Gender differences in patients with atrial fibrillation presenting with subclinical hypothyroidism: A nationwide retrospective analysis

Title : Gender differences in patients with atrial fibrillation presenting with subclinical hypothyroidism: A nationwide retrospective analysis

Abstract:

Background: While hyperthyroidism and atrial fibrillation has been extensively studied, in patients with atrial fibrillation, much remains unexplored regarding the presence of concurrent subclinical hypothyroidism and in-hospital outcomes. We will explore the national inpatient sample (NIS) to determine gender differences in clinical outcomes in patients with comorbid atrial fibrillation and subclinical hypothyroidism.

Methods: Data from the 2020 NIS was analyzed to identify patients admitted with a principal diagnosis of atrial fibrillation and a secondary diagnosis of subclinical hypothyroidism. Patients were stratified based on gender. Categorical variables were compared using chi-square tests and continuous variables with independent samples t-testing. We employed logistic and linear regression models to adjust for potential confounding variables. Confounders were selected through a univariate screen with a p-value cutoff of less than 0.2. The Charlson comorbidity index was utilized to account for comorbid conditions.

Results: In our analysis, we identified 55,070 hospitalizations of patients admitted with a principal diagnosis of atrial fibrillation and a secondary diagnosis of subclinical hypothyroidism. There was a statistically significant increase in acute kidney injury (adjusted odds ratio [OR]: 1.18, p-value=0.002), sepsis (OR: 1.49, p-value=0.028), myocardial infarction (OR: 1.39, p-value<0.001), and vasopressor use (OR: 1.65, p-value=0.024) in males compared to females. There was no statistically significant difference in all-cause mortality or stroke.

Conclusion: Subclinical hypothyroidism is an overlooked form of thyroid dysfunction, that often goes untreated during hospitalizations but can be associated with adverse outcomes. Thyroid hormones are a mediator in cardiovascular hemodynamics, so low thyroid hormone levels can lead to decreased contractility of the heart and organ ischemia, especially in those with preexisting cardiac conditions. Based on our analysis, subclinical hypothyroidism was associated with worse in-hospital outcomes in males with atrial fibrillation. Further studies are required why males have worse in-hospital outcomes and to determine the clinical benefit of thyroid hormone replacement in subclinical hypothyroidism.

Biography:

Dr. Mersal Samimi studied psychology and neuroscience at the University of California, Los Angeles. She then went on to receive her medical degree to address health disparities in her community. While volunteering abroad, she realized the depth of gender disparities in cardiovascular health and knowledge gaps in the community and how women have been underrepresented in major clinical trials. She became passionate about increasing awareness through research and health education in the differences in presentation, diagnosis, and treatment in women with cardiovascular disease. As she is currently training in the Central Valley, she is passionate about addressing racial and ethnic disparities in cardiovascular care among women, with a focus on Hispanic and South Asian women.