There is more than just longitudinal strain: prognostic significance of biventricular circumferential mechanics

 

Global longitudinal strain is a well-established predictive parameter of adverse outcomes in several cardiac diseases, therefore, it is widely used in clinical practice. Despite the significant contribution of circumferential shortening to the global ventricular function, data are scarce concerning the biventricular circumferential strain phenotypes and their prognostic value on long-term mortality.

Accordingly, the aim of our study was to assess both left (LV) and right ventricular (RV) global circumferential strain (GCS) using 3D echocardiography in order to determine the prognostic importance of the deterioration of biventricular circumferential mechanics.

Three hundred and sixty-four patients with various established left-sided heart diseases were retrospectively identified (age: 64.8±15.0 years, 69% males) with a median follow-up of 41 months. All patients underwent clinically indicated transthoracic echocardiography and left (LV) and right ventricular (RV) ejection fractions (EF) were measured by 3D analysis. 3D LV and RV GCS were also quantified by dedicated softwares. In order to determine the prognostic power of the different patterns of biventricular circumferential mechanics, we divided the patient population into four groups using the median values of LV and RV GCS (absolute values of 27.1% and 17.9%, respectively). Group 1 consisted of patients with both LV and RV GCS above median values; Group 2 was defined as patients with LV GCS above the median, while RV GCS below the median, whereas in Group 3 patients had LV GCS values below the median, while RV GCS was above median. Group 4 was defined as patients with both LV and RV GCS below the median. The primary endpoint of our study was all-cause mortality.

Fifty-five patients (15.1%) met the primary endpoint. The overall patient population showed balanced values of LV and RV EF (49.0±15.7 and 48.2±9.4%, respectively). Comparing the population separated into the above-mentioned four groups based on LV and RV GCS values enabled a detailed risk stratification as shown on the Kaplan-Meier curve (Figure 1.) When comparing Group 1 vs. Group 4, patients who had lower LV and RV GCS values the risk of all-cause mortality was more than 5 times higher than in patients with both LV and RV GCS above the median (HR, 5.240 [95% CI, 2.750–9.985], p<0.001). By comparing Group 2 with Group 3, the associated risks for all-cause mortality did not show a difference (HR, 0.461 [95% CI, 0.178 to 1.194], p=NS) as shown on the Kapan-Meier curve (Figure 2).

Based on the different phenotypes of LV and RV GCS, decreased biventricular circumferential shortening was associated with a significantly increased risk of long-term all-cause mortality. Interestingly, decreased RV GCS with maintained LV GCS showed a similar risk of adverse outcomes than decreased LV GCS with maintained RV GCS. Our results emphasize the importance of the assessment of biventricular circumferential mechanics.

Funding Acknowledgement

Type of funding sources: None.

Temporal changes of left atrial function after orthotopic heart transplantation using cardiac magnetic resonance imaging in a single-center prospective study

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ÚNKP-19-3-I New National Excellence Program of the Ministry for Innovation and Technology; National Research, Development and Innovation Office of Hungary (NKFIA; NVKP_16-1-2016-0017 National Heart Program)

Background

The geometry and function of the left atrium (LA) change after orthotopic heart transplantation (HTX) with bicaval technique, as the LA has a recipient part around the pulmonary veins and a donor part, and these often contract separately. Because of this altered LA function, the recognition of left ventricular diastolic dysfunction can be challenging. The standard echocardiographic diastolic parameters are often in abnormal range in HTX patients despite of normal left ventricular diastolic function.

Purpose

The aim of our prospective study was to investigate the LA volumes and function and their temporal changes after HTX  using cardiac magnetic resonance (CMR).

Method

To better understand the cardiac characteristics of HTX patients, we started a prospective trial in January 2018. CMR was performed at one, three and six months after HTX. Left atrial contour detection was performed in 2- and 4-chamber views. Patients who had ≥Grade II allograft rejection before the CMR examination, were excluded (n = 6). In the remaining HTX patients (n = 37, 52 ± 12y, 29 male) and in a control group (n = 20, 49 ± 5y, 15 male) LA ejection fraction (EF), BSA-corrected maximum and minimum LA volume (Vi), stroke volume (SVi) were evaluated using bi-plane mode. LA global longitudinal strain (GLS) was defined with CMR based deformation imaging, called feature tracking.

Results

HTX patients had significantly higher LA volumes (maxLAVi 65 ± 22 vs. 46 ± 7 ml/m2, minLAVi 47 ± 21 vs. 18 ± 6 ml/m2) lower LASVi (19 ± 5 vs. 29 ± 4 ml/m2), LAEF (31 ± 10 vs. 62 ± 8%) and LA-GLS (10 ± 4 vs. 39 ± 11%) compared to the control group (p < 0.0001).  Analysing the temporal changes in HTX patients, we found an increase in the LA-GLS already at three months (10 ± 4 vs. 12 ± 3%, p < 0.05). The LAEF improved significantly at six months (29 ± 10 vs. 33 ± 10%, p < 0.05).

