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.

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 of Quantitative 99mTc DPD Scintigraphy With Echocardiographic Alterations in Left Atrial Parameters in Transthyretin Amyloidosis.

AIM: Cardiac transthyretin amyloidosis (ATTR) patients have high rates of atrial arrhythmias. We evaluated echocardiographic structural and functional left atrial (LA) parameters and correlated these with technetium-99m 3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) bone scintigraphy tracer uptake within the LA in ATTR patients. METHODS: ATTR patients (wild-type, hereditary and asymptomatic transthyretin [TTR] variant carriers) who had undergone 99mTc-DPD and transthoracic echocardiogram (TTE) were selected. Quantitative 99mTc-DPD uptake analysis and echocardiographic evaluation of LA structural and functional parameters was performed. RESULTS: Forty (40) ATTR patients (wild-type n=17; hereditary ATTR and TTR variant carriers n=23; median age 68.8±22 years) were included. TTE parameters including indexed LA minimum (LAVmin) (r=0.66), and LA maximum volumes (LAVmax) (r=0.64), LA emptying fraction (LAEF) (r=-0.68), LA function index (LAFI) (r=-0.70) and reservoir strain (ƐR) (r=-0.70) (p<0.001 for all) demonstrated good correlation to LA tracer uptake. Normal LA volume (LAVmin and LAVmax) and function (LAEF, LAFI and ƐR) was observed in hereditary ATTR and TTR variant carriers without cardiac tracer uptake. The subgroup of ATTR patients with atrial fibrillation/flutter demonstrated increased LAVmin and LAVmax with further reduction in LA function (LAEF, LAFI and ƐR). Receiver operating characteristic curves demonstrated strong diagnostic accuracies for LA structural (LAVmin and LAVmax; area under the curve [AUC] of 0.83 and 0.84 respectively) and functional (LAEF, LAFI and ƐR; AUC 0.81, 0.88 and 0.85, respectively) parameters. CONCLUSION: Left atrial structural and functional parameters demonstrated good correlations with quantitative 99mTc-DPD tracer LA uptake. Echocardiography and 99mTc-DPD scintigraphy may have significant roles in identification and surveillance of ATTR patients likely to develop atrial arrhythmias.

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.

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 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.

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.