Feb. 8 (HealthDay News) -- While use of the clotting drug aprotinin (Trasylol) appears safe during on-pump cardiac surgeries, combining it with angiotensin-converting enzyme (ACE) inhibitors during off-pump cardiac surgery shows a significant risk of postoperative kidney dysfunction, British researchers say.

The study was prompted by previous research that noted an association between use of aprotinin -- which reduces the risk of bleeding during complicated surgeries -- and renal failure. Drug maker Bayer voluntarily suspended worldwide marketing of aprotinin after preliminary findings from a Canadian study (BART) suggested the drug increased the risk of death. That trial was halted in October 2007. Shortly after that, the U.S. Food and Drug Administration pulled the drug from the American market.

For this study, researchers analyzed the cases of 9,875 cardiac surgery patients. Most of the patients (5,434) had on-pump cardiac surgery, which means their hearts were stopped and they were hooked up to a heart-bypass machine during surgery. The other patients had off-pump cardiac surgery -- doctors operated on their beating hearts.

Among patients who had on-pump surgery, there was no significant association between aprotinin and postoperative renal dysfunction, irrespective of ACE inhibitor use. However, aprotinin was associated with a more than twofold increased risk of renal dysfunction among the 848 patients who had off-pump cardiac surgery and received both aprotinin and ACE inhibitors.

"We recommend that it might be beneficial for patients to discontinue any use of an ACE inhibitor before elective off-pump surgery, particularly patients with a history of renal impairment," wrote Dr. Ronelle Moulton and Kai Zacharowski, from the department of anesthesia, Bristol Royal Infirmary, United Bristol Healthcare Trust.

Their study was published in this week's issue of The Lancet.

A complete analysis of the BART findings will not be known for some time, Dr. Derek Hausenloy, of The Hatter Cardiovascular Institute, University College London Hospital and Medical School, and colleagues wrote in an accompanying comment.

"While waiting for that analysis, the use of aprotinin in the U.S. and in some European countries has been necessarily restricted, with the consequence that some high-risk patients having cardiac surgery might not receive optimum therapy," Hausenloy and colleagues noted.

SOURCE: The Lancet, news release, Feb. 7, 2008