Diuretics vs. Ultrafiltration: Isn’t the debate settled yet?

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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

1 comment

  1. I have definitely noticed a difference of opinion between the nephrologists and cardiologists with UF. The nephrologists seem hesitant about its efficacy and concerned about the potential complications (one important factor that non-nephrologists don't usually think of is ruining future access with PICC lines). The cardiologists at my institution are much stronger believers, although it certainly isn't used as a first line therapy.

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