Echocardiographic assessment of left ventricular radial strain to differentiate cardiac amyloidosis from Fabry disease

Background

Left ventricular (LV) wall thickening is a typical echocardiographic finding in infiltrative cardiomyopathies like cardiac amyloidosis (CA) and Fabry disease (FD). The discrimination of both infiltrative diseases remains challenging by standard as well as 2D speckle tracking echocardiography (2DSTE)-based analysis of longitudinal LV strain patterns. Over the recent years, a constant development in image quality and data processing provided better possibilities to analyse layer specific myocardial deformation indices. With regards to FD, specific layer LV strain patterns may be useful to rule-in FD in patients with suspected infiltrative cardiomyopathy.

Purpose

The aim of the present study was to investigate differences and the diagnostic value of layer specific 2D STE-based radial LV strain indices in CA and FD.

Methods

Next to standard parameters of a comprehensive echocardiographic assessment (Vivid E9 or E95, GE Vingmed, Horton, Norway, with an M5S 1.5–4.5MHz transducer), we retrospectively analysed the transmural radial LV strain (GSradial), the subendocardial radial LV strain (GSendo), the subepicardial radial LV strain (GSepi), and the strain gradient (GSendo − GSepi) (EchoPAC software, GE) in FD patients and CA patient from the amyloidosis registry at our study site. A Receiver operating curve (ROC) analysis was used to assess the diagnostic value of the respective LV strain values and the layer-specific strain gradient to discriminate FD and CA.

Results

A total of 38 FD and 40 CA patients were included in our analyses. In patients with FD, GSepi showed a marked impairment. LV radial and layer strain were significantly reduced in CA compared to FD patients [GSradial −12.0 (−16.2 to −9.9) in CA vs. −17.7 (−20.5 to −14.6) in FD; p<0.001); GSendo (−20.6 (−27.0 to −15.7) in CA vs. −30.0 (−32.0 to −25.6) in FD; p<0.001); and GSepi (−7.4 (−8.9 to −4.8) in CA vs. −9.1 (−11.86 to −7.6) in FD; p<0.001)]. The gradient of GSendo and GSepi was significantly lower in patients with CA compared to FD (−14.0±5.6 in CA vs. −19.4±4.3 in FD respectively; p<0.001). GSendo held the highest diagnostic accuracy to discriminate CA and FD (area under the curve [AUC] 0.83, 95% confidence interval [CI] 0.73–0.92). The layer-specific strain gradient GSendo − Gsepi showed an AUC of 0.79 (CI 0.69 to 0.89).

Conclusion

Layer-specific strain analysis demonstrated significantly reduced strain values in CA patients compared to FD. The analysis of GSendo held a high diagnostic accuracy to discriminate FD and CA in patients. The integration of layer-specific LV strain indices into the diagnostic work-up may improve the management of patients with an unclear thick heart pathology in future.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Alnylam Pharmaceuticals (Cambridge, MA, USA)

New echocardiographic approaches to differentiate cardiac amyloidosis and Fabry disease: the right heart and mitral valve thickness

Background

Infiltrative cardiomyopathies such as cardiac amyloidosis (CA) and Fabry disease (FD) are associated with high cardiovascular morbidity and mortality. Diagnosis is often challenging as CA and FD may present similar cardiac phenotypes on standard echocardiographic imaging, especially in early stages of disease.

Purpose

Our study focuses on right ventricular (RV) two-dimensional speckle tracking imaging and mitral valve thickness as diagnostic strategies to discriminate CA from FD. Here, we report preliminary data of our study registry of CA and FD patients.

Methods

We retrospectively screened patients with diagnosed CA or with genetically confirmed FD from our study registry. Global and free wall RV strain and mitral leaflet thickening in both groups were analysed using 2D speckle tracking echocardiography and linear measurements from a parastenal long axis view, respectively (Vivid E9 or E95, GE Vingmed, Horton, Norway, M5S 1.5–4.5MHz transducer). The diagnostic accuracy for discriminating CA and FD in both groups was evaluated using receiver operating characteristic (ROC) curve analysis.

Results

A total of 33 FD and 27 CA patients, including 17 patients with wild-type transthyretin-related (ATTR) CA, 8 patients with hereditary ATTR CA, one patient with light chain CA, and one patient with AA CA, were included. RV function was significantly reduced in CA compared to FD patients as measured by global longitudinal RV strain (−13.6±5.1 in CA vs. −18.4±3.9 in FD, p<0.001) and free wall longitudinal RV strain (−17.5±5.7 in CA vs. −21.3±4.4 in FD, p=0.005). Significantly lower longitudinal RV strain was observed in the basal to mid ventricular region in CA compared to FD patients, while RV apical strain was not significantly different between the two groups. RV global longitudinal strain had the highest diagnostic accuracy of strain analyses (area under the curve [AUC] 0.79, 95% confidence interval [CI] 0.66–0.93) to discriminate CA from FD. Additional measurement of the mitral valve in mid diastole in the parasternal long axis view revealed a significantly thickened leaflet in CA patients (4.6±1.2 mm in CA vs. 2.9±1.0 mm in FD, p<0.001) corresponding to an AUC of 0.84 (95% CI 0.72–0.96) in ROC analysis.

