The Impella device is a simple solution to a very complex problem. Used alone or in tandem sets it utilizes the concept of magnetic levitation to reduce moving parts to an absolute minimum thus reducing anticoagulation requirements. Cardiogenic shock has been historically addressed by many devices, most notably the Intra Aortic Balloon Pump. The technology deployed by the Impella device similarly alters the fundamental characteristics of the human circulatory system. As the propeller is accelerated to give respite to an acutely injured myocardium the circulatory system transitions from a pulsatile mechanism to continuous flow. Cellular response to cardiogenic shock is poorly described by either method. Control of directional flow of the device is under investigation in pursuit of addressing right versus left sided heart failure. Transseptal intervention in addressing physiologic mismatch in perfusion between left and right sided heart failure is in experimental status.
Impella provides results similar to venoarterial extracorporeal life support and TandemHeart. The Impella pump is recommended in the following practice guidelines:
Impella heart pumps are percutaneous microaxial pumps that act as mechanical circulatory support devices in patients in need of hemodynamic support. The pumps are mounted on support catheters and typically inserted through the femoral artery, although axillary and subclavian artery approaches are not uncommon.
Technology
The Impella Device is a generational extension of the Intra aortic balloon pump in addressing cardiogenic shock. Tech has allowed a single moving piece floated by magnetically steered mechanisms to deploy an "Archimedes Pump" just north of the Aortic Valve that purports to reduce both preload and afterload. The same tech can apparently also be deployed just above the pulmonary valve as a gate on right sided heart failure.
Left-sided support
Designed to provide hemodynamic support when the patient's heart is unable to produce sufficient cardiac output, Impella heart pumps can supply one to five liters per minute of blood flow. The physiological consequences of left-sided support are threefold. First, it unloads the left ventricle by reducing left ventricular end-diastolic volume and pressure, thereby decreasing ventricular wall stress, work, and myocardial oxygen demand. Second, it increases mean arterial pressure, diastolic pressure, and cardiac output, improving cardiac power output and cardiac index. The combined effects on wall stress and perfusion pressure augment coronary perfusion. Lastly, augmented cardiac output and forward flow from the left ventricle decreases pulmonary capillary wedge pressure and reduces right ventricular afterload.
Approval
In June 2008, the Impella 2.5 heart pump received FDA 510 clearance for partial circulatory support for periods of up to six hours during cardiac procedures not requiring cardiopulmonary bypass. In March 2015, it received FDA premarket approval for elective and urgent high-risk percutaneous intervention procedures. In December 2016, the premarket approval was expanded to include the Impella CP heart pump. In April 2009, the Impella 5.0 and Impella LD heart pumps received 510 clearance for circulatory support for periods of up to six hours during cardiac procedures not requiring cardiopulmonary bypass. In July 2010, the automated Impella controller received FDA 510 clearance for use by trained healthcare professionals in healthcare facilities and medical transport. In January 2015, the Impella RP was granted a humanitarian device exemption to provide circulatory assistance for patients with right heart failure. In February 2018, the FDA approved the sale of the Impella ventricular support systems.
