Morbidität und Mortalität bei Patient:innen im kardiogenen Schock unter Therapie der linksventrikulären Mikroaxialpumpe Impella®

Despite advancements in therapy cardiogenic shock remains associated with a high mortality. In order to achieve left ventricular unloading, temporary mechanical circulatory support systems such as the Impella® microaxial pump have been developed, especially considering the previously widely used IABP failed to demonstrate improvements in hemodynamics and mortality in cardiogenic shock. The objective of this study was to evaluate the effectiveness, handling and safety of Impella® in patients in cardiogenic shock. Different groups that could benefit from the microaxial pump were to be analyzed in terms of morbidity and mortality. Retrospective data from 112 patients in cardiogenic shock with Impella® from January 2013 to July 2015 in two centers were analyzed. The effectiveness of the microaxial pump was assessed based on the required catecholamine therapy, lactate levels and other laboratory parameters for organ function evaluation as well as intensive care scores. Additionally, Impella®-associated complications were analyzed and intrahospital and 30-day mortality were determined in different groups. The investigated cohort had a median age of 73.0 years (61.0-79.0 years). Basic characteristics were comparable between resuscitated and non-resuscitated patients (CPR+Schock vs. Schock) and in subgroups (Impella® 2.5 vs. CP, male (m) vs. female (f), < vs. ≥ 75 years). The most common cause of cardiogenic shock was acute myocardial infarction at 85.7% (43.8% STEMI, 42.0% NSTEMI). 86.6% had relevant coronary artery disease, with the majority (53.6%) having three-vessel CAD. Overall, a trend towards reduction in dobutamine therapy within the first 72 hours after Impella® implantation was observed (Implantation 333.3 μg/min (0-416.7 μg/min), 72h 250.0 μg/min (0-416.7 μg/min) [p=0.07]), significantly for women [p=0.02]. Additionally, a significant decrease in lactate levels with Impella® was observed (Implantation 2.5 mmol/l (1.0-6.25 mmol/l), 72h 1.0 mmol/l (1.0-2.0 mmol/l) [p=0.0002]). Compared to non-resuscitated patients (CPR+Schock vs. Schock), resuscitated patients showed at Impella® implantation an increased need for noradrenaline and adrenaline [p=0.05/p=0.001], CardShock risk Score [p=0.02] and a tendency towards increased lactate levels [p=0.08] and liver failure [p=0.15]. Mechanical ventilation [p<0.0001] and suspected hypoxic brain injury [p=0.0014] were significantly more frequent. Patients with Impella® CP tended to have higher noradrenaline doses (2.5 vs. CP p=0.13) and CardShock risk scores (2.5 vs. CP p=0.08) at implantation. Female patients also initially had a high noradrenaline requirement (m vs. f p=0.01). The handling of Impella® was uncomplicated regarding implantation, repositioning, and technical management. Impella®-associated bleeding at puncture site was rare (8.0%), but more frequent with Impella® CP (2.5 vs. CP p=0.03). Multifactorial bleeding required red blood cell transfusion especially in female patients (m vs. f p=0.03) and during Impella® CP treatment (2.5 vs. CP p=0.006). The overall intrahospital mortality with Impella® support was 58.9%. This was significantly higher for resuscitated patients (CPR+Schock vs. Schock 70.4% vs. 48.3% [p=0.02]). Even after 30 days, survival was better for patients without resuscitation (51.7% vs. 31.5% [p=0.009]). No difference in intrahospital and 30- day mortality was observed between Impella® models and within other subgroups. In conclusion, this study demonstrated the Impella® microaxial pump as a safe and easily manageable circulatory support system for patients in cardiogenic shock. Regarding effectiveness, the data suggested clinically relevant improvement in hemodynamics during Impella® treatment. Despite different ejection capabilities, no significant differences were observed between the two Impella® models. However, evaluating the clinical effect is complicated by the inherently high mortality of cardiogenic shock, especially in resuscitated patients. Therefore, randomized, controlled trials are needed to determine which patient group benefits from Impella® at which point in time and to what extent it positively influences the outcome of cardiogenic shock.