A nationwide analysis of the outcomes in hospitalized patients with atrial fibrillation and temperature-related illnesses

Highlights

• Temperature-Related Illness (TRI) describes physiologic aberrations that occur secondary to exposure to extreme cold or heat.

• Individuals with Atrial Fibrillation (AF) who present with TRI may be at increased risk of poor outcomes relative to patients without TRI.

• Our analysis shows that individuals with AF who develop a cold-related TRI face an increased risk of mortality as compared to those without TRI.

Abstract

Objectives

The authors evaluated mortality and indices of cost of care among inpatients with Atrial Fibrillation (AF) and a diagnosis of a Temperature-Related Illness (TRI). The authors also assessed trends in the prevalence of TRIs among AF hospitalizations.

Methods

In this cross-sectional study, the authors used discharge data from the Nationwide Inpatient Sample (NIS) collected between January 2005 and September 2015 to identify patients with a diagnosis of AF and TRI. Outcomes of interest included in-hospital mortality, invasive mechanical ventilation, hospital length of stay, and cost of hospitalization.

Results

A total of 37,933 encounters were included. The median age was 79 years. Males were slightly overrepresented relative to females (54.2% vs. 45.8%, respectively). Although Blacks were only 6.6% of the cohort, they represented 12.2% of the TRI cases. Compared to non-TRI-related hospitalizations, a diagnosis of a TRI was associated with an increased likelihood of invasive mechanical ventilation (16.5% vs. 4.1%, p< 0.001), longer length-of-stay (5 vs. 4 days, p <0.001), higher cost of care (10,082 vs. 8,607, in US dollars p <0.001), and increased mortality (18.6% vs. 5.1%, p <0.001). Compared to non-TRI, cold-related illness portends higher odds of mortality 4.68, 95% Confidence Interval (4.35-5.04), p <0.001, and heat-related illness was associated with less odds of mortality, but this was not statistically significant 0.77 (0.57-1.03), p= 0.88.

Conclusion

The occurrence of TRI among hospitalized AF patients is small but there is an increasing trend in the prevalence, which more than doubled over the decade in this study. Individuals with AF who are admitted with a TRI face significantly poorer outcomes than those admitted without a TRI including higher mortality. Cold-related illness is associated with higher odds of mortality. Further research is required to elucidate the pathogenic mechanisms underlying these findings and identify strategies to prevent TRIs in AF patients.

Keywords
Atrial fibrillation; Cold-related injury; Heat-related injury; Heatstroke; Frostbites; National inpatient sample