Anti-HMGCR myopathy presenting with acute systolic heart failure.

Necrotising autoimmune myopathy (NAM) is an immune-mediated myopathy that may be associated with statin use, malignancy or an autoimmune connective tissue disease, but it can also be idiopathic. Anti-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) myopathy is an extremely rare side effect of statin use, occurring in approximately 2-3 out of every 100 000 patients who use statins. Patients typically present with subacute proximal muscle weakness and creatine kinase levels >10 times the upper limit of normal. The diagnosis is suggested by muscle biopsy showing necrotic fibres with minimal inflammation along with positive anti-HMGCR antibodies. Treatment nearly always requires multiple immunosuppressive agents, the earlier use of which is associated with improved outcomes. Reports of statin-induced NAM leading to heart failure are limited. We present the case of a 69-year-old woman with statin-induced NAM who presented with acute systolic heart failure. Early initiation of high-dose corticosteroids and IVIG resulted in significant improvement in her symptoms.