SKStefan Klotz

Stefan Klotz

*This is an algorithmically generated author record based on publicly available information.

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Stefan Klotz has a total of 39 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Surgical approach to end-stage heart failure

    by Stefan Klotz, Hans H Scheld

    End-stage heart failure is a challenging disease with growing incidence. With decreasing heart transplant rates worldwide organ preserving therapies become, again, of interest. The purpose of the present review is to examine the potential challenges of surgical therapies in patients with end-stage heart failure. The gold-standard for end-stage heart failure is and will be cardiac transplantation. However, due to organ shortage this therapy is limited to a few patients. Therefore implantation of ventricular assist devices (VADs) or long-term minimal-invasive partial support devices will increase. Improvements in device design with smaller devices, easier implantation techniques, and modified anticoagulation outcome and long-term success will likely improve. In addition, good quality of life as destination therapy is almost available. Organ conservation surgery (coronary artery bypass grafting and surgical ventricular restoration or surgical repair of mitral valve regurgitation) in end-stage heart failure patients could not prove the expected results. Transcatheter or minimal-invasive approaches of these therapies might become routine in the near future. Due to the overwhelming outcome rates, cardiac transplantation is the most established surgical therapy for end-stage heart failure. VAD therapy is increasing and minimized VADs might further open the market for destination therapy/permanent support.


  • Partial Mechanical Long-Term Support with the CircuLite® Synergy® Pump as Bridge-to-Transplant in Congestive Heart Failure

    by S. Klotz, B. Meyns, A. Simon, T. Wittwer, P. Rahmanian, C. Schlensak, T. T. D. T. Tjan, H. H. Scheld, D. Burkhoff

    Background: Full mechanical support with a left ventricular assist device (LVAD) is often limited to very sick patients, as the only survival option. This European multicenter study analyzes the effect of partial mechanical support as bridge-to-transplant in a less sick heart failure patient group. Methods: The CircuLite® Synergy® device is implanted via a small right-sided thoracotomy with an inflow cannula in the left atrium and an outflow graft connected to the right subclavian artery without the use of extracorporeal circulation. The pump itself sits in a “pacemaker” pocket subcutaneously in the right clavicular groove. It is able to pump up to 3.0 l/min and partially unload the left ventricle. Results: The device was implanted in 25 patients on the cardiac transplant waiting list (20 males), aged 55.5 ± 9.6 yrs with an ejection fraction of 21.6 ± 6.0 %, a mean arterial pressure of 73.5 ± 8.5 mmHg, a pulmonary capillary wedge pressure of 27.2 ± 7.8 mmHg and cardiac index of 1.9 ± 0.4 l/min/m2. Duration of support ranged from 6 to 238 days. Right heart catheterization showed significant hemodynamic improvement in the short- and intermediate-term after implantation with increases in arterial pressure from 72.6 ± 11.0 to 79.4 ± 8.6 mmHg (p = 0.04) and in cardiac index from 2.0 ± 0.4 to 2.7 ± 0.6 l/min/m2 (p = 0.003) with a reduction in pulmonary capillary wedge pressure from 28.5 ± 6.0 to 19.7 ± 6.9 mmHg (p = 0.012). Conclusions: The CircuLite Synergy device is a partial support pump, which is easy to implant and which provides hemodynamic benefits in bridging heart failure patients to cardiac transplant.


  • Pre-operative prediction of post–VAD implant mortality using easily accessible clinical parameters

    by Stefan Klotz, Christian Vahlhaus, Christian Riehl, Christiane Reitz, Juergen R. Sindermann, Hans H. Scheld


  • Open Access

    Surgery of secondary mitral insufficiency in patients with impaired left ventricular function

    by Andreas Rukosujew, Stefan Klotz, Henryk Welp, Christian Bruch, Farshad Ghezelbash, Christoph Schmidt, Raluca Weber, Andreas Hoffmeier, Jürgen Sindermann, Hans H Scheld

