The Effect of Obesity on Echocardiographic Image Quality.

BACKGROUND: Increased body mass index (BMI) may reduce transthoracic echocardiogram (TTE) image quality, resulting in increased requirements for ultrasound enhancing agents (UEA), as recommended by the American Society of Echocardiography (ASE), and a greater incidence of non-diagnostic studies. METHODS: Over a 5-month period 1,108 TTEs were analysed as to (1) whether they could answer the clinical question posed by the ordering physician (i.e. were diagnostic vs non diagnostic), and (2) whether they required UEAs according to the ASE guidelines. Patient characteristics were gathered from the medical record. RESULTS: 12.9% of TTEs were non-diagnostic (21.0% of TTEs in the obese population [BMI≥30 kg/m2] vs 7.8% in the non-obese [p<0.001]). Predictors of a non-diagnostic study were BMI (OR 1.09, [95% CI 1.06-1.11], p<0.0001), male gender (OR 1.54, [1.06-2.25], p=0.02), and inpatient status (OR 1.75, [1.20-2.55], p=0.004). Obesity (BMI≥30) was strongly associated with non-diagnostic studies (OR 3.22, [2.23-4.51], p<0.001). Factors associated with increased requirement of UEAs were BMI (OR 1.10, [1.08-1.12], p<0.0001), age (OR 1.02, [1.01-1.03], p<0.0001) and inpatient status (OR 1.7, [1.29-2.24], p<0.05). Obesity (BMI>30) was strongly associated with contrast requirement (OR 3.16, [2.43-4.10], p<0.0001). CONCLUSIONS: Body mass index, male gender and inpatient status were associated with an increased incidence of non-diagnostic studies. Body mass index, age and inpatient status were associated with an increased requirement for UEAs.

Cardiotoxic Effect of Modern Anthracycline Dosing on Left Ventricular Ejection Fraction: A Systematic Review and Meta-Analysis of Placebo Arms From Randomized Controlled Trials.

Background Anthracyclines are a key chemotherapeutic agent used against hematological and solid organ malignancies. However, their benefits in cancer survival are limited by cumulative, dose-related cardiotoxicity. The impact of anthracyclines on left ventricular ejection fraction (LVEF), in the era of modern chemotherapy regimens, remains unclear. Methods and Results Three databases (CENTRAL, MEDLINE, and SCOPUS) were systematically searched for randomized trials evaluating cardioprotective agents against placebo, in preventing cardiotoxicity. Echocardiography or magnetic resonance measured LVEF pre- and post-anthracycline-based chemotherapy was abstracted from placebo trial arms. The key terms included "anthracycline," "cardiotoxicity" and "randomized." A doxorubicin equivalent anthracycline dose metric was calculated to compare different anthracyclines. A random-effects model was used to pool mean difference in LVEF after anthracycline. Meta-regressions were calculated to identify variation sources. We included 660 patients from 19 trials. The weighted mean baseline LVEF across studies was 62.6%, and follow-up LVEF assessment was performed at 6 months. The pooled mean decline in LVEF among placebo arms was 5.4% (95% CI, 3.5%-7.3%) with a doxorubicin equivalent anthracycline dose of 385 mg/m2. Meta-regression analysis showed no significant difference in LVEF against doxorubicin equivalent anthracycline dose as continuous (P=0.29) or against published cut-offs for cardiotoxicity (250 mg/m2, P=0.21; 360 mg/m2, P=0.40; and 400 mg/m2, P=0.66). The differences in mean LVEF were not associated with sex, adjunct chemotherapy, or cancer type. Conclusions The magnitude of LVEF impairment post-anthracycline therapy appears less than previously described with modern dosing regimens. This may improve the accuracy of power calculation for future clinical trials assessing the role of cardioprotective therapy.