#3807 Cardiac involvement in monoclonal gammopathies: a single center experience

Abstract Background and Aims Monoclonal gammopathies can be associated with systemic complications, including cardiac involvement, which is responsible for significant morbidity and mortality. The objective of this study is to describe the clinical, biological, and radiological characteristics of cardiac involvement associated with monoclonal gammopathies. Method We included all patients with monoclonal gammopathies and cardiac involevement identified between 2020 and 2024 in our department. Results Out of a total of 100 patients with monoclonal gammopathies and renal involvement, 15 (15%) had documented cardiac involvement. The mean age of these patients was 64.9 ± 16.17 years. Among them, 46.7% had no medical history, while 13.3% had a history of cardiac conditions such as atrial fibrillation (AF) or pacemaker implantation, and 53% were hypertensive. Additionally, none of the patients had heart failure prior to the diagnosis of monoclonal gammopathy. Regarding the types of gammopathies: 9 patients (60%) had multiple myeloma, 2 patients (13%) presented with MGRS (Monoclonal Gammopathy of Renal Significance), and 3 patients (20%) had AL amyloidosis without multiple myeloma. In the entire cohort, 80% of patients presented with a glomerular renal profile. Furthermore, among the patients with multiple myeloma (MM), 88% (8 cases) presented with a glomerular renal profile. Based on kidney biopsies, 3 cases were identified as AL amyloidosis, 2 cases as Randall's disease, and for 3 patients, no kidney biopsy was performed. The mean free light chain ratio was 62 ± 125. About cardiac manifestations, the most frequent clinical manifestation was dyspnea (80%) then hypotension (33%). In addition, five patients (33%) had electrical abnormalities. Echocardiography was practiced to all patients. We found 40% of LVH, also 40% showed interventricular septal hypertrophy with a hyperechoic appearance, then 1 case of restrictive cardiomyopathy, and 2 cases of reduced strain. LVEF was above 50% in 73% of patients. Global hypokinesia was observed in 3 cases (20%). In Biological findings, Elevated NT-proBNP levels (≥3500 pg/mL) were noted in 86.7% of cases, with an average troponin level of 105 ± 86 ng/mL. Conclusion Cardiac involvement associated with monoclonal gammopathies is common. Early identification based on clinical, biological, and echocardiographic characteristics is essential to improve patient outcomes.