Protected PCI with Impella® Heart Pumps

During a high-risk PCI, the function of the Impella heart pump can be compared to the function of a safety net. PCI supported by an Impella system is referred to as "Protected PCI”. It allows the clinician time and safety for a complete revascularization.

Protected PCI with Impella® Heart Pumps

Hemodynamic Support During a PCI

Many patients who could benefit from a percutaneous coronary intervention (PCI) have an unfavourably high risk profile. For these patients, the risk of hemodynamic instability increases during the procedure. In such cases, the Impella system can provide safety: it protects patients from hemodynamic instability (Protected PCI), allowing sufficient calm and ease during the procedure.

Percutaneous Coronary Intervention

The accumulation of fats, cholesterol, blood clots and calcifications within the arteries can lead to their constriction or occlusion. The significantly reduced blood flow can in turn result in a reduced supply of oxygen to the heart muscle and vital organs.

The percutaneous coronary intervention aims to enlarge stenosed or completely occluded coronary vessels. In order to perform the procedure, a catheter is inserted either through the femoral or the radial artery.

For the revascularization procedure, a catheter is inserted with a balloon at its tip. In addition, contrast medium is injected. By means of X-ray fluoroscopy, it is then possible to track how the contrast medium flows into the coronary vessels on screen and ensure that the catheter is placed correctly.

To achieve revascularization, the probe is navigated into the affected coronary vessel. There, the balloon gets inflated and keeps the blood vessel open. When the air is drained, a metal stent remains and keeps the blood vessel open. The catheter can then be withdrawn.

Safety During PCI

Impella 2.5® and Impella CP® heart pumps are indicated to support high-risk patients during a percutaneous coronary intervention (PCI) and to unload the left ventricle after a percutaneous coronary intervention (Post-PCI).

The position of the Impella heart pump
The graphic shows the position of the Impella catheter in the heart.
Position of the Impella heart pump during a PCI
Position of the Impella heart pump during a percutaneous coronary intervention



The Impella heart pump is inserted through a percutaneous catheter intervention, usually via the femoral artery. In the artery, it advances through the aorta and the aortic valve into the left ventricle. Properly placed, it pulls the blood from the left ventricle through the cannula to the ascending aorta. This occurs continuously and independently of the heart beat so that blood is also pumped into the aorta during the relaxation phase of the ventricle. Impella heart pumps thus improve the hemodynamics and ensure adequate organ perfusion.

Heart recovery

The support of the left ventricle has several favorable physiological effects:

  • It protects the patient from hemodynamic instability during the PCI, which may be a result of repeated reversible myocardial ischemia due to temporary coronary occlusions.
  • End-diastolic volume, end-diastolic pressure in the left ventricle and capillary wedge pressure are reduced by the continuous pumping function.
  • Due to reduced wall tension, the heart needs to perform less mechanical work, which leads to a reduced oxygen demand.
  • The mean arterial pressure increases, which improves blood circulation in the coronary vessels.
  • Due to the reduced workload of the ventricle and the improved oxygen supply to the heart muscle, the heart can recover and restore its pumping function as far as possible.

Complete revascularization

Patients with complex multi-vessel diseases can particularly benefit from the Impella heart pump: The Impella System not only allows for an intervention despite more complex conditions and higher risks, it also grants the clinician time to completely open every single obstructed vessel. This framework means that a complete revascularisation can be achieved even in the case of a risky intervention. It may minimize infarct size and further improve the patient’s quality of life. 5

Safety for physicians

Finally, the Impella heart pump acts as a "psychological backup" for the clinician and gives the certainty of being able to work under low-risk, safe conditions.

Positive Effects

The Impella heart pump is a left ventricular heart support system for intracorporeal use. Impella heart pumps increase ejection fraction while simultaneously reducing cardiac work. Therefore, the ventricle is unloaded and coronary circulation improves. Thus, myocardial oxygen consumption and demand are better balanced. 

The Impella heart pump also increases systemic aortic pressure and mean arterial pressure. Overall, the changes induced by the Impella heart pump optimize conditions for the natural recovery of the heart.1,2

High-Risk Patients Benefit from Impella Heart Pumps

As the life expectancy of the population increases, the number of older cardiac patients increases as well. Conditions such as diabetes mellitus, restricted renal function and frailty become more common. In addition, elderly coronary patients are often classified as inoperable due to difficult anatomical conditions or reduced left ventricular function.

Benefits for high-risk patients

For high-risk patients, the benefit of a PCI is high, but must always be weighed against the risks. This may lead to a decision against the intervention. However, with the Impella heart pump the risks of such an intervention can be better controlled and opening the possibility to also carry out the intervention in high risk patients.

Data from the USPella registry confirm this: 56% of patients who were supported by the Impella heart pump during a complex coronary intervention had previously been rejected for the intervention because of their risk factors.


Elective support during a PCI with an Impella heart pump (Protected PCI) is particularly recommended in the following situations:

  • Single-vessel coronary artery disease - Ischemia (reduced blood flow) or several high-grade stenoses (narrowing) of a coronary vessel
  • Complex coronary diseases - Multi-vessel disease; stenosis of at least two coronary vessels with severe left ventricular dysfunction, unstable angina and considerable risk of temporary ischemia
  • In-Stent stenosis - Constriction of a stent
  • Venous Bypass Opening - The risk of stenosis of a bypass vessel is significantly greater than that of a stenosed coronary artery, which is why Impella catheters can be used for support
  • Low ejection fraction or cardiac insufficiency
  • Acute coronary syndrome
  • Angina pectoris
  • STEMI or myocardial infarction
  • High risk of temporary ischemia
  • Post-PCI: To unload and support the left ventricle
  • Renal insufficiency

Clinical Studies Show the Benefits of Impella Heart Pumps

The efficacy and safety of Protected PCI with Impella heart pumps have been demonstrated in several studies with a total of over 1,600 patients:

PROTECT-I-study 3

  • The prospective PROTECT-I study with 20 patients demonstrated that the Impella catheter is safe and provides excellent hemodynamic support.

