UK audit of left ventricular ejection fraction estimation from equilibrium ECG gated blood pool images

Effect of variable left ventricular ejection fraction assessed by equilibrium radionuclide angiocardiography using different software packages on the diagnosis of cardiotoxicity in patients with cancer

BACKGROUND

The equilibrium radionuclide angiocardiography (ERNA) scan is an established imaging modality for assessing left ventricular ejection fraction (LVEF) in oncology patients. This study aimed to explore the interchangeability of two commercially available software packages (MIM and JS) for LVEF measurement for a cancer-therapy-related cardiac dysfunction (CTRCD) diagnosis.

METHODS

This is a single-center retrospective study among 322 patients who underwent ERNA scans. A total of 582 scans were re-processed using MIM and JS for cross-sectional and longitudinal LVEF measurements.

RESULTS

The median LVEF for MIM and JS were 56% and 66%, respectively (P < 0.001). LVEF processed by JS was 9.91% higher than by MIM. In 87 patients with longitudinal ERNA scans, serial studies processed by MIM were classified as having CTRCD in a higher proportion than serial studies processed by JS (26.4% vs 11.4%, P = 0.020). There were no significant differences in intra- or inter-observer LVEF measurement variability (R = 0.99, P < 0.001).

CONCLUSIONS

Software packages for processing ERNA studies are not interchangeable; thus, reports of ERNA studies should include details on the post-processing software. Serial ERNA studies should be processed on the same software when feasible to avoid discrepancies in the diagnosis and management of CTRCD.

The effect of trastuzumab on cardiac function in patients with HER2 ‐positive metastatic breast cancer and reduced baseline left ventricular ejection fraction

We investigated the effect of trastuzumab on cardiac function in a real‐world historic cohort of patients with HER2‐positive metastatic breast cancer (MBC) with reduced baseline left ventricular ejection fraction (LVEF). Thirty‐seven patients with HER2‐positive MBC and baseline LVEF of 40% to 49% were included. Median LVEF was 46% (interquartile range [IQR] 44%‐48%) and median follow‐up was 18 months (IQR 9‐34 months). During this period, the LVEF did not worsen in 24/37 (65%) patients, while 13/37 (35%) patients developed severe cardiotoxicity defined as LVEF <40% with median time to severe cardiotoxicity of 7 months (IQR 4‐10 months) after beginning trastuzumab. Severe cardiotoxicity was reversible (defined as LVEF increase to a value <5%‐points below baseline value) in 7/13 (54%) patients, partly reversible (defined as absolute LVEF increase ≥10%‐points from nadir to a value >5%‐points below baseline) in 3/13 (23%) patients and irreversible (defined as absolute LVEF increase <10%‐points from nadir and to a value >5%‐points below baseline) in 3/13 (23%) patients. Likelihood of reversibility was numerically higher in patients who received cardio‐protective medications (CPM), including ACE‐inhibitors, beta‐blockers and angiotensine‐2 inhibitors, compared to those who did not receive any CPM (71% vs 13%, P = .091). Sixty‐five percent of patients who received trastuzumab for HER2‐positive MBC did not develop severe cardiotoxicity during a median follow‐up of 18 months, despite having a compromised baseline LVEF. If severe cardiotoxicity occurred, it was at least partly reversible in more than two‐thirds of the cases. Risks and benefits of trastuzumab use should be balanced carefully in this vulnerable population.

Equilibrium radionuclide angiography: Intra- and inter-observer repeatability and reproducibility in the assessment of cardiac systolic and diastolic function

BACKGROUND

This study aimed to assess intra- and inter-observer agreement in assessing the systolic and diastolic function with equilibrium radionuclide angiography (ERNA).

MATERIALS AND METHODS

Thirty-two adults underwent baseline and repeat ERNA. An experienced and a trainee operator analyzed the data by assigning regions of interest manually, fully automatically, and semi-automatically. The Bland-Altman statistic (mean ± 1.96 standard deviations of the differences) was used to assess the repeatability (two different assessments of a single acquisition) and reproducibility (assessments of two different acquisitions).

RESULTS

Using the semi-automated technique the intraobserver repeatability and reproducibility of left ventricular ejection fraction for the experienced physician were - 0.1 ± 3.7 and 0.0 ± 3.8 and for the trainee 2.2 ± 10.6 and 1.9 ± 8.4, respectively. The inter-observer repeatability and reproducibility were - 1.8 ± 6.4 and 0.4 ± 9.0, respectively. Among the parameters of diastolic function, the intraobserver repeatability and reproducibility of the peak filling rate for the experienced physician were - 0.0 ± 1.1 and - 0.1 ± 1.1 and for the trainee 0.2 ± 3.5 and 0.4 ± 3.7, respectively. The inter-observer repeatability and reproducibility were 0.3 ± 1.5 and 0.5 ± 4.0, respectively. Similar was the pattern for the other diastolic indices. In all cases the limits of agreement varied according to the quantification approach.

