VENTRICULAR ASSIST DEVICE: AN UNDERUSED, LIFE-CHANGING MODALITY
Grace Oon Bee Gan UCD School of Medicine, University College Dublin, Belfield, Dublin 4.
Dr Alan Jacobsen, UCD School of Medicine, University College Dublin, Belfield, Dublin 4
Left ventricular assist device (LVAD) is a novel therapy in the treatment of end-stage heart failure. This technology may be used as a bridge to transplant or as destination therapy in patients who are not suitable for heart transplant. This paper presents the case of a gentleman at 11 months post-LVAD implantation who is currently awaiting heart transplant surgery. Over the years, research has shown improved long-term survival rates in ventricular assist device patients.
Cardiovascular disease remains the most common cause of death in Ireland, accounting for 30.6% of total deaths in 2014.  While heart transplant is the gold standard for treating end stage heart failure, due to the shortage of donors and ineligibility of some patients for transplant surgery, this option is not always available. In such patients a LVAD may be used. This device acts as a pump in place of the failing heart. The device consists of an inflow tube from the left ventricle connected to a pump and an outflow tract to the aorta. LVADs are powered by an external battery connected to the pump via a driveline. The first generation pulsatile LVADs (HeartMate XVE, Thoratec Corporation, United States) have now been largely replaced by the smaller more durable second generation continuous flow LVAD (HeartMate II, Thoratec Corporation, United States). Interestingly, Canseco et al. recently reported that LVADs were underutilized in clinical practice given the improvement in cardiac function associated with its long-term use.
This 50-year-old gentleman was seen in clinic 11 months post-LVAD implantation. He had been previously well until August 2014 when he suffered an acute ST elevation myocardial infarction while working in the United Kingdom. He was driving when he suffered acute central chest pain associated with dyspnoea and a sense of impending doom. He denied palpitations, syncope, or nausea and vomiting. He was brought in by ambulance to hospital where he was diagnosed with ST elevation myocardial infarction. An emergency angiogram revealed a large left main stem thrombus and occlusion of his left anterior descending artery. Following an emergency percuteaneous coronary intervention to his left anterior descending artery, he developed cardiogenic shock necessitating utilization of an intra-aortic balloon pump. His ejection fraction continued to deteriorate and he received veno-arterial extra-corporeal membrane oxygenation (ECMO) on day 5 of admission. On day 9 he was transferred from ECMO to an LVAD. His right heart function continued to deteriorate necessitating conversion to a bilateral ventricular assistdevice (BIVAD) on day 14. His hospital stay was further complicated by acute kidney injury and respiratory failure.
HE WAS DRIVING WHEN HE SUFFERED A SENSE OF IMPENDING DOOM
Over the next 3 months he improved sufficiently to be taken off BIVAD. At this stage the patient was on the newer second-generation LVAD and was well enough to be transferred back to Ireland where he spent 1 month as an in-patient in a high dependency unit. Four months after initial admission he received an automatic implantable cardioverter defibrillator for primary prevention of arrhythmias. This is routine for all patients on LVADs as they are unable to receive cardiac compressions due to the high risk of dislodging the device.
OUTCOME AND FOLLOW UP
The patient completed his heart transplant work-up 6 months post-LVAD surgery. Unfortunately, his transplant is likely to be delayed due to the success of the LVAD itself and because donors of his height are scarce. He has adapted well to living with an LVAD and has a positive outlook on life. He has greatly improved his lifestyle, has ceased smoking and does regular exercise. His heart failure is controlled with spironolactone, bisoprolol, furosemide, aspirin, ramipril, atorvastatin and sildenafil. He is anticoagulated with warfarin (currently supratherapeutic) and his target INR is 3.1. At an 11-month follow-up, he denied any complications associated to the LVAD such as infection, thromboembolism or device failure.
Since its introduction into clinical practice, VAD technology has significantly improved survival rates among patients with end stage heart failure. Patients receiving the second generation LVAD as destination therapy were shown to have almost three times better survival at 2 years compared to those on best medical therapy. Moreover, patients on LVAD reported better quality of life than those on medical therapy, calculated based on the Minnesota Living with Heart Failure Questionnaire .
Two major causes of mortality in patients with first generation LVADs were infection and mechanical failure. Patients with LVAD are at high risk of infection as the driveline exiting the skin is a potential sight of bacterial and fungal colonization. The incidence of mechanical failure has been greatly reduced with the more durable second generation LVADs. Nevertheless, it is important to note that the risk of complications is higher in VAD patients than those on medical treatment.
