimKDR+ cells, were analysed using fluorescence-activated cell sorting. EPCs were measured in 185 patients with CHF including 87 (47 %) patients with ischaemic aetiology and 98 (53 %) patients with non-ischaemic CHF and followed for a median time of 2.7 years. During this period, 34.7 % of patients experienced the primary study endpoint all-cause mortality. EPC count was a significant and independent inverse predictor of mortality with an hazard ratio hazard ratio (HR) per increase of one standard deviation (1-SD) of 0.47 (95 % confidence interval [CI]: 0.35-0.61; p<0.001) and remained significant after multivariable adjustment for a comprehensive set of cardiovascular risk factors and potential confounders with a HR per 1-SD of 0.54 (95 % CI: 0.4-0.73; p<0.001). EPCs further demonstrated additional prognostic information indicated by improvements in C-statistic, net reclassification index and integrated discrimination increment. In conclusion, in our study circulating EPCs turned out as strong and independent inverse predictors of mortality underlining the importance of an impaired endothelial repair mechanism in the pathophysiology and progression of CHF.

Editor’s Choice-Progress in the chain of survival and its impact on outcomes of patients admitted to a specialized high-volume cardiac arrest center during the past two decades

Aim: Cardiac arrest (CA) is still associated with high mortality and morbidity. Data on the changes in management and outcomes over a long period of time are limited. Using data from a single emergency department (ED), we assessed changes over two decades. Methods: In this single-center observational study, we prospectively included 4133 patients receiving cardiopulmonary resuscitation and being admitted to the ED of a tertiary care hospital between January 1992 and December 2012. Results: There was a significant improvement in both 6-month survival rates (+10.8%; p < 0.001) and favorable neurological outcome (+4.7%; p < 0.001). While the number of witnessed CA cases decreased (-4.7%; p < 0.001) the proportion of patients receiving bystander basic life support increased (+8.3%; p < 0.001). The proportion of patients with initially shockable ECG rhythms remained unchanged, but cardiovascular causes of CA decreased (-9.6%; p < 0.001). Interestingly, the time from CA until ED admission increased (+0.1 hours; p = 0.024). The use of percutaneous coronary intervention and therapeutic hypothermia were significantly associated with survival. Conclusions: Outcomes of patients with CA treated at a specialized ED have improved significantly within the last 20 years. Improvements in every link in the chain of survival were noted.