Prognostic Impact of Anemia in Patients with Significant Mitral Regurgitation: A Multicenter Cohort Study.

Abstract

Background and aim: Anemia may affect cardiac function and outcomes in cardiovascular diseases. However, there is scarce evidence on the impact of anemia in patients with mitral valve dysfunction. This study sought to investigate the prevalence of anemia in patients with significant mitral regurgitation (MR), as well as its association with outcomes.

Methods: A total of 4339 patients with moderate or greater MR in the China Valvular Heart Disease study were included in this analysis. Anemia was determined according to the World Health Organization definition. The primary outcome of this study was two-year all-cause mortality, and the secondary outcome was the composite of death and hospitalization for heart failure.

Results: Anemia was present in 33.1% (1435/4339) of the study population. During a median follow-up of 732 (704-748) days, 426 (9.8%) patients died and 686 (15.8%) experienced the composite endpoint. Both anemia and hemoglobin were independently associated with two-year outcomes (all P < 0.001). Similar results were observed in patients with conservatively managed MR, left ventricular ejection fraction ≤60%, or in subsets according to New York Heart Association functional class (I/II-IV), the diagnosis of heart failure, severity of valvular lesion, etiology of MR, and the presence of malnutrition. The combination of anemia with left atrial dilatation or impaired left ventricular systolic function identified high-risk patients with significantly poor survival, and the inclusion of anemia to EuroSCORE II model enhanced risk prediction in MR.

Conclusion: Anemia was common in patients with MR, and it was a significant predictor of poor prognosis. The high prevalence and negative impact of anemia make it as an important risk factor for prognostic evaluation and clinical decision-making.