To assess whether season or short-term temperature extremes are associated with patient characteristics and 30-day mortality among hospitalized patients with HFmrEF.
Approach:
Design and population: Retrospective analysis of 2,184 consecutive patients hospitalized with HFmrEF at University Medical Centre Mannheim, Germany, from January 2016 through December 2022.
Exposure and outcomes: Admissions were grouped by season. Daily meteorological data were used to identify temperature extremes and day-to-day fluctuations at admission and over the preceding 3 days. Multivariable Cox regression assessed associations with 30-day all-cause mortality, adjusting for age, sex, acute decompensated HF, myocardial infarction, and ischemic etiology.
Key Findings:
Admissions were distributed similarly across spring (25%), summer (25%), autumn (24%), and winter (26%); most measured clinical characteristics and discharge HF medications were also comparable by season.
There were 92 deaths within 30 days (4.2%). Admission season was not associated with 30-day mortality (log-rank p = 0.809).
Admission temperature in the lowest 5th percentile (≤0.8 °C) was associated with higher adjusted 30-day mortality (HR 2.012; 95% CI 1.003–4.033; p = 0.049). A similar association was reported for the preceding 3-day mean temperature ≤1.33 °C (adjusted HR 2.058; 95% CI 1.028–4.118; p = 0.042).
Extreme high temperature and top-5th-percentile day-to-day temperature fluctuation were not associated with 30-day mortality.
Interpretation:
In this cohort, admission season was not associated with 30-day mortality, while extreme cold at admission and over the preceding 3 days was associated with higher mortality. Extreme high temperature and large day-to-day temperature fluctuations were not associated with mortality.
Limitations:
The study was retrospective and conducted at a single medical centre in Germany.
The supplied article context does not report the full set of study limitations.
Conclusion:
Among hospitalized patients with HFmrEF in this single-centre cohort, season was not associated with 30-day mortality, whereas extreme cold at admission and during the preceding 3 days was associated with higher mortality.
