Wilfried Roethy

Neurocognitive function in patients with ventricular assist devices: a comparison of pulsatile and continuous blood flow devices.

The effect of successful ventricular assist device (VAD) implantation on neurocognitive function in terminal heart failure is uncertain. Additionally, the different impact of continuous versus pulsatile blood flow devices is unknown. A total of 29 patients (mean age 53 years), surviving implantation of a ventricular assist device as bridge to transplantation were prospectively followed (continuous flow: Micromed DeBakey, n = 11; pulsatile flow: Thoratec and Novacor, n = 18). Normative data were obtained in 40 age- and sex-matched healthy subjects (mean age 54 years). Neurocognitive function was objectively measured by means of cognitive P300 auditory evoked potentials before operation (baseline), at intensive care unit (ICU) discharge, and at the 8-week and 12-week follow-up. Before implantation of the VAD, cognitive P300 evoked potentials were impaired (prolonged) compared with age- and sex-matched healthy subjects (p < 0.001). After successful VAD implantation, P300 evoked potentials markedly improved compared with before operation (ICU discharge, p = 0.007; 8-week follow-up, p = 0.022; 12-week follow-up, p < 0.0001). Importantly, there was no difference between continuous and pulsatile VADs (before operation, p = 0.676; ICU discharge, p = 0.736; 8-week follow-up, p = 0.911 and 12-week follow-up, p = 0.397; respectively). Nevertheless, P300 peak latencies did not fully normalize at 12-week follow-up compared with healthy subjects (p = 0.012). Successful VAD implantation improves neurocognitive impairment in patients with terminal heart failure. Importantly, this effect is independent of the type of VAD (pulsatile vs. continuous blood flow).

Extensive coagulation monitoring in patients after implantation of the MicroMed Debakey continuous flow axial pump.

Ventricular assist device (VAD) implantation is associated with impaired primary hemostasis and thromboembolic complications. Recently, a new generation of implantable continuous flow axial pumps was introduced into clinical application. To study the potential thrombogenic properties of this type of pump, we applied extensive platelet monitoring was applied. In our institution, 13 patients received the MicroMed DeBakey VAD as a bridge to transplantation. Routine coagulation tests (platelet count, activated partial thromboplastin time, prothrombin time, antithrombin III activity) and platelet function tests (whole blood aggregometry, thrombelastography, flow cytometry) were performed. No clinically relevant thromboembolic events were detected. No correlation was found between global function tests, platelet aggregation, and thrombelastography. No correlation was detected between platelet activation and hemolysis parameters. Platelet aggregation and coagulation index were significantly suppressed early after operation. A subsequent phase of hyper-aggregability, starting around day 6, suggested the initiation of antiaggregation therapy. Platelet activation markers were upregulated in the postoperative period but were returned to preoperative levels after initiation of aspirin. In contrast to routine coagulation monitoring, platelet function tests reflect in detail the coagulation status of blood pump recipients and the efficiency of antiaggregation therapy. Aspirin and dipyridamole therapy in addition to oral anticoagulation using phenprocoumon may contribute to platelet function and clot mechanics restoration and is, therefore, recommended for patients after VAD implantation.

NEUROCOGNITIVE FUNCTION IN PATIENTS WITH VENTRICULAR ASSIST DEVICES

The effect of successful ventricular assist device (VAD) implantation on neurocognitive function in terminal heart failure is uncertain. Additionally, the different impact of continuous versus pulsatile blood flow devices is unknown. A total of 29 patients (mean age 53 years), surviving implantation of a ventricular assist device as bridge to transplantation were prospectively followed (continuous flow: Micromed DeBakey, n = 11; pulsatile flow: Thoratec and Novacor, n = 18). Normative data were obtained in 40 age- and sex-matched healthy subjects (mean age 54 years). Neurocognitive function was objectively measured by means of cognitive P300 auditory evoked potentials before operation (baseline), at intensive care unit (ICU) discharge, and at the 8-week and 12-week follow-up. Before implantation of the VAD, cognitive P300 evoked potentials were impaired (prolonged) compared with age- and sex-matched healthy subjects (p < 0.001). After successful VAD implantation, P300 evoked potentials markedly improved compared with before operation (ICU discharge, p = 0.007; 8-week follow-up, p = 0.022; 12-week follow-up, p < 0.0001). Importantly, there was no difference between continuous and pulsatile VADs (before operation, p = 0.676; ICU discharge, p = 0.736; 8-week follow-up, p = 0.911 and 12-week follow-up, p = 0.397; respectively). Nevertheless, P300 peak latencies did not fully normalize at 12-week follow-up compared with healthy subjects (p = 0.012). Successful VAD implantation improves neurocognitive impairment in patients with terminal heart failure. Importantly, this effect is independent of the type of VAD (pulsatile vs. continuous blood flow).