Kidney failure patients on dialysis often have other chronic diseases - heart disease topping the list. They're prescribed an average of 12 pills a day by physicians, according to Stanford nephrologist Tara Chang, MD, and they spend three-to-four hours at a treatment center three times a week connected to an artificial kidney machine.
For Chang, this makes it all the more important that any medication she prescribes for a patient on dialysis is both essential and effective.
The problem is, particularly in the case of treating kidney patients with heart disease, evidence-based treatment guidelines just aren’t available. Kidney doctors are left making best guesses based on guidelines written for the general population.
"Our patients might be different from patients not on dialysis," said Chang. "Dialysis patients have a lot of heart disease, yet rarely does a cardiology study enroll patients on dialysis, so we just don’t know."
This was part of the motivation behind Chang’s most recent study examining the use of anti-platelet drugs such as clopidogrel, one of the most commonly prescribed drugs for kidney patients. The researchers looked at the use of anti-platelet medications such as clopidogrel as treatment following stenting procedures to unclog arteries in the heart in 8,458 dialysis patients between 2007 and 2010. The data suggests that longer-duration of drug use may be of benefit to patients on dialysis who get drug-eluding stents but not those who get bare metal stents. Chang told me:
We found that for those who got drug-eluting stents who took the drug for 12 months compared to those who had stopped the drug at some earlier time point, there was a non-statistically significant trend towards lower risks of death and heart attacks. So for this group, following the same guidelines as for the general population may be appropriate. However, we found no indication of benefit with longer duration of anti-platelet drug use for patients on dialysis who got bare metal stents.
About half of the 400,000 patients in the U.S. on dialysis also have coronary artery disease, as referenced in the study. The number of those getting stents inserted to unclog arteries also has increased 50 percent in the past decade, the study states. The results of the study, while not definitive as to exactly how long doctors should prescribe the drug, does stress the need for more clinical research on patients with kidney failure to provide guidance on treatment strategies for heart disease.
"Because our study was not a randomized trial," said Chang, "we tried to be very measured in how we interpreted the results. What it does point to is the fact that we can’t assume that what works in non-dialysis patients works in dialysis patients. Hopefully our study will help convince researchers to include our dialysis patients in their studies."
The paper was published this week in the Journal of the American Heart Association.
Previously: Keeping kidney failure patients out of the hospital, Study shows higher rates of untreated kidney disease among older adults and Study shows daily dialysis may boost patients' heart function, physical health.
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