Evgenij Potapov - Academia.edu (original) (raw)

Papers by Evgenij Potapov

Research paper thumbnail of long-term VAD support Clinical significance of PlA polymorphism of platelet GP IIb/IIIa receptors during

Research paper thumbnail of Clinical Significance of PlA Polymorphism of Platelet GP IIb/IIIa Receptors During Long-Term VAD Support

Although bleeding and thromboembolism remain major complications after implantation of ventricula... more Although bleeding and thromboembolism remain major complications after implantation of ventricular assist devices (VADs), no standard anticoagulation protocols are available. Genetic polymorphism of platelet glycoprotein IIb/IIIa may contribute to the development of complications. The present study demonstrates a relationship between the PlA genotype and postoperative complications in patients implanted with pulsatile and axial flow VADs. The PlA genotype was determined in 41 consecutive patients treated with a VAD who received anticoagulation with phenprocoumon and aspirin. Pulsatile Novacor (Novacor Corp, Oakland, CA) and Berlin Heart VADs (Berlin Heart, Berlin, Germany) were implanted in 28 patients and the axial flow MicroMed DeBakey VAD (MicroMed Technology, Inc, Houston, TX) in 13. The relationship between the PlA genotype, the anticoagulation regime, and bleeding and thromboembolic events was analyzed. There were no differences between patients with the A1A1 and A1A2 genotype regarding demographic characteristics, weight, or infection episodes. The international normalized ratio (INR), platelet activation tests, and doses of aspirin and dipyridamol before events were similar in both groups. Patients with the A1A1 genotype developed more bleeding complications (39% vs 0%, p = 0.021), while patients with the A1A2 genotype showed a tendency toward more thromboembolic events (13% vs 30%, p = 0.33). With regard to different types of VAD, patients with the axial flow DeBakey VAD and the A1A1 genotype developed significantly more bleeding complications (70% vs 0%, p = 0.033). In patients with a long-term VAD determination of PlA polymorphism and subsequent adjustment of the anticoagulation regime may lead to a reduction of bleeding and thromboembolic complications.

Research paper thumbnail of Höhere Überlebensrate nach mechanischer Kreislaufunterstützung mittels eines pneumatischen, pulsatilen Unterstützungssystems bei Säuglingen und Kindern

Zeitschrift für Herz-,Thorax- und Gefäßchirurgie, 2005

und -überwachung signifikante Verbesserungen bei Überlebensrate und Möglichkeit zur Entlassung na... more und -überwachung signifikante Verbesserungen bei Überlebensrate und Möglichkeit zur Entlassung nach Hause erreicht werden.

Research paper thumbnail of LONG-TERM RESULTS OF HEART TRANSPLANTATION USING DONORS OVER 63 YEARS OF AGE

Research paper thumbnail of Ventricular assist device and mechanical circulatory support for children

Current Opinion in Organ Transplantation, 2007

ABSTRACT Purpose of review: There is a growing need for ventricular assist devices in children. T... more ABSTRACT Purpose of review: There is a growing need for ventricular assist devices in children. These systems have gained wide acceptance as a bridge to heart transplantation and, in some patients, to be explanted following myocardial recovery. We review studies investigating the role of pediatric ventricular assist devices. Recent findings: Use of ventricular assist devices supporting the failing heart is now routine in adults, and is being adopted in children. In Europe, only two ventricular assist devices designed for all age groups of children have been approved for commercial use. These devices are extracorporeal and pneumatically driven. In the USA, Food and Drug Administration approval is pending. Modifications of cannula design, use of heparin-coated blood pumps, individualized anticoagulation treatment and monitoring and earlier implantation have led to a significant increase in survival and discharge rate. In addition, for short-term support and expected rapid recovery, extracorporeal membrane oxygenation and centrifugal pumps continue to be applied. Summary: In children severe with heart failure, implantation of ventricular assist devices allows bridging to heart transplantation, or may lead to myocardial recovery enabling device explantation. Ventricular assist devices specifically designed for children also offer long-term support in infants previously only eligible for extracorporeal membrane oxygenation.

Research paper thumbnail of The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): first annual report†

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 27, 2015

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS) was founded on ... more The European Registry for Patients with Mechanical Circulatory Support (EUROMACS) was founded on 10 December 2009 with the initiative of Roland Hetzer (Deutsches Herzzentrum Berlin, Berlin, Germany) and Jan Gummert (Herz- und Diabeteszentrum Nordrhein-Westfalen, Bad Oeynhausen, Germany) with 15 other founding international members. It aims to promote scientific research to improve care of end-stage heart failure patients with ventricular assist device or a total artificial heart as long-term mechanical circulatory support. Likewise, the organization aims to provide and maintain a registry of device implantation data and long-term follow-up of patients with mechanical circulatory support. Hence, EUROMACS affiliated itself with Dendrite Clinical Systems Ltd to offer its members a software tool that allows input and analysis of patient clinical data on a daily basis. EUROMACS facilitates further scientific studies by offering research groups access to any available data wherein patient...

