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Background: Left ventricular assist devices (LVAD), while lifesaving, are also often associated with their own problems and complications including malposition of the inflow cannula, ventricular tachycardia (VT), cannula obstruction, and/or pump thrombosis. There may be a role for cardiac CT to evaluate these LVAD patients.
Methods: We reviewed our radiology and cardiology database to identify LVAD pts who had been referred to cardiac CT as part of a workup of a new clinical problem and/or potential complication of LVAD such as ventricular tachycardia, low flow alarms, and/or suspected pump thrombosis.
Results: We identified 128 CTs for evaluation of LVAD. The majority of pts were men (69%) and African-American (61%) with non-ischemic CMP (61%). CT was ordered for arrhythmia (9%), low flow alarms (32%), suspected throombosis (usually due to abnormal lab values of LDH and haptoglobin) (31%), or to evaluate for thoracic adhesions (26%). The LVAD was Heart Mate II in 32%, and HeartWare in 68%.
In VT pts, endocardial contact with the inflow cannula was identified in 45% (vs. 19% of other LVAD CTs). In low flow alarm pts, inflow cannula obstruction was identified in 2.5% (vs. 11% of other LVAD CTs), while thrombus was seen in 17% of low flow alarm CTs (vs. 18% of other LVAD CTs). In suspected pump thrombosis pts, thrombus was seen in 11% (vs. 8% of other LVAD CTs). Outcomes included PCI (of the outflow graft) in 3 pts, 9 operations (8 LVAD exchanges), and 1 in-hospital death.
Conclusions: Endocardial contact of the inflow cannula is common, and more so in LVAD pts with VT. Inflow cannula obstruction is uncommon, and is usually not identified in low flow alarm LVAD pts. Pump thrombosis is more common that inflow cannula obstruction in these pts. In LVAD pts with suspected pump thrombosis, the detection of visible thrombus is rare, and no different than LVAD pts referred to CT for other reasons. While cardiac CT has the potential to yield useful information in the LVAD pt experiencing a variety of problems, its utility is limited by metal artifact and inability to visualize pump interior and small thrombi. In rare cases however, CT may reveal dramatic findings that drive subsequent percutaneous intervention and/or LVAD pump exchange.
Poster Hall, Hall C
Friday, March 17, 2017, 10:00 a.m.-10:45 a.m.
Session Title: Non Invasive Imaging: Applications in Novel Disease States and Clinical Scenarios
Abstract Category: 27. Non Invasive Imaging: CT/Multimodality, Angiography, and Non-CT Angiography
Presentation Number: 1117-206
- 2017 American College of Cardiology Foundation