Conclusion

After HTX the LA volumes and function differ markedly from the normal population. The LA funcional parameters showed a moderate improvement after HTX. Better understanding the changes of left atrial function after HTX could help us to recognise  pathological conditions.

Abstract Figure. Strain analysis of the left atrium

Structural and functional cardiac changes after transplantation: experiences of the first year of the prospective Heart-TIming CMR substudy

Background

In case of heart transplantation (HTX) the heart is affected by several factors e.g. ischaemia/reperfusion, denervation, immunosuppression. During the adaptation, the heart may show marked temporal changes in terms of myocardial mechanics, function and tissue characteristics. To better understand cardiac temporal characteristics after orthotopic bicaval HTX we started the prospective Heart-TIming (Transplantation Imaging) trial in January 2018.

Purpose

In our CMR substudy we aimed to evaluate the physiological structural and functional left and right ventricular characteristics and their temporal changes after HTX using cardiac magnetic resonance.

Methods

As part of the study HTX patients underwent CMR at one, three, six and twelve months after HTX (n=49; 53±11y, 39 male). Cine images, T2-weighted, native T1 and T2 mapping, late gadolinium enhancement (LGE) and adenosine stress perfusion (at 1 and 12 month) images were acquired. In order to describe physiological characteristics of the transplanted heart we excluded pts with significant coronary artery disease, ischaemic scar, ≥Grade II allograft rejection from this present study (n=9). We evaluated the left (LV) and right ventricular (RV) ejection fractions (EF), volumes, masses (M) and the global LV strain values: longitudinal (GLS), circumferential (GCS) strain and the standard deviation (SD) of the peak longitudinal strain (LS) and the mechanical dispersion. In a basal short axis slice the native T1 and T2 mapping values were evaluated. We compared baseline CMR parameters to age and gender matched healthy controls (n=20; 48±10y, 16 male), and analyzed the temporal changes after HTX.

Results

Comparing the HTX patients' CMR parameters at one month with normal controls, HTX patients had lower end-diastolic volumes (LVEDVi: 74±15 vs 89±13 ml/m2; RVEDVi: 72±16 vs 89±15 ml/m2 p<0.05), stroke volumes (LVSVi: 45±7 vs 55±8 ml/m2, RVSVi: 43±8 vs 54±8 ml/m2, p<0.0001), higher LVMi (63±2 vs 55±3 g/m2, p<0.05), increased SD of peak LS (14±2 vs 10±2, p<0.0001) and more pronounced mechanical dispersion (18±5 vs 12±4, p<0.0001). The native T1 mapping values were significantly higher in HTX pts (1007±40 vs 975±24 ms, p<0,01). Examining temporal changes in HTX pts we found a decrease in LVMi (66±14 vs 59±10 g/m2, p<0.01) already at three months. At 12 months LVMi decreased further, less negative GLS (−25±4 vs −20±4, p<0.01) and GCS (−38±7 vs −34±4, p<0.05), and lower SD of the peak LS (14±2 vs 11±2, p<0.01) were measured.

Conclusions

Understanding the temporal changes of cardiac mechanics, function and tissue characteristics, furthermore the establishment of physiological values may help in the early, noninvasive identification of pathological changes in HTX pts.

Tissue specific information in HTX pts

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Project no. NVKP_16-1-2016-0017 has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the NVKP_16 funding scheme. Supported by the ÚNKP-18-3-IV New National Excellence Program of Human Capacities.

P345 Temporal changes of left atrial function after orthotopic heart transplantation in a single-center prospective study

Funding Acknowledgements

Project no. NVKP_16-1-2016-0017 has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary

The geometry and function of the left atrium (LA) change after orthotopic heart transplantation (HTX) with bicaval technique, as the LA has a recipient part around the pulmonary veins and a donor part, and these often contract separately. Because of this altered LA function, the recognition of left ventricular diastolic dysfunction can be challenging. The standard echocardiographic diastolic parameters are often in abnormal range in HTX patients despite of normal left ventricular diastolic function.

The aim of our prospective study was to investigate the LA volumes and function and their temporal changes after HTX using cardiac magnetic resonance (CMR).

To better understand the cardiac characteristics of HTX patients, we started a prospective trial in January 2018. CMR was performed at one, three and six months after HTX. Left atrial contour detection was performed in 2- and 4-chamber views. Patients who had ≥Grade II allograft rejection before the CMR examination, were excluded (n = 2). In the remaining HTX patients (n = 21) and in a control group (n = 21) LA ejection fraction (EF), BSA-corrected maximum and minimum LA volume (Vi), stroke volume (SVi) were evaluated using bi-plane mode. LA global longitudinal strain (GLS) was defined with CMR based deformation imaging, called feature tracking.

HTX patients had significantly higher LA volumes (maxLAVi 71 ± 22 vs. 47 ± 6 ml/m2, minLAVi 53 ± 22 vs. 18 ± 5 ml/m2) lower LASVi (19 ± 7 vs. 29 ± 4 ml/m2), LAEF (27 ± 10 vs. 62 ± 8%) and LA-GLS (8 ± 3 vs. 39 ± 10%) compared to the control group (p < 0.0001).

