Seasonal Variations of Arrhythmias and Their Impact on Mortality in Cancer Patients with Health Disparities: A Propensity Score Adjusted Machine Learning Analysis of Over 100 Million Hospitalizations Across 3 Years

Background Arrhythmias are observed to increase during high influenza activity seasons (HIA, December to February) with significant clinical impact among high-risk patients, so their outcomes may be optimized through closer monitoring of these populations. It is unknown if cancer is such a risk factor. Methods This is a retrospective analysis of arrhythmia-related mortality and the effect of health disparities in patients with cancer during HIA and non-HIA seasons in a nationally representative database. Machine Learning-augmented Propensity Score adjusted multivariable regression (ML-PSr) was performed using the 2016–2018 National Inpatient Sample (NIS), the United States’ largest all-payer hospitalized dataset. Results 16,795,379 (18.48%) patients presented with arrhythmia of whom 3,214,914 (19.14%) were during HIA. In ML-PSr, HIA did not significantly increase the odds of arrhythmia for cancer patients (OR 1.01, 95%CI 0.99–1.03, p = 0.37), but the odds of arrhythmia-related mortality were higher during HIA seasons (OR 1.19, 95%CI 1.12–1.27, p < 0.001) compared to non-HIA seasons (OR 1.17, 95%CI 1.13–1.22, p < 0.001). Primary malignancies with the highest prevalence of arrhythmias during HIA were lung (19.60%), leukemia (11.49%), non-Hodgkin lymphoma (NHL) (8.24%), prostate (8.15%), and multiple myeloma (MM) (6.21%) (p < 0.001). HIA increased arrhythmia-related mortality most for the following primary malignancies by year: gastrointestinal in 2016 (OR 1.15, 95%CI 1.01–1.32, p = 0.039), leukemia in 2017 (OR 1.31, 95%CI 1.10–1.54, p = 0.002), GI in 2018 (OR 1.14, 95%CI 1.01–1.29, p = 0.029), and renal in 2018 (OR 1.54, 95%CI 1.06–2.23, p = 0.025). Among patients with active cancer and arrhythmia, African Americans had significantly greater mortality than Caucasians (OR 1.13, 95%CI 1.03–1.23, p = 0.013) independent of socio-economic and clinical confounders. Conclusion This study suggests arrhythmia-related mortality was higher during HIA seasons compared to non-HIA seasons in cancer patients and showed notable disparities by race and worse outcomes by primary malignancy.