Research paper thumbnail of Concomitant surgery during ventricular assist device implantation

Annals of cardiothoracic surgery, 2014

Research paper thumbnail of Anticoagulation assessment

Annals of cardiothoracic surgery, 2014

Research paper thumbnail of Different surgical strategies for implantation of continuous-flow VADs-Experience from Deutsches Herzzentrum Berlin

Annals of cardiothoracic surgery, 2014

This manuscript summarizes our surgical experience with the implantation of recent continuous-flo... more This manuscript summarizes our surgical experience with the implantation of recent continuous-flow left ventricular assist devices (LVADs), with special emphasis on the HeartWare HVAD pump. THE HEARTWARE HVAD IS, IN OUR EXPERIENCE CURRENTLY IMPLANTED IN FOUR DIFFERENT TECHNIQUES: (I) "Classical" LVAD implantation with heart-lung machine and median sternotomy; (II) "Minimally-invasive" implantation without sternotomy and without heart-lung machine; (III) "Lateral implantation" to the descending aorta; (IV) Using two continuous-flow LVADs for implantable biventricular support. Five-hundred and four HeartWare HVADs have been implanted using the described techniques in our institution up to now. The HeartWare HVAD is a versatile device. It has been found to be eminently suited to these four different modes of implantation.

Research paper thumbnail of Minimally invasive continuous-flow left ventricular assist device implantation: Avoiding a median sternotomy

The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation, 2014

Research paper thumbnail of A promoter polymorphism -945C>G in the connective tissue growth factor in heart failure patients with mechanical circulatory support: a new marker for bridge to recovery?

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, 2015

Mechanical circulatory support (MCS) creates improvement of cardiac function in a small portion o... more Mechanical circulatory support (MCS) creates improvement of cardiac function in a small portion of patients with idiopathic dilated cardiomyopathy (iDCM). Among other factors, cardiomyocyte hypertrophy seems to represent an important prerequisite for MCS-related cardiac recovery. We have previously shown that connective tissue growth factor (CTGF) leads to adaptive cardiomyocyte hypertrophy associated with a protective cardiac function in transgenic mice. To test whether a functional genetic variant in the CTGF promoter impacts MCS-related cardiac recovery, three groups of iDCM patients with and without cardiac recovery on MCS were genotyped. The CTGF promoter variant (c.-945C>G) was analysed in 314 patients with iDCM receiving medical treatment only (Group I). Forty-nine iDCM patients who were either weaned from MCS for more than 6 months (Group II; n = 20) or bridged to cardiac transplantation (Group III: n = 29) were also genotyped. Patients on MCS were followed up for at leas...

Research paper thumbnail of Design changes in continuous-flow left ventricular assist devices and life-threatening pump malfunctions

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 10, 2014

The implantable continuous-flow left ventricular assist devices (LVADs) HeartMate II (HM II) and ... more The implantable continuous-flow left ventricular assist devices (LVADs) HeartMate II (HM II) and HeartWare HVAD (HW) underwent design modifications. The impact of these changes on life-threatening pump malfunctions was evaluated. We retrospectively analysed pump malfunctions due to thrombosis or cable damage in patients supported with primarily implanted HM II (n = 191) and HW (n = 347), separated into patients supported with the old and new pump designs. In 2010, the cable strain relief of the HM II device was improved (132 patients with old and 79 with new) and sealed grafts were introduced (68 patients with sealed inflow connector and outflow graft and 125 without). In 2011, titanium sintering of the inflow cannula of HW pumps was introduced (137 patients with a non-sintered and 210 with a sintered inflow cannula). The median support time was 1.12 (0-6.1) years for all HM II and 0.59 (0-4.2) years for all HW patients. The cumulative rate of events per patient-year (EPPY) was 0.11...

