By Peter Laird, MD
The FHN daily and nocturnal studies were conducted by researchers who have exhibited contempt and disdain in earlier writings against frequent hemodialysis protocols. Certainly the writings of the lead investigator, Glen Chertow, give one pause. His key note address at the Annual Dialysis Conference shortly after the publication of the daily FHN results could hardly be called heartfelt endorsement of more frequent hemodialysis even though his study did show significant benefits.
Since the publication of the failed FHN nocturnal study that only recruited approximately one third of the expected patients, the continued negative rhetoric from the FHN trial group authors is baseless and lacks intellectual evaluation of their own study. This provides further evidence of their innate bias against this technology that does have a proven clinical track record for improving lives, focusing benefits of cardiovascular preservation and significantly improved patients activities of daily living. Any patient that has endured conventional in-center hemodialysis and then converted to daily nocturnal hemodialysis will so attest.
The latest assault against frequent hemodialysis sadly comes once again from one of the principle authors of the FHN nocturnal study, Yoshio Hall, MD.
The Frequent Hemodialysis Network Trial Group recently found that compared with conventional in-center hemodialysis (HD) that is performed three times a week, frequent in-center HD (6 times a week) improved self-reported physical health and functioning for patients with end-stage renal disease (ESRD) but had no significant effect on objective physical performance, according to a report in the Clinical Journal of the American Society of Nephrology 2012;7:782-794).
Frequent nocturnal dialysis, for its part, showed no significant effects on any of these physical metrics. Nephrologist and study coauthor Yoshio Hall, MD, Assistant Professor of Medicine at the University of Washington, Seattle, discusses his team's findings with Renal & Urology News.
Were you Surprised and/or diasppointed by these findings?
Dr. Hall: We hypothesized that increasing the frequency of hemodialysis might further improve overall physical capacity through perhaps better control of uremia, preservation of nutritional status and muscle mass, correction of acid-base imbalances, and reduction of interdialytic weight gain and volume overload.
If the above description of why the investigators hypothesized frequent hemodialysis, especially noctural daily hemodialysis would improve physical function was the operative theory leading to the flawed design of the FHN nocturnal study, then I must question their understanding of the proposed benefits of nocturnal dialysis from the confluence of observational studies over several decades. The greatest detriment to chronic hemodialysis patients physical function is from cardiovascular disease, especially LVH leading to poor fluid control and CHF. What Dr. Hall did not mention in his negative diatribe against frequent dialysis is that reduction in LVH was an important finding of the short daily FHN trial.
Frequent hemodialysis, as compared with conventional hemodialysis, was associated with favorable results with respect to the composite outcomes of death or change in left ventricular mass and death or change in a physical-health composite score but prompted more frequent interventions related to vascular access.
The FHN nocturnal study is a failed study that should not be the basis for questioning the value of daily nocturnal hemodialysis. The FHN nocturnal study unexpectedly failed to show any benefit in the composite outcomes measured. When evaluating this surprising finding, one must keep in mind that the FHN nocturnal study has several disabling flaws, not the least of which was their well-publicized difficulty in recruiting patients. Recruitment only improved when patients were offered two different forms of home hemodialysis instead of baseline comparison to conventional in-center hemodialysis.
Despite the fact that many American dialysis researcher’s believe that there is still a need to carry out a randomized control trial of nocturnal dialysis vs. conventional in-center dialysis, the majority of patients offered participation in the FHN nocturnal trial declined because they desired nocturnal home hemodialysis (NHHD) and refused randomization. In addition, we have over forty years of well done observational studies which are all in agreement of the benefits of NHHD. Nevertheless, researchers noted that failing to eliminate selection bias could explain the positive outcomes, thus justifying the call for further study.
Aside from recruiting only 87 of the needed 275 patients randomized to this trial, several other factors limit the ability to utilize any meaningful results. Of those randomized, nearly 50% of these patients were "incident" patients without LVH, limiting the possibility of "regression" of left ventricular mass by nocturnal hemodialysis in such a short study period. In addition, of those randomized to the nocturnal arm only 87% completed the 12 months study period and nearly 25% of those that did participate in the nocturnal arm failed to adhere to the five times a week nocturnal schedule demonstrating a surprising degree of noncompliance.
Studying subjects who were much younger and healthier at baseline looking for LVH regression is an exercise in absurdity. Unfortunately, many may use this failed study as a basis for excluding nocturnal dialysis treatment availability by calling it negative when it is null and void because it is underpowered, over selected and seriously flawed.
There is no reason to doubt the benefits of NHHD even with this publication. Despite the lack of a significant finding in this trial, the result is not because of a treatment failure, but instead due to severe flaws within the study itself, some of which I have noted above. There truly is no need for further studies before offering NHHD to more American patients. The biggest failure of the FHN nocturnal study is that they called for it in the first place. We have wasted nearly ten years waiting for this study to only find disappointment in its serious shortcomings. Many opposed this study from the outset, they were right then, they are right today. It is time to proceed with our best evidence, even if much of it is observational.
I am greatly sadened that such a respected researcher from of all places, the University of Washington in Seattle where Scribner lead the charge promoting longer and more frequent hemodialysis would venture such an unsupported opinion from such a failed RCT. It appears that any result that comes from a randomized and controlled trial must be accepted as gospel truth even though there are fatal errors in execution and design of this study.
I believe the lack of a cogent hypothesis may be the root cause of researchers such as Dr. Hall making absurd recommendations against more frequent hemodialysis. We know and understand that short, infrequent hemodialysis results in serious cardiovascular decline and poor fluid management over a period of years on convention in-center hemodialysis. How can a researcher expect to find differences among 87 patients who have a significantly lower mortality to start than the standard USRDS population, higher residual urine function than the original FHN nocturnal protocol specified, higher levels of incident dialysis and less vintage patients who would have had the opportunity to develop LVH and cardiovascular compromise in the first place.
Understanding the demographics of the study population of the FHN nocturnal study, it is not surprising at all that there were no significant differences in LVH and physical activity scores in the study subjects. After all, these were healthier than normal patients at the onset of the study without enough time on dialysis to develop the types of cardiovascular morbidity and pathology that nocturnal dialysis best prevents. Perhaps one day, a major medical journal will publish a McMaster type review of the FHN nocturnal study so that the nephrology community can place this study in it's proper place as a failed and poorly executed randomized and controlled trial that did not meet its set goals or standards. Until that time, it appears that we will be subject to more and more negative diatribes from the FHN authors. I find that a sad use of millions of dollars and patients lives.