Tachyarrhythmias burden in hospitalized patients with cancer: A nationwide propensity matched analysis.
Authors: Kumar Manoj , Ali Shafaqat , Farooq Faryal , Byreddi Laxman Yashwant , Sultan Muhammad , Afzal Muhammad Sohaib , Nasir Bilal , Devarkonda Vishal , Atluri Sundeep 
Published: June 2024

e24032 Background: Remarkable progress has been made in the management of cancer with the advent of new therapies. However, significant concern exists over the cardiotoxic effects of chemotherapy and radiation therapy. We aim to evaluate the different cardiac tachyarrhythmias in hospitalized cancer patients. Methods: The national readmission database (2016-2020) was queried to identify all-cause admissions for patients with active malignancy of any origin. Multivariate regression model was used to obtain adjusted odds ratio (aOR). Univariate screening was utilized for regression building model. Multicollinearity among different variables were determined by variation inflation factor (VIF). VIF > 5 was taken as cut off for significant collinearity. Cohorts were stratified based on the presence of tachyarrhythmias. A propensity score matching (PSM) model, implementing complete Mahalanobis Distance Matching within the Propensity Score caliper (set at 0.2), matched cancer patients with and without tachyarrhythmias. Inverse Probability weighting(IPW) was utilized, and Pearson's x2 test was applied to the PSM matched cohorts to compare outcomes. Results: Among 10.6 million all-cause hospitalizations of cancer patients, about 1.7 million (16%) developed tachyarrhythmia. On a propensity-matched cohort, patients with active malignancy had the highest rates of atrial fibrillation (AF) (14.1%), followed by supraventricular tachycardia (SVT) (1.1%), ventricular tachycardia (VT) (0.8%) and atrial flutter (AFL) (0.4%) [p < 0.001]. Cancer patients with tachyarrhythmias had increased in-hospital mortality. The mortality was highest for VT (aOR 3.9, CI 3.7 - 4.01, P < 0.001), followed by SVT (aOR 2.6,CI 2.51 - 2.67, p < 0.001), AFL (aOR 2.5, CI 2.38 - 2.59, p < 0.001 ) and AF (aOR 1.54, CI 1.52 -1.56, p < 0.001). Readmissions among patients who developed tachyarrhythmias during index hospitalization showed that 18.7% and 34.3 % had recurrent AF, 17.4% and 33% had recurrent SVT, 17.3% and 32.1% had recurrent AFL, and 15.4% and 31.1% developed recurrent VT at 30 and 90- day readmissions respectively. Resource utilization was also higher in the cohort complicated by tachyarrhythmias, with the highest length of stay (LOS)(7 vs 4 days) and total cost ($31,718 vs $17,659) in hospitalization complicated by VT (p < 0.001). A similar increase in LOS and total inpatient cost was also seen in cancer patients whose hospitalization was complicated with SVT, AFT and AF compared to patients without arrhythmias (p < 0.01). Conclusions: Hospitalizations in cancer patients complicated by tachyarrhythmias were associated with higher in-hospital mortality, LOS, and adjusted cost. VT is associated with the highest mortality; however, AF appears to be most prevalent during index admission and readmissions. This study signifies the importance of close cardiac monitoring in hospitalized cancer patients to prevent adverse outcomes.