Pulmonary embolism response teams. A description of the first 36-month Australian experience

BACKGROUND

High/intermediate-risk pulmonary embolism (PE) confers increased risk of cardiovascular morbidity and mortality. International guidelines recommend the formation of a PE response team (PERT) for PE management because of the complexity of risk stratification and emerging treatment options. However, there are currently no available Australian data regarding outcomes of PE managed through a PERT.

AIMS

To analyse the clinical and outcome data of patients from an Australian centre with high/intermediate-risk PE requiring PERT-guided management.

METHODS

We performed a retrospective observational study of 75 consecutive patients with high/intermediate-risk PE who had PERT involvement, between August 2018 and July 2021. We recorded clinical and interventional data at the time of PERT and assessed patient outcomes up to 30 days from PERT initiation. We used unpaired t tests to compare right to left ventricular (RV/LV) ratios by computed tomography criteria or transthoracic echocardiogram (TTE) at baseline and after interventions.

RESULTS

Data were available for 74 patients. Initial computed tomography pulmonary angiography RV/LV ratio was increased at 1.65 ± 0.5 and decreased to 1.30 ± 0.29 following PERT-guided interventions (P < 0.001). TTE RV/LV ratio also decreased following PERT-guided management (1.09 ± 0.19 vs 0.93 ± 0.17; P < 0.001). 20% of patients had any bleeding complication, but two-thirds were mild, not requiring intervention. All-cause mortality was 6.8%, and all occurred within the first 7 days of admission.

CONCLUSION

The PERT model is feasible in a large Australian centre in managing complex and time-critical PE. Our data demonstrate outcomes comparable with existing published international PERT data. However, successful implementation at other Australian institutions may require adequate centre-specific resource availability and the presence of multispeciality input.

Cardiac "hypertrophy" phenotyping: differentiating aetiologies with increased left ventricular wall thickness on echocardiography

Aims

Differentiating phenotypes of cardiac "hypertrophy" characterised by increased wall thickness on echocardiography is essential for management and prognostication. Transthoracic echocardiography is the most commonly used screening test for this purpose. We sought to identify echocardiographic markers that distinguish infiltrative and storage disorders that present with increased left ventricular (LV) wall thickness, namely, cardiac amyloidosis (CA) and Anderson-Fabry disease (AFD), from hypertensive heart disease (HHT).

Methods

Patients were retrospectively recruited from Westmead Hospital, Sydney, and Princess Alexandra Hospital, Brisbane. LV structural, systolic, and diastolic function parameters, as well as global (LVGLS) and segmental longitudinal strains, were assessed. Previously reported echocardiographic parameters including relative apical sparing ratio (RAS), LV ejection fraction-to-strain ratio (EFSR), mass-to-strain ratio (MSR) and amyloidosis index (AMYLI) score (relative wall thickness × E/e') were evaluated.

Results

A total of 209 patients {120 CA [58 transthyretin amyloidosis (ATTR) and 62 light-chain (AL) amyloidosis], 31 AFD and 58 HHT patients; mean age 64.1 ± 13.7 years, 75% male} comprised the study cohort. Echocardiographic measurements differed across the three groups, The LV mass index was higher in both CA {median 126.6 [interquartile range (IQR) 106.4-157.9 g/m²]} and AFD [median 134 (IQR 108.8-152.2 g/m²)] vs. HHT [median 92.7 (IQR 79.6-102.3 g/m²), p < 0.05]. LVGLS was lowest in CA [median 12.29 (IQR 10.33-15.56%)] followed by AFD [median 16.92 (IQR 14.14-18.78%)] then HHT [median 18.56 (IQR 17.51-19.97%), p < 0.05]. Diastolic function measurements including average e' and E/e' were most impaired in CA and least impaired in AFD. Indexed left atrial volume was highest in CA. EFSR and MSR differentiated secondary (CA + AFD) from HHT [receiver operating curve-area under the curve (ROC-AUC) of 0.80 and 0.91, respectively]. RAS and AMYLI score differentiated CA from AFD (ROC-AUC of 0.79 and 0.80, respectively). A linear discriminant analysis with stepwise variable selection using linear combinations of LV mass index, average e', LVGLS and basal strain correctly classified 79% of all cases.