Research paper thumbnail of Reimplantation of left ventricular assist device late after weaning of device using a titanium plug

The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation, 2014

Research paper thumbnail of Mechanical Cardiac Support in the Young With the Berlin Heart EXCOR Pulsatile Ventricular Assist Device: 15 Years’ Experience

Seminars in Thoracic and Cardiovascular Surgery: Pediatric Cardiac Surgery Annual, 2006

Research paper thumbnail of Impact of body mass index on outcome after implantation of ventricular assist devices

The Thoracic and Cardiovascular Surgeon, 2008

Research paper thumbnail of First experiences with a novel magnetically suspended axial flow left ventricular assist device

Axial flow pumps have gained increased acceptance since their first clinical use in 1998. The pre... more Axial flow pumps have gained increased acceptance since their first clinical use in 1998. The present report summarizes the clinical experience with patients treated for severe cardiogenic shock for the first time with a newly developed axial flow pump with magnetically levitated bearings. Material and methods: The axial flow pump Incor was implanted in 24 patients between June 2002 and

Research paper thumbnail of VALUE OF CARDIAC TROPONIN I AND T FOR SELECTION OF HEART DONORS AND AS PREDICTORS OF EARLY GRAFT FAILURE 1

Transplantation, 2001

Cardiac troponin I and T (cTnI and cTnT) are sensitive and specific markers of myocardial damage.... more Cardiac troponin I and T (cTnI and cTnT) are sensitive and specific markers of myocardial damage. We evaluated them for the selection of heart donors and as predictors of early graft failure after heart transplantation. cTnI, cTnT, myoglobin, and creatine kinase (CK) levels and its isoenzyme MB (CKMB) activity and mass were measured in serum samples immediately before opening the pericardium from 126 consecutive brain-dead multi-organ donors over 10 years of age inspected by our harvesting team. Donors with serum creatinine >2.0 mg/dL (n=6) were excluded from the analysis. Donors for high-urgency status recipients (n=2) were also excluded. The remaining donors were retrospectively divided into three groups: group I (n=68), grafts with good function; group II (n=11), grafts with impaired function; and group III (n=39), grafts not accepted for transplantation. No differences in donor and recipient characteristics were found among the groups. The mean values of cTnI (0.36+/-0.88 microg/L, 4.45+/-3.28 microg/L, and 3.02+/-7.88 micog/L, respectively) and cTnT (0.016+/-0.029 microg/L, 0.134+/-0.114 microg/L, and 0.123+/-0.245 microg/L, respectively) were lower in group I when compared with groups II or III (cTnI: P<0.0001, P=0.018; cTnT: P<0.0001, P=0.012). The cTnI value was higher in group II compared with group III (P=0.023). The cTnT values were similar in groups II and III. A cTnI value >1.6 microg/L as a predictor of early graft failure had a specificity of 94%, and a cTnT value of >0.1 microg/L had a specificity of 99%. The odds ratio for the development of acute graft failure after heart transplantation was 42.7 for donors with cTnI >1.6 microg/L and 56.9 for donors with cTnT >0.1 microg/L. No differences of myoglobin, CKMB activity, or CKMB/CK ratio were found among the groups. Significantly higher cTnI and cTnT values were found in peripheral blood at the time of explantation in donors of hearts with subsequently impaired graft function and in not accepted donors. cTnI and cTnT are useful as additional parameters for heart donor selection.

Research paper thumbnail of EFFECT OF ACUTE BRAIN DEATH ON RELEASE OF ATRIUM AND B-TYPE NATRIURETIC PEPTIDES IN AN ANIMAL MODEL

Transplantation, 2004

Atrium and B-type natriuretic peptides (ANP and BNP) and big endothelin (ET)-1 are markers for se... more Atrium and B-type natriuretic peptides (ANP and BNP) and big endothelin (ET)-1 are markers for severity of heart failure and may be used in the quality assessment of donor hearts. Elevated cardiac troponins predict early graft failure after heart transplantation. This study evaluated the effects of acute brain death (BD) on the release of ANP, BNP, big ET-1, and cardiac troponins in an animal model. Pigs were randomized into a BD group (n=5) and a control group (n=5). In the first group, acute BD was induced, and anesthesia was stopped. In the control animals, a sham operation was performed, and anesthesia was continued. Parameters were measured at baseline and for 13 hours postoperatively. After acute BD, there were significant hemodynamic changes. In the control group, the BNP level was higher than in the BD group and decreased over time (P =0.016). There was no significant change in BNP release in the BD group up to 13 hours (P =0.1). ANP release remained stable over time in the control group (P =0.35) but decreased in the BD group (P =0.043). The big ET-1 levels were not different between groups. Cardiac troponin I was elevated in the BD group 5 hours after BD (P< 0.05) but remained under 1.5 mg/L throughout the study. Acute BD did not lead to an increase of BNP and ANP levels. Moreover, intact brain function seems to augment the release of natriuretic peptides from the myocardium. Further clinical evaluation of prognostic values of natriuretic peptides for the assessment of donor hearts is necessary. Cardiac troponins are a useful additional tool in the evaluation of donor hearts.

