Advice

The technology

The technology

Impella 2.5 is a miniaturised, catheter-based, intravascular blood pump that supports a patient's circulatory system. It provides continuous forward flow to increase overall cardiac output, unload work from the ventricle (decreasing myocardial oxygen demand) and improve coronary flow (increasing oxygen supply). This action is designed to support systemic haemodynamics and protect the myocardium from ischaemic damage.

Impella 2.5 is indicated for clinical use in cardiology and cardiac surgery for a number of indications. The primary indication is for cardiovascular support before, during and after urgent or elective high-risk percutaneous coronary intervention (PCI).

Impella 2.5 comprises 3 main components:

  • A sterile, single-use, intravascular catheter with an integrated blood pump that provides flow rates of up to 2.5 litres per minute.

  • A sterile, single-use purge cassette with an in-line purge pressure transmitter which is connected to the catheter purge lumen. The purge fluid is typically 5% dextrose in water (the maximum recommended level of dextrose is 40%) containing heparin, and prevents blood from entering the motor.

  • A reusable, external Automated Impella Controller (AIC), with a 10‑inch colour display, which is the main user interface and is used to control the pump. The controller can be mounted on a 4‑wheeled cart for use in the catheterisation laboratory, or on a bedside rail during patient transfer. The controller is powered by mains electricity or a rechargeable, lithium‑ion battery for patient transfer, which lasts for at least 60 minutes when fully charged. The controller is provided in packs of 2, because the manufacturer's internal safety guidelines state that a backup controller should always be available in case the first controller fails.

An Impella setup and insertion kit contains all the single-use, sterile accessories needed: an introducer kit to gain arterial access, a 260 cm catheter placement guide-wire and a catheter-to-controller connection cable, as well as the Impella 2.5 catheter and purge cassette components. Hospitals must provide their own diagnostic catheter and a 5 to 8 French (Fr) introducer.

The operator follows the instructions shown on the AIC to setup the catheter. This includes inserting and auto-priming the purge cassette, connecting the Impella catheter cable and lumen luer connectors, auto-priming the catheter purge lumen and manually priming the catheter placement signal lumen with dextrose solution.

The operator then inserts the Impella catheter using fluoroscopy to guide placement across the aortic valve and into the ventricular chamber. A radiopaque marker on the catheter shaft will be level with the aortic valve when the catheter is properly positioned in the left ventricle, indicating that the pump is ready to be started. When the pump is started, blood from the pump inlet area, which sits inside the left ventricle, is delivered through the cannula to the outlet opening in the ascending aorta. Operators monitor the correct positioning and functioning of the Impella device using the AIC.

A number of versions of the Impella device are available. Impella CP (Cardiac Power) and Impella 5.0 have increased flow rates of 3.5 litres and 5 litres respectively. Impella CP can be used for the same indications as Impella 2.5. The 5.0 version is for use in patients with shock and acute myocardial infarction. Impella LD (Left Direct) and Impella RP (Right Percutaneous) are also available but are indicated for use during open chest surgery and for right heart failure respectively. These additional versions and indications are beyond the scope of this briefing.

The innovation

Impella 2.5 directly unloads the left ventricle, providing continuous forward flow in the ascending aorta. This is different to an intra‑aortic balloon pump (IABP), which is used in current practice. Unlike Impella 2.5, the IABP is not a mechanical left ventricular assist device; it is a volume displacement device that provides pulsed therapy by inflating and deflating the balloon in time with the patient's heart rate.

The pulsed therapy of IABP relies on there being adequate time between triggers (electrocardiogram [ECG] or pulse pressure wave) to inflate and deflate the balloon. This can be problematic if the patient has tachycardia, and can result in failure if cardiac output stops altogether. The continuous flow support from Impella 2.5 is independent of the patient having any intrinsic cardiac output or rhythm.

Current NHS pathway

Currently, no national guidance exists in the UK for the use of haemodynamic support devices, such as Impella 2.5, in high‑risk PCI procedures.

