Major study clears Glaxo's Avandia of heart risk

* Large study shows no overall raised cardiovascular risk

* Confirms higher risk of heart failure, fractures

* Glaxo to submit latest clinical data to FDA

* Unclear if study will revive Avandia sales

By Ben Hirschler

LONDON, June 5 (Reuters) - GlaxoSmithKline's (GSK.L) controversial diabetes drug Avandia doesn't increase overall heart risks, according to final results of a large clinical study sponsored by the world's second largest drugmaker.

The so-called Record trial did, however, confirm that the medicine doubles the risk of heart failure -- a chronic condition where the heart struggles to pump enough blood around the body -- and also increases the danger of bone fractures.

Sales of Avandia, once Glaxo's second biggest drug, plunged in 2007 after a pooled analysis of past clinical trials by Cleveland Clinic cardiologist Steven Nissen concluded patients on Avandia had a 43 percent higher risk of heart attacks.