We have all been called in to see patients who have developed AKI after receiving mechanical ultrafiltration (UF) for acute decompensated heart failure (ADHF). In almost all situations I have experienced, UF was started early, perhaps without optimization of diuretic therapy. The UF program at our institution is run by the Cardiology service. In spite of the weight of the current evidence, I have seen a distinct specialty specific bias towards UF (Cardiology), and against UF (Nephrology).
After I received the nth consult for AKI in the above setting, I decided to review some evidence for a cardiologist friend. I thought it’ll make for a review of a pertinent situation that we all will continue to face.
In brief, three major randomized trials have compared UF against diuretics in ADHF, over the last eight years. The first one was the RAPID-CHF trial. The primary end point was weight loss at 24 hours. A larger trial was published in 2007, the UNLOAD trial. Both these trials showed a greater rate of fluid loss with UF than diuretic use. The UNLOAD trial also showed fewer rehospitalizations at 90 days, for the UF group. From a renal perspective, there was no significant increase in creatinine with UF reported in either trial.
The results from the above two trials really made UF almost a “first line” treatment for ADHF. On top of it all, I saw data from a study in Italy increasingly (and perhaps, erroneously) getting extrapolated to UF use for treatment of ADHF. Essentially, the Italian study had shown that intermittent hemodiafiltration could increase diuretic responsiveness and reduce the level of inflammatory cytokines. Equating hemodiafiltration to ultrafiltration would make me cringe as I struggled to explain the difference to my cardiology colleagues!
Finally, we had the CARRESS-HF trial late last year which tried to answer the same question in a slightly different way (stepped algorithm for dosing diuretics vs UF). At 96 hours, there was no significant difference in weight loss between the two groups. The primary end point of increase in serum creatinine was significantly worse in the UF group. The UF group also showed a significantly higher rate of other serious adverse events (eg, bleeding, anemia, thrombocytopenia, dyselectrolytemia, sepsis, heart failure). There also was a trend towards higher mortality for patients who received UF.
Given the relatively recent nature of the evidence against UF, it might be some time before we see a universal change in clinical practice. So I guess we nephrologists will continue to see patients of refractory ADHF with AKI, where perhaps diuretics weren’t used in a stepped fashion, or UF was used early. At this time, the American College of Cardiology recommends that UF be used only as a second line treatment for patients who do not respond to diuretic optimization.
I am curious to know what your experience has been in this setting? Have you experienced a difference of opinion between nephrologists and cardiologists?
Posted by Veeraish Chauhan
Posted by Veeraish Chauhan