Bernhard Richter

Prognostic value of apoptosis markers in advanced heart failure patients

AIMS Apoptosis plays an important role in the progression of heart failure (HF). The purpose of this study was to assess whether the pro-apoptotic molecules apoptosis-stimulating fragment (FAS, CD95/APO-1) and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) predict event-free survival of HF patients. METHODS AND RESULTS We assayed soluble (s)FAS and sTRAIL levels in 351 patients with advanced HF. During the median follow-up time of 16 months, 175 patients (50%) experienced the composite endpoints: rehospitalization and death. The hazard increased with sFAS concentrations, with a hazard ratio of 2.3 comparing fourth and first quartiles. This association remained significant after adjustment for B-type natriuretic peptide (BNP) and other risk factors in a Cox regression model (P = 0.014). Patients with high sFAS but low BNP had a comparable event-free survival rate with those with elevated BNP only (P = 0.78). Conversely, high sTRAIL concentrations were related to a better prognosis. Particularly, the risk of mortality dropped by 70% in the fourth quartile of sTRAIL (P = 0.001, multivariable Cox regression model). CONCLUSION sFAS is an independent risk predictor in advanced HF patients. It may be of particular value for the identification of high-risk patients in addition to BNP. Conversely, sTRAIL appears to be protective and could be an interesting therapeutic agent.

Frequency of Recurrence of Atrial Fibrillation Within 48 Hours After Ablation and Its Impact on Long-Term Outcome

Because of delayed structural and electrophysiologic effects of radiofrequency ablation of atrial fibrillation (AF), early recurrence of AF after ablation does not necessarily indicate long-term ablation failure. This study was intended to assess the prognostic value of early recurrence of AF within 48 hours after ablation. The study included 234 patients (aged 23 to 80 years; 72% men) with symptomatic drug-resistant paroxysmal (n = 165) or persistent AF (n = 69) who underwent either Lasso-guided segmental pulmonary vein isolation (n = 83) or CARTO-guided left atrial circumferential ablation (n = 151). After a median follow-up of 12.7 months, 64% of patients with paroxysmal and 45% of patients with persistent AF were AF free. Early recurrence of AF occurred in 43% of patients and was more frequently observed in the persistent-AF group (paroxysmal vs persistent 39% vs 54%; p = 0.037). Early recurrence of AF was a significant predictor of long-term ablation failure in univariate (hazard ratio [HR] 2.29, p <0.001) and multivariate (HR 2.17. p <0.001) Cox regression analysis. Nevertheless, 46% of patients with early recurrence of AF were AF free during long-term follow-up compared with 68% of patients without early recurrence of AF. The prognostic value of early recurrence of AF was found in patients with paroxysmal (HR 2.05, p = 0.005) and persistent AF (HR 2.35, p = 0.013). In conclusion, early recurrence of AF within 48 hours after ablation was a significant predictor of a poor long-term ablation outcome. However, because nearly half the patients with early recurrence of AF remained AF free during long-term follow-up, early recurrence of AF should not automatically result in an early repeated procedure.

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.

Routinely available biomarkers improve prediction of long-term mortality in stable coronary artery disease: the Vienna and Ludwigshafen Coronary Artery Disease (VILCAD) risk score.

AIMS Previous risk assessment scores for patients with coronary artery disease (CAD) have focused on primary prevention and patients with acute coronary syndrome. However, especially in stable CAD patients improved long-term risk prediction is crucial to efficiently apply measures of secondary prevention. We aimed to create a clinically applicable mortality prediction score for stable CAD patients based on routinely determined laboratory biomarkers and clinical determinants of secondary prevention. METHODS AND RESULTS We prospectively included 547 patients with stable CAD and a median follow-up of 11.3 years. Independent risk factors were selected using bootstrapping based on Cox regression analysis. Age, left ventricular function, serum cholinesterase, creatinine, heart rate, and HbA1c were selected as significant mortality predictors for the final multivariable model. The Vienna and Ludwigshafen Coronary Artery Disease (VILCAD) risk score based on the aforementioned variables demonstrated an excellent discriminatory power for 10-year survival with a C-statistic of 0.77 (P < 0.001), which was significantly better than an established risk score based on conventional cardiovascular risk factors (C-statistic = 0.61, P < 0.001). Net reclassification confirmed a significant improvement in individual risk prediction by 34.8% (95% confidence interval: 21.7-48.0%) compared with the conventional risk score (P < 0.001). External validation of the risk score in 1275 participants of the Ludwigshafen Risk and Cardiovascular Health study (median follow-up of 9.8 years) achieved similar results (C-statistic = 0.73, P < 0.001). CONCLUSION The VILCAD score based on a routinely available set of risk factors, measures of cardiac function, and comorbidities outperforms established risk prediction algorithms and might improve the identification of high-risk patients for a more intensive treatment.

