Background and aim: Abnormal myocardial acoustic properties have been reported in patients with idiopathic dilated cardiomyopathy (IDC). The aim of this study was to investigate the relationship between quantitative ultrasonic textural alterations of myocardium and clinical outcome in IDC.
Methods: Baseline clinical and echocardiographic variables were obtained from 28 patients with IDC. By using a videodensitometric approach, quantitative myocardial texture analysis was performed on images obtained from septum and posterior wall (PW). Cyclic variation (CV) index of mean gray level (MGL) was calculated according to the formula: (MGLdiast-MGLsyst)/MGLdiastx100. All patients were followed for an average of 11+/-5 months for the occurrence of cardiac death or repeated hospitalization due to worsening of heart failure.
Results: During follow-up, 10 patients experienced cardiac events (6 cardiac deaths and 4 heart failure events). The CV indexes of both septum and PW were significantly lower in patients with cardiac events than those of event free patients (6.8+/-9.6% vs. 13.6+/-8.2%, P<0.05 and 5.3+/-6.4% vs.15.7+/-7.2% P<0.001, respectively). Univariate analysis defined the following variables as predictors of outcome: PW-CV index (chi2=13.0, P=0.0003), transmitral E/A ratio (chi2=12.5, P=0.0004), symptom status (chi2=8.7, P=0.003), and septum-CV index (chi2=4.7, P=0.03). Multivariate stepwise regression analysis showed that the PW-CV index (chi2=7.5, P=0.006) and E/A ratio (chi2=6.5, P=0.01) were the independent predictors of outcome. The event-free survival rate of patients with PW-CV index <11% was significantly lower than those with an index > or = 11 (35.7% vs. 92.8%, P=0,001).
Conclusion: The assessment of severely depressed CV index provides valuable prognostic information in patients with IDC.