What are the chances for open heart surgery to fail?

My best friend has a heart problem, and will need to do open heart surgery. We're both really afraid that she'll die. Does anyone know how many chances she has of surviving?

This statistic will help it's an abstract hope it helps you out.
Change of the surface temperature of the leg during open-heart-surgery was determined in five patients, in whom either side of the femoral artery was ligated for cannulation. While the surface temperature at the patella was least influenced, that at the ankle paralleled closely the changes in the core body temperature and blood supply to the leg. Their difference(P-A difference) was studied to see if they can be used to predict prognosis of patients undergoing open-heart surgery. The P-A difference was followed for several hours after the open-heart surgery. It was marked positive when the surface temperature at the patella was higher than that at the ankle. Total of 54 patients were studied. Only one out of 29 patients with negative P-A difference succumbed. This is in sharp contrast to the 25 remaining patients with positive P-A difference, from whom as many as 12 died. In addition, the postoperative course of the 13 survivors from the latter group was more eventful. Since P-A difference seemed to indicate accurately cardiac output by reflecting the state of the peripheral circulation, it can be used as a useful parameter in prediction of the prognosis in open-heart surgery.

100% to fail, or have you ever heard
of a heart client still living after years
and never dying in the end?
I have no report, who ever.