Diagnostic utility and clinical implication of late gadolinium enhancement cardiac magnetic resonance for detection of catheter associated right atrial thrombus.

PURPOSE: To use delayed enhancement cardiac magnetic resonance (DE-CMR) as a reference standard to evaluate the prevalence and predictors of right atrial (RA) thrombus.
METHODS: In this retrospective study, 130 cancer patients with central venous catheters undergoing CMR from August 2012-January 2018 were included. CMR (cine-CMR and DE-CMR) and echocardiography were interpreted for RA thrombus blinded to other imaging results and clinical data. RA thrombus properties including the number of discrete masses, size, total thrombus area, and perimeter were also assessed. Cine-CMR was also used to quantify cardiac structure and function as markers of RA thrombus. Student's t-test was used to assess continuous variables; chi-square or Fisher's exact test were used to assess categorical variables.
RESULTS: 31/130 (24%) patients had RA thrombus on DE-CMR. Echocardiography (attained in 64% of the study population) demonstrated moderate sensitivity and specificity (75%, 90% respectively) in relation to DE-CMR; cine-CMR performance was higher (sensitivity 90%, specificity 98%). Patients with and without RA thrombus had similar right-sided structure/function and cancer diagnosis. Catheter depth approached significance in patients with RA thrombus (p = 0.05). 13% of patients with RA thrombus had concomitant pulmonary embolism within 60 days of CMR vs. 2% of patients without RA thrombus (p = 0.03). Embolic events were independent of RA thrombus size (p = 0.66).
CONCLUSION: Morphologic imaging by cine-CMR and echocardiography provide limited diagnostic utility for RA thrombus as established by DE-CMR tissue characterization. Catheter-associated RA thrombus occurs independently of right-sided structure or function and is associated with clinical embolic events and catheter depth.