Seasonality in Mortality in a Cardiology Department: A Five-Year Analysis in 500 Patients

BACKGROUND: Previous studies have indicated that cardiovascular mortality follows a seasonal trend. The aim of this work was to determine the evolution of mortality throughout the year in a cardiology department. METHODS: All admissions and deaths occurring in our Cardiology Department over a 5-year period (2013-2017) were recorded retrospectively. RESULTS: From a total of 17,829 hospital admissions, 500 patients died (2.8%, 0.3 patients/day). The mean age of deceased patients was 74.2 ± 13.1 years, and 186 (37.2%) were women. Mortality ranged from 0.17 deaths/day in August to 0.40 deaths/day in February (p = 0.03), and from 0.20 deaths/day in summer to 0.36 deaths/day in winter (p = 0.001). There was also a trend towards a variation in hospitalizations, with a peak in January (10.5 admissions/day) and the lowest figure in August (7.0 admissions/day), p = 0.047. We found no significant seasonal trend regarding mortality rate with respect to the number of hospital admissions (p = 0.89). The most common cause of death was refractory heart failure (267 patients [65.8%]). A noncardiac cause of death was observed in 134 patients (26.8%). CONCLUSIONS: In a cardiology department, there are twice as many deaths in winter as in summer. Hospitalizations also tend to be more frequent in winter than in summer.