CONCLUSION

A good repeatability but a moderate reproducibility was found in the assessment of the LVEF. Less good were the findings in the assessment of diastolic function.

Cardiac monitoring in HER2-positive patients on trastuzumab treatment: A review and implications for clinical practice

Trastuzumab prolongs progression-free and overall survival in patients with human epidermal growth factor receptor 2 (HER2) positive breast cancer. However, trastuzumab treatment is hampered by cardiotoxicity, defined as a left ventricular ejection fraction (LVEF) decline with a reported incidence ranging from 3 to 27% depending on variable factors. Early identification of patients at increased risk of trastuzumab-induced myocardial damage is of great importance to prevent deterioration to irreversible cardiotoxicity. Although current cardiac monitoring with multi gated acquisition (MUGA) scanning and/or conventional 2D-echocardiography (2DE) have a high availability, their reproducibility are modest, and more sensitive and reliable techniques are needed such as 3D-echocardiography (3DE) and speckle tracking echocardiography (STE). But which other diagnostic imaging modalities are available for patients before and during trastuzumab treatment? In addition, what is the optimal frequency and duration of cardiac monitoring? At last, which biomarker monitoring strategies are currently available for the identification of cardiotoxicity in patients treated with trastuzumab?

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Current MUGA is not sensitive and reliable enough to detect cardiotoxicity early.

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3DE (with STE) is most suitable for cardiac monitoring of patients on trastuzumab.

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The optimal frequency and duration of cardiac monitoring is not yet established.

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MPO and hs-troponin are promising biomarkers to detect cardiotoxicity.

NT-proBNP correlates with LVEF decline in HER2-positive breast cancer patients treated with trastuzumab

Background

Early identification of cardiac dysfunction by non-invasive imaging in HER2-positive breast cancer patients treated with trastuzumab is challenging. In particular multigated acquisition (MUGA) scan, which is most widely used, is unable to detect subclinical cardiac changes. The use of N-terminal pro-brain natriuretic peptide (NT-proBNP), a serum biomarker of myocardial stress, might improve timely diagnosis.

Methods

This prospective, single-center, cohort study included patients with HER2-positive breast cancer who started trastuzumab therapy. Echocardiography was scheduled at regular intervals every 3 months during one year follow-up for cardiac function monitoring. For research purposes, NT-proBNP was determined at the same time points. Trastuzumab-induced cardiotoxicity (TIC) was the primary study endpoint, defined as a left ventricular ejection fraction (LVEF) < 45%, and/or an absolute decline in LVEF > 10% since inclusion, and/or the incidence of a clinical cardiac event.

Results

A total of 135 patients were enrolled between April 2008 and June 2016, with a median age of 54 years (IQR: 47–61). By three-dimensional echocardiography (3DE), the median LVEF at baseline was 62% (IQR: 58–65). At a median of 6 months (IQR: 5–11), 45 patients (33%) reached the study endpoint of TIC. Patients with TIC had a mean change of − 9.5% in LVEF (95% CI -7.2 to − 11.7; p = 0.001) during 1 year of trastuzumab treatment. Both NT-proBNP at baseline (HR 1.04, 95% CI 1.02–1.07; p = 0.003) and LVEF decline during anthracycline treatment prior to the start of trastuzumab (HR 1.16, 95% CI 1.07–1.25; p < 0.001) were independently associated with development of TIC. The level of NT-proBNP during follow-up was associated too with development of TIC (HR 1.06 per 10 pmol/l difference, 95% CI 1.02–1.10; p = 0.008). No steadily or sudden increase in NT-proBNP prior to TIC was observed.

Conclusions

NT-proBNP cannot be used as a surrogate monitoring tool for trastuzumab-induced cardiotoxicity in HER2-positive breast cancer patients during the first year of treatment. Patients showing an LVEF decline during anthracycline pre-treatment appeared vulnerable for trastuzumab-induced cardiotoxicity.

Electronic supplementary material

The online version of this article (10.1186/s40959-019-0039-4) contains supplementary material, which is available to authorized users.

Accuracy of left ventricular ejection fraction by contemporary multiple gated acquisition scanning in patients with cancer: comparison with cardiovascular magnetic resonance

BACKGROUND

Multiple gated acquisition scanning (MUGA) is a common imaging modality for baseline and serial assessment of left ventricular ejection fraction (LVEF) for cardiotoxicity risk assessment prior to, surveillance during, and surveillance after administration of potentially cardiotoxic cancer treatment. The objective of this study was to compare the accuracy of left ventricular ejection fractions (LVEF) obtained by contemporary clinical multiple gated acquisition scans (MUGA) with reference LVEFs from cardiovascular magnetic resonance (CMR) in consecutive patients with cancer.

