The main cause of mortality in patients with Dermatomyositis, Polymyositis, Anti-Synthetase Syndrome, Anti-MDA5, etc is respiratory failure. This may be due to infection, the unrelenting autoimmune attack, or both.
Unfortunately, once intubated, very few survive.
Given the widespread use of statins, it should not be surprising that it is the most common cause of an elevated CK. This is seldom very high, and patients may not experience bothersome myalgia.
For those who are very symptomatic, or if the CK exceeds 10 times above upper limit of the normal range, the statin may need to be replaced.
Unfortunately, Ezetimibe reduces LDL but this is not commensurate with reduction in cardiovascular events, while Evolocumab promises to be pricey.
For more details on statin-induced myopathy, read the following posts.