PROTECT-II study 4,5

  • In the PROTECT II study, the left ventricular support of the Impella 2.5 heart pump was compared to that of the intra-aortic balloon pump (IABP) in high-risk patients undergoing an elective, complex PCI.
  • The combined endpoints ‘Major Adverse Events’ (MAE) and ‘Major Adverse Cardiovascular and Cerebral Events’ (MACCE) were significantly less frequent after 90 days in the Impella 2.5 group compared to the IABP: MAE decreased from 51 to 40 % (p = 0.023). MACCE decreased from 31 to 22 % (p = 0.033), corresponding to a reduction of the MACCE incidence by 29 %.
  • The Impella 2.5 catheter also reduced the risk of a new revascularization within 90 days compared to the IABP by 52 % (6 vs. 13 %, p = 0.024) within 90 days.
  • The Impella system lead to a shorter hospital stay of an average of 2 days (7 vs. 9 days, p = 0.008).

USpella-Registry 6

  • The data from the USpella register show that the application of an Impella 2.5 catheter is safe and feasible under real-world conditions, i.e. in the work routine of hospitals.
  • Revascularization was successful in 99 % of the patients with an average improvement of the ejection fraction from 31 to 36 % (p <0.0001).
  • In 51 % of patients, the NYHA status improved by more than one class (p <0.001).
  • After 30 days, the MACCE rate was 8 % and survival was 96 %.


  1. Lam K, et al. Improved microcirculation in patients with an acute ST-elevation myocardial infarction treated with the Impella LP2.5 percutaneous left ventricular assist device. Clin Res Cardiol. 2009; 98: 311–18.
  2. Anderson MB et al. Benefits of a novel percutaneous ventricular assist device for right heart failure. The prospective RECOVER RIGHT study of the Impella RP device. J Heart Lung Transplant. 2015; 34: 1549–60.
  3. Dixon SR, et al. A prospective feasibility trial investigating the use of the Impella 2.5 system in patients undergoing high-risk percutaneous coronary intervention (The PROTECT I Trial): initial U.S. experience. JACC Cardiovasc Interv. 2009; 2: 91–96.
  4. O'Neill WW, et al. A prospective, randomized clinical trial of hemodynamic support with Impella 2.5 versus intra-aortic balloon pump in patients undergoing high-risk percutaneous coronary intervention: the PROTECT II study. Circulation. 2012; 126: 1717–27.
  5. Dangas GD et al. Impact of Hemodynamic Support With Impella 2.5 Versus Intra-Aortic Balloon Pump on Prognostically Important Clinical Outcomes in Patients Undergoing High-Risk Percutaneous Coronary Intervention (from the PROTECT II Randomized Trial). Am J Cardiol 2013; 113: 222–228. 
  6. Maini B, et al. Real-world use of the Impella 2.5 circulatory support system in complex high-risk percutaneous coronary intervention: the USpella Registry. Catheter Cardiovasc Interv. 2012; 80: 717–25

Related literature:

  • Rajani R, et al. Evolving trends in percutaneous coronary intervention. Br J Cardiol. 2011; 18: 73–76.
  • Yan AT, et al. Management patterns in relation to risk stratification among patients with non-ST elevation acute coronary syndromes. Arch Intern Med. 2007; 167: 1009–16.
  • Waldo SW, et al. Surgical ineligibility and mortality among patients with unprotected left main or multivessel coronary artery disease undergoing percutaneous coronary intervention. Circulation. 2014; 130: 2295–301.
  • Burzotta F, et al. Impella ventricular support in clinical practice: Collaborative viewpoint from a European expert user group. International Journal of Cardiology. 2015; 201: 684–91.
  • Gershlick AH, et al. Randomized Trial of Complete Versus Lesion-Only Revascularization in Patients Undergoing Primary Percutaneous Coronary Intervention for STEMI and Multivessel Disease: The CvLPRIT Trial. J Am Coll Cardiol. 2015; 65: 963–72.
  • Kovacic JC, et al. Patients with 3-vessel coronary artery disease and impaired ventricular function undergoing PCI with Impella 2.5 hemodynamic support have improved 90-day outcomes compared to intra-aortic balloon pump: a sub-study of the PROTECT II trial. J Interv Cardiol. 2015; 28: 32–40.
  • Flaherty MP, Pant S, Patel SV, Kilgore T, Dassanayaka S, Loughran J, Rawasia W, Dawn B, Cheng A, Bartoli CR. Hemodynamic Support with a Micro-Axial Percutaneous Left Ventricular Assist Device (Impella®) Protects Against Acute Kidney Injury in Patients Undergoing High-Risk Percutaneous Coronary Intervention. Circ Res. 2017 Jan 10. pii: CIRCRESAHA.116.309738. doi:10.1161/CIRCRESAHA.116.309738. [Epub ahead of print] PubMed PMID: 28073804.