Increased extracellular volume in asymptomatic cocaine abusers detected by cardiovascular magnetic resonance imaging

Background Cocaine abuse is associated with an increased risk for coronary artery disease and myocardial infarction. However, there is a paucity of data on myocardial injury in asymptomatic cocaine abusers. T1 mapping cardiovascular magnetic resonance (CMR) has the ability to quantify diffuse alterations in myocardial tissue composition by assessing the extracellular volume fraction (ECV). This study aimed at detecting silent myocardial injury in cocaine abusers using CMR. Methods CMR was performed in eleven cocaine abusers and eleven matched controls without a history of cardiovascular disease. CMR protocol consisted of standard cine-, T2-STIR- and late gadolinium enhancement (LGE) CMR sequences to assess cardiac volumes and function, myocardial edema and focal myocardial fibrosis, respectively. Myocardial extracellular volume fraction (ECV) was assessed using a T1 mapping sequence (MOLLI) before and after administration of 0.075 mmol/kg gadolinium BOPTA: T1 maps were calculated with a dedicated plug-in written for the OsiriX software. Relaxation rates (1/T1 = R1) were calculated for myocardium and blood pool. The difference in R1 between pre- and post contrast media was calculated as ΔR1. Myocardial ECV was then estimated using the formula: ECV = 1-hematocrit * (ΔR1myocardium/ΔR1blood pool).