Insertion of Impella 5.0 to Improve Candidacy for HeartMate II Left Ventricular Assist Device Placement

ABSTRACT: The Impella 5.0 is a minimally invasive heart assist device that can be used to stabilize patients with cardiogenic shock. We present the case of a 49-year-old female in cardiogenic shock who required left ventricular assist device placement, but was not an optimal candidate for surgery due to severe deconditioning and malnutrition. An Impella 5.0 pump was surgically implanted via right axillary artery approach, which allowed the patient time to improve nutritional and functional status before subsequent placement of HeartMate II left ventricular assist device.

J INVASIVE CARDIOL 2014;26(4):E40-E41 

Key words: heart failure, ventricular assist device, cardiogenic shock

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Patients in cardiogenic shock are at high risk for left ventricular assist device (LVAD) implantation.¹ We present a case using the Impella 5.0 microaxial pump to improve patient candidacy for HeartMate II LVAD placement. 

Case Report. A 49-year-old female was transferred to our institution with decompensated heart failure. She had a large anterior myocardial infarction 2 months prior to transfer. Successful revascularization was performed at the time, but her presentation was late, leaving her with significant heart failure and an ejection fraction of 15%. The patient was volume overloaded and suffering from low-output heart failure with a cardiac index of 1.6 L/min/m². Despite initiation of milrinone and then dobutamine, elevated filling pressures and low cardiac output continued. Five days following admission, the patient became oliguric and hypotensive with worsening renal function. An intra-aortic balloon pump (IABP) was inserted via femoral artery to stabilize the patient. 

During this time, the patient underwent evaluation for heart transplantation or LVAD placement. It was apparent that the severity of her illness precluded listing for transplantation. There was no absolute contraindication to proceeding with LVAD placement, but her cardiac cachexia was worrisome. She was malnourished with low albumin (2.3 mg/dL) and prealbumin (9.0 mg/dL) and her functional capacity was poor as she required major assistance to ambulate. Although placement of IABP improved her hemodynamics, she was no longer able to ambulate. Therefore, we decided to implant an Impella 5.0 microaxial pump (AbioMed) to improve her candidacy for HeartMate II placement. The patent was taken to a hybrid operating room and a 5 cm skin incision was made underneath the right clavicle to expose the right axillary artery. A 10 mm vascular graft was anastomosed to the right axillary artery in an end-to-side fashion. The graft was passed through the subcutaneous soft tissue and exited caudal and lateral to the incision site. Using fluoroscopic guidance, the Impella 5.0 was inserted via the right axillary artery across the aortic valve into the left ventricle. The device was sutured to the chest wall with multiple stitches to maintain stability. RPM on the device was adjusted over the next 24 hours to achieve flow of 4.0 L/min. Intravenous heparin was administered through the Impella 5.0 device to a target activated clotting time of 160-180 seconds. The patient was transferred to the intensive care unit and extubated on postoperative day 1. The IABP was removed. Upper extremity access allowed the patient to ambulate daily to improve conditioning and muscle strength. Improved appetite and supplemental enteral feeding improved prealbumin to 21.0 mg/dL and albumin to 2.9 mg/dL. Creatinine improved from 1.25 to 0.69 mg/dL. No problems were noted with hemolysis or device thrombosis. The patient underwent placement of HeartMate II LVAD after 8 days of Impella 5.0 support. She did well and was discharged home 14 days after LVAD placement. 

Discussion. Various mechanical circulatory support devices have been used in “bridge to decision” strategies to facilitate long-term LVAD placement.² The Impella 5.0 has some advantages over other pumps: it can be deployed without requiring a sternotomy and the upper extremity approach outlined here allows for ambulation.³ Its use as a bridge to improve candidacy for long-term LVAD placement has not been well described. Although our patient was stable on IABP support, we were concerned that her risk for HeartMate II LVAD placement was high given her deconditioned status, malnutrition, and acute renal failure. Poor nutrition and markers of end-organ dysfunction such as acute renal failure are adverse prognostic factors for patients undergoing long-term LVAD placement.⁴ We believed that using the Impella 5.0 before HeartMate II placement would allow for end-organ function to improve and for her nutrition and functional status to improve as well. Previous studies have shown the utility of the Impella 5.0 for cardiogenic shock complicating acute myocardial infarction and following cardiac surgery as a bridge to myocardial recovery.^3,5 Our case report suggests another indication — to lower the perioperative risk associated with LVAD implantation.

Conclusion. In summary, the Impella 5.0 device can provide hemodynamic support in the setting of low cardiac output. The upper extremity access has the advantage of longer-term support, which may be needed if ventricular recovery is delayed or if several days are required to optimize patients for subsequent surgery such as LVAD implantation. 

References

1. Boyle AJ, Ascheim DD, Russo MJ, et al. Clinical outcomes for continuous-flow left ventricular assist device patients stratified by pre-operative INTERMACS classification. J Heart Lung Transplant. 2011;30(4):402-407.
2. Worku B, Pak SW, van Patten D, et al. The CentriMag ventricular assist device in acute heart failure refractory to medical management. J Heart Lung Transplant. 2012;31(6):611-617.
3. Sassard T, Scalabre A, Bonnefoy E, Sanchez I, Farhat F, Jegaden O. The right axillary artery approach for the Impella Recover LP 5.0 microaxial pump. Ann Thorac Surg. 2008;85(4):1468-1470.
4. Lietz K, Long JW, Kfoury AG, et al. Outcomes of left ventricular assist device implantation as destination therapy in the post-REMATCH era: implications for patient selection. Circulation. 2007;116(5):497-505.
5. Griffith BP, Anderson MB, Samuels LE, Pae WE Jr, Naka Y, Frazier OH. The RECOVER I: a multicenter prospective study of Impella 5.0/LD for postcardiotomy circulatory support. J Thorac Cardiovasc Surg. 2013;145(2):548-554.

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From the Gill Heart Institute, University of Kentucky, Lexington, Kentucky.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted March 26, 2013, provisional acceptance given May 21, 2013, final version accepted August 27, 2013.

Address for correspondence: Navin Rajagopalan, MD, University of Kentucky, 900 South Limestone Street, Lexington, KY 40536. Email: n.rajagopalan@uky.edu