Research paper thumbnail of MEDIUM-TERM RESULTS OF HEART TRANSPLANTATION USING DONORS OVER 63 YEARS OF AGE1

Transplantation, 1999

The continual shortage of hearts for transplantation (HTx) led to the expansion of the donor pool... more The continual shortage of hearts for transplantation (HTx) led to the expansion of the donor pool by accepting older donors. We compared the medium-term follow-up of patients after HTx with older hearts (over the age of 63 years) with those of patients after HTx with younger hearts. Since April 1994 we have used hearts for HTx from donors older than the age of 63 years. Until November 1998, 309 HTx and 9 re-HTx were performed in 309 adults with a mean age of 50.7+/-10.9 years (range 17-68 years). There were 252 men and 57 women. The patients were divided into two groups: group I--donor age under 63 years (296 patients, mean age 50.4+/-11 years; mean donor age 38.1+/-13 years; mean follow-up 1.7+/-1.6 years); group II-donor age of more than 63 years (13 patients, mean age 57.4+/-5.6 years; mean donor age 65.1+/-2.1; mean follow-up 2.2+/-1.6 years). There were no differences in the etiology of heart failure, gender, or ischemia time between the groups. The patients in group II were significantly older (P = 0.008). Multiple factors were analyzed in the groups, which included changes in the left/right ventricle ejection fraction, early postoperative mortality (up to 30 days), cumulative survival rates and cardiac-dependent morbidity [myocardial infarction, malignant arrhythmias, coronary stenosis (>50% in one of the main coronary arteries) and transplant vasculopathy]. Additionally, freedom from cytomegalovirus infection (rise of titer or seroconversion) and freedom of acute rejection episodes grade > or =2 (International Society of Heart & Lung Transplantation [ISHLT]) were analyzed. After 1 year mean left and right ventricle ejection fraction were good in both groups and did not significantly change for up to 2 years. No Re-HTx was performed in group II. The early postoperative mortality was similar in both groups (P = 0.8). Also, the cumulative survival rates were similar in both groups (P = 0.87). Long-term cardiac morbidity was lower in group I (P = 0.03). The long-term freedom from cytomegalovirus infection in group I was significantly higher when compared with group II (P = 0.0002). The long-term freedom from severe rejection episodes was similar in both groups (P = 0.3) The study found a significant increase in long-term cardiac morbidity due to more focal coronary stenosis in group II, and freedom from cytomegalovirus infection, but did not find significant differences in the long-term survival between patients who received hearts from donors of up to 63 years of age and from those more than 63 years. The acceptance of donors older than 63 years old for HTx does not worsen the outcome of the recipients. The careful selection of older donors, with close monitoring of the coronary situation after HTx and expanded indications for revascularization of older hearts, could make HTx with older hearts, even in older recipients, a safe option.

Research paper thumbnail of Tissue-Engineering Bioreactors: A New Combined Cell-Seeding and Perfusion System for Vascular Tissue Engineering

Tissue Engineering, 2002

One approach to the tissue engineering of vascular structures is to develop in vitro conditions i... more One approach to the tissue engineering of vascular structures is to develop in vitro conditions in order ultimately to fabricate functional vascular tissues before final implantation. In our experiment, we aimed to develop a new combined cell seeding and perfusion system that provides sterile conditions during cell seeding and biomechanical stimuli in order to fabricate autologous human vascular tissue in vitro. The cell seeding and perfusion system is made of Plexiglas and is completely transparent (Berlin Heart, Berlin, Germany; University Hospital Benjamin Franklin, Berlin, Germany). The whole system consists of a cell seeding chamber that can be incorporated into the perfusion system and an air-driven respirator pump connected to the bioreactor. The cell culture medium continuously circulates through a closed-loop system. We thus developed a cell seeding device for static and dynamic seeding of vascular cells onto a polymeric vascular scaffold and a closed-loop perfused bioreactor for long-term vascular conditioning. The cell seeding chamber can be easily connected to the bioreactor, which combines continuous, pulsatile perfusion and mechanical stimulation to the tissue-engineered conduit. Adjusting the stroke volume, the stroke rate, and the inspiration/expiration time of the ventilator allows various pulsatile flows and different levels of pressure. The whole system is a highly isolated cell culture setting, which provides a high level of sterility and a gas supply and fits into a standard humidified incubator. The device can be sterilized by ethylene oxide and assembled with a standard screwdriver. Our newly developed combination of a cell seeding and conditioning device provides sterile conditions and biodynamic stimuli for controlled tissue development and in vitro conditioning of an autologous tissue-engineered vessel.

