It's important to realize that the predictability of a cardiac event with a high CAC score is...only if you do nothing. No lifestyle changes, no meds.
Make the all changes, take the meds and the chances of a heart attack can go way down.

For what it's worth, I had a terrible problem with statins. My current cardiologist and I tried every one on the Markey and I has stunningly-painful leg cramps within a week of starting any in them, including micro doses. So I wouldn't be surprised if statins are affecting muscles and tendons. There are a few newer non-statin, anti-cholesterol drugs on the market that, purportedly, don't take a toll on the musculoskeletal system. And there are over-the-counter phytosterols that a lot of people have good experience with so there are statin alternatives. And diet can affect the kind and molecule-size of cholesterol as well. Lastly, I'm a firm believer in getting second, or even third for something life-saving, opinions. But keep focused on what you can do next so that 'paralysis by analysis' doesn't overwhelm.