Strain measurement for 2D echo with ultrasound enhancing agents can be performed with software available for non-enhanced recordings

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): ABACUS Cardiovascular Research Centre, Mazankowski Alberta Heart Institute

Background

Global longitudinal strain (GLS) measurement are less reliable when 2D image quality is reduced. While ultrasound enhancing agents (UEA; also known as "echo contrast") have been shown to enhance the reliability of EF measurements, there has been sparse evidence on performing GLS measurements after UEA injection. The aim of this study was to assess the feasibility of GLS analysis using the same software validated for non-enhanced 2D recordings.

Methods

GLS measurements were performed before and after injection of an approved UEA in 131 patients with acceptable image quality for GLS measurements. These patients were referred prior to chemotherapy initiation or were being monitored for potential cardiotoxic effects. As all these patients undergo echocardiography with UEA in order to achieve the best reproducibility of EF measurements, comparison of GLS measurements with and without UEA was possible. A commercially available ultrasound system was used and the same analysis software was applied. On end-diastolic and end-systolic frames, the inner border of the region of interest was manually adjusted to align with interface between the compact and trabeculated myocardium on non-enhanced images and the LV blood pool on the recordings with UEA.

Results

GLS measurements on recordings with UEA were performed in 131 patients. A strong positive correlation (r 0.67, p < 0.001) was found between measurements on non-enhanced recordings with mean bias 0.58% (see figure). Mean GLS was 19.5 +/- 2.1% from non-enhanced recordings and 20.1 +/- 2.2% from UEA recordings. Differences in GLS > 2% between methods were related to foreshortening or suboptimal delineation of segments on non-contrast recordings.

Conclusion

On a commercially available echocardiography scanner, software developed for GLS measurements on non-enhanced 2D recordings can be also applied to recordings that use UEA. Comparable results are obtained, provided the LV cavity is well delineated and not foreshortened. Abstract Figure 1

Prevalence and predictors of right ventricular dysfunction in cancer patients treated with cardiotoxic chemotherapy – a prospective cardiovascular magnetic resonance study

Background

Right ventricular (RV) function has an established incremental prognostic value in cardiomyopathy. Studies on cancer therapeutics-related cardiac dysfunction (CTRCD) primarily focused on the left ventricle (LV), with conflicting results from small studies dedicated to RV dysfunction.

Purpose

We sought to investigate the influence of chemotherapy on RV function relative to LV function using serial cardiac magnetic resonance (CMR).

Methods

Patients were enrolled as part of Cardiotoxicity Prevention Research Initiative (CAPRI) Registry aimed at evaluating CMR-based markers for surveillance of CTRCD. Patients underwent non-contrast CMR imaging prior to initiation of anthracyclines and/or trastuzumab and serially every 3 months during the first year, then annually thereafter. We included patients who had a baseline and ≥1 follow-up scan and excluded those with baseline LV ejection fraction (EF)<50%, providing 320 patients completing 1,453 CMR studies. Cine images were analysed to calculate chamber volumes indexed to body surface area and EF. We defined LV CTRCD using CMR modality specific criteria of a drop in LV EF ≥5% from baseline to <57%; RV CTRCD as a drop ≥5% to <49% in females and <47% in males. We used linear mixed models to study the changes in ventricular volumes and EF with time.

Results

The majority of patients were females (80%), had breast cancer (68%) or lymphoma (32%), with a mean age of 52.7±13 years. Figure 1 shows temporal changes in mean ventricular volumes and function over the first year. Mean changes in RV function followed those of the LV, with the nadir of EF and maximum of volumes occurring at 6 months. Respective values for mean decrease in LV and RV EF at this time point versus baseline were 4.1 and 2.9% (p<0.001). Concomitant mean increase in indexed RV end-diastolic (ED) and end-systolic (ES) volumes were 1.6 and 2.7 ml/m2 (p=0.2 and <0.001). There was significant interaction of chemotherapy regimen with time for RV volumes (p=0.001 and 0.003), but not RV EF (p=0.7), with worst changes occurring with combined anthracyclines and trastuzumab. In all, 70 (22%) and 28 (9%) patients met criteria for LV and RV CTRCD, respectively. Among those who developed RV CTRCD, 10 had persistently normal LV function. Figure 2 shows the results of logistic regression to predict RV CTRCD. Significant univariable predictors included combined chemotherapy regimen and baseline LV and RV volumes and LV EF. Adjusting for age, sex, and chemotherapy regimen, baseline RV ED volume remained associated with RV CTRCD (odds ratio 1.6; p=0.005).

Conclusion

In this large study, RV volumes and function were similarly influenced by chemotherapy versus comparable LV-based measures. Using similar threshold criteria, the incidence of RV CTRCD was lower than for LV CTRCD; however, one third of those who develop RV CTRCD showed normal LV function. Future studies are warranted to study the prognostic influence of RV injury in cancer patients.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Alberta InnovatesGenome Alberta Figure 1. Temporal changes in LV & RV functionFigure 2. Predictors of RV CTRCD

Strategies incorporating spiral CT for the diagnosis of acute pulmonary embolism: a cost-effectiveness analysis

OBJECTIVE

To assess the cost-effectiveness of spiral CT for the diagnosis of acute pulmonary embolism.

DESIGN

Computer-based cost-effectiveness analysis.

PATIENTS

Simulated cohort of 1,000 patients with suspected acute pulmonary embolism (PE), with a prevalence of 28.4%, as in the Prospective Investigation of Pulmonary Embolism Diagnosis study.

INTERVENTIONS

Using a decision-analysis model, seven diagnostic strategies were compared, which incorporated combinations of ventilation-perfusion (V/Q) scans, duplex ultrasound of the legs, spiral CT, and conventional pulmonary angiography.

MEASUREMENTS AND RESULTS

Expected survival and cost (in Canadian dollars) at 3 months were estimated. Four of the strategies yielded poorer survival at higher cost. The three remaining strategies were as follows: (1) V/Q +/- leg ultrasound +/- spiral CT, with an expected survival of 953.4 per 1,000 patients and a cost of $1,391 per patient; (2) V/Q +/- leg ultrasound +/- pulmonary angiography (the "traditional" algorithm), with an expected survival of 953.7 per 1,000 patients and a cost of $1,416 per patient; and (3) spiral CT +/- leg ultrasound, with an expected survival of 958.2 per 1,000 patients and a cost of $1,751 per patient. The traditional algorithm was then excluded by extended dominance. The cost per additional life saved was $70,833 for spiral CT +/- leg ultrasound relative to V/Q +/- leg ultrasound +/- spiral CT.

CONCLUSIONS

Spiral CT can replace pulmonary angiography in patients with nondiagnostic V/Q scan and negative leg ultrasound findings. This approach is likely as effective as-and possibly less expensive than-the current algorithm for diagnosis of acute PE. When spiral CT is the initial diagnostic test, followed by leg ultrasound, expected survival improves but costs are also considerably higher. These findings were robust to variations in the assumed sensitivity and specificity of spiral CT.