Anemia is not a risk factor for developing pulmonary embolism.
OBJECTIVE
Our aim was to validate the previously published claim of a positive relationship between low blood hemoglobin level (anemia) and pulmonary embolism (PE).


METHODS
This was a retrospective study of patients undergoing cross-sectional imaging to evaluate for PE at an academic medical center. Patients were identified using billing records for charges attributed to either magnetic resonance angiography or computed tomography angiography of the chest from 2008 to 2013. The main outcome measure was mean hemoglobin levels among those with and without PE. Our reference standard for PE status included index imaging results and a 6-month clinical follow-up for the presence of interval venous thromboembolism, conducted via review of the electronic medical record. Secondarily, we performed a subgroup analysis of only those patients who were seen in the emergency department. Finally, we again compared mean hemoglobin levels when limiting our control population to an age- and sex-matched cohort of the included cases.


RESULTS
There were 1294 potentially eligible patients identified, of whom 121 were excluded. Of the remaining 1173 patients, 921 had hemoglobin levels analyzed within 24 hours of their index scan and thus were included in the main analysis. Of those 921 patients, 107 (11.6%; 107/921) were positive for PE. We found no significant difference in mean hemoglobin level between those with and without PE regardless of the control group used (12.4 ± 2.1 g/dL and 12.3 ± 2.0 g/dL [P = .85], respectively).


CONCLUSIONS
Our data demonstrated no relationship between anemia and PE.
University of Wisconsin-Madison, BerbeeWalsh Department of Emergency Medicine.
John B
JB
Harringa
University of Wisconsin-Madison, BerbeeWalsh Department of Emergency Medicine. Electronic address: rbracken@medicine.wisc.edu.
Rebecca L
RL
Bracken
University of Wisconsin-Madison, Department of Radiology.
Scott K
SK
Nagle
University of Wisconsin-Madison, Department of Radiology.
Mark L
ML
Schiebler
University of Wisconsin-Madison, BerbeeWalsh Department of Emergency Medicine.
Brian W
BW
Patterson
University of Wisconsin-Madison, BerbeeWalsh Department of Emergency Medicine.
James E
JE
Svenson
University of Wisconsin-Madison, BerbeeWalsh Department of Emergency Medicine; University of Wisconsin-Madison, Department of Radiology.
Michael D
MD
Repplinger
D000328:Adult; D000740:Anemia / Q000453:epidemiology* / Q000378:metabolism; D016022:Case-Control Studies; D000072226:Computed Tomography Angiography; D004636:Emergency Service, Hospital; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D020246:Venous Thrombosis / Q000453:epidemiology
D006454:Hemoglobins