Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Helmut Drexler is active.

Publication


Featured researches published by Helmut Drexler.


Circulation | 2006

Intracoronary Bone Marrow Cell Transfer After Myocardial Infarction Eighteen Months’ Follow-Up Data From the Randomized, Controlled BOOST (BOne marrOw transfer to enhance ST-elevation infarct regeneration) Trial

Gerd Peter Meyer; Kai C. Wollert; Joachim Lotz; Jan Steffens; Peter Lippolt; Stephanie Fichtner; Hartmut Hecker; Arnd Schaefer; Lubomir Arseniev; Bernd Hertenstein; Arnold Ganser; Helmut Drexler

Background— Intracoronary transfer of autologous bone marrow cells (BMCs) may enhance recovery of left ventricular (LV) function in patients after acute myocardial infarction (AMI). However, clinical studies addressing the effects of BMCs after AMI have covered only limited time frames ranging from 3 to 6 months. The critical question of whether BMC transfer can have a sustained impact on LV function remains unanswered. Methods and Results– After percutaneous coronary intervention with stent implantation (PCI) of the infarct-related artery, 60 patients were randomized 1:1 to a control group with optimal postinfarction therapy and a BMC transfer group that also received an intracoronary BMC infusion 4.8±1.3 days after PCI. Cardiac MRI was performed 3.5±1.5 days, 6±1 months, and 18±6 months after PCI. BMC transfer was not associated with adverse clinical events. In the control group, mean global LV ejection fraction increased by 0.7 and 3.1 percentage points after 6 and 18 months, respectively. LV ejection fraction in the BMC transfer group increased by 6.7 and 5.9 percentage points. The difference in LVEF improvement between groups was significant after 6 months but not after 18 months (P=0.27). The speed of LV ejection fraction recovery over the course of 18 months was significantly higher in the BMC transfer group (P=0.001). Conclusions– In this study, a single dose of intracoronary BMCs did not provide long-term benefit on LV systolic function after AMI compared with a randomized control group; however, the study suggests an acceleration of LV ejection fraction recovery after AMI by BMC therapy.


Circulation | 2002

Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) Trial Carvedilol as the Sun and Center of the β-Blocker World?

Kai C. Wollert; Helmut Drexler

Heart failure is a deadly disease that has reached epidemic proportions in industrialized countries. Patients living with heart failure carry a heavy burden in terms of morbidity. Many patients require repeated hospitalizations for cardiovascular problems, especially for episodes of worsening heart failure. In fact, heart failure is one of the most important causes of hospital admissions in the United States, accounting for over 2.5 million admissions per year. Once hospitalized, patients with heart failure have an increased risk of recurrent hospitalizations and death. Approximately 30% to 40% of patients are readmitted within 6 months of an index hospitalization. Angiotensin-converting enzyme (ACE) inhibitors, digitalis, and spironolactone decrease the risk of hospitalization in heart failure patients; however, the annual rate of hospital admission for worsening heart failure has remained high.1–3⇓⇓ See p 2194 Given these challenges, clinical trials conducted in the mid 1990s that demonstrated that β-blocker therapy in addition to ACE inhibitors and digitalis reduces the risk of hospitalization in heart failure patients by about 20% to 30% represented remarkable progress. These beneficial effects of β-blocking agents on morbidity were recognized well before favorable effects on survival were unequivocally established (Table). In some, but not all, trials, the clinical benefits of β-blocker treatment included improved heart failure symptoms as assessed by physicians and patients. View this table: Large-Scale Clinical Trials Reporting β-Blocker Effects on Heart Failure Morbidity Previous trials addressing the effects of β-blockers on morbidity have been conducted in patients …


European Heart Journal | 2009

Intracoronary bone marrow cell transfer after myocardial infarction: 5-year follow-up from the randomized-controlled BOOST trial

Gerd Peter Meyer; Kai C. Wollert; Joachim Lotz; Jens Pirr; Ulrike Rager; Peter Lippolt; Andreas Hahn; Stephanie Fichtner; Arnd Schaefer; Lubomir Arseniev; Arnold Ganser; Helmut Drexler

