Multimodality imaging of myocardial injury and coronary microvascular dysfunction in congenital thrombotic thrombocytopenic purpura.

Congenital thrombotic thrombocytopenic purpura is an ultra-rare autosomal recessive disorder associated with mutations in the ADAMTS13 gene. The gene product is an enzyme responsible for cleavage of ultra-large von Willebrand factor multimers, and severe deficiency results in a thrombotic microangiopathy. We present the case of subclinical cardiac involvement characterized by myocardial fibrosis/scarring and impaired myocardial flow reserve in an affected patient who temporarily discontinued enzyme replacement therapy. This case highlights the complementary value of cardiac magnetic resonance and PET myocardial perfusion imaging in congenital thrombotic thrombocytopenic purpura where subclinical myocardial injury may coexist with impaired myocardial flow reserve despite the absence of focal inducible ischemia.