Background: Anemia is associated with increased mortality after cardiovascular interventions and patients (pts) with high risk for bleeding are increasingly offered left atrial appendage closure (LAAC).  This study aims to investigate the procedural safety and long-term outcomes of LAAC in patients with anemia as compared to non-anemic patients in a real-world setting.

Methods: The LAArge registry is a prospective, multicentre observational registry of patients undergoing LAAC in Germany. Anemia was defined as hemoglobin <8 g/dl before the procedure.

Results: A total of 638 pts (anemia 142/638 vs non-anemia 496/638) were included. The anemia group had significantly higher CHA2DS2-VASc (4.8 vs 4.4, p=0.017), HAS-BLED (4.3 vs 3.8, p<0.001) and history of bleeding (94.4% vs 75.2%, p<0.001) compared with the control group. Anemia pts with major bleeding as indication were more likely to have  had GI bleeding (77.8% vs 30.2%, p<0.001) and received blood transfusion (82.3% vs 47.1%, p<0.001) but less likely to have intracranial bleeding (12.7% vs 60.3%, p<0.001) and surgery for bleeding (27.4% vs 44.6%, p=0.024). Implant success was high in both groups (99.3% vs 97.2%). Before LAAC, pts with anemia had similar rates of anticoagulation (AC) (46.5% vs 50.0%, p=0.46) but more double antithrombotic therapy (DAT) (15.5 vs 6.9, p=0.001). After the procedure, DAPT (87.3% vs 83.4%, p=0.26) and DAT (7.0% vs 6.9%, p=0.95) were similar between the groups. The combined outcome of in-hospital MACCE and other severe complications was significantly lower in the anemia group (0.7% vs 5.6%, p=0.01). In the one-year follow-up, mortality was not significantly different between both groups but associated with an increased hazard ratio (16.0% vs 10.3%, HR 1.61 (95%-CI: 0.97-2.67). Affirmatively, the composite outcomes of death/stroke (16.0% vs 11.1%, HR 1.49 (95%-CI: 0.90-2.44) and death/stroke/systemic embolism (16.0% vs 11.4%, HR 1.46 (95%-CI: 0.89-2.39) were numerically higher in the anemia cohort with an increased hazard ratio. The adjusted outcome of death/stroke/systemic embolism in anemic patients was associated with a hazard ratio of 1.04 (95%-KI 0.62-1.73)

Conclusion: Anemia is common in patients presenting for LAAC. Major bleeding and anemia is associated with chronic GI-bleeding whereas major bleeding and no-anemia is associated with intracranial haemorrhage. Anemia is not associated with compromised procedural safety. Longterm mortality seems to be mainly driven by co-morbidities. 

 Figure 1: Patients presenting with major bleeding as indication for interventional closure GI: gastrointestinal; displayed in the bars are percentages; P-values <0.05 are considered significant, tested with either Pearson chi-squared test or Mann-Whitney-Wilcoxon test