Prognostic utility of differential tissue characterization of cardiac neoplasm and thrombus via late gadolinium enhancement cardiovascular magnetic resonance among patients with advanced systemic cancer

BACKGROUND: Late gadolinium enhancement (LGE-) cardiovascular magnetic resonance (CMR) is well-validated for cardiac mass (C(MASS)) tissue characterization to differentiate neoplasm (C(NEO)) from thrombus (C(THR)): Prognostic implications of C(MASS) subtypes among systemic cancer patients are unknown. METHODS: C(MASS) + patients and controls (C(MASS) -) matched for cancer diagnosis and stage underwent a standardized CMR protocol, including LGE-CMR (IR-GRE) for tissue characterization and balanced steady state free precession cine-CMR (SSFP) for cardiac structure/function. C(MASS) subtypes (C(NEO), C(THR)) were respectively defined by presence or absence of enhancement on LGE-CMR; lesions were quantified for tissue properties (contrast-to-noise ratio (CNR); signal-to-noise ratio (SNR) and size. Clinical follow-up was performed to evaluate prognosis in relation to C(MASS) etiology. RESULTS: The study population comprised 126 patients with systemic neoplasms referred for CMR, of whom 50% (n = 63) had C(MASS) + (C(NEO) = 32%, C(THR) = 18%). Cancer etiology differed between C(NEO) (sarcoma = 20%, lung = 18%) and C(THR) (lymphoma = 30%, GI = 26%); cardiac function (left ventricular ejection fraction: 63 ± 9 vs. 62 ± 10%; p = 0.51∣ right ventricular ejection fraction: 53 ± 9 vs. 54 ± 8%; p = 0.47) and geometric indices were similar (all p = NS). LGE-CMR tissue properties assessed by CNR (13.1 ± 13.0 vs. 1.6 ± 1.0; p < 0.001) and SNR (29.7 ± 20.4 vs. 15.0 ± 11.4, p = 0.003) were higher for C(NEO), consistent with visually-assigned diagnostic categories. C(THR) were more likely to localize to the right atrium (78% vs. 25%, p < 0.001); nearly all (17/18) were associated with central catheters. Lesion size (17.3 ± 23.8 vs. 2.0 ± 1.5 cm(2); p < 0.001) was greater with C(NEO) vs. C(THR), as was systemic disease burden (cancer-involved organs: 3.6 ± 2.0 vs. 2.3 ± 2.1; p = 0.02). Mortality during a median follow-up of 2.5 years was markedly higher among patients with C(NEO) compared to those with C(THR) (HR = 3.13 [CI 1.54–6.39], p = 0.002); prognosis was similar when patients were stratified by lesion size assessed via area (HR = 0.99 per cm(2) [CI 0.98–1.01], p = 0.40) or maximal diameter (HR = 0.98 per cm [CI 0.91–1.06], p = 0.61). C(THR) conferred similar mortality risk compared to cancer-matched controls without cardiac involvement (p = 0.64) whereas mortality associated with C(NEO) was slightly higher albeit non-significant (p = 0.12). CONCLUSIONS: Among a broad cancer cohort with cardiac masses, C(NEO) defined by LGE-CMR tissue characterization conferred markedly poorer prognosis than C(THR), whereas anatomic assessment via cine-CMR did not stratify mortality risk. Both C(NEO) and C(THR) are associated with similar prognosis compared to C(MASS) - controls matched for cancer type and disease extent.