Impella-Assisted Balloon Aortic Valvuloplasty

ABSTRACT: The Impella LP 2.5 left ventricular assist device (Abiomed) is safe and effective for assisting high-risk percutaneous interventions. A 77-year-old woman with severe aortic stenosis, severe coronary artery disease, an ejection fraction of 20%, severe peripheral vascular disease, and other comorbidities presented to a private, tertiary referral hospital with shortness of breath that had been worsening over 2 weeks. The patient underwent a successful, Impella-assisted balloon aortic valvuloplasty (BAV) without complications. Impella support may be considered during BAV in high-risk patients with contraindications for a TandemHeart device (CardiacAssist, Inc.).

J INVASIVE CARDIOL 2012;24(1):E19-E20

Key words: high-risk PTCA, interventional cardiology, valvular heart disease

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Surgical aortic valve repair is the optimal treatment for patients with severe aortic stenosis (AS). However, many patients with severe AS are elderly with significant comorbidities and are at high-risk for perioperative complications and death. When surgery is deemed too high-risk, percutaneous balloon aortic valvuloplasty (BAV) is a palliative option. Aortic valvuloplasty, while less risky than surgery, is still a high-risk procedure, especially in patients with severe coronary artery disease (CAD) and reduced left ventricular function who are not surgical candidates. In this setting, left ventricular assist devices may reduce major procedural complications. A case is described in which an Impella device (Abiomed), placed across the aortic valve, was used to assist with BAV.

Case Report. A 77-year-old woman with severe AS, a history of coronary artery bypass graft surgery, diffuse, critical stenoses in the remaining coronary arteries and vein graphs, reduced left ventricular function (ejection fraction 20%), severe restrictive lung disease, asthma, hypertension, diabetes mellitus, and chronic renal insufficiency presented with shortness of breath worsening over 2 weeks. Aortic valve replacement was deferred because of ischemic cardiomyopathy and advanced lung disease. Hemodynamic support was indicated during BAV because a procedural complication would have a high probability of causing death due to a low cardiac output (2.3 L/min), elevated right-sided pressures (pulmonary capillary wedge pressure 33, pulmonary arterial pressure 100/47), and critical CAD. Severe peripheral arterial disease precluded the use of a TandemHeart device (CardiacAssist, Inc.), so the Impella LP 2.5 device was used. BAV was performed with a 20 mm balloon while the Impella device was placed across the aortic valve. The patient’s mean aortic valve gradient was reduced from 13 mm Hg to 4 mm Hg; her aortic valve area increased from 0.58 cm² to 1.03 cm²; and her cardiac output increased from 2.34 to 3.18 L/min. The Impella access site was closed using a Perclose ProGlide device (Abbott Vascular) using the preclose technique. The patient tolerated the procedure well with no complications. The patient’s symptoms improved and she was discharged home 5 days later.

Discussion. The patient described was deemed too high-risk for surgical aortic valve replacement due to ischemic cardiomyopathy, severe restrictive lung disease, and prior sternotomy. As the population continues to age the number of poor surgical candidates with critical AS will increase. Moreover, if percutaneous aortic valve implantation becomes widespread, the use of BAV may increase as BAV is used to prepare the stenotic aortic valve for implantation of the prosthetic valve.1 For high risk, non-surgical patients, BAV is a less invasive, palliative therapy.^1-3

While less risky than open aortic valve replacement surgery, BAV is not without risk, especially in patients with severely depressed left ventricular function and critical CAD. In such patients, the procedural risk may be reduced with the use of left ventricular assist devices to augment cardiac output and unload the left ventricle. The intra-aortic balloon pump has minimal impact on cardiac output and would likely be insufficient in the presence of a major mechanical complication due to BAV. The TandemHeart device (Cardiac-Assist) may be preferred in this setting because it augments cardiac output without crossing the aortic valve. In the patient described, the severity of peripheral arterial disease, which is common in the elderly, precluded use of a TandemHeart device, which utilizes a 15 Fr inflow catheter, placed in the femoral artery. As such, the Impella device was utilized to reduce procedural risk in this patient. The Impella device is inserted through a 13 Fr sheath and placed across the aortic valve with an inflow chamber within the left ventricle and an outflow tract within the ascending aorta. The device was in place across the aortic valve during high-pressure balloon inflation, which successfully increased the aortic valve area. Impella-assisted BAV improved aortic valve parameters as described and improved the patient’s symptoms without complications.

The motor portion of the Impella device that crosses the aortic valve measures 12 Fr (0.127 cm²; 0.4 cm in diameter). This patient’s aortic valve area was 0.58 cm² (0.86 cm diameter). It has been reported that an Impella-assisted BAV was done on an aortic valve with an area of 0.4 cm² (0.71 cm diameter) without any complications. Thus, Impella assistance during BAV has been successful in a 0.4 cm² valve and efficacy might be limited in valves <0.4 cm².

Conclusion. BAV palliates symptoms in patients with severe AS who are not candidates for surgical aortic valve replacement. Left ventricular assist devices may reduce procedural risk during BAV. The Impella device was used successfully and without complications in our patient undergoing BAV for severe AS.

References

1. Hara H, Pedersen WR, Ladich E, et al. Percutaneous balloon aortic valvuloplasty revisited: time for a renaissance? Circulation. 2007;115(12):E334-E338.
2. Agarwal A, Kini AS, Attanti S, et al. Results of repeat balloon valvuloplasty for treatment of aortic stenosis in patients aged 59 to 104 years. Am J Cardiol. 2005;95(1):43-47.
3. NHLBI Balloon Valvuloplasty Registry Participants. Percutaneous balloon aortic valvuloplasty. Acute and 30-day follow-up results in 674 patients from the NHLBI Balloon Valvuloplasty Registry. Circulation. 1991;84(6):2383-2397.

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From the ¹Heart Institute, Good Samaritan Hospital, Los Angeles, California and ²Department of Cardiology, Good Samaritan Hospital, Los Angeles, California.
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 June 24 2011, provisional acceptance given June 28 2011, final version accepted July 6, 2011.
Address for correspondence: Bryan Schwartz, MD, Heart Institute, Good Samaritan Hospital, 1225 Wilshire Blvd., Los Angeles, CA 90017-2395. Email: bschwartz15@hotmail.com