P790 Bi-ventricular dysfunction in patients after bone marrow transplant: the value of strain imaging

Background

Cardiovascular events are a significant cause of morbidity and mortality in cancer survivors, particularly occurring at 5-10 years after their cancer therapy.

Purpose

To assess the utility of strain imaging by 2-dimensional (2D) speckle tracking echocardiography in detecting bi-ventricular dysfunction, as compared to traditional measures, in patients post bone marrow transplantation (BMT) with previous anthracycline (AC) therapy for haematological conditions.

Methods

50 consecutive patients post BMT + AC, reviewed at a long-term survivor clinic, were compared to 50 age and gender matched controls. 48/50 patients received AC doses below the recommended cumulative lifetime thresholds set by the European Society of Medical Oncology. 2D left ventricular global longitudinal strain (LV GLS) and right ventricle free wall strain (RV FWS) were compared to conventional measures of bi-ventricular function.

Results

The mean LVEF (58 ± 6% vs 63 ± 6%) and RV fractional area change (FAC) (39 ± 5% vs 44 ± 5%), although reduced in the BMT + AC group vs controls, were within normal limits. LV GLS was reduced in BMT + AC patients as compared to controls (-17.8 ± 3.1% vs -20.5 ± 2.2%, p < 0.01) while RV FWS was also reduced (-23.2 ± 4.0% vs -27.9 ± 2.7%, p < 0.001). In BMT + AC patients with a preserved LVEF (LVEF > 53%), 28% (11/40) had reduced GLS (GLS < -17%) while 52% (24/46) of those with preserved FAC (FAC > 35%) had reduced FWS (FWS < -25%). Major adverse cardiac events (MACE) occurred in 9/50 patients in the BMT + AC group and none in the control group. 8/9 patients had normal biventricular function as assessed by traditional parameters (LVEF and RV FAC) but 5/9 patients had reduced LV GLS and/or RV FWS.

Conclusions

Subclinical bi-ventricular dysfunction is common in patients post BMT + AC therapy, and can be detected using strain analysis, despite preserved LV and RV systolic function using conventional measures. MACE occurred at a significantly higher rate in BMT patients exposed to AC. More than half of MACE events occurred in patients with reduced LV or RV strain, with preserved bi-ventricular function by traditional measures. LV GLS and RV FWS should be utilised for early identification of subclinical dysfunction in BMT patients.

P309 The use of echocardiographic parameters to predict clinical outcomes in AL-amyloidosis cardiomyopathy

Background

AL-amyloidosis has a rapid clinical progression, with cardiac involvement associated with a particularly poor prognosis. Cardiac amyloidosis is diagnosed by either invasive biopsy or conventional echocardiographic parameters such as increased wall thickness, in the absence of other causes. More recently, novel parameters including 2D longitudinal strain have demonstrated diagnostic utility in a range of infiltrative cardiomyopathies including cardiac amyloidosis.

Aim/Method: We sought to evaluate traditional and novel echocardiographic parameters in their ability to predict adverse outcomes in a cohort of AL-amyloid patients. 80 patients who had transthoracic echocardiograms at a single centre were included. Comprehensive echocardiographic assessment was performed, including left ventricular ejection fraction (LVEF), LV Global Longitudinal Strain (GLS), LV mass (indexed to BSA). The primary endpoint was a composite of of major adverse cardiac events (MACE) and all-cause mortality, that was assessed by interrogation of the medical records on a specified censor date.

Results

At a mean follow-up (time from echo to censor date) of 5.4 ± 2.6years, 38/80 (47.5%) of patients experienced the primary endpoint of MACE or death, of which 25/80 (31%) were deaths. LVEF (59 ± 5.6%vs56 ± 6.4%, p = 0.04), GLS (17.4 ± 3.9%vs14.8 ± 4.9%, p = 0.01) basal longitudinal strain (12.3 ± 3.2%vs9.6 ± 3.9%, p = 0.002), indexed LV mass (107 ± 36g/m2vs130 ± 34g/m2, p = 0.06) and E/E’ (13.7 ± 4.9vs20.6 ± 9.6, p < 0.001) were all significantly different between patients who experienced the primary endpoint and those that didn’t. The strongest predictors of outcome were E/E’ (AUC 0.74), LV mass (AUC 0.73) and the ratio GLS:LV mass (AUC 0.73). An E/E’ of 15 had a sensitivity of 71% and specificity of 69%, while an indexed LV mass of 108 had a sensitivity and specificity of 74% and 67% respectively. GLS to LV mass as a cutoff of 0.16 had a sensitivity and specificity of 70% and 69% respectively.

