[Clinical features of atrial fibrillation complicated with occult pulmonary embolism]

Objective: To investigate the clinical features of patients with atrial fibrillation (AF) and occult pulmonary embolism (PE). Methods: Clinical data of 67 AF patients complicated with PE (AP group) admitted to the Tianjin Chest hospital from January 2014 to July 2018 were analyzed. A total of 70 AF patients without PE served as the control group (AF group). The AP group was divided into 2 subgroups: AF with occult PE (OPE subgroup) and symptomatic PE (SPE subgroup). The clinical features of OPE subgroup were analyzed. Results: The levels of leukocyte counts, C-reactive protein, D-dimer and N-terminal pro-brain natriuretic peptide in the AP group were (7.4±2.7)×10(9)/L, 18.0 (5.9, 65.7) mg/L, 2.61 (1.63, 3.72) mg/L and 1 657 (600, 3 172)ng/L, which were higher than those in the AF group (P=0.008, P<0.001, P<0.001 and P=0.002, respectively); Arterial oxygen pressure in the AP group was (74±13) mmHg (1 mmHg=0.133 kPa), lower than the AF group (P<0.001); and pulmonary artery systolic pressure was (46±16) mmHg, higher than the AF group (P<0.001). In the OPE subgroup, 12 cases (66.7%) were complicated with localized pulmonary embolism, more than those in the SPE subgroup (P=0.008), and pulmonary artery systolic pressure was (39±11) mmHg, which was lower than the SPE subgroup (P<0.001); the levels of leukocyte counts, C-reactive protein and D-dimer in the OPE subgroup were (7.6±2.3)×10(9)/L, 18.3 (3.7, 67.3) mg/L and 2.31 (1.27, 3.61) mg/L, higher than the AF group (all P<0.05); arterial oxygen pressure in the OPE subgroup was (75±12) mmHg, lower than the AF group (P<0.05). Conclusions: Occult pulmonary embolism is not uncommon in patients with atrial fibrillation. Comparing with AF group, the OPE subgroup was associated with increased levels of inflammatory markers and D-dimer and hypoxemia.