Prognostic utility of differential contrast-enhancement patterns on late gadolinium enhancement cardiac MRI (LGE-CMR) in patients with cancer-associated cardiac masses
Authors: Chan A , Dinsfriend W , Kim J , Steingart R , Weinsaft J.W 
Published: November 2020

Abstract

Background
LGE-CMR tissue characterization is widely used to identify cardiac masses (CMASS) in cancer patients – including neoplasm (NEO) and thrombus (THR). Prognostic utility of their differential LGE patterns is unknown.

Purpose
To determine incremental prognostic utility of LGE patterns in CMASS

Methods
The population comprised of cancer patients with CMASS on LGE-CMR, for which etiology was classified based on presence (NEO) or absence (THR) of enhancement, and controls matched for cancer type/stage. LGE-CMR tissue properties of NEO was classified based on extent of contrast enhancement – diffusely enhancing (DE), mixed (ME), and predominantly avascular (PA). Clinical follow up was performed for embolic events within 6 months of CMR and all-cause mortality.

Results
330 cancer patients (55% M; 55±16yo) with an array of cancer diagnoses (19% sarcoma, 17% GI, 13% GU) were studied. Among CMASS+ pts (n=190), 66% had NEO and 34% had THR on LGE. All THR were non-enhancing. Among NEO, LGE pattern was variable (46% DE, 41% ME, 13% PA); ME lesions were larger than other groups (Fig. 1A). Quantitative tissue properties were consistent with qualitative groups, as evidenced by stepwise variation in signal intensity and CNR. Cumulative embolic events were 3-fold higher in CMASS+ than controls (All: 20% vs. 7%, p=0.001; PE: 13% vs. 5%, p=0.02; CVA/systemic embolism: 10% vs. 3%, p=0.01). Median time to event was 1.3 months [IQR 0.1–2.3] from CMR. Aggregate events were similar between NEO and THR, reflecting similar rates of PE and CVA (p=NS). Among CMASS pts with embolic events, 56% were on anticoagulation at time of event (59% NEO, 50% THR, p=0.61). Regarding CMASS morphology, emboli were 3-fold higher among intracavitary (IC) or highly mobile (HM) CMASS (IC: 25% vs 7%, p&lt;0.001; HM: 38% vs 12%, p=0.001). Regarding location, right sided CMASS were associated with a 3–5 fold increase in PE (IC: 19% vs 6%; HM: 35% vs 7%, both p&lt;0.001) and similar CVA events among left sided CMASS (IC: 17% vs. 6%, p=0.02; HM: 33% vs 6%, p=0.05). Embolic events were similar when partitioned based on quantitative LGE patterns between patients with and without embolic events. As for all-cause mortality, NEO on CMR conferred increased mortality than THR (HR 3.06 [CI=1.84–5.1], p&lt;0.001) and matched controls (HR 2.08 [CI=1.42–3.04], p&lt;0.001) during a median follow-up of 9.4 months [IQR 3.6–23.2]. Among NEO subgroups (Fig. 1B), survival was lower in patients with heterogeneous LGE patterns vs matched controls: the lowest survival in ME (p=0.002) suggests increased vascularity and tumor hypoxia/necrosis associated with aggressive tumors and hence larger lesions.

Conclusions
Among cancer patients, CMR-evidenced CMASS confers high short-term embolic risk, which are equivalently common between NEO and THR. Intra-cavitary location and increased mobility augment embolic risk irrespective of CMASS tissue properties whereas differential LGE patterns on CMR strongly impact prognosis.

Funding Acknowledgement
Type of funding source: None