Bjoern Sill

Endothelin-1 in Humans Is Increased by Oxygen-Derived Radicals Ex Vivo and In Vivo

Endothelin-1, angiotensin II, and oxygen-derived radicals are pivotal factors in the development and progression of atherosclerosis. In vitro studies suggest that generation of oxygen-derived radicals by angiotensin II is an important mechanism increasing endothelin-1 synthesis, which consecutively may trigger effects such as cell proliferation and hypertrophy. The aim of this study was to confirm our previous data in an ex vivo and an in vivo setting. Explanted segments of internal mammary arteries were analyzed for big endothelin-1 expression following incubation with xanthine oxidase, angiotensin II, superoxide dismutase, and catalase to stimulate or to specifically inactivate oxygen-derived radicals. Endothelin-1 concentrations were determined by immunostaining and enzyme-linked immunosorbent assay. Further, oxypurinol was given to patients undergoing coronary angioplasty, a procedure known to increase plasma endothelin-1 concentrations. Angiotensin II and xanthine oxidase dose-dependently increased big endothelin-1 concentrations (p < .01 and p < .0001); the effects could be inhibited by coincubation with superoxide dismutase and catalase as determined by both semiquantitative immunofluorescence and enzyme-linked immunosorbent assay (p < .01). Patients undergoing coronary angioplasty exhibited significantly elevated big endothelin-1 concentrations 60 minutes after angioplasty (p = .03); in patients also receiving oxypurinol immediately after angioplasty, big endothelin-1 concentrations decreased (p = .001). Our results may explain the association between elevated angiotensin II levels, increased oxidative stress, and increased endothelin-1 concentrations in atherosclerosis. The data therefore support the concept that oxygen-derived free radicals stimulate the release of endothelin-1, which subsequently induces effects such as proliferation and enhanced agonist-induced vasoconstriction, previously attributed directly to angiotensin II.

Prediction of volume responsiveness using pleth variability index in patients undergoing cardiac surgery after cardiopulmonary bypass

BackgroundThe pleth variability index (PVI) is derived from analysis of the plethysmographic curve and is considered to be a noninvasive parameter for prediction of volume responsiveness. The aim of our prospective clinical study was to evaluate if volume responsiveness can be predicted by PVI in patients undergoing cardiac surgery after cardiopulmonary bypass.MethodsEighteen patients were prospectively studied. Directly after cardiac surgery, PVI, stroke volume variation (SVV), and cardiac index (CI) were recorded. Colloid infusion (4xa0ml/kg body weight) was used for volume loading, and volume responsiveness was defined as increase of CI more than 10xa0%.ResultsSVV and PVI measures were found to be highly correlated at rxa0=xa00.80 (pxa0<xa00.001). Receiver operating characteristics curve (ROC) analysis resulted in an area under the curve of 0.87 for SVV and 0.95 for PVI, which values did not differ statistically significant from each other (pxa0>xa00.05). The optimal threshold value given by ROC analysis was ≥11xa0% for SVV with a sensitivity and specificity of 100xa0% and 72.2xa0%. For PVI, optimal threshold value was ≥16xa0% with a sensitivity and specificity of 100xa0% and 88.9xa0%. Positive and negative predictive values estimating an increase of CI ≥10xa0% for SVV were 44.4xa0% and 100xa0% and 66.7xa0% and 100xa0% for PVI.ConclusionsFor consideration of fluid responsiveness PVI is as accurate as SVV in patients after cardiopulmonary bypass. Methodological limitations such as instable cardiac rhythm after cardiopulmonary bypass and right- or left ventricular impairment seem to be responsible for low specificity and positive predictive values in both parameters PVI and SVV.

Gender differences and outcomes in left ventricular assist device support: The European Registry for Patients with Mechanical Circulatory Support

BACKGROUNDnDespite the increasing use of ventricular assist devices (VADs), gender differences in indications, hemodynamics, and outcome are not well understood. We examined gender differences and gender-specific predictors for perioperative outcome in patients on ventricular support.nnnMETHODSnMulticenter data of 966 patients (median age 55 years, 151 women) from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) were analyzed. Median follow-up was 1.26 years.nnnRESULTSnAt the time of VAD implantation, women were more often in an unstable condition (Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS] profile 1 and 2) (51.7% vs 41.6% in men), experiencing significantly more often major bleeding (p = 0.0012), arrhythmias (p = 0.022), and right ventricular (RV) failure (p < 0.001) with need for additional RV support. The survival of women on isolated LVAD support was significantly worse (1-year survival 75.5% vs 83.2% in men). Age-adjusted Cox regression analyses showed significant associations with mortality for preoperative inotropic therapy, percutaneous mechanical support, INTERMACS profile 1 and 2, RV dysfunction, major bleeding, cerebral bleeding, ischemic stroke, and RV failure. In women, pump thrombosis was more strongly related with mortality compared to men, while the direction of the association of renal dysfunction with mortality was different for women and men (p-value interaction 0.028 and 0.023, respectively).nnnCONCLUSIONSnWomen and men differ in perioperative hemodynamics, adverse events, and mortality after VAD implantation. A gender-dependent association of pump thrombosis with mortality was seen. The impact on treatment practice needs to be shown.

