Seasonality and Daily Weather Conditions in Relation to Myocardial Infarction and Sudden Cardiac Death in Olmsted County, Minnesota, 1979 to 2002
Key result
Winter season is linked to ~17% higher SCD risk, largely driven by colder daily temperatures.
- RR 1.17
- 95% CI 1.03 to 1.32
Why the study?
Winter peaks in coronary heart disease have been documented, but it is uncertain if seasonality exists for both incident MI and SCD and the role of weather conditions is unclear.
Do winter season and low daily temperatures increase the risk of incident myocardial infarction and sudden cardiac death?
Population
2,676 MI and 2,066 SCD cases in Olmsted County, Minnesota
Comparison
Winter season and low temperatures (below 0 degrees C) vs summer season and higher temperatures (18 to 30 degrees C)
Design
Observational study using Poisson regression models
Follow-up
1979 to 2002
Authors
Discussion
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Member takes
Implication
Low daily temperatures account for the observed winter peak in sudden cardiac death, particularly in patients without prior coronary heart disease.
Key Points
- To assess how season and daily weather patterns influence incident myocardial infarction and sudden cardiac death, and to test whether winter peaks in cardiac mortality are driven by weather.
- Analyzed daily incident myocardial infarction (N=2,676) and sudden cardiac death (N=2,066) cases in Olmsted County, Minnesota between 1979 and 2002 alongside National Weather Service data.
- Used Poisson regression models adjusted for age, gender, and calendar year to calculate relative risks across seasons and climatic variables.
- Stratified sudden cardiac death into events with antecedent coronary heart disease and unexpected events occurring without prior heart disease.
- Adjusted sudden cardiac death risk increased in winter versus summer (RR = 1.17, 95% CI 1.03 to 1.32) and at temperatures below 0°C versus 18°C to 30°C (RR = 1.20, 95% CI 1.07 to 1.35), whereas myocardial infarction risk showed no seasonal variation.
- Low temperature associations were significantly stronger for unexpected sudden cardiac death than for cases with prior coronary heart disease (P < 0.05).
- After comprehensive adjustment for climatic factors, low temperature remained strongly associated with unexpected sudden cardiac death (RR = 1.38, 95% CI 1.10 to 1.73), while the seasonal effect was eliminated (RR = 1.06, 95% CI 0.83 to 1.35).
Study Design
Type
Observational
Multicenter
No
Structured PICO
Do winter season and low daily temperatures increase the risk of incident myocardial infarction and sudden cardiac death?
P
Population
Population-based study in Olmsted County, Minnesota, analyzing 2,676 incident myocardial infarctions and 2,066 sudden cardiac deaths between 1979 and 2002.
E
Exposure
Winter season and low daily temperatures (below 0 degrees C)
C
Comparator
Summer season and higher temperatures (18 to 30 degrees C)
O
Outcome
Daily occurrence of incident myocardial infarction (MI) and sudden cardiac death (SCD)hard clinical
Main Result
Relative Risk: 1.17 (95% CI 1.03–1.32)
Low daily temperatures account for the observed winter peak in sudden cardiac death, particularly in patients without prior coronary heart disease.
Cite This Study
Gerber et al. (2006) conducted an observational in Myocardial infarction and sudden cardiac death. Winter season and low temperatures vs. Summer season and higher temperatures was evaluated on Sudden cardiac death (SCD) (RR 1.17, 95% CI 1.03 to 1.32). Winter season was associated with an increased risk of sudden cardiac death (RR 1.17; 95% CI 1.03-1.32), an association that was largely accounted for by low daily temperatures.