Author + information
- Nowell M. Fine, MD,
- Sahar S. Abdelmoneim, MBBCh, MSc,
- Amy Dichak, RDCS,
- Sudhir S. Kushwaha, MD,
- Soon J. Park, MD, MS and
- Sharon L. Mulvagh, MD∗ ()
- ↵∗Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55901.
Transthoracic echocardiography (TTE) is an important tool for the evaluation of cardiac and device function in left ventricular assist device (LVAD)–supported patients. Echocardiographic imaging may be technically challenging in some LVAD patients because the position of the device and its inflow and outflow cannula may obscure standard acoustic imaging windows. Ventricular cavity opacification using ultrasound contrast agents enhances endocardial border detection and improves assessment of chamber dimensions and systolic function (1); however, to date, only a single case report describes the use of a contrast agent in an LVAD patient (2). The purpose of this report is to describe the feasibility, safety, and efficacy of contrast echocardiography (CE) in LVAD patients from a single-center experience.
We retrospectively reviewed the records of patients with an implantation of an LVAD followed at our center between November 2005 and April 2013. Patients who received an ultrasound contrast agent during clinically indicated TTE were identified. Commercially available contrast agents were used during the study period: Optison (General Electric Healthcare, Princeton, New Jersey) or Definity (Lantheus Medical Imaging, Billerica, Massachusetts). CE was performed in accordance with American Society of Echocardiography guidelines, using the same protocol as that used for non-LVAD patients (1). According to our echocardiography laboratory's CE clinical protocol, the efficacy of CE for aiding image interpretation was reported by the interpreting echocardiologist at the time of CE as the following: aided image interpretation, worsened image interpretation, or did not change image interpretation.
During the study period, a total of 2,323 TTE studies were performed in 251 LVAD patients. Of them, 10 patients (4.0%) underwent a total of 12 CE studies (0.5%) (2 patients had repeat CE examinations). All patients underwent CE due to suboptimal endocardial border definition during noncontrast TTE. All but 1 patient was supported by a HeartMate II (Thoratec Corporation, Pleasanton, California) continuous-flow LVAD, and this patient was supported by a HeartMate XVE (Thoratec Corporation) pulsatile-flow LVAD. CE was performed successfully in all patients. Definity contrast was used in 9 CE examinations, and Optison was used in 3. Representative 2-dimensional echocardiography images before and after contrast administration are shown in Figure 1. The use of contrast aided image interpretation in 10 CE examinations (83%) and did not change image interpretation in 2 (17%). CE contributed to a change in LVAD patient management in 5 examinations (42%), including adjustment of pump speed in 3 patients, intensification of inotrope support in 1 patient after identification of severe right ventricular systolic dysfunction, and intensification of anticoagulation therapy in 1 patient after identification of a previously unrecognized nonobstructive left ventricular apical thrombus adjacent to the LVAD inflow cannula (Fig. 1, Online Video 1). No adverse events or known side effects of ultrasound contrast agents were reported during or after CE in any patient. Importantly, no changes in device function parameters were noted during or after CE.
To our knowledge, this is the first report to describe the use of CE in multiple LVAD patients. CE was successfully performed using a standard imaging protocol used for non-LVAD patients. Uncertainty regarding both the risk of causing adverse reactions or device function interference and the feasibility of diagnostic image acquisition during continuous blood flow into the device cannula has likely led to a significant underuse of CE in this population. Even at our institution, CE was used in only 0.5% of TTE studies performed on LVAD patients, although it is likely that many more would have benefited from its use. By comparison, CE is used in ∼5% of all resting TTE studies in our laboratory. In summary, CE was feasible and safe and improved image interpretation in a small sample of LVAD patients undergoing clinically indicated echocardiography. CE should be used as needed during the echocardiographic evaluation of LVAD patients with technically difficult images.
For a supplemental video, please see the online version of this article.
Please note: Dr. Mulvagh has received research grants from Lantheus Medical Imaging. Dr. Park is a consultant for Thoratec Corporation. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation