7 Tesla MRI Study in Patients With Statin Related Muscle Complaints

Overview

Roughly 5-10% of statin-treated patients report muscle pain, aches, weakness, cramps, stiffness, or "heaviness" - typically occurring symmetrically in the legs. For healthcare providers, the major diagnostic challenge is to unambiguously link these symptoms to statin use, especially since some patients can have normal serum creatine kinase (CK) levels despite demonstrable weakness and muscle biopsy proven statin-induced myopathy . No well accepted, standardized, or Food and Drug Administration (FDA)-endorsed diagnostic method exists for statin-induced muscle injury. This lack of an objective diagnostic methodology blocks vertical advancement of the field. The successful completion of this project will develop in vivo techniques that will provide insight into how statins affect muscle metabolism and help establish a methodology to objectively diagnose muscle injury due to statins. The development of an MRS technique will allow for in-vivo analyses and the data accumulated here will serve as preliminary data for futher extramural funding of studies with much larger sample sizes. Ultimately, this focus of research will lead to improved diagnosis and treatment of patients with statin-related muscle complaints, which is central to obtaining the cardiovascular risk reduction from lipid-lowering drugs.

The goal of the first study will be to generate hypothesis regarding the long-term effects of statin in muscles by studying 7T MRS findings in patients who are currently experiencing statin-related muscle complaints or who have a history of severe reactions to statins (i.e. rhabdomyolysis, anti-HMGCR-associated autoimmune myopathy, or CK elevation \> 10 times the upper limit of normal). We anticipate enrolling roughly 5 such patients. The protocol involves a single visit for a blood draw and MRS of calf muscle. The data will be compared to historical controls provided by the Advanced Imaging Research Center. Second, we will study the effect of short-term statin administration in 5 patients with a history of statin related muscle complaints and 5 controls with no statin related muscle complaints . Controls will be matched for age, weight, and body mass index. Patients will undergo a wash-out of lipid lowering drugs followed by a challenge with simvastatin 40 mg daily (similar to a statin withdrawal and rechallenge). We chose simvastatin since it is the most common statin that caused myopathy according to our preliminary data (as well as most other published reports). Each patient will have 5 visits. The screening visit will involve a review of inclusion/exclusion criteria, blood draw, questionnaire, and instructions to withhold all lipid lowering drugs until visit 1. Any patient with known antibodies to HMGCR will be excluded from the remainder of the study. Visit 1 will occur 2 weeks after stopping all lipid lowering drugs. A minimum 2 week period off lipid lowering drugs is required to allow clearance of any medication from the systemic circulation. Patients will undergo MRS of the calf muscle and a blood draw. Patients will then start simvastatin 40 mg daily.