Conclusion

In a cohort of 80 patients with AL-amyloid cardiomyopathy, almost half (47.5%) reached the primary composite endpoint. Diastolic dysfunction as expressed as E/E’, and LV mass were the most powerful predictors of outcome, while global longitudinal strain and LV basal strain were also reduced, and showed superiority over LV ejection fraction in predicting prognosis.

P1543 The assessment of regional myocardial strain in classifying amyloid cardiomyopathy

Background

An infiltrative cardiomyopathy is a common manifestation of AL-amyloidosis, with cardiac involvement associated with a poor prognosis. Wild-type transthyretin amyloidosis (wt-TTR), is a distinct clinical entity occurring predominantly in men > 65 yrs, that has gained interest recently due to novel treatment options. Regional strain analysis has been shown to discriminate both forms of cardiac amyloidosis from other causes of concentric left ventricular hypertrophy, with a characteristic pattern of ‘apical sparing’. Due to the significant difference in both the course of the disease and treatment options between groups, a non-invasive echocardiographic method of determining subtype would be valuable.

Aim/Method: We sought to compare traditional and novel echocardiographic parameters in a cohort of AL ( n = 80) and wild type (wt-TTR) amyloid ( n = 32) patients. All amyloid patients underwent comprehensive transthoracic echocardiography, including both conventional parameters and LV longitudinal strain. Further novel parameters were computed including the ratio of global longitudinal strain (GLS) to LV ejection fraction (LVEF), as well as GLS to indexed LV mass.

Results

wt-TTR patients had significantly greater LV mass (176 ± 59g/m2vs118 ± 37g/m2, p < 0.001), and worse diastolic dysfunction as expressed as E/E’ (21.5 ± 11vs17 ± 8, p = 0.04). LVEF was significantly lower in wt-TTR patients however remained in the normal range in both groups (53 ± 6%vs57 ± 6%, p = 0.001), whilst GLS was significantly reduced compared to AL-amyloid patients (11.5 ± 3.4%vs16.2 ± 4.6%, p < 0.001). LVEF:GLS was significantly higher in wt-TTR patients (4.93 ± 1.4vs3.87 ± 1.3, p = 0.001) reflecting a more profound reduction in strain with a relatively preserved ejection fraction. Similarly, the ratio of GLS to LV mass was significantly lower in wt-TTR amyloidosis (0.078 ± 0.05vs0.155 ± 0.07, p < 0.001), reflecting a more significant reduction in strain for a given wall thickness in wt-TTR patients. GLS:LV mass was the strongest discriminator between subtypes (AUC 0.82), with a cutoff of 0.09 giving a sensitivity and specificity of 71% and 80% respectively, for detecting wt-TTR.

Conclusion

In this cohort, patients with wt-TTR had significantly greater increase in LV wall thickness and diastolic dysfunction, which may in part reflect their increased age (77vs62). However, GLS was also significantly reduced compared to AL-amyloid, even when accounting for LV ejection fraction and LV mass, suggesting these composite parameters may have value in determining the subtype of cardiac amyloidosis.

Clinical and echocardiographic characteristics of cardioembolic stroke

BACKGROUND AND PURPOSE

Ischaemic stroke frequently has a cardioembolic (CE) source. Clinical and echocardiographic parameters associated with CE stroke were evaluated.

METHODS

In all, 93 consecutive ischaemic stroke patients who underwent a transthoracic echocardiogram were retrospectively analysed; strokes were classified by TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. Echocardiographic parameters related to CE stroke, including left atrial volumes and function, were compared to 73 healthy controls.

RESULTS

Of 93 patients (mean age 66.1 years, 56% male), nine (10%) had large artery atherosclerosis, 38 (41%) CE stroke, two (2%) small vessel disease, two (2%) other and 42 (45%) undetermined aetiology. Left atrial (LA) maximum volumes (LAVI_max ) and minimum volumes (LAVI_min ) were larger in the CE group than the non-CE group (45 vs. 32 ml/m² , 32 vs. 13 ml/m² , respectively, P < 0.001), whilst LA function indices including LA emptying fraction and LA function index (LAFI) were lower in the CE group (34% vs. 55%, and 0.12 vs. 0.35, respectively, P < 0.001). Adjusting for clinical characteristics, LAFI ≤0.3 was an independent predictor of CE stroke (adjusted odds ratio 5.3, P = 0.001). Additionally, LAVI_max and LAVI_min were larger (61 vs. 44 and 32 vs. 24 ml/m² respectively, P < 0.01) and LAFI significantly lower (0.34 vs. 0.52, P < 0.001) in the undetermined aetiology group versus healthy controls.

