N-Acetylcysteine for Preventing Renal Injury After Cardiac Surgery
Status:
Completed
Trial end date:
2007-07-01
Target enrollment:
Participant gender:
Summary
Cardiac surgery improves the survival and quality of life of people with heart disease.
Nonetheless, several complications continue to adversely affect outcomes following cardiac
surgery. Kidney failure is a particularly important complication that is associated with
increased death and duration of hospitalization. The most severe form of postoperative kidney
failure, the need for dialysis, is uncommon at present. It is however likely to increase in
the future. Patients undergoing cardiac surgery are getting older with more heart failure,
diabetes, high blood pressure, and pre-existing kidney disease. Given that these are risk
factors for postoperative kidney injury, dialysis rates will likely increase. Although
multiple therapies have been tested, none have prevented postoperative kidney failure.
N-acetylcysteine (NAC) is a drug that is commonly used to treat Tylenol overdoses. Over the
past 2 years, it has also been used to prevent kidney damage after exposure to IV dye. There
is good evidence that NAC will reduce kidney damage after IV dye exposure. There are strong
reasons to believe that NAC may also prevent postoperative kidney failure. NAC is safe. Its
major side-effects are allergic reactions, but serious reactions are rare. Since dialysis is
uncommon, large studies are needed to determine if NAC prevents postoperative dialysis. In
this situation, a pilot study is needed to determine if such a large trial is feasible. This
proposal describes a pilot study. We will determine NAC's effects on creatinine clearance, a
measure of how well the kidney works. Reduced creatinine clearance is closely related to
dialysis and death after cardiac surgery. This biological marker allows us to determine NAC's
effects on kidney function with a reduced sample size. If NAC improves creatinine clearance,
it would suggest that NAC prevents postoperative dialysis, and would justify a larger study.
A pilot study will help us estimate how many patients will be willing to participate in
similar studies, vital for planning a future large study. Finally, our results will estimate
how well NAC will reduce dialysis rates. This is needed for calculating the sample size for
future studies.The study design is a randomized, double-blinded, placebo-controlled clinical
trial among patients undergoing bypass surgery or heart valve surgery at the Toronto General
Hospital (Toronto, ON). We will recruit 176 people who are at increased risk for developing
kidney failure after surgery. Participants will receive either NAC or sugar solution during
their operation. If participants have returned home within a month of surgery, they will be
contacted at home on the 30th day after surgery to determine if they had any kidney-related
problems since returning home. All participants will return to the Toronto General Hospital
(TGH) during the 8th week after surgery for creatinine blood test and weight.