AIMS We assessed whether a single intracoronary infusion of autologous bone marrow cells (BMCs) can have a sustained impact on left ventricular ejection fraction (LVEF) in patients after ST-elevation myocardial infarction (STEMI). In the BOne marrOw transfer to enhance ST-elevation infarct regeneration (BOOST) trial, 60 patients with STEMI and successful percutaneous coronary intervention were randomized to a control and a cell therapy group. As previously reported, BMC transfer led to an improvement of LVEF by 6.0% at 6 months (P = 0.003) and 2.8% at 18 months (P = 0.27). METHODS AND RESULTS Left ventricular ejection fraction and clinical status were re-assessed in all surviving patients after 61 +/- 11 months. Major adverse cardiac events occurred with similar frequency in both groups. When compared with baseline, LVEF assessed by magnetic resonance imaging at 61 months decreased by 3.3 +/- 9.5% in the control group and by 2.5 +/- 11.9% in the BMC group (P = 0.30). Patients with an infarct transmurality > median appeared to benefit from BMC transfer throughout the 61-month study period (P = 0.040). CONCLUSION A single intracoronary application of BMCs does not promote a sustained improvement of LVEF in STEMI patients with relatively preserved systolic function. It is conceivable that a subgroup of patients with more transmural infarcts may derive a sustained benefit from BMC therapy. However, this needs to be tested prospectively in a randomized trial.


European Journal of Heart Failure | 2009

Inflammation as a therapeutic target in heart failure? A scientific statement from the Translational Research Committee of the Heart Failure Association of the European Society of Cardiology

Stephane Heymans; Emilio Hirsch; Stefan D. Anker; Pal Aukrust; Jean-Luc Balligand; Jan W. Cohen-Tervaert; Helmut Drexler; Gerasimos Filippatos; Stephan B. Felix; Lars Gullestad; Denise Hilfiker-Kleiner; Stefan Janssens; Roberto Latini; Gitte Neubauer; Walter J. Paulus; Burkert Pieske; Piotr Ponikowski; Blanche Schroen; Heinz-Peter Schultheiss; Carsten Tschöpe; Marc van Bilsen; Faiez Zannad; John J.V. McMurray; Ajay M. Shah

The increasing prevalence of heart failure poses enormous challenges for health care systems worldwide. Despite effective medical interventions that target neurohumoral activation, mortality and morbidity remain substantial. Evidence for inflammatory activation as an important pathway in disease progression in chronic heart failure has emerged in the last two decades. However, clinical trials of ‘anti‐inflammatory’ therapies (such as anti‐tumor necrosis factor‐α approaches) have to date failed to show benefit in heart failure patients. The Heart Failure Association of the European Society of Cardiology recently organized an expert workshop to address the issue of inflammation in heart failure from a basic science, translational and clinical perspective, and to assess whether specific inflammatory pathways may yet serve as novel therapeutic targets for this condition. This consensus document represents the outcome of the workshop and defines key research questions that still need to be addressed as well as considering the requirements for future clinical trials in this area.


Circulation | 2000

Cardioprotective Effects of the Na+/H+ Exchange Inhibitor Cariporide in Patients With Acute Anterior Myocardial Infarction Undergoing Direct PTCA

H.-J. Rupprecht; Jürgen vom Dahl; Wolfram Terres; Karl Melchior Seyfarth; Gert Richardt; Heinz-Peter Schultheiß; Michael Buerke; Florence H. Sheehan; Helmut Drexler

