Diagnosis and Treatment of Right-Sided Valve Disease in Cardiac Carcinoid Syndrome: A Systematic Review

Carcinoid heart disease (CaHD) is a severe complication of neuroendocrine tumors, characterized by progressive fibrotic involvement of right-sided heart valves due to serotonin and other vasoactive substances. This condition significantly worsens prognosis and quality of life, yet therapeutic strategies remain heterogeneous and based on low-level evidence. The objective of this study was to systematically review diagnostic approaches and therapeutic options for right-sided valvular disease in CaHD, assessing indications, advantages, limitations, and outcomes.

A systematic review was conducted according to PRISMA guidelines and registered in PROSPERO (CRD42023392363). Searches were performed in PUBMED/MEDLINE, LILACS, and EMBASE for studies published between 2002 and 2024. Eligible studies included clinical trials, observational studies, case series, and case reports evaluating pharmacologic, surgical, or percutaneous interventions for CaHD with reported cardiovascular outcomes. Risk of bias was assessed using ROBINS-I V2 and JBI tools.

Of 183 total records, 45 studies met inclusion criteria (30 case reports, 8 case series, 7 observational studies). Tricuspid regurgitation was the most prevalent lesion (90%), followed by pulmonary regurgitation (73%). Somatostatin analogs were frequently used but did not prevent progression of valve disease. Surgical valve replacement, predominantly with bioprostheses, remains the cornerstone for severe symptomatic cases, providing symptomatic and echocardiographic improvement, but with a perioperative mortality of up to 10%. Percutaneous valve therapies, though limited to small series and case reports, demonstrated promising short-term outcomes without major complications. Additional strategies such as patent foramen ovale (PFO) closure and hepatic resection showed potential prognostic benefit. No significant difference in outcomes was observed between biological and mechanical prostheses.

Surgical valve replacement remains the most effective evidence-based therapy for CaHD, while percutaneous techniques emerge as feasible alternatives in high-risk patients. Adjunctive measures such as PFO closure and hepatic metastasis resection may improve prognosis. Drug therapies control carcinoid syndrome but are insufficient to halt cardiac disease progression. Further prospective studies are needed to define optimal timing, patient selection, and long-term outcomes of interventional strategies.