Impact of Preprocedural Anemia on Outcomes ofPatients With Mitral Regurgitation Who UnderwentMitraClip Implantation

MitraClip is a novel therapeutic option for mitral regurgitation (MR). Anemia is associated with unfavorable outcomes of patients with cardiovascular diseases. In this study, we aimed to clarify the effect of preprocedural anemia on outcomes of patients who underwent MitraClip implantation. Anemia was defined as a serum hemoglobin level of <13 g/dl in men and <12 g/dl in women according to the World Health Organization criteria. Among the 392 patients receiving MitraClip implantation, anemia was prevalent in 56% (n = 220). Men tended to be more common in patients with anemia (71% vs 62%, p = 0.069). Patients with anemia were older than those without anemia (76 ± 8 vs 74 ± 10years, p = 0.008). Baseline New York Heart Association class IV (35 vs 22%, p = 0.006) and chronic kidney disease (79 vs 67%, p = 0.011) were more common in patients with anemia. Severity of MR was similar at baseline in the two groups, and it equally improved after MitraClip implantation. Despite similar improvement in MR, N-terminal pro b-type natriuretic peptide did not decrease in patients with anemia, and Kaplan-Meier curves showed that patients with anemia had lower survival (log-rank p = 0.013). After adjustment for covariates, preprocedural anemia was still associated with higher mortality after MitraClip implantation (p = 0.027, hazard ratio 1.802). The negative prognostic impact of preprocedural anemia was prominent in patients with higher baseline N-terminal of pro-Brain Natriuretic Peptide. These results suggest that preprocedural anemia was common and negatively affected patient survival. Establishing optimal management of anemia before MitraClip implantation is necessary, particularly for patients with severe heart failure.