Research paper thumbnail of long-term VAD support Clinical significance of PlA polymorphism of platelet GP IIb/IIIa receptors during

Research paper thumbnail of Clinical Significance of PlA Polymorphism of Platelet GP IIb/IIIa Receptors During Long-Term VAD Support

Although bleeding and thromboembolism remain major complications after implantation of ventricula... more Although bleeding and thromboembolism remain major complications after implantation of ventricular assist devices (VADs), no standard anticoagulation protocols are available. Genetic polymorphism of platelet glycoprotein IIb/IIIa may contribute to the development of complications. The present study demonstrates a relationship between the PlA genotype and postoperative complications in patients implanted with pulsatile and axial flow VADs. The PlA genotype was determined in 41 consecutive patients treated with a VAD who received anticoagulation with phenprocoumon and aspirin. Pulsatile Novacor (Novacor Corp, Oakland, CA) and Berlin Heart VADs (Berlin Heart, Berlin, Germany) were implanted in 28 patients and the axial flow MicroMed DeBakey VAD (MicroMed Technology, Inc, Houston, TX) in 13. The relationship between the PlA genotype, the anticoagulation regime, and bleeding and thromboembolic events was analyzed. There were no differences between patients with the A1A1 and A1A2 genotype regarding demographic characteristics, weight, or infection episodes. The international normalized ratio (INR), platelet activation tests, and doses of aspirin and dipyridamol before events were similar in both groups. Patients with the A1A1 genotype developed more bleeding complications (39% vs 0%, p = 0.021), while patients with the A1A2 genotype showed a tendency toward more thromboembolic events (13% vs 30%, p = 0.33). With regard to different types of VAD, patients with the axial flow DeBakey VAD and the A1A1 genotype developed significantly more bleeding complications (70% vs 0%, p = 0.033). In patients with a long-term VAD determination of PlA polymorphism and subsequent adjustment of the anticoagulation regime may lead to a reduction of bleeding and thromboembolic complications.

Research paper thumbnail of Höhere Überlebensrate nach mechanischer Kreislaufunterstützung mittels eines pneumatischen, pulsatilen Unterstützungssystems bei Säuglingen und Kindern

Zeitschrift für Herz-,Thorax- und Gefäßchirurgie, 2005

und -überwachung signifikante Verbesserungen bei Überlebensrate und Möglichkeit zur Entlassung na... more und -überwachung signifikante Verbesserungen bei Überlebensrate und Möglichkeit zur Entlassung nach Hause erreicht werden.

Research paper thumbnail of LONG-TERM RESULTS OF HEART TRANSPLANTATION USING DONORS OVER 63 YEARS OF AGE

Research paper thumbnail of Ventricular assist device and mechanical circulatory support for children

Current Opinion in Organ Transplantation, 2007

ABSTRACT Purpose of review: There is a growing need for ventricular assist devices in children. T... more ABSTRACT Purpose of review: There is a growing need for ventricular assist devices in children. These systems have gained wide acceptance as a bridge to heart transplantation and, in some patients, to be explanted following myocardial recovery. We review studies investigating the role of pediatric ventricular assist devices. Recent findings: Use of ventricular assist devices supporting the failing heart is now routine in adults, and is being adopted in children. In Europe, only two ventricular assist devices designed for all age groups of children have been approved for commercial use. These devices are extracorporeal and pneumatically driven. In the USA, Food and Drug Administration approval is pending. Modifications of cannula design, use of heparin-coated blood pumps, individualized anticoagulation treatment and monitoring and earlier implantation have led to a significant increase in survival and discharge rate. In addition, for short-term support and expected rapid recovery, extracorporeal membrane oxygenation and centrifugal pumps continue to be applied. Summary: In children severe with heart failure, implantation of ventricular assist devices allows bridging to heart transplantation, or may lead to myocardial recovery enabling device explantation. Ventricular assist devices specifically designed for children also offer long-term support in infants previously only eligible for extracorporeal membrane oxygenation.

Research paper thumbnail of The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): first annual report†

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 27, 2015

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS) was founded on ... more The European Registry for Patients with Mechanical Circulatory Support (EUROMACS) was founded on 10 December 2009 with the initiative of Roland Hetzer (Deutsches Herzzentrum Berlin, Berlin, Germany) and Jan Gummert (Herz- und Diabeteszentrum Nordrhein-Westfalen, Bad Oeynhausen, Germany) with 15 other founding international members. It aims to promote scientific research to improve care of end-stage heart failure patients with ventricular assist device or a total artificial heart as long-term mechanical circulatory support. Likewise, the organization aims to provide and maintain a registry of device implantation data and long-term follow-up of patients with mechanical circulatory support. Hence, EUROMACS affiliated itself with Dendrite Clinical Systems Ltd to offer its members a software tool that allows input and analysis of patient clinical data on a daily basis. EUROMACS facilitates further scientific studies by offering research groups access to any available data wherein patient...

