Abstract
Polycythemia vera (PV) is a chronic myeloproliferative neoplasm (MPN), which is characterized by clonal proliferation of myeloid cells with variable morphologic maturity and hematopoietic efficiency. PV is distinguished clinically from the other MPNs by the presence of an elevated red blood cell mass, and are commonly noted to have persistent leukocytosis and thrombocytosis. Pruritus, hypertension, vasomotor symptoms like erythromelalgia, thrombosis and bleeding events are well known clinical features of PV, however there is insufficient data on PV and associated cardiac arrhythmias and its repercussions. Through this study we aim to determine baseline characteristics of PV patients with and without arrhythmias and its impact on morbidity, mortality and overall hospital length of stay.
We identified all adult hospitalized patients with PV, during the time frame of January 2016 to December 2018, and divided them into groups with and without cardiac arrhythmias using ICD-10-CM Codes from National Inpatient sample Database. We compared patient's baseline characteristics, associated comorbidities, mortality, length of stay and hospitalization costs among PV patients with and without documented arrhythmias. Propensity-score matching for age, sex, income, and co-morbidities were performed among both groups. SAS 9.4 software was used for statistical analysis.
We analyzed a total of 61265 patients. Out of this cohort, 20165 (32.9%) patients were found to have cardiac arrhythmias. The group with cardiac arrhythmias were noted to have a higher mean age (75.6±11.6 vs 68.2±14.4 yrs), were predominantly males (57.4 vs 42.6%), and had higher prevalence of associated comorbidities such as congestive heart failure (16.7 vs 8.3%), coronary artery disease (40.1 vs 23.9%), peripheral vascular disease (11.8 vs 9.9%), chronic obstructive lung disease (25.7 vs 23.9%), renal failure (15.5 vs 10.9%), and coagulopathy (7.2 vs 6.2%). In terms of propensity matched outcomes, the group with PV and associated arrhythmias had higher inpatient mortality (5.8 vs 3.2%), longer length of stay (6.4±7.7 vs 5.2±5.3 days) and higher total hospitalization costs (18744±28815 vs 13870±16527 $). Amongst arrhythmias, atrial fibrillation was noted to be the most common arrhythmia (77.6%), followed by atrial flutter (8.2%), ventricular tachycardia (6.6%) and supraventricular tachycardia (6.4%).(p<0.001).
Our study suggests that presence of arrhythmias in patients with PV significantly increases the hospital mortality, total cost and length of stay. Both PV and Arrhythmias are independent risk factors for thrombosis which increases morbidity and mortality outcomes in the patients. We identified a high incidence of atrial arrhythmias among patients with PV. The patients were older, cumulating more cardiovascular risk factors inducing more thrombotic events mainly in arteries, and have a higher incidence of death. PV presents the physician with a significant therapeutic challenge, where the physician has to carefully reflect and act on treating the strong thrombophilic state of PV and arrhythmias with careful caution to prevent bleeding catastrophes. With mounting epidemiological evidence of association and fatal outcomes, our study also shines light on a significant knowledge gap in the field of MPN such as PV and concurrent cardiac arrhythmias and warrants further studies to better delineate pathogenesis and early diagnostic and treatment strategies specifically curated for PV associated arrhythmias.
No relevant conflicts of interest to declare.
Author notes
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