    Secondary mitral insufficiency (SMI) is an indicator of a poor prognosis in patients with ischemic and dilated cardiomyopathies. Numerous studies corroborated that mitral valve (MV) surgery improves survival and may be an alternative to heart transplantation in this group of patients.The aim of the study was to retrospectively analyze the early and mid-term clinical results after MV repair resp. replacement in patients with moderate-severe to severe SMI and left ventricular ejection fraction (LVEF) below 35%. We investigated 40 patients with poor LVEF (mean, 28 +/- 5%) and SMI who underwent MV repair (n = 26) resp. replacement (n = 14) at the University Hospital Muenster from January 1994 to December 2005. All patients were on maximized heart failure medication. 6 pts. had prior coronary artery bypass grafts (CABG). Twenty-seven patients were in New York Heart Association (NYHA) class III and 13 were in class IV. Eight patients were initially considered for transplantation. During the operation, 14 pts had CABG for incidental disease and 8 had tricuspid valve repair. Follow-up included echocardiography, ECG, and physician's examination and was completed in 90% among survivors. Additionally, the late results were compared with the survival after orthotope heart transplantation (oHTX) in adults with ischemic or dilated cardiomyopathies matched to the same age and time period (148 patients). Three operative deaths (7.5%) occurred as a result of left ventricular failure in one and multiorgan failure in two patients. There were 14 late deaths, 2 to 67 months after MV procedure. Progress of heart failure was the main cause of death. 18 patients who were still alive took part on the follow-up examination. At a mean follow-up of 50 +/- 34 (2-112) months the NYHA class improved significantly from 3.2 +/- 0.5 to 2.2 +/- 0.4 (p < 0.001). The LVEF improved significantly from 29 +/- 5% to 39 +/- 16 (p < 0.05). There were no differences in survival after MV repair or replacement. The 1-, 3-, 5-year survival rates in the study group were 80%, 58% and 55% respectively. In the group of patients after oHTX the survival was accordingly 72%, 68%, 66% (p > 0.05). High risk mitral valve surgery in patients with cardiomyopathy and SMI offers a real mid-term alternative method of treatment of patients in drug refractory heart failure with similar survival in comparison to heart transplantation.


  • A computational method of prediction of the end-diastolic pressure–volume relationship by single beat

    by Stefan Klotz, Marc L Dickstein, Daniel Burkhoff

    The end-diastolic pressure–volume relation (EDPVR) is an important descriptor of passive cardiac pump properties. However, clinical utility has been limited by the need for measurement of pressures and volumes over relatively large ranges. In this protocol, we describe an algorithm to estimate the entire EDPVR in humans from a single measured pressure–volume (P–V) point. This algorithm was developed from observations made from accurately measured EDPVRs of human hearts, which indicated that when normalized by appropriate left ventricular volume scaling (to arrive at volume-normalized EDPVRs, EDPVRn) EDPVRns were nearly identical in all patients. In this protocol, we demonstrate how to use EDPVRns to predict a second P–V point on the EDPVR, in which case the entire EDPVR can then be predicted. With recent advances for accurate noninvasive measurement of end-diastolic pressure and volumes, this protocol permits the assessment of passive properties in a broader range of research and clinical settings.


  • Primary Extracorporeal Membrane Oxygenation Versus Primary Ventricular Assist Device Implantation in Low Cardiac Output Syndrome Following Cardiac Operation

    by Stefan Klotz, Andreas Rukosujew, Henryk Welp, Christof Schmid, Tonny D.T. Tjan, Hans H. Scheld

    Mechanical support is often the only therapeutic option in low cardiac output (LCO) following cardiac operation using extracorporeal circulation (ECC). However, the question whether primary ventricular assist device (VAD) or primary extracorporeal membrane oxygenation (ECMO) followed by secondary VAD implantation is superior remains unclear. We analyzed the outcome of 183 patients with LCO following ECC. Primary VAD implantation (VAD) was performed on 20 patients and 163 patients underwent ECMO implantation (ECMO). Out of this group, 13 patients received a secondary VAD (ECMO-VAD). Age was significantly lower in the VAD group, while gender and type of operation were similarly distributed. Thirty-day mortalities were 50, 75, and 46% (VAD, ECMO, and ECMO-VAD, respectively; P < 0.05 ECMO vs. VAD and ECMO-VAD). Survival was best with VAD implantation 1.2 +/- 1.2 days following LCO. In conclusion, the outcome of LCO following ECC remains poor. Early VAD support provides best survival. Primary or secondary VAD implantation has no impact on survival.


  • Reversible Pulmonary Hypertension in Heart Transplant Candidates: To Transplant or Not to Transplant

    by Stefan Klotz, Frauke Wenzelburger, Joerg Stypmann, Henryk Welp, Gabriele Drees, Christof Schmid, Hans H. Scheld


  • Does Continuous Flow Left Ventricular Assist Device Technology Have a Positive Impact on Outcome Pretransplant and Posttransplant?

    by Stefan Klotz, Joerg Stypmann, Henryk Welp, Christof Schmid, Gabriele Drees, Andreas Rukosujew, Hans H. Scheld


  • Chirurgische Therapie der Herzinsuffizienz

    by Stefan Klotz, Andreas Loeher, Gabriele Drees, Hans Heinrich Scheld