Research paper thumbnail of Concomitant surgery during ventricular assist device implantation

Annals of cardiothoracic surgery, 2014

Research paper thumbnail of Anticoagulation assessment

Annals of cardiothoracic surgery, 2014

Research paper thumbnail of Different surgical strategies for implantation of continuous-flow VADs-Experience from Deutsches Herzzentrum Berlin

Annals of cardiothoracic surgery, 2014

This manuscript summarizes our surgical experience with the implantation of recent continuous-flo... more This manuscript summarizes our surgical experience with the implantation of recent continuous-flow left ventricular assist devices (LVADs), with special emphasis on the HeartWare HVAD pump. THE HEARTWARE HVAD IS, IN OUR EXPERIENCE CURRENTLY IMPLANTED IN FOUR DIFFERENT TECHNIQUES: (I) "Classical" LVAD implantation with heart-lung machine and median sternotomy; (II) "Minimally-invasive" implantation without sternotomy and without heart-lung machine; (III) "Lateral implantation" to the descending aorta; (IV) Using two continuous-flow LVADs for implantable biventricular support. Five-hundred and four HeartWare HVADs have been implanted using the described techniques in our institution up to now. The HeartWare HVAD is a versatile device. It has been found to be eminently suited to these four different modes of implantation.

Research paper thumbnail of Minimally invasive continuous-flow left ventricular assist device implantation: Avoiding a median sternotomy

The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation, 2014

Research paper thumbnail of A promoter polymorphism -945C>G in the connective tissue growth factor in heart failure patients with mechanical circulatory support: a new marker for bridge to recovery?

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, 2015

Mechanical circulatory support (MCS) creates improvement of cardiac function in a small portion o... more Mechanical circulatory support (MCS) creates improvement of cardiac function in a small portion of patients with idiopathic dilated cardiomyopathy (iDCM). Among other factors, cardiomyocyte hypertrophy seems to represent an important prerequisite for MCS-related cardiac recovery. We have previously shown that connective tissue growth factor (CTGF) leads to adaptive cardiomyocyte hypertrophy associated with a protective cardiac function in transgenic mice. To test whether a functional genetic variant in the CTGF promoter impacts MCS-related cardiac recovery, three groups of iDCM patients with and without cardiac recovery on MCS were genotyped. The CTGF promoter variant (c.-945C>G) was analysed in 314 patients with iDCM receiving medical treatment only (Group I). Forty-nine iDCM patients who were either weaned from MCS for more than 6 months (Group II; n = 20) or bridged to cardiac transplantation (Group III: n = 29) were also genotyped. Patients on MCS were followed up for at leas...

Research paper thumbnail of Design changes in continuous-flow left ventricular assist devices and life-threatening pump malfunctions

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 10, 2014

The implantable continuous-flow left ventricular assist devices (LVADs) HeartMate II (HM II) and ... more The implantable continuous-flow left ventricular assist devices (LVADs) HeartMate II (HM II) and HeartWare HVAD (HW) underwent design modifications. The impact of these changes on life-threatening pump malfunctions was evaluated. We retrospectively analysed pump malfunctions due to thrombosis or cable damage in patients supported with primarily implanted HM II (n = 191) and HW (n = 347), separated into patients supported with the old and new pump designs. In 2010, the cable strain relief of the HM II device was improved (132 patients with old and 79 with new) and sealed grafts were introduced (68 patients with sealed inflow connector and outflow graft and 125 without). In 2011, titanium sintering of the inflow cannula of HW pumps was introduced (137 patients with a non-sintered and 210 with a sintered inflow cannula). The median support time was 1.12 (0-6.1) years for all HM II and 0.59 (0-4.2) years for all HW patients. The cumulative rate of events per patient-year (EPPY) was 0.11...