BACKGROUND Activation of Na(+)/H(+) exchange in myocardial ischemia and/or reperfusion leads to calcium overload and myocardial injury. Experimental studies have shown that Na(+)/H(+) exchange inhibitors can attenuate Ca(2+) influx into cardiomyocytes. We therefore performed a multicenter, randomized, placebo-controlled clinical trial to test the hypothesis that inhibition of Na(+)/H(+) exchange limits infarct size and improves myocardial function in patients with acute anterior myocardial infarction (MI) treated with direct PTCA. METHODS AND RESULTS One hundred patients were randomized to receive placebo (n=51) or a 40-mg intravenous bolus of the Na(+)/H(+) exchange inhibitor cariporide (HOE 642) (n=49) before reperfusion. Global and regional left ventricular functions were analyzed by use of paired contrast left ventriculograms performed before and 21 days after PTCA and myocardial enzymes (ie, creatine kinase ¿CK, CK-MB, and LDH) as markers for myocardial tissue injury were evaluated. At follow-up, the ejection fraction was higher (50% versus 40%; P<0.05) and the end-systolic volume was lower (69.0 versus 97.0 mL; P<0.05) in the cariporide group. Significant improvements in some indices of regional wall motion abnormalities were observed, such as the percentage of chords with hypokinesis < -2 SD (P=0.045) and the severity of hypokinesis in the border zone of the infarct region (P=0.052). In addition, CK, CK-MB, or LDH release was significantly reduced in the cariporide patients. CONCLUSIONS Our findings suggest that inhibition of Na(+)/H(+) exchange by cariporide may attenuate reperfusion injury and thereby improve the recovery from left ventricular dysfunction after MI.


Nature Protocols | 2009

Evaluation of postnatal arteriogenesis and angiogenesis in a mouse model of hind-limb ischemia

Anne Limbourg; Thomas Korff; L. Christian Napp; Wolfgang Schaper; Helmut Drexler; Florian P. Limbourg

Blood vessel growth in adult organisms involves the following two fundamental processes: angiogenesis, the proliferation and extension of capillary networks; and arteriogenesis, the growth of functional arteries. We provide a protocol for the evaluation of postnatal arteriogenesis and angiogenesis in a mouse model of hind-limb ischemia. Surgical ligation of the femoral artery at a specific site triggers arteriogenesis of small, pre-existing collateral arteries into functional conduit vessels proximally and ischemic angiogenesis distally. The vascular response to hind-limb ischemia can be readily evaluated by laser Doppler-based perfusion measurements, histological quantification of arteriogenesis and angiogenesis or whole-mount visualization of arteries in limb muscles. Depending on the experimental design, the protocol takes between 4 and 29 d to complete; however, the net working time is about 2 d per mouse. The concurrent and specific analysis of postnatal angiogenesis and arteriogenesis in the same animal is a unique feature of the protocol.


Circulation | 2010

Serial Measurement of Growth-Differentiation Factor-15 in Heart Failure Relation to Disease Severity and Prognosis in the Valsartan Heart Failure Trial

Inder S. Anand; Tibor Kempf; Thomas S. Rector; Heike Tapken; Tim Allhoff; Franziska Jantzen; Michael A. Kuskowski; Jay N. Cohn; Helmut Drexler; Kai C. Wollert

