Acquisition candidate Guidant has revealed that another 54,000 of its early-model pacemakers may have faults that could cause them to fail with ‘serious health consequences.'

The medical device firm, currently the object of a tug of war between rival suitors Boston Scientific and Johnson & Johnson, said that a flaw in the hermetic sealing of the units could allow moisture to seep in.

In July, Guidant was forced to recall thousands of its pacemaker and defibrillator products as a result of the problem, which played havoc with its revenues in the latter half of the year, slicing 15% off fourth-quarter revenues. 78,000 devices were affected by this recall.

Nine models, encompassing 54,000 units manufactured between October 1998 and December 2000, are affected by the new warning, but together they account for only 1% of Guidant’s sales of the devices. The company said the US Food and Drug Administration may expand its recall notice as a result of the new finding.

Guidant said it estimated that 19,300 devices in this second device population remain implanted worldwide.

The news lends weight to the view that the current bidding war between Boston Scientific and J&J for Guidant could put the eventual winner at risk of overpaying for the company. Boston Scientific currently has the upper hand in the tussle, having pulled out all the stops with a $27.2 billion bid last week.