Seasonal variation in occurrence of aortic diseases: The database of hospital discharge data of the Emilia-Romagna region, Italy

In analogy with other cardiovascular events, e.g., myocardial infarction and stroke, acute aortic diseases do not randomly occur over time but show definite chronobiologic variations, characterized by a higher frequency during morning hours and winter months. This study was aimed to confirm, on the large number of cases of a regional database, the existence of a seasonal variation in acute aortic diseases. We utilized the database of all hospital admissions of the Emilia Romagna region, Italy, Center for Health Statistics, between January 2000 and December 2006. Cases were categorized by month of onset of each event, and the test for goodness of fit was used for statistical analysis on total population, and subgroups according to sex, age, and type of acute event, e.g., dissection or rupture. The total sample consisted of 4,615 subjects (77% males, mean age 70 ± 13 years; 59.8% dissections, 40.2% ruptures). A seasonal pattern, characterized by a lowest frequency in summer, was shown for total cases, and subgroups by sex and age. Separate analysis by type of event, confirmed this seasonal pattern for dissection but not for rupture subgroup, independently of the presence or not of hypertension.