Background— Growth-differentiation factor-15 (GDF-15) is emerging as a prognostic biomarker in patients with coronary artery disease. Little is known about GDF-15 as a biomarker in patients with heart failure. Methods and Results— The circulating concentration of GDF-15 was measured at baseline (n=1734) and at 12 months (n=1517) in patients randomized in the Valsartan Heart Failure Trial (Val-HeFT). GDF-15 levels at baseline ranged from 259 to 25 637 ng/L and were abnormally high (>1200 ng/L) in 85% of patients. Higher levels were associated with features of worse heart failure and biomarkers of neurohormonal activation, inflammation, myocyte injury, and renal dysfunction. Baseline GDF-15 levels (per 100 ng/L) were associated with the risks of mortality (hazard ratio, 1.017; 95% confidence interval, 1.014 to 1.019; P<0.001) and first morbid event (hazard ratio, 1.020; 95% confidence interval, 1.017 to 1.023; P<0.001). In a comprehensive multiple-variable Cox regression model that included clinical prognostic variables, B-type natriuretic peptide, high-sensitivity C-reactive protein, and high-sensitivity troponin T, GDF-15 remained independently associated with mortality (hazard ratio, 1.007; 95% confidence interval, 1.001 to 1.014; P=0.02) but not first morbid event. At 12 months, the GDF-15 levels had increased by a similar amount in the placebo and valsartan groups (P=0.94). Increases in GDF-15 over 12 months were independently associated with the risks of future mortality and first morbid event also after adjustment for clinical prognostic variables, B-type natriuretic peptide, high-sensitivity C-reactive protein, and high-sensitivity troponin T and their changes. Conclusions— GDF-15 reflects information from several pathological pathways and provides independent prognostic information in heart failure. GDF-15 levels increase over time, suggesting that GDF-15 reflects a pathophysiological axis that is not completely addressed by the therapies prescribed in Val-HeFT.Background— Growth-differentiation factor-15 (GDF-15) is emerging as a prognostic biomarker in patients with coronary artery disease. Little is known about GDF-15 as a biomarker in patients with heart failure. Methods and Results— The circulating concentration of GDF-15 was measured at baseline (n=1734) and at 12 months (n=1517) in patients randomized in the Valsartan Heart Failure Trial (Val-HeFT). GDF-15 levels at baseline ranged from 259 to 25 637 ng/L and were abnormally high (>1200 ng/L) in 85% of patients. Higher levels were associated with features of worse heart failure and biomarkers of neurohormonal activation, inflammation, myocyte injury, and renal dysfunction. Baseline GDF-15 levels (per 100 ng/L) were associated with the risks of mortality (hazard ratio, 1.017; 95% confidence interval, 1.014 to 1.019; P <0.001) and first morbid event (hazard ratio, 1.020; 95% confidence interval, 1.017 to 1.023; P <0.001). In a comprehensive multiple-variable Cox regression model that included clinical prognostic variables, B-type natriuretic peptide, high-sensitivity C-reactive protein, and high-sensitivity troponin T, GDF-15 remained independently associated with mortality (hazard ratio, 1.007; 95% confidence interval, 1.001 to 1.014; P =0.02) but not first morbid event. At 12 months, the GDF-15 levels had increased by a similar amount in the placebo and valsartan groups ( P =0.94). Increases in GDF-15 over 12 months were independently associated with the risks of future mortality and first morbid event also after adjustment for clinical prognostic variables, B-type natriuretic peptide, high-sensitivity C-reactive protein, and high-sensitivity troponin T and their changes. Conclusions— GDF-15 reflects information from several pathological pathways and provides independent prognostic information in heart failure. GDF-15 levels increase over time, suggesting that GDF-15 reflects a pathophysiological axis that is not completely addressed by the therapies prescribed in Val-HeFT. # Clinical Perspective {#article-title-40}


European Heart Journal | 2008

Bone marrow cells are a rich source of growth factors and cytokines: implications for cell therapy trials after myocardial infarction

Mortimer Korf-Klingebiel; Tibor Kempf; Thomas Sauer; Eva Brinkmann; Philipp Fischer; Gerd Peter Meyer; Arnold Ganser; Helmut Drexler; Kai C. Wollert

AIMS Results from clinical trials suggest that cardiac function after acute myocardial infarction (AMI) can be enhanced by an intracoronary infusion of autologous unselected nucleated bone marrow cells (BMCs). Release of paracrine factors has been proposed as a mechanism for these therapeutic effects; however, this hypothesis has not been tested in humans. METHODS AND RESULTS BMCs and peripheral blood leucocytes (PBLs) were obtained from 15 patients with AMI and cultured in serum-free medium to obtain conditioned supernatants (SN). BMC-SN stimulated human coronary artery endothelial cell proliferation, migration, and tube formation, and induced cell sprouting in a mouse aortic ring assay. Moreover, BMC-SN protected rat cardiomyocytes from cell death induced by simulated ischaemia or ischaemia followed by reperfusion. While PBL-SN promoted similar effects on endothelial cells and cardiomyocytes, BMC-SN and PBL-SN in combination promoted synergistic effects. As shown by ProteinChip and GeneChip array analyses (each performed in triplicate), BMCs and PBLs expressed distinct patterns of pro-angiogenic and cytoprotective secreted factors. CONCLUSION Our data support the paracrine hypothesis and suggest that characterization of the BMC secretome may lead to an identification of factors with therapeutic potential after AMI.


