Background: According to current guidelines, the use of active mechanical support devices for haemodynamic stabilisation of patients in cardiogenic shock (CS) should be considered. Active ventricular unloading by the axial flow pump Impella is a common approach that mechanically unloads the left ventricle and increases cardiac output. Until now, there are no published data showing the acute haemodynamic effect of left ventricular unloading by the Impella support in patients suffering from CS. The aim of the current registry trial was to observe the influence of the Impella heart pump on acute haemodynamic and metabolic parameters, as well as outcome data of patients in CS.
Results: We included 132 consecutive patients with CS and implantation of an Impella axial flow pump in clinical routine (mostly Impella CP). Before and after 24 hours of Impella support, invasive haemodynamic and metabolic parameters were assessed. There was an increase in pulmonary artery oxygen saturation from 52.60 ± 14.24 initially to 62.59 ± 9.45% after 10–30 min of Impella support (p>0.01), and an increase in cardiac output from 4.09 ± 1.65 l/min to 5.13 ± 1.63 (p>0.001) within the first 24 hours. There was a non-significant reduction in mean pulmonary artery pressure within 24 hours, from 29.25 ± 8.94 to 20.73 ± 8.48 mmHg (p=0.17). Despite no change in the mean arterial blood pressure within 24 hours (from 74.29 mmHg to 70.96 mmHg after 24 hours, p=not significant), a reduction of serum lactate from 5.54 ± 6.17 to 4.27 ± 6.21 mmol/l after support was started (p<0.03) was achieved. The overall mortality after 30 days was 78 out of 132 patients (59.09%). The mortality of patients >75 years (n=33) was 75%, and for patients ≤75 years (n=99) mortality was 25%.
Conclusion: The implantation of an Impella axial flow pump in patients suffering from cardiogenic shock leads to early left ventricular mechanical unloading and improvement of haemodynamic and metabolic parameters even after 24 hours. There is much higher mortality in patients >75 years of age.