Volume and volume-mass ratio by freehand 3D echo predict improvement in advanced cardiomyopathy treated by carvedilol
Amyloid Neuropathies, Familial
Carvedilol, a promising adrenergic antagonist for treatment of advanced cardiomyopathy, produces reversal of LV remodeling in chronic heart failure. In end-stage heart failure associated with LV dilation and a low EF, the ratio of LV volume to mass increases. At some point increasing LV volume should exceed myocardial capacity to further increase LV function. Hypothesis: That EDV/MASS ratio below a critical value at baseline will predict patients that will be improved (reverse remodeling) by long-term treatment with Carvedilol from those that will not be improved. Methods: 21 patients with dilated ventricles and heart failure (17 males, 4 females, 62±12yrs, 12 idiopathic, 9 ischemic, EF=23.3±8.0, range: 11-38%) treated by Carvedilol had serial determination of ventricular volume, mass and EF by freehand 3D echo using a surface reconstruction algorithm and a line of intersection display for guidance. Patients improved (+ΔEF≥8% at 8+weeks) vs. not improved were compared by the unpaired T test and Pearson's correlation. Results: EDV/MASS EDV n Mean±SD p Mean±SD p Improved 12 0.835±0.095 0.0003 213.8±40.4 0.0089 Not Improved 9 1.059±0.117 339.0±107.0 Thus, EDV/MASS ratio and EDV at baseline among improved patients are significantly less than among those not improved. An EDV/MASS <1.0 and EDV <280ml. afforded the best separation of favorable treatment response (12/14) from those not improved. The 7 patients with an EDV/MASS >1.0 and EDV > 280 ml. did not improve. Significant correlations of ΔEF vs EDV/MASS (r=-0.491, p=0.024) and ΔEF vs. EDV (r=-0.456,p=0.0.038) were present. Conclusion: EDV/MASS ratio is the best discriminator of those patients with advanced, dilated cardiomyopathy that are improved vs. not improved by Carvedilol. Improvement is not likely (0/7) if baseline EDV/MASS ratio is greater than 1.0, whereas it is likely (12/14) with a ratio of <1.0. The EDV/MASS ratio by freehand 3D echo may be a useful index for identifying important stages in the development or failure of development of compensatory hypertrophy in patients with progressive ventricular dilation.