Heart Rhythm | 2008

Efficacy of pulmonary vein isolation by cryoballoon ablation in patients with paroxysmal atrial fibrillation.

Gunnar Klein; Hanno Oswald; Ajmal Gardiwal; Ulrich Lüsebrink; Christoph Lissel; Hong Yu; Helmut Drexler

BACKGROUND Radiofrequency ablation of pulmonary veins (PVs) has emerged as an effective treatment for patients with paroxysmal atrial fibrillation (AF). However, serious complications raise concern about an even wider application. In terms of safety, cryoenergy has advantages compared with radiofrequency. A new cryoenergy balloon catheter has been recently developed to make AF ablation shorter and safer. OBJECTIVE The purpose of this study was to test the 6-month efficacy of this new device for ablation of paroxysmal AF. METHODS Twenty-one patients with highly symptomatic paroxysmal AF, normal left atrial size, and frequent episodes of AF were included. All PVs were targeted during cryoballoon ablation. Patients received 24-hour Holter electrocardiograms (ECGs) and event recorder during follow-up after 1, 3, and 6 months. RESULTS A total of 81 (95%) of 85 PVs could be completely isolated with a single-balloon technique. Procedure time was 165 +/- 35 minutes, and fluoroscopy time was 39 +/- 9 minutes. After 6 months, 86% of the patients were free of symptomatic AF. In two of three patients with recurrence of AF, complete PV isolation has not been achieved initially. After a second procedure (1.04 procedures per patient), 90% of the patients were free of symptomatic AF. Three phrenic nerve palsies occurred during ablation of the right superior PV; two completely resolved after 6 and 9 months, and one is still persisting after 2 months. CONCLUSION This is the first study that reports the results of the new cryoballoon AF ablation approach showing 86% freedom from AF recurrence after 6 months. Cryoballoon PV ablation promises to be effective for patients with paroxysmal AF and normally sized left atria.


Circulation | 2003

Alterations in Janus kinase (JAK)-signal transducers and activators of transcription (STAT) signaling in patients with end-stage dilated cardiomyopathy.

Edith Podewski; Denise Hilfiker-Kleiner; Andres Hilfiker; Henning Morawietz; Artur Lichtenberg; Kai C. Wollert; Helmut Drexler

Background—Experimental studies indicate that interleukin-6 (IL-6)–related cytokines, signaling via the shared receptor gp130, Janus kinases (JAKs), and signal transducers and activators of transcription (STATs), provide a critical cardiomyocyte survival pathway in vivo. Little is known about the activation of this signaling pathway in the myocardia of patients with end-stage dilated cardiomyopathy (DCM). Methods and Results—We performed a comprehensive expression and activation analysis of IL-6–related cytokines, receptors, signal transducers, and signal transduction inhibitors in left ventricular (LV) myocardia from patients with DCM (n=10) and non-failing (NF) donor hearts (n=5). Differential expression (DCM versus NF) was observed by immunoblotting at each level of the signaling cascade, including receptor ligands (IL-6: −59%, P <0.01; leukemia inhibitory factor [LIF]: +54%, P <0.05), receptor subunits (LIF receptor: −16%, P <0.05), signaling molecules (the Janus kinase TYK2: −48%, P <0.01; STAT3: −47%, P <0.01), and suppressors of cytokine signaling (SOCS1: +97%, P <0.05; SOCS3: −49%, P <0.01). Tyrosine-phosphorylation status of gp130 was increased (+60%, P <0.05), whereas tyrosine-phosphorylation status of JAK2 was reduced in DCM (−72%, P <0.01). Moreover, as shown by immunohistochemistry, the number of STAT3-positive cardiomyocytes was reduced in DCM (−42%, P <0.01). Conclusion—Signaling via gp130 and JAK-STAT is profoundly altered in DCM. Importantly, tyrosine-phosphorylation of JAK2 is reduced in the face of increased gp130 phosphorylation, indicating impaired downstream activation of this critical pathway in DCM.

Collaboration


Dive into the Helmut Drexler's collaboration.

Top Co-Authors

Avatar

Kai C. Wollert

Uppsala University Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Gunnar Klein

Hannover Medical School

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge