[CARL-Controlled reperfusion of the whole body]. / CARL ­ kontrollierte Reperfusion des ganzen Körpers: Von der kardiopulmonalen Reanimation zur zielgerichteten eCPR.

BACKGROUND: The incidence and mortality of acute cardiovascular arrest have been consistently high for decades. OBJECTIVE: How to improve the currently unsatisfactory outcome after resuscitation regarding survival and neurological, especially cerebral, sequelae? MATERIAL AND METHODS: Development of a therapeutic approach to curtail ischemia/reperfusion injury in an animal model. Development of a device system optimized for resuscitation that can be used to implement controlled reperfusion of the whole body outside the hospital. RESULTS: Establishment of CARL treatment in the clinic and in the treatment of OHCA patients. Transfer of the CARL treatment and system in a clinical observational study. First case reports in which patients survived OHCA without brain damage even after ischemia times up to 2 h. CONCLUSION: CARL treatment is potentially suitable to treat patients suffering from cardiovascular arrest refractory to treatment even for prolonged periods.

Myocardial infarction type 1 is frequent in refractory out-of-hospital cardiac arrest (OHCA) treated with extracorporeal cardiopulmonary resuscitation (ECPR).

Extracorporeal cardiopulmonary resuscitation (ECPR) is a last resort treatment option for refractory cardiac arrest performed in specialized centers. Following consensus recommendations, ECPR is mostly offered to younger patients with witnessed collapse but without return of spontaneous circulation (ROSC). We report findings from a large single-center registry with 252 all-comers who received ECPR from 2011-2019. It took a median of 52 min to establish stable circulation by ECPR. Eighty-five percent of 112 patients with out-of-hospital cardiac arrest (OHCA) underwent coronary angiography, revealing myocardial infarction (MI) type 1 with atherothrombotic vessel obstruction in 70 patients (63% of all OHCA patients, 74% of OHCA patients undergoing coronary angiography). Sixty-six percent of 140 patients with intra-hospital cardiac arrest (IHCA) underwent coronary angiography, which showed MI type 1 in 77 patients (55% of all IHCA patients, 83% of IHCA patients undergoing coronary angiography). These results suggest that MI type 1 is a frequent finding and - most likely - cause of cardiac arrest (CA) in patients without ROSC, especially in OHCA. Hospital survival rates were 30% and 29% in patients with OHCA and IHCA, respectively. According to these findings, rapid coronary angiography may be advisable in patients with OHCA receiving ECPR without obvious non-cardiac cause of arrest, irrespective of electrocardiogram analysis. Almost every third patient treated with ECPR survived to hospital discharge, supporting previous data suggesting that ECPR may be beneficial in CA without ROSC. In conclusion, interventional cardiology is of paramount importance for ECPR programs.

[Freiburg Cardiac Arrest Receiving Team (CART) : Interdisciplinary solution for the acute management of non-traumatic out-of-hospital cardiac arrest]. / Freiburger Cardiac Arrest Receiving Team (CART) : Konzept zur Strukturierung des Behandlungsablaufs nach nichttraumatischem außerklinischem Herz­Kreislauf-Stillstand in einem interdisziplinären Team.

Standard procedures and guidelines provide specific instructions for basic and advanced cardiac life support. Recommendations for the admission of patients from preclinical into clinical structures after successful cardiopulmonary resuscitation (CPR) are available, but only a few are detailed. In the presence of ST-elevation myocardial infarction after return of spontaneous circulation (ROSC), coronary angiography must be performed as soon as possible. However, acute management and consecutive diagnostic procedures after hospital admission are up to the doctor on duty, who can rely on standard internal hospital procedures at best. Despite the enormous progress and new findings in intensive care and emergency medicine, intra-hospital mortality, as well as long-term survival, after CPR remains low and depends on a wide variety of influencing factors. To optimize in-hospital acute care of successfully resuscitated patients, an interdisciplinary admission team, a so-called cardiac arrest receiving team (CART), has been implemented at the University Hospital of Freiburg, Germany. The aim of the CART is to provide primary care to resuscitated patients as quickly and in as standardized a manner as possible with predefined diagnostic and therapeutic pathways by a team with special expertise in the field of CPR and post-resuscitation management. Accordingly, clear criteria for procedures and the location of primary care (e.g. emergency room vs. cardiac catheter laboratory), the composition of the CART and concrete treatment measures were defined.

Superior neurologic recovery after 15 minutes of normothermic cardiac arrest using an extracorporeal life support system for optimized blood pressure and flow.

OBJECTIVE: Sudden cardiac arrest is one of the leading causes of death. Conventional CPR techniques after cardiac arrest provide circulation with reduced and varying blood flow and pressure. We hypothesize that using pressure- and flow-controlled reperfusion of the whole body improves neurological recovery and survival after 15 min of normothermic cardiac arrest. METHODS: Pigs were randomized in two experimental groups and exposed to 15 min of ventricular fibrillation (VF). After this period, the animals in the control group received conventional CPR with open chest compression (n=6), while circulation in the treatment group (n=6) was established with an extracorporeal life support system (ECLS) to control blood pressure and flow. Follow-up included the assessment of neurological recovery and magnetic resonance imaging (MRI) for up to 7 days. RESULTS: Five of the six animals in the control group died, one animal was resuscitated successfully. In the treatment group, 1/6 could not be separated from ECLS. Five out of the six pigs survived and were transferred to the animal facility. One animal was unable to walk and had to be sacrificed 30 hours after ECLS. The remaining 4 animals of the treatment group and the surviving pig from the control group showed complete neurological recovery. Brain MRI revealed no pathological changes. CONCLUSION: We were able to demonstrate a significant improvement in survival after 15 minutes of normothermic cardiac arrest. These results support our hypothesis that using an ECLS for pressure- and flow-controlled circulation after circulatory arrest is superior to conventional CPR.

