276. Left Ventricular Assist Devices and Renal Dysfunction with Dr. Brian Houston and Dr. Nisha Bansal

CardioNerds (Dr. Amit Goyal), Dr. Sonu Abraham (CardioNerds Ambassador from Lahey Hospital and Medical Center, Burlington, MA) discuss left ventricular assist devices (LVAD) and the implications of renal dysfunction with Dr. Brian Houston and Dr. Nisha Bansal. This episode will focus on the intersection of left ventricular assist devices and renal dysfunction. Patients with a combination of heart failure and renal dysfunction overall have a guarded prognosis and their management poses unique challenges to the clinician. We initially discuss the basics of an LVAD and general approach to LVAD candidacy evaluation. We then discuss specific implications of acute kidney injury, presence of preexisting CKD, and end stage renal disease in patients with/being considered for an LVAD. Risk factor identification and prognostication allows for appropriate selection of the right candidates for an LVAD in the context of renal disease. Dr. Brian Houston is the Director of the Mechanical Circulatory Support program at Medical University of South Carolina. Dr. Nisha Bansal is an Associate Professor and the Arthur Stach Family Endowed Professor in the Division of Nephrology, an investigator at the Kidney Research Institute, the Director of Nephrology Clinical and Research Education, and the Director of the Kidney-Heart Service at the University of Washington. Notes were drafted by Dr. Sonu Abraham and episode audio was edited by student Dr. Chelsea Amo-Tweneboah. Check out the CardioNerds Failure Heart Success Series Page for more heart success episodes and content! CardioNerds Heart Success Series PageCardioNerds Episode PageCardioNerds AcademyCardionerds Healy Honor Roll CardioNerds Journal ClubSubscribe to The Heartbeat Newsletter!Check out CardioNerds SWAG!Become a CardioNerds Patron! Pearls - Left Ventricular Assist Devices and Renal Dysfunction End stage renal disease (CKD on dialysis) is considered an absolute contraindication for LVAD implantation. Select young patients who are being considered for heart-kidney transplantation in the near future may be candidates for an LVAD as a bridge to heart-kidney transplantation. LVAD implantation can improve kidney function in the short term in patients with AKI primarily caused by cardio-renal syndrome. Patients with pre-existing CKD (not dialysis dependent) have a greater risk of developing AKI after LVAD implantation. Several dialysis modalities including in-center hemodialysis, home hemodialysis, and peritoneal dialysis are available for LVAD patients. However, there are several challenges associated with each modality. An AV graft is a useful vascular access option in LVAD patients undergoing hemodialysis due to a lower risk of infection and ease of immediate use. Causes for anemia in patients with an LVAD and renal dysfunction include anemia of chronic disease, gastrointestinal bleeding, and pump thrombosis leading to hemolysis. Show notes - Left Ventricular Assist Devices and Renal Dysfunction Notes: (drafted by Dr. Sonu Abraham) What is a left ventricular assist device (LVAD) and what are its components? An LVAD supports circulation by unloading the left ventricle and providing increased cardiac output to help support organ perfusion. Use in properly selected patients is associated with improved quality of life and increased survival. The current iteration of LVADs offer continuous flow, as opposed to the older versions which employed pulsatile flow. Components of the LVAD: Inflow cannula (sucks blood from the LV) Pump Outflow cannula (dumps blood into the aorta) Percutaneous driveline Electrical controller How is a patient evaluated for LVAD candidacy? The 2 main questions to be answered during the evaluation of a patient for an LVAD are: 1. Are they sick enough? Do they have end stage heart failure? 2. Do we expect the benefits of an LVAD to outweigh the risks? Presence/absence of right ventricular failure Other life limiting organ failure: Kidney failure/lung disease/liver failure/vascular disease Anatomic concerns (ex. LV size) Surgical risk (ex. Prior sternotomies, calcified aorta, etc) Psychosocial aspects Shared decision making (Does the patient want the device?) What are the outcomes of patients with end stage renal disease (chronic kidney disease on dialysis) after LVAD implantation? Patients with ESRD have a high burden of comorbidities. 40% of dialysis patients have heart failure. The combination of heart failure and ESRD propounds a poor prognosis. Patients with ESRD without heart failure have a 40% survival in 5 years. Conversely, those with ESRD and heart failure have a 30% after LVAD implantation. In patients who have AKI after LVAD implantation, 30-day mortality is 18% and 1 year mortality is 40% with increased risk of infection, multisystem organ failure, and longer length of stay. Common causes of AKI after LVAD implantation include:Right ventricular failureBleeding requiring blood products and crystalloids, contributing to congestion.Longer cardio-pulmonary bypass Hemolysis Based on a 10-year case series from the Mayo clinic, 15% of patients with LVAD require renal replacement therapy. If GFR<45 and there is proteinuria, the risk increased to 40%. The 4 risk factors to predict AKI and RRT requirement after LVAD: Presence of a low GFR Proteinuria Increased RA pressure Longer cardio-pulmonary bypass time The HEARTMATE III Risk Score provides individual survival prediction at 1- and 2-years post LVAD implantation - includes BUN and sodium levels What are the options available to patients in terms of long-term dialysis once LVAD patients are dialysis dependent? There are 3 main options for long term RRT:In-center hemodialysisHome hemodialysis Peritoneal dialysis Considerations:In center Hemodialysis:Challenges: large ultrafiltration rates can lead to lower MAPs, anticoagulation considerations (bleeding complications), high risk of infection (central venous catheter), pragmatic challenges (technical expertise of the dialysis staff, comfort of the attending nephrologist, transportation issues). Peritoneal dialysis:Benefits: decreased risk of infection (however anatomical considerations with respect to proximity to the driveline should be taken into account), more physiological and less hemodynamic instability, no need for anticoagulation. Challenge: home based therapy (burden on the patient and family members) What are the options in terms of vascular access in patients with an LVAD who are started on hemodialysis? Central venous HD catheters – high risk of infection and therefore, not preferred. AV fistula – low rates of infection, however, it takes 2-3 months for fistula maturation. AV graft – preferred due to lower risk of infection, ability to use immediately. What are the causes for anemia in patients with an LVAD and renal dysfunction? Anemia of chronic disease Increased risk of gastrointestinal bleedAnticoagulation requirementAcquired Von Willebrand deficiency Higher burden of arterio-venous malformations Pump thrombosis can lead to hemolysis