Characteristics, Frequency, and Disposition of Patients With a HeartMate II Left Ventricular Assist Device Presenting to the ED
Abstract
Background: Left ventricular assist devices (LVADs) are used to treat patients with end-stage heart failure, either as a bridge to heart transplantation or as destination therapy for patients not suitable for heart transplant. The number of patients with LVADs and the number of medical centers in the United States involved in implantation of these devices is increasing. Although the HeartWare Ventricular Assist Device (Medtronic) is currently the most common implant, based on previous popularity, there are still more HeartMate IIs (HMIIs) (Abbott Laboratories) currently in use. Given the high likelihood that a patient with an LVAD will seek ED care at some point, emergency physicians must be able to identify and manage the complications associated with these devices.
The purpose of this study was to identify the type, frequency, and disposition of patients with an HMII LVAD who presented to an urban tertiary care referral center ED.
Methods: This was a retrospective study of patients with an HMII LVAD who presented to an urban ED between April 1, 2009 and September 9, 2012. All patients with an HMII LVAD who presented to the ED were included in the study, and there were no exclusion criteria. Electronic medical records were reviewed by study investigators to identify all ED visits by HMII LVAD patients during the study period to identify the reason for presentation, the frequency of ED visits, and final patient disposition.
Results: A total of 98 patients in the catchment area had an HMII LVAD implanted during the study period. Sixty-seven (68%) of these presented to the ED, for a total of 248 ED visits. The average number of ED visits per patient was 3.7. The most common reasons for presentation included bleeding (14.9%); volume overload (14.9%), weakness/lightheadedness/dizziness/syncope (9.6%), device malfunction (8.1%), and infection (2.8%). Approximately 56% of the ED visits were directly LVAD-related. Fifty-seven percent of the patients required admission to the hospital.
Conclusions: Approximately two-thirds of patients with an HMII LVAD presented to the ED, many of whom presented multiple times. The most common complications observed were bleeding and volume overload. Fifty-seven percent of these patients required hospitalization.
Another limitation of our study is the relatively small total number of patients (98) and that our findings may not apply to other patient populations. This limitation, however, would be true for any hospital system that limits the type of LVAD implant procedure to one manufacturer (HMII in this instance).
Conclusion
Emergency physicians must be prepared to evaluate the LVAD patient presenting to the ED. A little over 55% of the time, the visit will be directly related to the LVAD; in the remainder of cases, patient presentation will be due to a non-LVAD-related cause. At initial presentation, however, the EP should assume that the ED visit is related to the LVAD, until a thorough history and physical examination can exclude otherwise.
Because of the high incidence of GI bleeding in LVAD patients, a rectal examination for blood in the stool should be performed for any complaint that may be related, such as generalized weakness, syncope, or shortness of breath. In the majority of cases, a complete blood count; complete metabolic profile, including lactic acid dehydrogenase; and coagulation studies, including prothrombin time and INRs, are indicated. Most patients with an LVAD will require a member of the VAD team (typically the perfusionist or biomedical engineer) to interrogate the controller if there is any concern about its function, including alarm sounding or lights flashing.