Research paper thumbnail of Reimplantation of left ventricular assist device late after weaning of device using a titanium plug

The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation, 2014

Research paper thumbnail of Mechanical Cardiac Support in the Young With the Berlin Heart EXCOR Pulsatile Ventricular Assist Device: 15 Years’ Experience

Seminars in Thoracic and Cardiovascular Surgery: Pediatric Cardiac Surgery Annual, 2006

Research paper thumbnail of Impact of body mass index on outcome after implantation of ventricular assist devices

The Thoracic and Cardiovascular Surgeon, 2008

Research paper thumbnail of First experiences with a novel magnetically suspended axial flow left ventricular assist device

Axial flow pumps have gained increased acceptance since their first clinical use in 1998. The pre... more Axial flow pumps have gained increased acceptance since their first clinical use in 1998. The present report summarizes the clinical experience with patients treated for severe cardiogenic shock for the first time with a newly developed axial flow pump with magnetically levitated bearings. Material and methods: The axial flow pump Incor was implanted in 24 patients between June 2002 and

Research paper thumbnail of VALUE OF CARDIAC TROPONIN I AND T FOR SELECTION OF HEART DONORS AND AS PREDICTORS OF EARLY GRAFT FAILURE 1

Transplantation, 2001

Cardiac troponin I and T (cTnI and cTnT) are sensitive and specific markers of myocardial damage.... more Cardiac troponin I and T (cTnI and cTnT) are sensitive and specific markers of myocardial damage. We evaluated them for the selection of heart donors and as predictors of early graft failure after heart transplantation. cTnI, cTnT, myoglobin, and creatine kinase (CK) levels and its isoenzyme MB (CKMB) activity and mass were measured in serum samples immediately before opening the pericardium from 126 consecutive brain-dead multi-organ donors over 10 years of age inspected by our harvesting team. Donors with serum creatinine >2.0 mg/dL (n=6) were excluded from the analysis. Donors for high-urgency status recipients (n=2) were also excluded. The remaining donors were retrospectively divided into three groups: group I (n=68), grafts with good function; group II (n=11), grafts with impaired function; and group III (n=39), grafts not accepted for transplantation. No differences in donor and recipient characteristics were found among the groups. The mean values of cTnI (0.36+/-0.88 microg/L, 4.45+/-3.28 microg/L, and 3.02+/-7.88 micog/L, respectively) and cTnT (0.016+/-0.029 microg/L, 0.134+/-0.114 microg/L, and 0.123+/-0.245 microg/L, respectively) were lower in group I when compared with groups II or III (cTnI: P<0.0001, P=0.018; cTnT: P<0.0001, P=0.012). The cTnI value was higher in group II compared with group III (P=0.023). The cTnT values were similar in groups II and III. A cTnI value >1.6 microg/L as a predictor of early graft failure had a specificity of 94%, and a cTnT value of >0.1 microg/L had a specificity of 99%. The odds ratio for the development of acute graft failure after heart transplantation was 42.7 for donors with cTnI >1.6 microg/L and 56.9 for donors with cTnT >0.1 microg/L. No differences of myoglobin, CKMB activity, or CKMB/CK ratio were found among the groups. Significantly higher cTnI and cTnT values were found in peripheral blood at the time of explantation in donors of hearts with subsequently impaired graft function and in not accepted donors. cTnI and cTnT are useful as additional parameters for heart donor selection.

Research paper thumbnail of EFFECT OF ACUTE BRAIN DEATH ON RELEASE OF ATRIUM AND B-TYPE NATRIURETIC PEPTIDES IN AN ANIMAL MODEL

Transplantation, 2004

Atrium and B-type natriuretic peptides (ANP and BNP) and big endothelin (ET)-1 are markers for se... more Atrium and B-type natriuretic peptides (ANP and BNP) and big endothelin (ET)-1 are markers for severity of heart failure and may be used in the quality assessment of donor hearts. Elevated cardiac troponins predict early graft failure after heart transplantation. This study evaluated the effects of acute brain death (BD) on the release of ANP, BNP, big ET-1, and cardiac troponins in an animal model. Pigs were randomized into a BD group (n=5) and a control group (n=5). In the first group, acute BD was induced, and anesthesia was stopped. In the control animals, a sham operation was performed, and anesthesia was continued. Parameters were measured at baseline and for 13 hours postoperatively. After acute BD, there were significant hemodynamic changes. In the control group, the BNP level was higher than in the BD group and decreased over time (P =0.016). There was no significant change in BNP release in the BD group up to 13 hours (P =0.1). ANP release remained stable over time in the control group (P =0.35) but decreased in the BD group (P =0.043). The big ET-1 levels were not different between groups. Cardiac troponin I was elevated in the BD group 5 hours after BD (P< 0.05) but remained under 1.5 mg/L throughout the study. Acute BD did not lead to an increase of BNP and ANP levels. Moreover, intact brain function seems to augment the release of natriuretic peptides from the myocardium. Further clinical evaluation of prognostic values of natriuretic peptides for the assessment of donor hearts is necessary. Cardiac troponins are a useful additional tool in the evaluation of donor hearts.