Conclusion

Simple echocardiographic parameters differentiate between different "hypertrophic" cardiac phenotypes. These have potential utility as a screening tool to guide further confirmatory testing.

A novel echocardiographic risk score for light-chain amyloidosis

Aims

The prognosis of light-chain (AL) amyloidosis, a plasma cell dyscrasia, is largely determined by the presence of cardiac involvement. Conventional staging is achieved using cardiac biomarkers (high-sensitivity troponin, N-terminal pro-beta natriuretic peptide) and free light-chain difference (Mayo staging). We sought to evaluate the role of echocardiographic parameters as prognostic markers in AL amyloidosis and examine their utility compared with conventional staging.

Methods and results

Seventy-five consecutive patients with AL amyloidosis reviewed at a referral amyloid clinic who underwent comprehensive echocardiographic assessment were retrospectively identified. The evaluated echocardiographic parameters included left ventricular (LV) ejection fraction, mass, diastolic function parameters, global longitudinal strain (GLS), and left atrial (LA) volume. Mortality was assessed through a review of clinical records. During a median follow-up of 51 months, 29/75 (39%) patients died. Patients who died had a larger LA volume (47 ± 12 vs. 35 ± 10 mL/m², P < 0.001) and a higher E/e' (18 ± 10 vs. 14 ± 6, P = 0.026). Univariate clinical and echocardiographic predictors of survival included LA volume, E/e', e', LVGLS, and Mayo stage (at significance of P < 0.1). Left atrial volume and LVGLS were significant determinants of mortality when examined using clinical cut-offs, although E/e' was not. A composite echocardiographic risk score comprising LA volume and LVGLS provided similar prognostic performance to Mayo stage [area under the curve (AUC) 0.75, 95% confidence interval (CI) 0.64-0.85 vs. AUC 0.75, 95% CI 0.65-0.858, P = 0.91].

Conclusion

Left atrial volume and LVGLS were independent predictors of mortality in AL amyloidosis. A composite echocardiographic score combining LA volume and LVGLS has similar prognostic power to Mayo stage for all-cause mortality.

A novel echocardiographic risk score predicts prognosis in AL-amyloidosis

Background

Prognosis in light chain (AL) amyloidosis is largely determined by the severity of cardiac involvement. Conventional (Mayo) staging includes 1) hs troponin 2) N-terminal pro-beta natriuretic peptide (NT-pro BNP) and 3)free light chain difference.

Methods

In a retrospective study of 75 AL amyloidosis patients referred to a quaternary amyloid clinic, all patients underwent comprehensive echocardiographic assessment. Echocardiographic parameters included left ventricular (LV) ejection fraction, LV mass, diastolic function, global longitudinal strain (GLS) and indexed left atrial volume (LAVI). Mortality was assessed through review of clinical records.

Results

Over a median follow up of 51 months, 29/75 (39%) of patients died. LAVI, E/e', e', LVGLS, were univariate predictors of mortality (p&lt;0.1). LAVI was the only independent echocardiographic predictor in a multivariable model. Kaplan Meir analysis evaluated LAVI, LVGLS and E/e' using clinical cutoffs as a predictor of survival; only LAVI and LVGLS were significant. A novel “Echo score” comprising of LAVI (&gt;42 ml/m2) and LVGLS (&lt;−12%) was a predictor of mortality with similar prognostic performance as Mayo stage. (Echo score AUC 0.745, 95% CI 0.64–0.85 vs Mayo score AUC 0.752 95% CI 0.66–0.86, p=0.9).

Conclusion

LAVI, a simple, echocardiographic parameter was as an independent predictor of mortality in AL amyloidosis. A composite echocardiographic score combining LAVI and LVGLS stratified AL-amyloidosis patients into 3 distinct groups with similar prognostic power as Mayo stage for all-cause mortality.

Funding Acknowledgement

Type of funding sources: None.

Alterations in multi-layer strain in AL amyloidosis

BACKGROUND

Cardiac involvement in AL amyloidosis portends a poor prognosis. 2D-speckle tracking echocardiography (2D-STE) strain can identify subclinical cardiac involvement. This study performed multilayer and multiplanar 2D-STE myocardial strain analysis.

METHODS

We compared 75 AL amyloidosis patients to 49 hypertensive patients and 49 healthy controls. Longitudinal strain was obtained from epicardial, mid-myocardial and endocardial layers; segmental strain was measured from mid-myocardial basal, mid and apical segments.