Conclusion

Global longitudinal RV strain was significantly reduced in CA patients while the mitral valve leaflets were significantly thickened compared to FD patients. Therefore, both parameters may be useful to discriminate CA from FD in the echocardiographic workup of patients with unclear left ventricular wall thickening.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Alnylam Pharmaceuticals (Cambridge, MA, USA)

Patient reported experience and adherence to remote patient management in chronic heart failure patients: a posthoc analysis of the TIM-HF2 trial

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Federal Ministry of Education and Research

Background

Remote Patient Management (RPM) enables early detection and prevention of cardiac deterioration in heart failure (HF) patients by measuring vital signs. Clinical trials reported inconsistent results. Patient adherence was suggested to be one of the main reasons for inconsistent results in previous trials (2-4). The "Telemedical interventional management in heart failure II (TIM-HF2)" study showed the superiority of non-invasive RPM compared to usual care (UC) in terms of mortality and unplanned cardiovascular (CV) hospitalisation (1).

Purpose

The objective of the analysis is to assess the patient experience with RPM, the adherence to daily measurements and outline factors affecting both aspects.

Methods

TIM-HF2 was conducted 2013-2018 with 1,538 HF patients in a 12-month follow-up (5). Inclusion criteria were HF in NYHA class II or III with either LVEF ≤45% or, if LVEF >45%, patients had been treated with oral diuretics; and HF hospitalisation within the last 12 months. Patients with major depression were excluded. Patients were randomly assigned (1:1) to RPM or UC. RPM-Patients had to measure daily weight, blood pressure, ECG and self-rated health status. Data were sent automatically to the telemedical centre (TMC). In case of conspicuous findings, the TMC contacted the patient or GP for therapy adjustment. At the study end, RPM-patients were asked to evaluate the program through a 9-question survey. Adherence was distinguished between measurement of at least one (incomplete adherence- IA) and all vital parameters (complete adherence- CA) and defined as ratio of the number of days of measurements taken divided by the number of days of possible measurements. All data were analysed descriptively (mean ± standard deviation). Differences between groups were analysed by ANOVA and T-Test.

Results

The survey was answered by n=564 patients (response rate: 79.7%). The patients were satisfied with the program and device usability. CA was 89.1±14.1% and consistently high over the study course (table 1). Reasons for dropouts (n=37) were e.g. frustration with the devices and physical inability to complete the measurement protocol.

Patients <70 years and living in rural areas had lower IA rates. The mean adherence was independent of severe of disease (LVEF, NTproBNP, NYHA). Patients (n=244) had significantly lower IA the week prior to an unplanned CV hospitalisation (difference by -5.2±20.5%) compared to the entire study period. IA was significantly lower by -12.8±24.7% in the week after an unplanned CV hospitalisation compared to the entire study period.

Conclusions

In a setting with user-friendly devices, pre-interventional patient training, regular TMC-patient contact and close cooperation between primary physicians and TMC a long-lasting and high adherence and satisfaction regarding RPM could be achieved. A change in adherence might detect deterioration in health status and indicate the need to intensify telemedical care.

P1537 Myocardial work in patients with aortic stenosis before and short term after transcatheter aortic valve replacement

Objective

The newly introduced noninvasive myocardial work analysis could potentially be beneficial in predicting the best timing for aortic valve replacement as well as clinical outcomes in patients with high grade aortic valve stenosis (AS), which is the leading valvular disease in the modern aging society. However, to date there is little data on the applicability of the method in the setting of extremely increased left ventricular (LV) afterload.

Purpose

In this pilot study, we aimed to apply myocardial work analysis in patients with increased LV afterload due to severe AS and to investigate the differences of myocardial work parameters in patients with different AS entities. In addition, we analyzed the early changes of myocardial work after the afterload reduction by transcatheter aortic valve replacement (TAVR).

Methods

We retrospectively studied echocardiographic data of 28 consecutive patients with severe AS before and 7 days after TAVR. Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW) and Global Work Efficiency (GWE) were calculated using commercially available software based on noninvasive pressure-strain loops. In order to correct for underestimation of intraventricular pressure, we added the mean aortic valve pressure gradient to the peripheral systolic blood pressure used by the software.

Results

From the included patients (mean age 76 ± 10 years) 13 were classified as having normal flow (NF) severe AS, 8 had low flow low gradient (LFLG) and 7 paradoxical low flow low gradient (PLFLG) AS. GWI and GCW were significantly lower in patients with LFLG AS compared to patients with NF or PLFLG AS (936 ± 528 mmHg% vs. 2493 ± 485 mmHg% vs. 1959 ± 469 mmHg% [p < 0.005] and 1132 ± 477 mmHg% vs. 2770 ± 507 mmHg% vs. 2189 ± 603 mmHg%, [p < 0.005], respectively). 7 days after TAVR, GCW and GWI decreased significantly in patients with NF AS. In other AS entities, a trend towards increased GWI and GCW was observed, but the difference did not reach statistical significance. GWI and GCW remained significantly lower in LFLG AS group when compared to NF and PLFLG groups (1069 ± 378 mmHg% vs. 1919 ± 310 mmHg% vs. 2064 ± 842 mmHg% [p < 0.005] and 1286 ± 346 mmHg% vs. 2107 ± 258 mmHg% vs. 2227 ± 949 mmHg% [p < 0.005]) early after TAVR. GWE and GWW did not differ between the groups and were not influenced by TAVR.

Conclusion

In this pilot study we applied the adapted myocardial work analysis in patients with increased afterload due to severe AS. We have shown that GCW and GWI are significantly higher in patients with NF AS when compared to LFLG and PLFLG AS. The differences between the groups persisted early after TAVR in spite of significant reduction of GWI and GWC in patients with NF AS. The clinical and prognostic importance of these findings are still to be investigated in a bigger cohort study.