Rupal Mehta @RupalMehtaMD
Rupal Mehta, MD is an Assistant Professor of Medicine in the Division of Nephrology and Hypertension and a core member of the Center for Translational Metabolism and Health within the Institute for Public Health and Medicine at Northwestern University Feinberg School of Medicine. Her research program uses complementary population-based and interventional patient-oriented research studies to identify and advance potential targets for the prevention and treatment of heart failure in patients with chronic kidney disease.
Competitors for the Heart Failure Devices Region
The cardiorenal region is at it again! In NephMadness 2022, diuretic resistance treatments made it to the championship round, and although a formidable opponent, lost handedly to social determinants of health. But we’re back! This year’s cardiorenal bracket is taking on a new look as we pair down from 32 to 16 teams – yay, one hurdle already won! This year, we’re focusing on heart failure devices.
The ultimate goal of mechanical support is to help promote myocardial recovery, or to bridge patients to destination durable assist devices or heart transplantation. Heart transplantation is limited by age restrictions, requirement of minimal comorbidity burden and a scarce donor pool. This launched the utilization of temporary and long-term circulatory support. Given the rapidly evolving strategies to treat advanced heart failure, many questions related to kidney function and kidney disease have emerged, along with lots of new acronym cardiology consults – AKI in the setting of PCI with Impella, IABP, ECMO, LVAD, RVAD, HM3! Nephrologists must ask themselves, what impact do these devices have on acute kidney injury? Can they help reverse kidney injury? Should chronic kidney disease populations be considered for these heart failure devices? And finally, do they improve cardiovascular, kidney or mortality outcomes?
It’s easy for one to reconcile that by improving hemodynamics and augmenting cardiac output using temporary mechanical support, we can improve renal perfusion, venous congestion and neurohormonal regulation. Renal recovery from acute kidney injury is likely an important surrogate for improved end-organ perfusion and better long-term outcomes. Some patients are even able to come off of acutely needing renal replacement therapy after implantation of heart failure devices, no small feat!
Implantation of long-term durable assist devices can also result in kidney function improvement in the acute setting. However, data demonstrate worsening kidney function over time after implantation. The 5-year survival for patients with long-term durable assist devices is just under 60%. Requiring renal replacement therapy after device implantation places patients at an even higher risk for death. Long-term dialysis in patients with left ventricular assist device therapy is also onerous. Finding suitable outpatient dialysis centers, management of hypotension and optimizing volume status are not easy tasks. But once again we must remember, what was the ultimate purpose of mechanical support? If we can allow time for myocardial recovery or bridge patients to heart or heart/kidney transplantation, that would be considered a huge success!
We are now seeing more centers implanting both temporary and durable mechanical support in patients with end-stage kidney disease. Although not surprising, seeing a study that shows median survival for patients with end-stage kidney disease receiving long-term durable devices to be 16 days is still shocking! It is a reminder that although end-stage kidney disease may no longer be an absolute contraindication for durable assist devices, we must be thoughtful and selective as providers. Patient selection is essential. We bear the responsibility to find candidates that will benefit from mechanical support while also remembering what our patients’ long term goals are.
The field of cardiac devices continues to rapidly evolve. Who knows, in the next decade, we may see even smaller, more physiologic and more hemocompatible devices that lead to better outcomes for patients with and without kidney disease. We may even see changes in dialysis therapy with wearable dialysis and implantable artificial kidneys! But until then, if there is ever an opportune time for mechanical support, it is likely early. Early enough to prevent kidney injury as appreciated with Impella support or intra-aortic balloon pumps in the setting of high-risk coronary revascularization, or early in the course of decompensated heart failure where acute kidney injury may still be reversible. End-stage kidney disease, whether it be before or after mechanical support placement, is likely a harbinger of badness. My vote is for devices in acute kidney injury!
– Guest Post written by Rupal Mehta @RupalMehtaMD
As with all content on the AJKD Blog, the opinions expressed are those of the author of each post, and are not necessarily shared or endorsed by the AJKD Blog, AJKD, the National Kidney Foundation, Elsevier, or any other entity unless explicitly stated.