Diagnostic value of parametric imaging of left ventricular wall motion from contrast-enhanced echocardiograms in patients with poor acoustic windows.

BACKGROUND: Analysis of left ventricular (LV) regional wall motion (RWM) is subjective and may be challenging in patients with suboptimal images, even with contrast enhancement. It was hypothesized that the amplitude and timing of RWM obtained from contrast-enhanced echocardiograms can be accurately represented in still-frame parametric images. This study was designed to (1) test this hypothesis, (2) establish the diagnostic value of these images as an aid for inexperienced readers, and (3) test the feasibility of automated quantitative analysis of RWM. METHODS: Contrast-enhanced apical 4-chamber, 2-chamber, and 3-chamber LV views were acquired in 45 patients with poor acoustic windows. The interpretation of dynamic images by an experienced reader who classified RWM as normal or abnormal was used as a reference for comparisons against (1) visual interpretation of parametric images, (2) interpretation of dynamic images by two inexperienced readers (American Society of Echocardiography level I) without and subsequently with parametric images, and (3) automated quantification of RWM. RESULTS: Expert readers detected abnormal RWM in 30 patients (437 of 945 segments). Visual interpretation of parametric images showed good agreement with the reference (sensitivity, 85%; specificity, 82%; accuracy, 84%). The interpretations by inexperienced readers improved with the addition of parametric images, with increases in specificity (from 58% to 79%) and accuracy (from 74% to 84%), despite a slight decrease in sensitivity (from 92% to 91%). Automated classification was feasible and accurate (sensitivity, 82%; specificity, 78%; accuracy, 80%). CONCLUSION: Parametric images derived from contrast-enhanced echocardiograms of patients with poor acoustic windows accurately depicted RWM, improved the diagnostic accuracy of inexperienced readers, and allowed the objective detection of RWM abnormalities.

Gender-specific prediction of cardiac disease: importance of risk factors and exercise variables.

Current guidelines recommend targeting the intensity of preventive cardiovascular interventions to the level of the patient's risk, which is usually obtained from a global risk score such as the Framingham equations. However, a large proportion of asymptomatic U.S. women (approximately 80-90%) are classified as low risk by the Framingham score, although they have a 1 in 2 chance of dying from cardiovascular disease (CVD) during their lifetime. A promising avenue for improving CVD risk stratification has come from recent studies evaluating the prognostic value of exercise testing in asymptomatic populations using test variables that are not related to exercise-induced ST-segment depression. In particular, it has been shown that 2 easily obtained noninvasive measures, low exercise capacity and slow heart rate recovery, have been linked to increased CVD and all-cause death in both women and men. These 2 simple yet powerful measures of risk that are readily available are useful tools for the practicing cardiologist who desires more accurate assessment of risk in a female patient, particularly if she is deemed as intermediate risk by the Framingham score. In addition, both exercise capacity and heart rate recovery are at least partially modifiable by regular physical activity. Exercise recommendations of at least 30 minutes of moderate physical activity most days of the week have been associated with 30% to 50% reductions in coronary events and coronary mortality and should be recommended to all patients regardless of their Framingham risk score.