Arrhythmia in Multiple Myeloma Patients Treated with Hematopoietic Stem Cell Transplantation (HSCT): A Propensity Matched Analysis
Authors: Sivasubramanian Barath Prashanth , Ravikumar Diviya Bharathi , Ismail Sharieff Ibthisam , Tamdin Tenzin , Ghosh Aditya 
Published: December 2024

Introduction:
The incidence of cardiovascular events in the first 100 days post-HSCT was found to be 19%, with arrhythmia having the highest incidence of 12% (p&lt;0.0001). The incidence of cardiovascular events is 6.7% in patients with multiple myeloma treated with HSCT (HSCT-MM) [1]. However, the literature on arrhythmia in HSCT-MM patients is limited. Given the high risk of cardiac events in HSCT patients, we aimed to determine the impact of arrhythmia in patients with HSCT-MM.
Methods:
We conducted a retrospective analysis using the National Inpatient Sample Database (2018-2021). Adult patients with HSCT-MM who were primarily admitted for life-threatening arrhythmias were identified using ICD-10 codes [2]. We performed propensity matching and multivariate regression, considering a p-value of ≤0.05 as significant.
Results:
In 14,232 HSCT-MM patients, 168 (1.2%) had arrhythmia. The prevalence of arrhythmia in HSCT-MM patients was higher than in the remaining HSCT recipients (1.2% vs 0.9%, p&lt;0.01). In HSCT-MM, atrial fibrillation (69.6%) and atrial flutter (19%) were the common arrhythmias. Arrhythmia in HSCT-MM patients was more prevalent in those over the age of 60 years (84.5% vs 68.5%, p&lt;0.001), males (72.6% vs 58.2%, p&lt;0.001), and in the White race (84.8% vs 67.3%, p&lt;0.001) compared to those without arrhythmia. Arrhythmia was less common in those with bone marrow dysfunction compared to those with normocellular marrow (anemia 1% vs 1.5%, p&lt;0.01; thrombocytopenia 1% vs 1.2%, p&gt;0.05; neutropenia 0.7% vs 1.3%, p&lt;0.05; pancytopenia 0.9% vs 1.4%, p&lt;0.01). Among the HSCT-MM patients with arrhythmia, long-term anticoagulation was less frequently given than those without arrhythmia (44.6% vs 55.4%, p&lt;0.001). The arrhythmia cohort had less frequent acute kidney injury (19.1% vs 27.5%, p=0.01). The arrhythmia cohort required more vasopressors (2.4% vs 2.1%, p&gt;0.05) but had lower mortality (1.2% vs 4.5%, p&lt;0.05). Patients with arrhythmia had shorter hospital stays (Coefficient -3 days; 95% CI -3.8 to -2.3 days; p&lt;0.001) and lesser hospital charges (Coefficient $-41,200; CI $-55,700 to $-26,600; p&lt;0.001) compared to those without. However, the arrhythmia cohort had higher rates of acute heart failure (17.9% vs 9.1%, p&lt;0.001) and the risk of acute heart failure was also higher in those with arrhythmia (adjusted odds ratio 2.2; 95% CI 1.3 to 3.6; p&lt;0.01). In patients with acute heart failure and arrhythmia, atrial fibrillation was present in 76.7% and atrial flutter in 20%. In patients with acute heart failure and arrhythmia, bone marrow dysfunction was more common than normocellular bone marrow (anemia 22.2% vs 12.8%, p&gt;0.05; thrombocytopenia 38.7% vs 13.1%, p=0.001; neutropenia 18.2% vs 14.3%, p&gt;0.05; pancytopenia 8.7% vs 21.3%, p&gt;0.05). In the arrhythmia cohort, long-term anticoagulation was commonly given in those with acute heart failure compared to those without (53.3% vs 46.7%, p&gt;0.05), and acute kidney injury also occurred more frequently in those with heart failure (26.7% vs 17.4%, p&gt;0.05).
Conclusion:
Acute heart failure is a serious risk associated with arrhythmia in multiple myeloma patients treated with HSCT, with atrial fibrillation emerging as the most common arrhythmia. It is essential to prevent heart failure in those with arrhythmia, especially in patients with thrombocytopenia. Preventive measures could include more frequent follow-ups and having a multidisciplinary team to manage renal failure, monitor anticoagulation, and ensure rhythm control in these patients.
References: Aghel N, Lui M, Wang V, et al.: Cardiovascular events among recipients of hematopoietic stem cell transplantation-A systematic review and meta-analysis. Bone Marrow Transplant. 2023, 58:478-90. 10.1038/s41409-023-01928-22021 ICD-10-CM. Accessed: July 14, 2024. https://www.cms.gov/medicare/coding-billing/icd-10-codes/2021-icd-10-cm.