METHODS

In a cross-sectional study, we compared MUGA clinical and CMR reference LVEFs in 75 patients with cancer who had both studies within 30 days. Misclassification was assessed using the two most common thresholds of LVEF used in cardiotoxicity clinical studies and practice: 50 and 55%.

RESULTS

Compared to CMR reference LVEFs, MUGA clinical LVEFs were only lower by a mean of 1.5% (48.5% vs. 50.0%, p = 0.17). However, the limits of agreement between MUGA clinical and CMR reference LVEFs were wide at -19.4 to 16.5%. At LVEF thresholds of 50 and 55%, there was misclassification of 35 and 20% of cancer patients, respectively.

CONCLUSIONS

MUGA clinical LVEFs are only modestly accurate when compared with CMR reference LVEFs. These data have significant implications on clinical research and patient care of a population with, or at risk for, cardiotoxicity.

Left ventricular ejection fraction estimation using mutual information on technetium-99m multiple-gated SPECT scans

Background

A new non-linear approach was applied to calculate the left ventricular ejection fraction (LVEF) using multigated acquisition (MUGA) images.

Methods

In this study, 50 patients originally for the estimation of the percentage of LVEF to monitor the effects of various cardiotoxic drugs in chemotherapy were retrospectively selected. All patients had both MUGA and echocardiography examinations (ECHO LVEF) at the same time. Mutual information (MI) theory was utilized to calculate the LVEF using MUGA imaging (MUGA MI).

Results

MUGA MI estimation was significantly different from MUGA LVEF and ECHO LVEF, respectively (p < 0.005). The higher repeatability for MUGA MI can be observed in the figure by the higher correlation coefficient for MUGA MI (r = 0.95) compared with that of MUGA LVEF (r = 0.80). Again, the reproducibility was better for MUGA MI (r = 0.90, 0.92) than MUGA LVEF (r = 0.77, 0.83). The higher correlation coefficients were obtained between proposed MUGA MI and ECHO LVEF compared to that between the conventional MUGA LVEF and ECHO LVEF.

Conclusions

MUGA image with the aid of MI is promising to be more interchangeable LVEF to ECHO LVEF measurement as compared with the conventional approach on MUGA image.

Comparison of estimates of left ventricular ejection fraction obtained from gated blood pool imaging, different software packages and cameras

OBJECTIVE

To determine how two software packages, supplied by Siemens and Hermes, for processing gated blood pool (GBP) studies should be used in our department and whether the use of different cameras for the acquisition of raw data influences the results.

METHODS

The study had two components. For the first component, 200 studies were acquired on a General Electric (GE) camera and processed three times by three operators using the Siemens and Hermes software packages. For the second part, 200 studies were acquired on two different cameras (GE and Siemens). The matched pairs of raw data were processed by one operator using the Siemens and Hermes software packages.

RESULTS

The Siemens method consistently gave estimates that were 4.3% higher than the Hermes method (p < 0.001). The differences were not associated with any particular level of left ventricular ejection fraction (LVEF). There was no difference in the estimates of LVEF obtained by the three operators (p = 0.1794). The reproducibility of estimates was good. In 95% of patients, using the Siemens method, the SD of the three estimates of LVEF by operator 1 was ≤ 1.7, operator 2 was ≤ 2.1 and operator 3 was ≤ 1.3. The corresponding values for the Hermes method were ≤ 2.5, ≤ 2.0 and ≤ 2.1. There was no difference in the results of matched pairs of data acquired on different cameras (p = 0.4933) CONCLUSION: Software packages for processing GBP studies are not interchangeable. The report should include the name and version of the software package used. Wherever possible, the same package should be used for serial studies. If this is not possible, the report should include the limits of agreement of the different packages. Data acquisition on different cameras did not influence the results.

UK audit of quantification of left-ventricular function using gated myocardial perfusion imaging

PURPOSE

The aim of the study was to evaluate UK-wide interinstitutional reproducibility of left-ventricular functional parameters, end-systolic volume, end-diastolic volume and ejection fraction, obtained from gated myocardial perfusion imaging (GMPI) studies using technetium-99m-labelled radiopharmaceuticals. The study was carried out by the UK Institute of Physics and Engineering in Medicine Nuclear Medicine Software Quality Group.

MATERIALS AND METHODS

Ten anonymized clinical GMPI studies, five with normal perfusion and five with perfusion defects, were made available in DICOM and proprietary formats for download and through manufacturers' representatives. Two of the studies were duplicated in order to assess intraoperator repeatability, giving a total of 12 studies. Studies were made available in 8 and 16 frames/cycle.

