In a research note Tuesday, Fitch Ratings said Energy Future Holdings’ bankruptcy pushed the U.S. leveraged loan trailing 12-month rate to a multiyear high of 3.9% in April.

Fitch notes that leveraged buyout defaults stemming from deals between 2004 and 2007 have affected $55.3 billion in bonds and $64.5 billion in institutional leveraged loans.

Among the $161 billion in institutional leveraged loan defaults between 2007 and April 2014, LBOs accounted for 41% of the total, with Energy Future Holdings accounting for 12% alone.