The association of functional mitral regurgitation and anemia in patients with non-ischemic dilated cardiomyopathy.

Background: We investigated the association between anemia and functional mitral regurgitation (MR) in non-ischemic dilated cardiomyopathy (DCM) patients with sinus rhythm and normal renal function.

Methods: Sixty non-ischemic DCM patients with sinus rhythm and left ventricular ejection fraction < 40% were recruited. Functional MR was quantified with the proximal isovelocity surface area method. MR was graded according to the mitral regurgitant volume (Reg Vol) or effective regurgitant orifice (ERO) area. The clinical, biochemical and echocardiographic correlates of functional MR severity were investigated in patients with DCM.

Results: Hemoglobin degrees were significantly different between various MR levels (mild MR 13.9 +/- 1.7 mg/dL, moderate MR 12.3 +/- 1.5 mg/dL, moderate to severe MR 10.8 +/- 0.9 mg/dL). Receiver operating characteristic (ROC) analysis was performed to assess the utility of hemoglobin levels to predict moderate or severe functional MR. A hemoglobin level less than 12.5 mg/dL predicted moderate or high MR with 80% sensitivity and 58% specificity (AUC: 0.789, 95% CI: 0.676-0.901, p < 0.0001). Logistic regression analysis was performed to determine the independent predictors of moderate or severe levels of MR. The left atrium diameter (OR: 19.3, 95% CI: 1.4-27.1, p = 0.028) and presence of anemia (OR: 11.9, 95% CI: 1.22-42.5, p = 0.0045) were independent predictors of moderate or severe functional MR.

Conclusions: The presence of anemia and enlarged left atrium are independent predictors of moderate or severe functional MR in non-ischemic DCM patients with normal renal function. Hemoglobin levels less than 12.5 mg/dL should alert the physician for the presence of moderate or severe MR in patients with DCM.