title: Impact of weather and climate on the incidence of acute coronary syndromes.
abstract: BACKGROUND
  First investigations of the interactions between weather and the incidence of acute myocardial infarctions date back to 1938. The early observation of a higher incidence of myocardial infarctions in the cold season could be confirmed in very different geographical regions and cohorts. While the influence of seasonal variations on the incidence of myocardial infarctions has been extensively documented, the impact of individual meteorological parameters on the disease has so far not been investigated systematically. Hence the present study intended to assess the impact of the essential variables of weather and climate on the incidence of myocardial infarctions.
  
  
  METHODS
  The daily incidence of myocardial infarctions was calculated from a national hospitalization survey. The hourly weather and climate data were provided by the database of the national weather forecast. The epidemiological and meteorological data were correlated by multivariate analysis based on a generalized linear model assuming a log-link-function and a Poisson distribution.
  
  
  RESULTS
  High ambient pressure, high pressure gradients, and heavy wind activity were associated with an increase in the incidence of the totally 6560 hospitalizations for myocardial infarction irrespective of the geographical region. Snow- and rainfall had inconsistent effects. Temperature, Foehn, and lightning showed no statistically significant impact.
  
  
  CONCLUSIONS
  Ambient pressure, pressure gradient, and wind activity had a statistical impact on the incidence of myocardial infarctions in Switzerland from 1990 to 1994. To establish a cause-and-effect relationship more data are needed on the interaction between the pathophysiological mechanisms of the acute coronary syndrome and weather and climate variables.
authors.affiliation: Cardiology, Swiss Cardiovascular Center, University Hospital, Bern, Switzerland. stefan.goerre@hin.ch
authors.forename: Stefan
authors.initials: S
authors.lastname: Goerre
authors.forename: Claude
authors.initials: C
authors.lastname: Egli
authors.forename: Stefan
authors.initials: S
authors.lastname: Gerber
authors.forename: Claudio
authors.initials: C
authors.lastname: Defila
authors.forename: Christoph
authors.initials: C
authors.lastname: Minder
authors.forename: Hans
authors.initials: H
authors.lastname: Richner
authors.forename: Bernhard
authors.initials: B
authors.lastname: Meier
mesh_terms: D002980:Climate; D005260:Female; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008297:Male; D009203:Myocardial Infarction / Q000453:epidemiology*; D016012:Poisson Distribution; D012042:Registries; D013557:Switzerland / Q000453:epidemiology; D014887:Weather