Adverse outcomes of acute pericarditis in patients with active multiple myeloma: Insights from a national inpatient cohort

Abstract Background: Current literature suggests that patients with hematologic malignancies are predisposed to poorer cardiovascular disease outcomes. Despite this, there remains limited data on outcomes of mortality and morbidity in patients with active multiple myeloma that are admitted for acute pericarditis. This study evaluates whether multiple myeloma predicts worse outcomes of mortality, cardiogenic shock and acute kidney injury in patients admitted for acute pericarditis. Methods: We queried the 2016-2019 National Inpatient Database (NIS) and identified acute pericarditis, with a co-diagnosis of active multiple myeloma. The primary outcome was mortality while the secondary outcomes included cardiogenic shock (CS) requiring pressors or mechanical respiratory support and acute kidney injury (AKI). Multivariate linear and logistic regression models were used to adjust for demographics, Charlson comorbidity index, and hospital factors. Results: Of all those admitted with a primary diagnosis of acute pericarditis (N = 48,985), 0.22% had a secondary diagnosis of active multiple myeloma. Similarly of those admitted for a diagnosis of acute pericarditis 77% were males, 57% were Caucasian, and 57% were Medicare patients. Inpatient deaths (0.82% vs. 9.09%) were higher in the cohort of multiple myeloma patients (adjusted OR 5.3 and p=0.03). Moreover patients with active multiple myeloma where more likely to develop an acute kidney injury (adjusted OR 3.04 and p=0.019) and cardiogenic shock (adjusted OR 4.17 and p=0.048) during their hospitalization course compared to their counter cohort of patients without multiple myeloma. Conclusion: Patients admitted with acute pericarditis and concurrent active multiple myeloma experience significantly worse clinical outcomes, including increased in-hospital mortality, higher rates of cardiogenic shock and heart failure, and a greater incidence of acute kidney injury (AKI). These adverse outcomes are likely multifactorial, driven by both disease-related and treatment-associated mechanisms. Underlying cardiac amyloidosis may impair myocardial and pericardial function, predisposing patients to hemodynamic instability. Renal dysfunction, either from light chain nephropathy or chemotherapy-associated nephrotoxicity, may further contribute to fluid overload and impaired clearance of inflammatory mediators. Immunosuppression, whether from the disease itself or from ongoing therapy, may blunt the clinical presentation and delay diagnosis or intervention. Additionally, the frequent use of corticosteroids in the treatment of multiple myeloma may contribute to fluid retention and exacerbate heart failure risk in the setting of pericardial inflammation. This highlights the importance of early cardiovascular assessment and multidisciplinary management in this high risk population.