Strength training increases maximum working capacity in patients with COPD--randomized clinical trial comparing three training modalities.

BACKGROUND AND OBJECTIVE Skeletal muscle dysfunction contributes to exercise limitation in patients with chronic obstructive pulmonary disease (COPD). Strength training increases muscle strength and muscle mass, but there is an ongoing debate on the additional effect concerning the exercise capacity. The purpose of this study was to compare the effects of three different exercise modalities in patients with COPD including endurance training (ET), progressive strength training (ST) and the combination of strength training and endurance training (CT). DESIGN A prospective randomized trial. METHODS Thirty-six patients with COPD were randomly allocated either to ET, ST, or CT. Muscle strength, cardiopulmonary exercise testing, lung function testing and quality of life were assessed before and after a 12-week training period. RESULTS Exercise capacity (Wmax) increased significantly in all three training groups with increase of peak oxygen uptake (VO2peak) in all three groups, reaching statistical significance in the ET group and the CT group. Muscle strength (leg press, bench press, bench pull) improved in all three training groups, with a higher improvement in the ST (+39.3%, +20.9%, +20.3%) and the CT group (+43.3%, +18.1%, +21.6%) compared to the ET group (+20.4%, +6.4%, +12.1%). CONCLUSIONS Progressive strength training alone increases not only muscle strength and quality of life, but also exercise capacity in patients with COPD, which may have implications in prescription of training modality. CLINICALTRIALS.GOV IDENTIFIER: NCT01091623.

Differences in the predictive value of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in advanced ischemic and non-ischemic heart failure

OBJECTIVE To assess the prognostic value of the pro-apoptotic, but also cell growth-inducing molecule soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) in heart failure (HF). METHODS We assayed sTWEAK levels in 351 patients with advanced HF (non-ischemic: 130, ischemic: 221). During a median follow-up of 4.9 years, 195 patients (56%) died. RESULTS sTWEAK concentrations were associated with extended survival in patients with non-ischemic (P=0.022), but not with ischemic HF (P=0.82). The inverse association in non-ischemic HF remained significant in a multivariable Cox regression model (P=0.025) with a hazard ratio of 0.40 (95% confidence interval: 0.21-0.77) comparing the third to the first tertile (P=0.007). CONCLUSION Low sTWEAK levels independently predict mortality in advanced non-ischemic HF. sTWEAK-induced proliferation of cardiomyocytes may explain its impact on suvival. The different prognostic value of sTWEAK in ischemic and non-ischemic HF may point towards distinct pathogenic pathways determining the course of disease.

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.

Time course of markers of tissue repair after ablation of atrial fibrillation and their relation to left atrial structural changes and clinical ablation outcome

BACKGROUND Radiofrequency ablation of atrial fibrillation (AF) creates left atrial (LA) tissue damage with a subsequent healing process. We sought to prospectively assess the time course of biomarkers of tissue repair after ablation and to evaluate their association with clinical variables. METHODS 30 consecutive patients (57.9 ± 1.7 yrs, 63% males) with paroxysmal AF underwent a CARTO-guided LA circumferential ablation, Lasso-guided segmental pulmonary vein isolation and ablation of complex fractionated atrial electrograms. Matrix metalloproteinase-9 (MMP-9) and transforming growth factor-β1 (TGF-β1), both key regulators of tissue repair, and the aminoterminal propeptide of type III procollagen (PIIINP), reflecting collagen synthesis, were determined in blood samples before and 6h, 1, 2, 7, 30, 90 and 180 days post-ablation. RESULTS All markers showed a significant ablation-induced up-regulation (MMP-9: 1.8 ± 0.1-fold, TGF-β1: 2.4 ± 0.4-fold, PIIINP: 1.3 ± 0.1-fold). MMP-9 was significantly up-regulated until day 90, TGF-β1 only on day 2. PIIINP increased from day 2 to 7. The area under the curve (AUC) of MMP-9 and TGF-β1 correlated with the ablation-induced reduction of LA volume (both p<0.05). The AUC of MMP-9 was additionally associated with the amount of radiofrequency energy delivered during ablation (p < 0.05). At 12 months of follow-up 57% of patients were free of AF off antiarrhythmic drugs. The AUC of PIIINP independently predicted recurrent AF (p < 0.05). CONCLUSIONS Markers of healing showed a significant up-regulation after AF ablation detectable for up to 90 days. A more pronounced up-regulation of MMP-9 or TGF-β1 is associated with a greater reduction of LA size. High PIIINP levels after ablation predict a poor ablation outcome.

