# Ambient Temperature and the Frequency of Subsequent Heart Failure Decompensations in an Emergency Department

## TL;DR

This study found that colder temperatures are linked to more heart failure decompensations in an emergency department in Eastern Austria.

## Contribution

The study provides new evidence on the relationship between cold ambient temperatures and increased heart failure decompensations in a continental climate zone.

## Key findings

- Lower daily maximum temperatures correlated with a higher number of heart failure decompensations the next day.
- The association remained significant after adjusting for other meteorological factors.
- The effect was observed in heart failure patients with preserved and reduced ejection fraction, but not in those with mildly reduced ejection fraction.

## Abstract

Background/Objectives: The impact of cold temperature on heart failure (HF) decompensations in continental climate zones is unclear. We aimed to evaluate the association between daily temperature and the subsequent frequency of HF decompensations in an emergency department (ED) in Eastern Austria. Methods: A systematic retrospective medical chart review of all admissions to the ED of a tertiary care center within 12 months was conducted. Maximal daily temperature and further meteorological data were obtained from the National Institute for Meteorology and Geodynamics. Results: Among 32.028 ED admissions, there were 1.248 HF decompensations. Median maximal daily temperature ranged from 4.3 °C in January to 28.7 °C in August, and the frequency of decompensations ranged from 65 in August to 143 in January. Maximal daily temperature correlated negatively with the number of decompensations on the subsequent day (beta = −0.07 [95% confidence interval, −0.09 to −0.05], p < 0.001). The association remained significant in a multivariate linear regression model adjusted for other meteorological parameters (adjusted beta = −0.07 [−0.10 to −0.04], p < 0.001). Moreover, it was present across HF with preserved (n = 375; beta = −0.08 [−0.14 to −0.03], p = 0.004) and reduced (n = 331; beta = −0.08 [−0.13 to −0.02], p = 0.005) ejection fraction, but not with mildly reduced ejection fraction (n = 160; beta = −0.03 [−0.07 to 0.01], p = 0.200). Conclusions: In a European continental climate zone region, lower temperature was associated with a linear increase in subsequent HF decompensations. The sequelae of climate change on HF decompensations may burden healthcare systems in the future and should be systematically investigated in further studies.