Clinical characteristics of acute pulmonary embolism at different altitudes in plateau areas

Abstract

Objective: To analyze the clinical characteristics of pulmonary embolism patients from different altitudes in plateau areas. Methods: A retrospective cross-sectional study was used to analyze the patients with acute pulmonary embolism diagnosed definitely by pulmonary angiography or pulmonary artery CT angiography admitted to Tibet Autonomous Region People's Hospital from August 2014 to December 2018. The subjects were divided into 3 groups according to the altitude of long-term residence before onset, i.e. low-altitude group (group 1, 2 700 m ≤ altitude ≤3 700 m, n=44), medium-altitude group (group 2, 3 700 m<altitude ≤4 000 m, n=30) and high altitude group (group 3, 4 000 m<altitude ≤4 800 m, n=32). The clinical data, auxiliary examination and risk stratification of pulmonary embolism patients at different altitudes were compared and analyzed. Results: The incidence of chest pain, dyspnea and lower limb fracture in the three groups were statistically significant (P<0.05). The incidence of chest pain in group 2 (70%) was higher than that in group 1(40.9%), and dyspnea in group 3 (93.8%) was higher than that in group 2(66.7%), while lower limb fracture in group 3 (43.8%) was higher than that in group 1(15.9%). The differences in arterial oxygen partial pressure, hemoglobin and D-dimer among the three groups were statistically significant (P<0.05). The arterial oxygen partial pressure [52(43.5-63.5)mmHg] in group 3 was lower than that in group 1 [60 (53.25-73) mmHg]. The hemoglobin (163.1±43.3 g/L) and D-dimer [5.6(3.7-12.6)mg/L] in group 3 were higher than those in group 1 [143.5±38.9 g/L and 3.8(2.0-7.5)mg/L respectively]. The risk stratification of the three groups of patients was moderate or low, and there was no statistical difference among the three groups. In patients with the same low-risk grade, the D-dimer in group 3 was higher than that in group 1 [5.8(4.2-14.8)mg/L and 3.6(2.3-5.8)mg/L respectively, P<0.05]. In patients with the same moderate risk level, the arterial oxygen partial pressure in group 3 was lower than that in group 1 [47.0(36.0-58.0)mmHg and 59.5(52.3-68.5)mmHg, respectively, P<0.05]. Conclusion: There was no difference in the risk stratification of pulmonary embolism from different altitudes in plateau areas, but patients who lived at higher altitudes for a long time showed more significant hypoxemia and increased hemoglobin and D-dimer levels.