DISCUSSION
In this retrospective cohort, we aimed to verify the existence of a correlation between anemia and ventricular tachycardia outcomes in the inpatient population. Anemia has a high prevalence in the US12 and it is associated with poor outcomes in heart diseases due to its hyperdynamic state13-16. Although there are data on the relation between anemia and heart failure and atrial fibrillation7-9, its relation to ventricular tachycardia lack evidence. In this study, authors used the national inpatient sample from 2016 to 2020 to analyze the difference in outcomes in patients with a primary diagnosis of ventricular tachycardia and anemia compared with the general population.
Weidner K et al found in their study comparing the relation between anemia and ventricular tachyarrhythmias an increase in the mortality rate in patients with anemia17. It was a study with 2184 patients, retrospective, registry-based in patients who developed ventricular tachyarrhythmia. In their study, length of stay, and total hospital charges were not analyzed and neither anemias were classified on subtypes. In our study the primary outcome of death had statistical odds ratio of 1.95 with p < 0.001 for patients with any type of anemia, they also stayed an average of 3.09 more days and had a cost of an average of 61507.92 more dollars. Our mortality outcome is similar to the one Weidner K et al had on their study. There is strong data suggesting anemia is related to worse outcomes in patients with ventricular tachycardia.
Although we aimed to analyze all types of anemia in this study, our population was composed mostly of iron deficiency anemia, chronic diseases anemia and other unspecified anemias. The results from other subtypes might have been impacted by sample size.
This study has some limitations, firstly, the secondary diagnosis ICD 10 code can be misclassified at the time of putting it on the hospital system. Secondary diagnosis also can be part of medical history instead of an active problem, although anemia usually is a chronic condition, some patients with resolved anemia could have it on the list as past medical history. Several conditions can have anemia as consequence and not all of them are considered when calculating the Charlson Comorbidity Index to adjust the results making it a possible confounder. It is important to do a prospective study in this subject for better evaluation and also to see if treatment of anemia improves outcomes on these patients.