Prolonged cardiac arrest and resuscitation by extracorporeal life support: favourable outcome without preceding anticoagulation in an experimental setting.

State-of-the-art cardiopulmonary resuscitation (CPR) restores circulation with inconsistent blood-flow and pressure. Extracorporeal life support (ECLS) following CPR opens the opportunity for "controlled reperfusion". In animal experiments investigating CPR with ECLS, systemic anticoagulation before induced cardiac arrest is normal, but a major point of dispute, since preliminary heparinization in patients undergoing unwitnessed cardiac arrest is impossible. In this study, we investigated options for ECLS after an experimental 15 minutes normothermic cardiac arrest, without preceding anticoagulation, in pigs. Neurological recovery was assessed by a scoring system, electroencephalography and brain magnetic resonance imaging. Additionally, brain histology was performed on day seven after cardiac arrest. We demonstrated that preliminary heparin administration was not necessary for survival or neurological recovery in this setting. Heparin flushing of the cannulae seemed sufficient to avoid thrombus formation. These findings may ease the way to using ECLS in patients with sudden cardiac arrest.

Closed circuit MR compatible pulsatile pump system using a ventricular assist device and pressure control unit.

The aim of this study was to evaluate the performance of a closed circuit MR compatible pneumatically driven pump system using a ventricular assist device as pulsatile flow pump for in vitro 3D flow simulation. Additionally, a pressure control unit was integrated into the flow circuit. The performance of the pump system and its test-retest reliability was evaluated using a stenosis phantom (60% lumen narrowing). Bland-Altman analysis revealed a good test-retest reliability (mean differences = -0.016 m/s, limits of agreement = ±0.047 m/s) for in vitro flow measurements. Furthermore, a rapid prototyping in vitro model of a normal thoracic aorta was integrated into the flow circuit for a direct comparison of flow characteristics with in vivo data in the same subject. The pneumatically driven ventricular assist device was attached to the ascending aorta of the in vitro model to simulate the beating left ventricle. In the descending part of the healthy aorta a flexible stenosis was integrated to model an aortic coarctation. In vivo and in vitro comparison showed significant (P = 0.002) correlations (r = 0.9) of mean velocities. The simulation of increasing coarctation grade led to expected changes in the flow patterns such as jet flow in the post-stenotic region and increased velocities.

Clinical experience with the VentrAssist left ventricular assist device.

INTRODUCTION: Left ventricular mechanical assist device (LVAD) support is well established as a bridge to transplantation and as an alternative to transplantation in patients with end-stage heart failure. There are currently various LVAD systems available based on different types of pump technology. We present the VentrAssist LVAD, a centrifugal pump, and focus on a surgical implantation technique that may help reduce the complications typically associated with VAD surgery. METHODS AND RESULTS: 412 patients underwent VentrAssist LVAD implantation between June 2003 and January 2009 worldwide. The overall rate of success was 81 % (i.e., ongoing, HTX, or recovery). Interestingly hemolysis is greatly reduced with this intracorporeal centrifugal LVAD compared to other VAD systems with other pump designs. Our surgical implantation technique and strategy may contribute to reducing complications. CONCLUSION: The VentrAssist is a powerful and effective LVAD; its use can considerably reduce hemolysis. Long-term follow-up is necessary to determine whether the VentrAssist is appropriate as a bridge to transplant as well as feasible for long-term application.

Viability of the myocardium after twenty-four-hour heart conservation--a preliminary study.

BACKGROUND: Orthotopic heart transplantation following ischemic times beyond four hours is associated with increased risk of early graft failure. The use of modern myocardial preservation strategies could enable safe transplantation after long-term conservation. In this study, we tested a new myocardial protection regime in an experimental model of 24 h storage. METHODS: Orthotopic heart transplantations (n=15) were performed in a pig model. Donor hearts were flushed with Bretschneider solution, excised, and stored for 24 hours at 4 degrees C. During implantation, controlled reperfusions with substrate-enriched leukocyte-depleted blood cardioplegia were performed after each anastomosis. Blood cardioplegia contained 1 mmol/l of the Na(+)-H(+)-exchange inhibitor HOE 642 and 100 mg/l of adenosine. Controlled reperfusion was continued with leukocyte-depleted blood for 20 min. A microaxial pump was inserted after heart transplantation and circulatory assistance was maintained for five hours to prevent right heart failure. RESULTS: No initial graft failure could be observed. Thirteen hearts could be weaned from extracorporeal circulation. Due to bleeding problems, kidney and lung failure only five hearts could be included in the final analysis. Hemodynamics of these hearts remained stable with epinephrine at 0.1 micro g/kg/min. Myocardial oxygen consumption 20 min after start of reperfusion (5.3+/-2.0 ml/100 g/min) did not differ significantly versus baseline (6.8+/-2.0 ml/100 g/min). Oxygen extraction six hours after heart transplantation was also well preserved compared to baseline (58.0+/-10.2 versus 49.2+/-8.8 %). Histological examination six hours after transplantation using luxol fast blue staining revealed that only 1.0 % of the myocytes were irreversibly damaged. CONCLUSIONS: The data indicate full viability of the myocardium after 24 h conservation. The preservation technique described could contribute to the extension of conservation times in heart transplantation and enable transplantation of marginal donor hearts.