Mitral effective regurgitant orifice area versus left ventricular ejection fraction as prognostic indicators in patients with dilated cardiomyopathy and heart failure.

BACKGROUND: This study aimed at investigating the relative powers of the quantitative evaluation of functional mitral regurgitation (FMR) and ejection fraction (EF) in predicting the clinical changes and prognosis of dilated cardiomyopathy (DCM) with severe systolic dysfunction. METHODS: A total of 81 patients with DCM, EF < 0.40 and at least mild FMR were prospectively evaluated during a mean follow-up of 24 +/- 7 months. Twenty cardiac deaths were recorded. At the time of enrolment all patients underwent echocardiographic evaluation of the effective regurgitant orifice area (ERO), EF, left atrial area, and tenting area. In 42/81 patients, the data obtained at enrolment were compared to those measured at a mean follow-up of 10 +/- 2 months. A multivariate analysis was performed to determine the best predictor of NYHA class and mortality. RESULTS: There was a correlation between the NYHA class and the ERO (chi2 = 26.1, p = 0.0001) but not with EF (chi2 = 4.3, p = 0.22) and at multivariate analysis, the ERO was found to be the main determinant of the NYHA class (r = 0.64, standard error 0.6, p = 0.0001). The NYHA class remained unchanged or improved in 28/42 (67%) and deteriorated in 14/42 (33%) patients. In the first group, the ERO increased from 22.3 +/- 10 to 30.2 +/- 16.4 mm2 (p = 0.05) and the tenting area from 5.8 +/- 1.8 to 6.8 +/- 1.8 cm2 (p = 0.001); in the second group, the ERO increased from 25.1 +/- 5.6 to 39.0 +/- 14.5 mm2 (p = 0.04) and the tenting area from 5.9 +/- 2.1 to 7.6 +/- 1.8 cm2 (p = 0.0001), in both groups without significant changes in EF. The mortality was 8.1% in patients with an ERO < 21 mm2, 30.3% in patients with an ERO of 21-30 mm2, and 50% in those with an ERO > 30 mm2. The EF was similar in the three subgroups. At Cox multivariate analysis the best predictors of mortality were the ERO (chi2 = 13.83, p = 0.0001), EF (chi2 = 5.48, p = 0.019), and left atrial area (chi2 = 4.52, p = 0.04). CONCLUSIONS: FMR in DCM well correlated with the clinical status of the patients and its worsening was suggestive of progression of the disease. The ERO was found to be the best predictor of the NYHA class and mortality.

[Quantitative evaluation of functional mitral insufficiency in dilated cardiomyopathy: morphological and functional correlations]. / Valutazione quantitativa dell'insufficienza mitralica funzionale nella cardiomiopatia dilatativa: correlazioni morfologiche e funzionali.

BACKGROUND: Angiography and echo-color Doppler imaging are routinely used for the semiquantitative grading of functional mitral regurgitation (MR) in dilated cardiomyopathy. However, in case of severe regurgitation the results obtained using these two methods are discrepant. We propose quantitative echocardiographic evaluation and the related morphological parameters of remodeling of the ventricular and mitral apparatuses for the estimate of severe regurgitation. METHODS: Fifty-two patients with dilated cardiomyopathy and functional MR (28 males, 24 females, ejection fraction < or = 40%) were evaluated by means of echocardiography for a total of 73 echocardiograms (basal and 21 at the sixth month). The echo measurements included the left ventricular end-diastolic and end-systolic volumes, ejection fraction, area jet/left atrial area, diastolic and systolic mitral annulus areas and fractional contraction (MAC, %), systolic tenting area (TA, cm2, area enclosed between the annular plane and mitral leaflets), systolic tethering length (TL, cm, papillary tips and intervalvular fibrosa distance); quantitative Doppler (using the mitral and aortic stroke volumes) and PISA methods were averaged to calculate the regurgitant volume (RV, ml/beat), regurgitant fraction (RF, %), and effective regurgitant orifice (ERO, mm2). RESULTS: The strongest correlation with ERO, RV and RF was obtained with systolic TA (beta = 0.40, 0.67 and 0.60; SE 1.68, 1.56 and 1.38; p = 0.01, p = 0.0001 and p = 0.0001, respectively) and MAC (beta = -0.33, -0.61 and -0.61; SE 0.31, 0.31 and 1.49; p = 0.03, p = 0.0001 and p = 0.0001, respectively). We did not find any correlation with ejection fraction (p = NS). The following values were found to be indicative of severe functional MR: ERO > or = 40 mm2, RV > or = 49 ml/beat, RF > or = 57%, MAC < or = 12.5%, TA > or = 7.7 cm2, and TL > or = 4.7 cm. CONCLUSIONS: We did not find any significant correlation between the quantitative functional MR echo parameters and systolic dysfunction. The major determinants of ERO, RV and RF were the loss of MAC and larger systolic TAs. These parameters are significantly proportional to the severity of functional MR as assessed by the semiquantitative criteria commonly adopted in the clinical practice. We propose the values of ERO, RV, RF, TA, MAC and TL as indicative of severe functional MR.