Research paper thumbnail of MEDIUM-TERM RESULTS OF HEART TRANSPLANTATION USING DONORS OVER 63 YEARS OF AGE1

Transplantation, 1999

The continual shortage of hearts for transplantation (HTx) led to the expansion of the donor pool... more The continual shortage of hearts for transplantation (HTx) led to the expansion of the donor pool by accepting older donors. We compared the medium-term follow-up of patients after HTx with older hearts (over the age of 63 years) with those of patients after HTx with younger hearts. Since April 1994 we have used hearts for HTx from donors older than the age of 63 years. Until November 1998, 309 HTx and 9 re-HTx were performed in 309 adults with a mean age of 50.7+/-10.9 years (range 17-68 years). There were 252 men and 57 women. The patients were divided into two groups: group I--donor age under 63 years (296 patients, mean age 50.4+/-11 years; mean donor age 38.1+/-13 years; mean follow-up 1.7+/-1.6 years); group II-donor age of more than 63 years (13 patients, mean age 57.4+/-5.6 years; mean donor age 65.1+/-2.1; mean follow-up 2.2+/-1.6 years). There were no differences in the etiology of heart failure, gender, or ischemia time between the groups. The patients in group II were significantly older (P = 0.008). Multiple factors were analyzed in the groups, which included changes in the left/right ventricle ejection fraction, early postoperative mortality (up to 30 days), cumulative survival rates and cardiac-dependent morbidity [myocardial infarction, malignant arrhythmias, coronary stenosis (>50% in one of the main coronary arteries) and transplant vasculopathy]. Additionally, freedom from cytomegalovirus infection (rise of titer or seroconversion) and freedom of acute rejection episodes grade > or =2 (International Society of Heart & Lung Transplantation [ISHLT]) were analyzed. After 1 year mean left and right ventricle ejection fraction were good in both groups and did not significantly change for up to 2 years. No Re-HTx was performed in group II. The early postoperative mortality was similar in both groups (P = 0.8). Also, the cumulative survival rates were similar in both groups (P = 0.87). Long-term cardiac morbidity was lower in group I (P = 0.03). The long-term freedom from cytomegalovirus infection in group I was significantly higher when compared with group II (P = 0.0002). The long-term freedom from severe rejection episodes was similar in both groups (P = 0.3) The study found a significant increase in long-term cardiac morbidity due to more focal coronary stenosis in group II, and freedom from cytomegalovirus infection, but did not find significant differences in the long-term survival between patients who received hearts from donors of up to 63 years of age and from those more than 63 years. The acceptance of donors older than 63 years old for HTx does not worsen the outcome of the recipients. The careful selection of older donors, with close monitoring of the coronary situation after HTx and expanded indications for revascularization of older hearts, could make HTx with older hearts, even in older recipients, a safe option.

Research paper thumbnail of Tissue-Engineering Bioreactors: A New Combined Cell-Seeding and Perfusion System for Vascular Tissue Engineering

Tissue Engineering, 2002

One approach to the tissue engineering of vascular structures is to develop in vitro conditions i... more One approach to the tissue engineering of vascular structures is to develop in vitro conditions in order ultimately to fabricate functional vascular tissues before final implantation. In our experiment, we aimed to develop a new combined cell seeding and perfusion system that provides sterile conditions during cell seeding and biomechanical stimuli in order to fabricate autologous human vascular tissue in vitro. The cell seeding and perfusion system is made of Plexiglas and is completely transparent (Berlin Heart, Berlin, Germany; University Hospital Benjamin Franklin, Berlin, Germany). The whole system consists of a cell seeding chamber that can be incorporated into the perfusion system and an air-driven respirator pump connected to the bioreactor. The cell culture medium continuously circulates through a closed-loop system. We thus developed a cell seeding device for static and dynamic seeding of vascular cells onto a polymeric vascular scaffold and a closed-loop perfused bioreactor for long-term vascular conditioning. The cell seeding chamber can be easily connected to the bioreactor, which combines continuous, pulsatile perfusion and mechanical stimulation to the tissue-engineered conduit. Adjusting the stroke volume, the stroke rate, and the inspiration/expiration time of the ventilator allows various pulsatile flows and different levels of pressure. The whole system is a highly isolated cell culture setting, which provides a high level of sterility and a gas supply and fits into a standard humidified incubator. The device can be sterilized by ethylene oxide and assembled with a standard screwdriver. Our newly developed combination of a cell seeding and conditioning device provides sterile conditions and biodynamic stimuli for controlled tissue development and in vitro conditioning of an autologous tissue-engineered vessel.