RESULTS

Global longitudinal strain was reduced in epicardial (-14.3 ± -4.0% vs. -17.4 ± 2.2% vs. -17.5 ± -2.0%, p < .001), mid-myocardial (-16.3 ± -4.5% vs. -19.7 ± 2.5% vs. -19.7 ± -2.2%, p < .001) and endocardial layers (-18.7 ± -4.9% vs. -22.2 ± 3.0% vs. -22.3 ± -2.6%, p < .001) in amyloid patients compared to hypertensive and healthy controls. Segmental strain confirmed significant reduction in basal (-11.2 ± -3.9% vs. -17.6 ± 2.7% vs. -20.9 ± -3.4%, p < .001) and mid (-14.8 ± -4.3% vs. -19.2 ± 2.5% vs. -19.6 ± -2.2%, p < .001) LV segments in the AL amyloid group. Receiver operating curve analysis demonstrated that an optimal cut-off of -16% for basal segmental strain better differentiated AL amyloid from hypertensive group (sensitivity 96%, specificity 70%, AUC 0.93), compared to relative apical sparing (AUC of 0.85).

CONCLUSION

Strain demonstrated myocardial involvement in all layers in AL amyloidosis, with reduced basal segmental longitudinal strain a likely marker of early disease.

Correlation Between Quantitative Uptake of 99mTC-DPD and Echocardiographic Parameters in Cardiac ATTR: A Novel Follow-Up Strategy

Aims: There has been a paradigm shift in diagnosis of cardiac transthyretin amyloidosis (ATTR) with non-invasive techniques including technetium-99m 3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) bone scintigraphy. We evaluated structural and functional biventricular alterations by transthoracic echocardiography (TTE) and determined the correlation with 99mTc-DPD tracer uptake in ATTR. Materials and Methods: ATTR patients (wild-type, hereditary or asymptomatic transthyretin [TTR] variant carriers) with 99mTc-DPD and TTE were selected; 99mTc-DPD uptake was analyzed quantitatively. TTE assessment of left ventricle (LV) and right ventricle (RV) parameters was performed. Results: Forty ATTR patients (wild-type n = 17; hereditary ATTR and TTR variant carriers n = 23; median age 68.8 ± 22 years) were included. TTE parameters displaying good correlation with 99mTc-DPD tracer uptake included LV average wall thickness (r = 0.837), LV indexed mass (LVMI; r = 0.802), RV wall thickness (r = 0.610), average e' (r = -0.830), E/e' ratio (r = 0.786), LV global longitudinal strain (GLS; r = 0.714) and RV GLS (r = 0.632; p < 0.001 for all). Hereditary ATTR and TTR variant carriers without cardiac tracer uptake had normal echocardiographic parameters. Receiver operating characteristic curves demonstrated strong diagnostic accuracies for structural (LV wall thickness, LVMI and RV wall thickness; area under the curve (AUC) of 0.96 for all) and functional (LV and RV GLS; AUC of 0.86 and 0.88, respectively) parameters. Conclusion: Good correlations between TTE biventricular structural and functional parameters were demonstrated with quantitative 99mTc-DPD uptake. Echocardiography may potentially assume a significant role in longitudinal follow-up for monitoring disease progression and for evaluating treatment response.

The utility of strain imaging in the cardiac surveillance of bone marrow transplant patients

OBJECTIVE

To evaluate the utility of two-dimensional multiplanar speckle tracking strain to assess for cardiotoxicity post allogenic bone marrow transplantation (BMT) for haematological conditions.

METHODS

Cross-sectional study of 120 consecutive patients post-BMT (80 pretreated with anthracyclines (BMT+AC), 40 BMT alone) recruited from a late effects haematology clinic, compared with 80 healthy controls, as part of a long-term cardiotoxicity surveillance study (mean duration from BMT to transthoracic echocardiogram 6±6 years). Left ventricular global longitudinal strain (LV GLS), global circumferential strain (LV GCS) and right ventricular free wall strain (RV FWS) were compared with traditionl parameters of function including LV ejection fraction (LVEF) and RV fractional area change.