RESULTS

A total of 58 institutions across England, Scotland, Wales and Northern Ireland participated in this study using six different computer packages. Studies were processed at centres using their normal clinical computers and software. The overall mean±SD ejection fraction for all centres was 58.5±3%; the mean end-diastolic volume was 114±12 ml and the mean end-systolic volume was 54±6 ml. The results were affected by the number of frames per cycle and by the postprocessing computer package, but not by the reconstruction filter in the filtered back-projection.

CONCLUSION

Calculation of functional parameters from GMPI using technetium-99m-labelled radiopharmaceuticals is reliable and shows limited variability across the UK.

Results from an Australian and New Zealand audit of left ventricular ejection fraction from gated heart pool scan analysis

AIM

A voluntary audit was undertaken to compare left ventricular ejection fraction (LVEF) calculations from gated heart pool studies using software packages currently available throughout Australia and New Zealand (ANZ).

METHODS

A data set previously developed by a task group of the Institute of Physics and Engineering in Medicine (IPEM) consisting of 12 planar gated studies with LVEF ranging from 17 to 67% was provided to each site with worksheets to record individual technologist's results as well as information about individual department's equipment, software used for calculation of LVEF and experience of the analysers. Data analysis included calculation of an overall mean LVEF and standard deviation (SD) for all patients, which were compared with the mean IPEM LVEF. A comparison among software packages was done to examine differences in mean LVEF.

RESULTS

Results were received from a total of 22 sites using six different software packages, with 187 processed studies included for analysis. Reproducibility of studies 4 and 8 showed good agreement, with an SD of 1.0 EF units (P=0.5290). Good correlation was found between the ANZ mean LVEF and the corresponding IPEM value per patient study, with R=0.98. The ANZ overall mean LVEF was 47%, which was higher that the IPEM mean by 4.9 EF units. The average difference among all software packages was +5.1 EF units.

CONCLUSION

Differences were found between the IPEM mean and the ANZ mean LVEF. Variability in LVEF values between software packages was demonstrated, with an average of 5.1 EF units. The ANZ overall mean for LVEF was 47.2%, being 4.9 EF units higher than the IPEM value.

Newest echocardiographic techniques for the detection of cardiotoxicity and heart failure during chemotherapy

Chemotherapy-induced cardiotoxicity has become a significant public health issue. Left ventricular ejection fraction is routinely used to monitor cardiotoxicity but fails to detect subtle alterations in cardiac function. Improvements in the measurement of left ventricular ejection fraction, physical or pharmacologic stressors, and novel cardiac functional indices may be useful in the detection of cardiotoxicity. The improvements in the detection and therapy of cancer have led to the emergence of chemotherapy-induced cardiotoxicity. New echocardiographic techniques may be useful in the detection of patients undergoing chemotherapy treatments who could benefit from alternative cancer treatments, therefore decreasing the incidence of cardiotoxicity.

Chemotherapy-associated cardiotoxicity: how often does it really occur and how can it be prevented?

Cardiotoxicity remains the limiting factor for many forms of cancer therapy and is the focus of growing research and clinical emphasis. This article outlines the current clinical evidence for left ventricular dysfunction and heart failure for the two most important classes of cardiotoxic chemotherapeutic agents, examines the potential pitfalls that have led to underestimated rates of left ventricular dysfunction from these agents, and reviews strategies for screening for and providing prophylaxis against chemotherapy-associated left ventricular dysfunction.

Investigation of normal ranges for left ventricular ejection fraction in cardiac gated blood pool imaging studies using different processing workstations

BACKGROUND

An investigation has been undertaken to calculate normal ranges for left ventricular ejection fraction (LVEF) measured by the gated blood pool (GBP) technique. A common set of normal studies was used at 11 hospitals within the south of England to assess the variability of results and normal ranges.

METHODS

Normal studies were identified by retrospective review of patients who had undergone a GBP study and echocardiogram at the Royal United Hospital, Bath. Patients who had left ventricular function qualitatively identified as normal on echocardiogram and normal wall motion for the GBP were included. In total, 64 datasets were found to match the criteria. All the studies were made anonymous prior to being distributed to the participating hospitals. The upper and lower limits for normal ejection fraction were defined for each system using the 95% confidence limits around the mean value, before and after normalizing the results to remove systematic differences between the processing systems.

RESULTS

The lower cut-off for normal function varied between 40 and 51%. Analysis of the individual operator results gave an inter-operator standard deviation of 4.2 and an intra-operator standard deviation of 2.7.

CONCLUSIONS

It is recommended that all studies should be processed at least twice and an average taken to minimise these sources of uncertainty. If there is a significant difference the study should be reprocessed. Due to random differences between results from different systems it is suggested that an equivocal range be used between clearly normal and abnormal function.