**6. Future trends**

been described as safe and feasible, resulting in hemodynamic improvement. Data from the USpella registry have further demonstrated the feasibility of protected PCI through Impella®

Mortality of patients suffering from acute myocardial infarction (AMI) complicated by CS remains high. Given the potential benefits of pVADs in this specific scenario, short-term circulatory support seems to be a promising therapeutic option. Hypoperfusion caused by cardiogenic shock triggers the so called "shock spiral" by systemic hypoxemia leading to dismal systemic regulatory efforts. The implantation of a pVAD may halt this downward spiral by increasing cardiac output, decreasing LVEDP by unloading of the left ventricle, and therefore reducing oxygen consumption of the myocardium. As appealing as this approach may sound, there is currently no randomized, controlled trial available that may prove the benefit of pVADs in this scenario. The IMPRESS (IMPella versus IABP REduces mortality in STEMI patients treated with primary PCI IN SEVERE and deep cardiogenic SHOCK) trial, a recent controlled, randomized, multi-center study by Ouweneel et al. has found no difference in short-term and 6-month mortality in patients undergoing pVAD support through the Impella® CP in cardiogenic shock compared to Intra-aortic balloon pump (IABP) [18]. Furthermore, a recent meta-analysis from the same authors evaluating the three available randomized trials of Impella® usage in CS patients and comparing it to IABP also revealed

Interestingly, there seems to be differences in survival in-between men and women. Data from the cVAD registry (catheter-based ventricular assist device registry), a database retrospectively enrolling patients that underwent pVAD support with Impella®, showed that early initiation of hemodynamic support in patients with AMI complicated by CS was associated with a greater survival benefit in women compared to men [20]. These data are encouraging, as women usually suffer higher unadjusted mortality rates and experience the use of

Although the concept of pVADs in CS seems convincing and there is ample data showing improved hemodynamic parameters, there is still no evidence from RCTs that pVADs improve survival in these patients. One issue is certainly identifying patients that might profit from pVAD implantation and selecting the appropriate pVAD. Future trials should therefore focus on identifying the "right" patient and the "right" time for Impella® implan-

The Impella® RP received FDA approval in 2015 upon completion of the RECOVER RIGHT (The Use of Impella RP Support System in Patients with Right Heart Failure: A Clinical and Probable Benefit Study) trial, resembling the first percutaneous right ventricular assist device [21]. This prospective, multi-center, single-arm study included 32 patients from 15 institutions

2.5 in a real-world setting [17].

no survival benefit at 30 days and 6 months [19].

guideline-recommended therapies to a lesser extent.

tation in CS.

**5.3. Right ventricular failure**

**5.2. Cardiogenic shock**

188 Interventional Cardiology

A multitude of case reports has reported potential indications for Impella. For example, Deshpande et al. reported a case of acute embolic myocardial infarction and heart failure in a Fontan patient resolved by Impella support followed by successful transplantation [23]. These descriptions on a case-by-case basis highlight promising future indications for the Impella system. However, clinical data in terms of randomized and controlled trials are missing for all of the mentioned indications. **Table 1** further reported the indications for Impella® support.


Table 1. Emerging indications for Impella® support.

#### **6.1. Combination of ECMO and Impella**

Multiple authors have introduced the concept of multi-device approaches in patients with cardiogenic shock [24, 25]. By using different pVADs either simultaneously or in a sequential order, negative effects of one individual device may be balanced by the use of another system.

This concept seems especially efficient for the simultaneous implantation of VA-ECMO and Impella. Pappalardo et al. compared in a recent study 21 patients undergoing VA-ECMO and Impella with 42 propensity-matched patients undergoing VA-ECMO alone for cardiogenic shock [24]. Hospital mortality was significantly lower in patients implanted with both devices (47.0 vs. 80.0%, *P* < 0.001).

The implantation of an Impella® device may address one of the important pitfalls of VA-ECMO, hence explaining the reported improved outcomes. VA-ECMO leads to an increased afterload due to retrograde blood flow impairing unloading of the left ventricle and increasing LVEDP. Overcoming these dismal effects and supporting unloading of the left ventricle by Impella® may therefore prove a valuable concept in the future.