Haemodynamic support devices can be used during some PCI procedures to maintain blood flow. This may be necessary for some high‑risk procedures, such as those in patients with complex coronary artery disease (unprotected left main disease, last remaining vessel or multi‑vessel disease), compromised left ventricular function or ongoing ischaemia (Jones et al. 2012). The specialist commentators who contributed to this briefing estimated that between 0.2% and 5.0% of patients having PCI need a haemodynamic support device.

IABPs are the most common device used to provide haemodynamic support during PCI, although intra‑corporeal or extra corporeal pumps may also be used. Impella 2.5 could be used to provide haemodynamic support for suitable patients instead of IABPs.

NICE is aware of another CE‑marked device which fulfils a similar purpose as the Impella 2.5:

Population, setting and intended user

Impella 2.5 would be used in patients needing haemodynamic support before, during or after elective or urgent high‑risk PCI procedures, instead of an IABP. It is also indicated for patients with reduced left ventricular function, such as in post‑cardiotomy, low output syndrome, cardiogenic shock after acute myocardial infarction, or myocardial protection after acute myocardial infarction. These indications are beyond the scope of this briefing.

Impella 2.5 is contraindicated in patients with certain conditions, as detailed in the instructions for use.

Impella 2.5 and IABP have different mechanisms of action and safety profiles. They are both considered to be parts of a comprehensive mechanical assist solution, with the most appropriate device being used based on the clinical scenario.

Impella 2.5 would be used by interventional cardiologists trained in cardiac catheterisation who have appropriate training in all Impella system components.

In some clinical scenarios, Impella 2.5 could be used for up to 5 days in patients who need prolonged haemodynamic support. In these cases interventional cardiologists would be responsible for the implant and removal, while general intensivists and advanced heart failure cardiologists would be responsible for ongoing care.

Costs

Device costs

The reusable controller has an anticipated lifespan of 7 years. The Impella 2.5 catheter is designed to provide circulatory support for up to 5 days.

The controller needs scheduled maintenance and safety checks once a year. Three service options are available:

  • Service on call – Charged at a rate of £1,676 (€2,000) per service.

  • Maintenance agreement – In place for 3 years and includes preventative maintenance, maintenance parts and software and hardware updates, costing £2,386* (€2,850) per system per year.

  • Full service with extended warranty – In place for 3 years, in addition to services provided under the maintenance agreement, all repairs and spare parts for repair and loaner units during repair are covered, costing £3,014* (€3,600) per system per year.

The manufacturer provides 2 training programmes with the purchase of the system, included with the purchase cost. Initial training lasts a few hours, introducing the science of haemodynamic support and providing an overview of the Impella system and procedure. A 1‑day advanced training programme is also available, which provides more hands‑on experience and case reviews.

Table 1 Current costs of Impella 2.5 system components

Description

Cost (excluding VAT)*

Additional information

Automated Impella Controller

€42,000 (£35,049)

Includes 2 reusable units

Impella 2.5 setup and insertion kit

€8,000 to €18,000€

(£6,676 to £15,022): discount available based on quantity purchased per year

Single-use, containing all sterile accessories including the Impella 2.5 catheter and purge cassette

Full service agreement for the AIC

€3,600 (£3,004)

Pricing per year, minimum 3 years. Includes an extended warranty

Abbreviation: AIC, Automated Impella Controller.

* Note that prices were converted from euros to pounds using the XE currency converter in July 2016.

Costs of standard care

IABPs are the most common device used to provide haemodynamic support during PCI. The unit cost of an IABP is estimated to be £603 (taken from the appendices of NICE's guideline on acute heart failure).

Resource consequences

Impella 2.5 is likely to be used instead of an IABP for suitable patients in the current clinical pathway. The unit cost for Impella 2.5 is considerably greater than that for an IABP so the technology would pose an additional expense to the NHS.

The literature review identified 3 economic studies (Roos et al. 2013, Gregory et al. 2013 and Wohns et al. 2014) which reported that Impella 2.5 was cost effective compared with IABPs. However, the cost savings were based on treatments and care pathways offered outside of the UK and so these results are not directly generalisable to NHS practice.