Cardiac Metastases in Patients with Neuroendocrine Tumours: Clinical Features, Therapy Outcomes, and Prognostic Implications

Background: Cardiac metastases (CM) from neuroendocrine tumours (NET) are rare; however, with the introduction of new molecular imaging modalities, such as ⁶⁸Ga-DOTATATE PET-CT for NET diagnosis and re-staging, they are now identified more frequently. This study presents a single-institution experience on the NET CM characteristics, management, and prognostic implications. Methods: Between January 1998 and January 2020, 25 NET patients with CM were treated in our unit. A retrospective review of electronic records was performed. Overall survival (OS) was assessed by the Kaplan-Meier method. Cox regression models were used to evaluate the association of various clinical variables with OS. Results: The median age in the NET CM cohort was 64 years, with small intestine being the most common primary (84%). Nearly half of the patients suffered either from shortness of breath (48%) or had palpitations (12%). Peptide receptor radionuclide therapy (PRRT) was applied in more than half of the patients (64%), who had an improved trend for a longer median OS compared to those patients who did not receive PRRT (76.0 vs. 14.0 months, p = 0.196). The multivariate analysis demonstrated that concomitant skeletal or pancreatic metastases, as well as N-terminal pro-B-type natriuretic peptide (NT pro-BNP) >2 × upper limit of normal (ULN), were independent poor prognosticators. Conclusions: Clinical features of NET CM ranged from asymptomatic patients to heart failure. Concomitant bone or pancreatic metastases and NT pro-BNP levels >2 ULN predicted shorter survival time. PRRT serves as a feasible therapy with promising survival benefits; however, more data are needed.