DefiPaceTM System, A New Device for Cardioversion of Atrial Fibrillation After Cardiac Surgery - Preliminary Results.

Objectives: Postoperative atrial fibrillation (POAF) is a frequent complication following cardiac surgery. This study examined the safety and efficacy of the new DefiPace TM system consisting of two bi-atrial temporary pacing and cardioversion electrodes, a ventricular electrode and the DefiPace TM device (combined external pacemaker and cardioverter) for low-energy atrial cardioversion. Methods: The temporary electrodes were placed on the left and right atrium during open heart surgery. Pacing thresholds and sensing were measured up to the 6th postoperative day. The satisfactory handling of the electrodes was measured with a visual analog scale (VAS) 1-10, with 10 being the best and 1 being the lowest. In case of POAF, R-wave synchronous low-energy shocks (0.5-10 J) were applied for cardioversion. Results: Temporary electrodes were implanted in 29 patients (age 65.6 ± 10.4 years; 21 males, 14 OPCAB, 15 on-pump cardiac operations). Left or right atrial pacing thresholds ranged from 1.9 ± 1.3 V/ms to 5.0 ± 3.3 V/ms and P-wave sensing from 0.9 ± 0.6 mV to 1.5 ± 0.7 mV. VAS for handling of electrodes: implantation 7.1 ± 0.8 and removal 8.4 ± 1.0. POAF was observed in four patients. Two patients had successful atrial cardioversion with 3.5 J and 4.5 J. One patient converted spontaneously, and one patient remained in PAOF. There were no device-related adverse events. Conclusions: The DefiPace TM system can be used safely in patients undergoing cardiac surgery.

A New Apheresis Device for Antithrombotic Drug Removal during Off-Pump Coronary Artery Bypass Surgery.

Background and Objectives: The hemoadsorption device CytoSorb® (CytoSorbents Inc., Princeton, NJ, USA) has been shown to efficiently remove ticagrelor from whole blood in vitro. A promising clinical experience was made with the integration of the hemoadsorption cartridge on the cardiopulmonary bypass (CPB) circuit during cardiac surgery to reduce adverse events. Materials and Methods: In this report, we describe a novel approach using a new apheresis platform, PUR-01 (Nikkisio Co., Ltd., Tokyo, Japan), which was used as the extracorporeal circuit where CytoSorb® could be installed for the removal of ticagrelor during off-pump coronary artery bypass (OPCAB) procedures. Results: In a 74-year-old male (index case) with coronary artery disease and dual antiplatelet therapy, hemoadsorption was initiated with a skin incision for OPCAB surgery and was continued for 221 min to eliminate ticagrelor. The blood volume that had circulated through the CytoSorb® was 39.04 L in total. Thus far, this treatment strategy has been used in four cases with CHD and DAPT who needed OPCAB surgery. The intraoperative and postoperative courses were uneventful in all patients. No device-related adverse events occurred. Conclusions: The combination of the PUR-01 apheresis pump and hemoadsorption with the CytoSorb® column during OPCAB procedures appears to be safe and effective in eliminating antiplatelet drugs.

A new method to measure oxygenator oxygen transfer performance during cardiopulmonary bypass: clinical testing using the Medtronic Fusion oxygenator.

BACKGROUND: There is no acceptable method of testing oxygen transfer performance in membrane oxygenators quickly and easily during cardiopulmonary bypass. Pre-clinical testing of oxygenators is performed under controlled situations in the laboratory, correlating oxygen transfer to blood flow using 100% oxygen. This laboratory method cannot be used clinically as oxygen transfer values vary significantly at each blood flow and the FiO2 is not kept at 1. Therefore, a formula was developed which corrects the existing FiO2 to attain a PaO2 of 150 mmHg: the corrected FiO2 at 150 mmHg. In graph form, this corrected FiO2 (x-axis) is correlated to the patient's oxygen consumption levels (y-axis), which determines the membrane oxygenator oxygen transfer performance. METHODS: Blood gas and hemodynamic parameters taken during cardiopulmonary bypass using the Medtronic Fusion were used to calculate the oxygen consumption (inlet conditions to the oxygenator) and the corrected FiO2 for a PaO2 of 150 mmHg. Validation of the formula "FiO2-PaO2/(Pb-pH2O)+0.21" was carried out by plotting the calculated values on a graph using PaO2 values between 145 to 155 mmHg and then, using the corrected FiO2 for PaO2s outside of this range. RESULTS: All trend-lines correlated significantly to confirm that the Medtronic Fusion had an extrapolated oxygen transfer of 419 milliliters O2/min at an FiO2 of 1 to achieve a PaO2 of 150 mmHg. CONCLUSIONS: Use of the corrected FiO2 correlated to the oxygen transfer conditions of the membrane oxygenator can easily be used on a routine basis, providing valuable information clinically. When used by the manufacturer under laboratory conditions, further clinically relevant data is provided in terms of FiO2 and resultant PaO2s instead of the present limitations using blood flow. In this way, a clinically justifiable method has been developed to finally establish a standard in testing membrane oxygenator performance.

Antithrombotic drug removal with hemoadsorption during off-pump coronary artery bypass grafting.

BACKGROUND: Patients requiring coronary artery bypass grafting (CABG) are often loaded with antithrombotic drugs (AT) and are at an increased risk for perioperative bleeding complications. Active AT removal by a hemoadsorption cartridge integrated in the cardiopulmonary bypass circuit is increasingly used in this setting to reduce bleeding, and herein we describe the extension of this application in patients on AT undergoing off-pump coronary artery bypass (OPCAB). METHODS: Ten patients (80% male; mean age: 67.4 ± 9.2years) were treated with ticagrelor (eight patients), rivaroxaban and ticagrelor (one patient), and rivaroxaban (one patient) prior to OPCAB surgery. AT's were discontinued one day before surgery in nine patients and on the day of surgery in one patient, and all patients were also on aspirin. The cohort mean EuroSCORE-II was 2.9 ± 1.5%. A hemoadsorption cartridge was integrated into a dialysis device (n=4) or a stand-alone apheresis pump (n=6) periprocedural, for a treatment time of 145 ± 33 min. Outcome measures included bleeding according to Bleeding Academic Research Consortium (BARC)-4 and 24-hour chest-tube-drainage (CTD). RESULTS: Mean operation time was 184 ± 35 min. All patients received a left internal thoracic artery with a mean of 2.3 ± 0.9 total grafts. One patient had a BARC-4 bleeding event and there were no surgical re-explorations for bleeding. Mean 24-hours CTD was 680 ± 307mL. During follow-up of 19.5 ± 17.0 months, none of the patients died or required further reinterventions. No device-related adverse events were reported. CONCLUSIONS: Hemoadsorption via a stand-alone apheresis pump during OPCAB surgery was feasible and safe. This innovative and new approach showed favorable bleeding rates in patients on antithrombotic drugs requiring bypass surgery.