Criteria for mitral regurgitation classification were inadequate for dilated cardiomyopathy.

Background: Mitral regurgitation (MR) is common in patients with dilated cardiomyopathy (DCM). It is unknown whether the criteria for MR classification are inadequate for patients with DCM.

Objective: We aimed to evaluate the agreement among the four most common echocardiographic methods for MR classification.

Methods: Ninety patients with DCM were included. Functional MR was classified using four echocardiographic methods: color flow jet area (JA), vena contracta (VC), effective regurgitant orifice area (ERO) and regurgitant volume (RV). MR was classified as mild, moderate or important according to the American Society of Echocardiography criteria and by dividing the values into terciles. The Kappa test was used to evaluate whether the methods agreed, and the Pearson correlation coefficient was used to evaluate the correlation between the absolute values of each method.

Results: MR classification according to each method was as follows: JA: 26 mild, 44 moderate, 20 important; VC: 12 mild, 72 moderate, 6 important; ERO: 70 mild, 15 moderate, 5 important; RV: 70 mild, 16 moderate, 4 important. The agreement was poor among methods (kappa=0.11; p<0.001). It was observed a strong correlation between the absolute values of each method, ranging from 0.70 to 0.95 (p<0.01) and the agreement was higher when values were divided into terciles (kappa = 0.44; p < 0.01) CONCLUSION: The use of conventional echocardiographic criteria for MR classification seems inadequate in patients with DCM. It is necessary to establish new cutoff values for MR classification in these patients.