RESULTS

LV GLS (-17.7±3.0% vs -20.2±1.9%), LV GCS (-14.7±3.5% vs -20.4±2.1%) and RV FWS (-22.6±4.7% vs -28.0±3.8%) were all significantly (p=0.001) reduced in BMT+AC versus controls, while only LV GCS (-15.9±3.5% vs -20.4±2.1%) and RV FWS (-23.9±3.5% vs -28.0±3.8%) were significantly (p=0.001) reduced in BMT group versus controls. Even in patients with LVEF >53%, ~75% of patients in both BMT groups demonstrated a reduction in GCS.

CONCLUSION

Multiplanar strain identifies a greater number of BMT patients with subclinical LV dysfunction rather than by GLS alone, and should be evaluated as part of post-BMT patient surveillence. Reduction in GCS is possibly due to effects of preconditioning, and is not fully explained by AC exposure.

Comparative Assessments of Left and Right Ventricular Function by Two-Dimensional, Contrast Enhanced and Three-Dimensional Echocardiography with Gated Heart Pool Scans in Patients Following Myocardial Infarction

Multiple noninvasive imaging modalities are available to measure biventricular function, although limited studies have assessed agreement between modalities in assessing left and right ventricular ejection fraction (LVEF & RVEF) in the same cohort of patients. In this study we prospectively compared the agreement of 2-dimensional echocardiography (2DE), contrast enhanced 2DE, 3-dimensional echocardiography (3DE), and gated heart pool scan (GHPS) measures of LVEF and RVEF in patients with acute ST-elevation myocardial infarction. We recruited 95 consecutive ST-elevation myocardial infarction patients (mean age 61.4 ± 12.0, male: 79.5%) admitted to a major tertiary hospital between July 2016 and May 2018. Despite minimal inter- and intra-observer variability (coefficient of variance < 5% in both categories), substantial discrepancies exist between modalities with Pearson's correlation coefficients ranging from 0.64 to 0.91 for LVEF measurements, and 0.27 to 0.86 for RVEF measurements. Bland-Altman plots demonstrated no systematic bias between modalities. GHPS and 3DE offered the closest agreement for both LVEF and RVEF, demonstrating the greatest correlation coefficient (r = 0.91 and 0.86 respectively), lowest mean absolute differences (4% and 3% respectively), and narrowest Bland-Altman limits of agreement (19% and 18% respectively). Greater than 10% of 2DE and contrast enhanced 2DE scans discordantly showed LVEF values >40% for patients whose LVEF was measured as ≤ 40% by 3DE or GHPS. In conclusion, substantial variation exists between modalities when assessing LVEF and RVEF, although we demonstrate that 3DE and GHPS have the closest agreement. This variability should be considered in clinical management of patients, and modalities should not be used interchangeably in sequential patient follow-up.

The role of intracoronary thrombolysis in selected patients presenting with ST-elevation myocardial infarction: a case series

Background

Primary percutaneous coronary intervention (PCI) is the cornerstone of management for ST-elevation myocardial infarction (STEMI). However, large intracoronary thrombus burden complicates up to 70% of STEMI cases. Adjunct therapies described to address intracoronary thrombus include manual and mechanical thrombectomy, use of distal protection device and intracoronary anti-thrombotic therapies.

Case summary

This series demonstrates the use of intracoronary thrombolysis in the setting of large coronary thrombus, bifurcation lesions with vessel size mismatch, diffuse thrombosis without underlying plaque rupture, and improving coronary flow to allow vessel wiring and proceeding to definitive revascularization.

Discussion

Larger intracoronary thrombus burden correlates with greater infarct size, distal embolization, and the associated no-reflow phenomena, and propagates stent thrombosis, with subsequent increase in mortality and major adverse cardiac events. Intracoronary thrombolysis may provide useful adjunct therapy in highly selected STEMI cases to reduce intracoronary thrombus and facilitate revascularization.

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 &lt; 0.01) while RV FWS was also reduced (-23.2 ± 4.0% vs -27.9 ± 2.7%, p &lt; 0.001). In BMT + AC patients with a preserved LVEF (LVEF &gt; 53%), 28% (11/40) had reduced GLS (GLS &lt; -17%) while 52% (24/46) of those with preserved FAC (FAC &gt; 35%) had reduced FWS (FWS &lt; -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 &lt; 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 &gt; 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 &lt; 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 &lt; 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 &lt; 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.