Macrophage-modulating cytokines predict adverse outcome in heart failure

Cytokines regulating the mobilisation, recruitment and survival of mononuclear cells may play an important role in progression of heart failure. Therefore, we investigated the role of granulocyte colony stimulating factor (G-CSF), monocyte chemoattractant protein 1 (MCP-1) and macrophage colony stimulating factor (M-CSF) in patients with advanced heart failure. G-CSF, MCP-1 and M-CSF were determined in plasma of 351 patients with advanced heart failure by specific ELISAs. During a median follow up period of 16 months (95% confidence interval [CI]: 15-17 months) 175 patients (50%) experienced the composite endpoint rehospitalisation and all-cause mortality. M-CSF tertiles were associated with a gradually increasing risk with hazard ratios (HR) of 2.2 (95% CI: 1.5-3.2; for trend, p<0.001) for the composite endpoint and 2.6 (95% CI: 1.5-4.6; for trend, p=0.002) for all-cause mortality comparing third and first tertile. These associations remained significant in a multivariable Cox regression model after adjustment for BNP and other known risk factors (p=0.043 and p=0.024). High MCP-1 concentrations were associated with an increased risk of all-cause mortality with an adjusted HR of 1.9 (third vs. first tertile, 95% CI: 1.1-3.3; for trend, p=0.034). In contrast, G-CSF tertiles were not significantly associated with the composite endpoint or all-cause mortality in multivariable Cox regression. In conclusion, the independent and concentration-dependent association of macrophage-modulating cytokines and in particular of M-CSF with adverse outcome in advanced HF patients suggests that these cytokines may play an important pathophysiological role in progression of cardiomyopathy.

Hepatocyte growth factor is a strong predictor of mortality in patients with advanced heart failure

Objective To assess the prognostic value of the mitogenic, antiapoptotic, angiogenic and antifibrotic hepatocyte growth factor (HGF) in heart failure (HF). Design Prospective cohort study. Setting/patients Assessment of HGF levels at inclusion in 351 patients with advanced HF (median 75 years, interquartile range (IQR) 63–82, 66% male). Main outcome measures All-cause mortality, cardiovascular mortality. Results During a median follow-up of 16 months, 26% of patients died. HGF tertiles were associated with an increasing risk for all-cause mortality (p<0.001) with a hazard ratio (HR) of 3.06 (95% confidence interval (CI) 1.69 to 5.53) for the third compared with the first tertile. This association remained significant after multivariable adjustment for B-type natriuretic peptide (BNP) and other risk factors (p=0.002). Subgroup analysis revealed that HGF was a strong predictor of the secondary end point cardiovascular mortality in ischaemic HF (p=0.009) with an adjusted HR of 6.2 (95% CI 1.76 to 21.8) comparing the third with the first tertile but not in non-ischaemic HF (HR=1.47, 95% CI 0.48 to 4.49, p=0.5). Patients with high HGF but low BNP had a comparable survival rate to those with elevated BNP but low HGF (p=0.66). Of note, the dose of angiotensin converting enzyme (ACE) inhibitors inversely correlated with HGF concentrations (r=−0.25, p<0.001). Conclusions HGF is a strong and independent predictor of mortality in advanced HF and, in particular, in ischaemic HF. These results indicate that HGF with its multiple effects on myocardial function exerts an overall deleterious effect in advanced HF. HGF may be of special interest for risk prediction and tailoring of HF treatment.