Source: DGNews  |  Posted 1 year ago

By John Otrompke

DENVER -- November 24, 2010 -- Cardiac surgeons may continue using the
antifibrinolytic agent epsilon-aminocaproic acid, as a study presented here at
the American Society of Nephrology (ASN) Renal Week 2010 shows evidence that
its use is not associated with the high acute kidney injury (AKI) caused by its
former competing agent, aprotinin.

“Antifibrinolytic agents are used in cardiac surgery to block the fibrinolytic
process, promoting some clotting and reducing bleeding,” said Jeremiah R.
Brown, PhD, Dartmouth Institute, Lebanon, New Hampshire, on November 18. “When
surgeons are tying in the vein grafts to the vessels, there’s a lot of bleeding
until the tissue reconnects and solidifies.”

Aprotinin was removed from the market in 2007, because of US Food and Drug
Administration concerns over a 50% greater risk in AKI, and higher 30-day
mortality, said Dr. Brown.

For the study, researchers analysed data from 2,333 patients who received
epsilon-aminocaproic acid and from 2,093 patients who received high-dose
aprotinin.

Consecutive patients undergoing cardiac surgery dialysis were excluded. All
patients received aprotinin before it was removed from the market.

The relative risk of 5-year mortality was 2.09 times greater for patients on
aprotinin than for those on epsilon-aminocaproic acid. Patients on aprotinin
also had longer duration of AKI (7 vs 3.8 days).

For those patients with an AKI of 1 or 2 days, the risk was 2.47 times greater;
for those with an AKI lasting between 3 and 6 days, the risk was 1.9 times
greater. For those with an AKI lasting >=7 days, the relative risk was 1.56
times greater for patients on aprotinin.

“Use of both drugs was off-label in cardiac surgery,” said Dr. Brown, noting
that aprotinin was usually used in high-risk cases.

“Now epsilon-aminocaproic acid is in routine use in medical centres, and is
associated with less nephrotoxicity,” said Dr. Brown, who suggested the trial’s
findings were supportive evidence to reassure surgeons that use of
epsilon-aminocaproic acid was not associated with the harmful effects of
aprotinin.

Duration of AKI may provide the sensitivity and specificity for evaluating
renal outcomes in clinical trials.

[Presentation title: Acute Kidney Injury Duration Varies by
Anti-Fibrinolytic Agent in Cardiac Surgery. Abstract TH-PO039]