“Anemia is encountered in patients with nonvalvular atrial fibrillation (NVAF) on oral anticoagulants (OACs), but the prognostic impact was not well scrutinized in real-world settings,” investigators of a study published in the Journal of Arrhythmia wrote.
The researchers conducted a multicenter registry study of patients with NVAF taking OACs and evaluated outcomes such as major bleeding, hemorrhagic stroke, ischemic events, ischemic stroke, and all-cause mortality.
A total of 7558 patients with NVAF on OACs were divided into 3 groups based on their hemoglobin (Hb) levels: moderate/severe anemia (Hb <11.0 g/dL), mild anemia (Hb 11.0-12.9 g/dL for men, Hb 11.0-11.9 g/dL for women), and no anemia. Overall, 28% of patients had anemia. Patients with anemia were generally older and had higher HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) scores, indicating a greater risk for bleeding complications.
“The elevated risk of major bleeding was prominent in those with moderate/severe anemia whose incidence was 14.9% at 4 years, but those with mild anemia were also at higher risk of major bleeding, adjusting for other clinically relevant variables,” the researchers reported. The adjusted hazard ratios (HRs) for major bleeding were 1.96 (95% CI, 1.49-2.58) for moderate/severe anemia and 1.48 (95% CI, 1.17-1.87) for mild anemia compared with the no anemia group. However, the researchers noted that “ischemic events or strokes were not associated with the presence or degree of anemia among those patients.”
Lastly, regarding all-cause mortality, the cumulative incidences were 21.2%, 15.7%, and 5.2% for the moderate/severe, mild, and no anemia groups, respectively. All-cause mortality rates per 1000 patient-years were 69.5, 36.7, and 12.5, respectively. Adjusted HRs revealed that moderate/severe anemia exhibited an HR of 3.77 (95% CI, 2.95-4.83) and mild anemia had an HR of 2.44 (95% CI, 1.95-3.05) compared with the no anemia group.
“If anemia was considered a risk for future major bleeding, blood transfusion before starting OACs could be an option,” the researchers wrote. “We should investigate the cause of anemia before considering the use of OACs, and several underlying conditions could be corrected before the use of OACs.”