Can ultra short-term changes in ambient temperature trigger myocardial infarction?

Area of Science:

• Environmental Health
• Cardiovascular Medicine
• Epidemiology

Background:

• Climate change is increasing global temperatures and extreme weather events.
• Both high and low ambient temperatures are linked to increased mortality.
• The specific cardiovascular impacts of hourly temperature fluctuations remain understudied.

Purpose of the Study:

• To assess the association between hourly ambient temperature and the risk of myocardial infarction (MI).
• To investigate the impact of short-term temperature changes on cardiovascular events in New York State residents.

Main Methods:

• A time-stratified case-crossover study design was employed.
• Data from 791,695 primary MI hospital admissions in New York State (2000-2015) were analyzed.
• Hourly ambient temperature was linked to patient residential ZIP codes for up to 48 hours prior to MI.

Main Results:

• A positive association was found between temperature in the 6 hours preceding MI and MI risk.
• A 7.9% increase in MI rate was estimated for an 11°C to 27°C temperature increase (lag hours 0-5).
• Men, individuals under 65, and first-time MI patients showed higher sensitivity.

Conclusions:

• Increases in hourly ambient temperature can precipitate myocardial infarction.
• Health-based definitions of extreme heat should incorporate hourly temperature data.
• Findings can guide improved preparedness strategies for extreme heat events.