Are Meteorological Parameters a Risk Factor for Pulmonary Embolism? A Retrospective Analysis of 530 Patients

Abstract

Background: The influence of meteorological conditions on cardiovascular morbidity and mortality has been known for a long time. However, few reports have been published on the influence of meteorological parameters on the occurrence of acute pulmonary embolism (PE). Aims: In this retrospective study, we compared the meteorological parameters between PE patients with risk factors and idiopathic PE patients. Study Design: Cross-sectional study. Methods: Medical documentation of 1180 patients with suspected acute pulmonary embolism diagnosed between January 2010 and December 2012 was retrospectively analyzed. A total of 530 patients with PE confirmed by computed tomography pulmonary angiography and/or ventilation/perfusion scan were included for further analysis. We divided the patients into two groups: PE with risk factors (provoked) and PE without risk factors (unprovoked). The meteorological data were collected from the relevant time period: temperature, humidity, pressure, and wind velocity. As the exact time of PE onset was unknown, the meteorological values attributed to each patient were the means of the values in the months or weeks at the time of diagnosis of PE. Results: The highest numbers of cases were seen in autumn (29.8%), followed by summer (28.9%), spring (22.1%), and winter (19.2%). In terms of months, the greatest number of cases occurred in June (57), followed by November (56) and October (54). Case distribution according to the months and seasons were statistically significant. The wind direction also affected the incidence of PE. There was a statistically significant positive correlation between case frequency and air temperature (r=0.300; p=0.031). No correlation was found between the unprovoked PE cases’ monthly distribution and pressure, humidity, or temperature. However, there was a statistically significant positive correlation between the monthly distribution of the group with provoked PE cases and air temperature (r=0.586; p=0.045). Conclusion: A statistically significant inverse correlation between atmospheric pressure and temperature and the number of all PE cases was observed in our study, which is in accordance with other reports. However, in unprovoked PE cases, there was no correlation between meteorological parameters and case incidence.

Keywords

• Meteorological factors
• pulmonary embolism
• risk factors