Despite these better survival rates, Miller et al. reported an underutilization of LVADs in clinical practice. As a comparison, the number of new VAD implants per year in the U.S. was estimated at 1700, as opposed to only 430 a year in Europe. In Ireland, there are currently only 5 patients with an LVAD. This small number is primarily due to the expense of the device and the low availability of VAD centres. At present there is only one VAD centre in Ireland. Additionally, certain demographic groups have been shown to be less likely to receive an LVADs, including women. This may have previously been due to the large size of first generation pulsatile LVADs relative to the size of the average female body. However, with the introduction of the smaller second generation LVADs it is expected that in the coming years there will be a rise in VAD implantation among women with end-stage heart failure.
Furthermore, difficulty in patient selection for LVAD surgery has been a limiting factor. There are currently no consensus guidelines for the utilization of LVAD. The following are some considerations taken into account:
- NYHA Class IV
- Life expectancy less than 2 years without VAD
- Patient does not meet transplant criteria
- Heart failure refractory to medical treatment at least 60/90 days
- Left ventricular ejection fraction less than 25%
- Cardiogenic shock or cardiac failure unresponsive to medical treatment
- IV inotrope therapy to be discontinued due to systemic failure
- Potential for recovery from heart failure
- Other terminal illnesses such as malignant metastases
- Patients above 65 years of age with both right and left heart failure
- Impaired ability to care for device (e.g. neurological or psychiatric illnesses)
- Active systemic infection
- High risk of renal or hepatic failure
- Anticoagulation contraindicated (e.g. recent hemorrhagic stroke)
Table 1: Indications and contraindications for LVAD 
Concrete funding schemes as well as precise guidelines are required before LVAD can be considered an equally viable alternative to heart transplant.
The use of LVAD in end-stage heart failure patients has been proven to be more effective than conventional medical therapy. Utilization of this modality of treatment is expected to rise in various demographic groups in the coming years either as a bridge-to-transplant or as destination therapy.
The VAD routine was very difficult to begin with. The patient was required to connect batteries every morning and was not able to work or to lift heavy loads. In regards to aftercare, it is possible that the wound site should be checked more often for infection and that the family should be more involved with access to councillors and psychiatrists. The patient’s outlook for the future is to receive a transplant and to try and lead a normal healthy life as much as possible, both before and after the transplant.
The author would like to thank Dr Alan Jacobsen and Dr Aideen Gough who contributed greatly by reviewing this case report. Thanks also extended to the patient who consented for his case to be used for educational purposes.
- Central Statistics Office. Vital Statistics Yearly Summary [Internet]. Dublin: Central Statistics Office; 2015 [updated 2015 May 29; cited 2015 October 3]. Available from: http://www.cso.ie/en/releasesandpublications/ep/p-vsys/vitalstatisticsyearlysummary2014/
- Canseco DC, Kimura W, Garg S, Mukherjee S, Bhattacharya S, Abdisalaam S, Das S, Asaithamby A, Mammen P, Sadek H. Human Ventricular Unloading Induces Cardiomyocyte Proliferation. Journal of the American College of Cardiology. 2015 March; 65(9):892-900.
- Grossman S, Brady W, Brown D, Rosen P. Cardiovascular Problems in Emergency Medicine: A Discussion-Based Review. West Sussex: Wiley-Blackwell; 2011.
- Rose E, Geljins A, Moskowitz AJ, Heitjan DF, Stevenson LW, Dembitsky W, Long JW, Ascheim DD, Tierney AR, Levitan RG, Watson JT, Meier P, Ronan NS, Shapiro PA, Lazar RM, Miller LW, Gupta L, Frazier OH, Desvigne-Nickens P, OZ MC, Poirier VL. Long-Term Use of a Left Ventricular Assist Device for End-Stage Heart Failure. New England Journal of Medicine. 2001 Nov; 345:1435-1443.
- Cowger J, Sundareswaran K, Rogers JG, Park SJ, Pagani FD, Bhat G, Jaski B, Farrar DJ, Slaughter MS. Predicting Survival in Patients Receiving Continuous Flow Left Ventricular Assist Device. Journal of the American College of Cardiology. 2013 Jan; 61(3):313-321.
- Miller L. Is Left Ventricular Assist Device Underutilized in the Treatment of Heart Failure? American Heart Association Journal. 2011; 123:1552-1558.
- Birks E. The Comparative Use of Ventricular Assist Devices. Difference between Europe and the United States. Texas Heart Institute Journal. 2010; 37(5): 565-567.
- Wilson S, Mudge G, Stewart G, Givertz M. Evaluation for a Ventricular Assist Device. American Heart Association Journal. 2009: 119: 2225-2232.