CONCLUSIONS

Left atrial enlargement with reduced LA function was associated with CE stroke and LAFI was the best independent predictor. LA parameters were also altered in the undetermined aetiology group, suggesting an underlying LA myopathy in this subset.

Durations of second stage of labor and pushing, and adverse neonatal outcomes: a population-based cohort study

OBJECTIVE

The associations between duration of second stage of labor, pushing time and risk of adverse neonatal outcomes are not fully established. Therefore, we aimed to examine such relationships.

STUDY DESIGN

A population-based cohort study including 42 539 nulliparous women with singleton infants born in cephalic presentation at ⩾37 gestational weeks, using the Stockholm-Gotland Obstetric Cohort, Sweden, and the Swedish Neonatal Quality Register, 2008 to 2013. Poisson regression was used to analyze estimated adjusted relative risks (RRs), with 95% confidence intervals (CIs). Outcome measures were umbilical artery acidosis (pH <7.05 and base excess <-12), birth asphyxia-related complications (including any of the following conditions: hypoxic ischemic encephalopathy, hypothermia treatment, neonatal seizures, meconium aspiration syndrome or advanced resuscitation after birth) and admission to neonatal intensive care unit (NICU).

RESULTS

Overall rates of umbilical artery acidosis, birth asphyxia-related complications and admission to NICU were 1.08, 0.63 and 6.42%, respectively. Rate of birth asphyxia-related complications gradually increased with duration of second stage: from 0.42% at <1 h to 1.29% at ≥4 h (adjusted RR 2.46 (95% CI 1.66 to 3.66)). For admission to NICU, corresponding rates were 4.97 and 9.45%, and adjusted RR (95% CI) was 1.80 (95% CI 1.58 to 2.04). Compared with duration of pushing <15 min, a duration of pushing ⩾60 min increased rates of acidosis from 0.57 to 1.69% (adjusted RR 2.55 (95% CI 1.51 to 4.30)).

CONCLUSION

Prolonged durations of second stage of labor and pushing are associated with increased RRs of adverse neonatal outcomes. Clinical assessment of fetal well-being is essential when durations of second stage and pushing increases.

SU-E-T-107: Uncertainty Estimate of a Practical EBT-2 Film Dosimetry Approach: Transpose-And-Scan Technique

PURPOSE

To estimate the uncertainty of a practical EBT2 film dosimetry approach that has been established at our institution and used for routine patient-specific plan verifications, particularly for SBRT and RapidArc, as well as planning system commissioning. Our technique is unique from other common dosimetry protocols with respect to calibration, irradiation and scanning.

METHODS

Film dosimetry for patient-specific quality assurance of 29 patient plans were retrospectively reviewed. For each case, four films were irradiated; two for calibration and two for treatment plan. Each pair of two films were irradiated together in a phantom with one film transposed (rotated 180 degrees relative to the other) to compensate for asymmetric film response. After a minimum of 12 hrs post-irradiation, each film was scanned in four different orientations to mitigate non-uniform response of the scanner light and detector elements. The scanned 8 calibration and 8 plan images were averaged into one calibration and one plan film image, respectively. Each color channel of the calibration film was correlated to the reference dose matrix to produce a 3rd order polynomial calibration curve. Finally, each color channel of the plan film was converted to a dose map using the corresponding calibration curve. Average dose maps of the red and green channels were correlated to the treatment planning dose matrix, and the mean dose differences at the center of dose distributions (5×5mm̂2 area) as well as a gamma analysis were evaluated.

RESULTS

The absolute dose differences were -0.8±1.7% (range=-4.5-3.0%). The gamma pass-rates (3%/3mm) were 94±7% (min.=74%). The pass rate increased to 99±3%(min.=87%) with the film scaled relatively to the plan doses.

CONCLUSIONS

Based on a large number of cases, our approach appears to be robust to non-uniform film and scanner responses, and is shown to have an uncertainty (1SD) of less than 2% for absolute film dosimetry.