Surgical Technique of Lower Lobe Lung Transplantation

Among patients with end-stage lung disease awaiting lung transplantation, pediatric and small adult patients have a significantly lower chance of getting size-matched pulmonary grafts in time because of the severe scarcity of small donors. It is our strategy to perform lobar lung transplantations in small recipients with restrictive pulmonary disease once their clinical status demands urgent transplantation. Here we describe our surgical technique and discuss the benefits and risks of this procedure.

Failing stentless Bioprostheses in patients with carcinoid heart valve disease.

BackgroundCarcinoid tumor with consecutive endocardial fibroelastosis of the right heart, known as carcinoid heart valve disease (CHVD) or Hedinger’s syndrome, is accompanied by combined right-sided valvular dysfunction with regurgitation and stenosis of the affected valves. Cardiac surgery with replacement of the tricuspid and/or pulmonary valve is an established therapeutic option for patients with Hedinger’s syndrome. Little is known about the long term outcome and the choice of prosthesis for the pulmonal position is still a matter of debate.MethodsThe authors report three cases of pulmonary valve replacement with stentless bioprostheses (Medtronic Freestyle®, Medtronic PLC, Minneapolis, MN, USA) due to severe pulmonary valve degeneration in consequence of Hedinger’s syndrome.ResultsAll patients presented with re-stenosis of the pulmonal valve conduit at the height of the anastomoses in a premature fashion. Due to the increased risk for repeat surgical valve replacement, two patients were treated by transcatheter heart valves.ConclusionWe do not recommend the replacement of the pulmonary valve with stentless bioprostheses in patients with CHVD. These valves presented with an extreme premature degeneration and consecutive re-stenosis and heart failure.

Preoperative Ticagrelor administration leads to a higher risk of bleeding during and after coronary bypass surgery in a case-matched analysis

OBJECTIVESnTo evaluate the effect of Ticagrelor on intra- and postoperative bleeding complications in patients undergoing coronary bypass surgery.nnnMETHODSnFor this study, patients who underwent on-pump or off-pump coronary bypass surgery with preoperative acetylsalicylic acid (ASA) and Ticagrelor administration, between January 2014 and December 2014, were included. In the matched control group, continued dual antiplatelet therapy (DAPT) consisted of Clopidogrel and ASA. A total of 28 consecutive patients (24 males; 73 ± 6.6 years) with preoperative Ticagrelor intake underwent elective (n = 22), urgent (n = 2) or emergency (n = 4) cardiac bypass surgery. The postoperative blood loss, red blood cell units given and intra- and postoperative bleeding complications were documented. To evaluate the effect of Ticagrelor treatment on bleeding during and after coronary bypass surgery in a non-randomized study, we used a case-matched analysis.nnnRESULTSnBaseline parameters showed no important differences between the study group and the control group regarding the matching variables, left ventricular function, preoperative clinical status and risk stratification. The preoperative laboratory analysis showed no important differences regarding coagulation and blood cell count parameters. Overall blood loss was significantly higher in the study group with a mean loss of 1028.8 ± 735.5 ml (P = 0.0002). Accordingly, units of red blood cells administered were also significantly higher in the study group (P = 0.0002). In the Ticagrelor group, there were six rethoracotomies due to postoperative bleeding with a blood loss of more than 1200 ml in the first 3 h. With no rethoracotomies in the Clopidogrel group, this also showed statistical significance for the postoperative course (P = 0.02). There were no differences found regarding ICU stay and ventilation time. Comparing the mean hospital stay, the study group presented a significantly longer stay than the control group (P = 0.001).nnnCONCLUSIONSnRecent studies about bleeding complications in patients with Ticagrelor intake undergoing CABG in a real-life scenario presented inconsistent data. We were able to show in a case-matched analysis that Ticagrelor administration leads to significantly higher blood loss, more red blood cell units transfused and a higher rate of rethoracotomies. The data also present a longer hospital stay to the disadvantage of the study group. Consequently, Ticagrelor intake before CABG procedures should be avoided or at least discontinued 3 days before cardiac surgery.

Dual-chamber pacemaker implantation with left ventricular pacing in a patient with a right ventricular assist device

A 63-year-old patient developed right ventricular failure and intermittent complete heart block after an acute dissection of the right coronary artery. An emergency bypass surgery did not prevent right heart failure. Initially bridged with an extracorporeal membrane oxygenation, a HeartWare® …