elevated liver sgmt levels & Cpk levels higly elevated

I started taking Toprol XL in Febr. 09. Since then my Cpk number has increased from 324 to 712 as of May 18th. The only drug new to my medication regime is 50 mg of Toprol XL. Since 2003 I have taken 1500 mg. of Niaspan, 40 mg. Zocor, 81 mg. of aspirin, 150 mg. of CoQ -10. I have not experienced any other physical signs--. Is there any evidence that the Toprol would cause the Cpk levels to rise and after taking the statin for 7 years that the liver function results would indicate a reason for stopping the statin? I am CABG patient since 2002-which is the reason for the medicine regime.