Analysing the temporal changes in HTX patients, we found an increase in the LAEF (26 ± 8 vs. 30 ± 5%) and LA-GLS (8 ± 3 vs. 11 ± 3%) at three months (p < 0.05), there was no significant difference between the LA parameters at three and six months.

Better understanding of the changes of left atrial function after HTX could help us to recognise pathological conditions.

Abstract P345 Figure. Strain analysis of the left atrium

P761The effect of extracorporeal photopheresis on cardiac allograft rejection and on lymphocyte subclasses

Background

Cardiac allograft rejection is known to have a profound impact on graft survival and mortality after heart transplant. Previous data on the efficacy of extracorporeal photopheresis (ECP) in the management of cardiac allograft rejection is encouraging. Though, clear evidence on the exact indication and data regarding its effect on distinct lymphocyte subtypes are still lacking. Based on their cytokine production, both helper and cytotoxic T cells can differentiate into either regulatory cells participating in the suppression of rejection or into effector cells responsible for its maintenance. Regulatory T cells are essential for the termination of rejection, while B lymphocytes and natural killer (NK) cells contribute to it.

Purpose

We aimed to investigate the anti-rejection efficacy and the impact of ECP on peripheral blood lymphocyte subclasses in adult heart transplant recipients.

Methods

In a retrospective analysis of 12 consecutive patients treated with ECP for cardiac allograft rejection between 2013 and 2019, we examined the grade of rejection in endomyocardial biopsies (EMB) based on the International Society for Heart and Lung Transplantation classification. We analysed the absolute counts and the percentages of helper, cytotoxic and regulatory T cells, B lymphocytes and NK cells with fluorescence activated cell sorting. Measurements were performed both before and after the ECP treatment period. Data values were given as either mean±standard deviation or median [min–max].

Results

The patients underwent 26 [2–39] ECP treatments in addition to standard immunosuppressant therapy. Whereas grade 2R cellular rejection was detected in 83% of the cases prior to initiating ECP, none of the examined EMB specimen revealed rejection greater than grade 1R cellular rejection post ECP therapy. The average grade of cellular rejection improved significantly (1.25±0.45 vs. 0.50±0.53; p=0.022). The absolute count and the percentage of helper T cells increased significantly post ECP therapy (0.34 G/l±0.26 G/l vs. 0.51 G/l±0.39 G/l; p=0.018 and 3.43%±2.24% vs. 5.98%±3.64%; p=0.017, respectively). There was also a significant rise in the percentage of cytotoxic T cells (2.33%±1.46% vs. 4.16±2.98%; p=0.027). We noticed an almost significant twofold increase in the percentage of regulatory T cells on completion of the ECP therapy (0.20%±0.22% vs. 0.37%±0.20%; p=0.060). Neither B lymphocyte nor NK cell counts revealed any significant changes.

Conclusion

ECP was effective in reducing the severity of cardiac allograft rejection episodes. The significant decrease in rejection rates might be indicative of the predominance of anti-inflammatory helper and cytotoxic T cell subpopulations and the increase of regulatory T cell count post ECP therapy. However, discussion of the results are limited by small sample size and the effect of medical therapy on the lymphocytes.

P3558Cardiac magnetic resonance characteristics of the transplanted heart: first results of the prospective Heart-TIming CMR substudy

Background

In case of heart transplantation (HTX) the heart is affected by several factors e.g. ischaemia/reperfusion, denervation, immunosuppression. During the adaptation, the heart may show marked temporal changes in terms of myocardial mechanics, function and tissue characteristics. To better understand temporal characteristics after orthotopic bicaval HTX we started the prospective Heart-TIming (Transplantation Imaging) trial in January 2018 including standard 12-lead ECG, 24-hour Holter monitor, endomyocardial biopsy, transthoracic echocardiography, invasive coronary angiography with intravascular ultrasound and optical coherence tomography and cardiac magnetic resonance (CMR).

Aim

In our CMR substudy we aimed to evaluate the physiological structural and functional left and right ventricular characteristics and their temporal changes after HTX using CMR.

Methods

As part of the study HTX patients underwent CMR at 1, 3 and 6 months after HTX (n=31; 52±10.5y, 25 male). Cine images, T2-weighted, late gadolinium enhancement (LGE) and adenosine stress perfusion (at 1 month) images were acquired. In order to describe physiological characteristics of the transplanted heart we excluded pts with significant coronary artery disease, ischaemic scar, ≥Grade II allograft rejection from this present study (n=6). We assessed the left (LV) and right ventricular (RV) ejection fractions, volumes, masses (M) and LV strain. We assessed the global strain values: longitudinal, circumferential (GCS) strain and the standard deviation (SD) of the peak longitudinal strain (LS) and the left ventricular mechanical dispersion. We compared baseline volumetric and strain parameters to age matched healthy controls (n=20; 47±11.4y, 15 male), and the temporal changes between one, three and 6 months.

Results

Comparing the HTX patients' CMR parameters at one month with normal controls, HTX patients had lower LV and RV end-diastolic volumes (LVEDVi: 76.6±15.9 vs 90.6±11.6ml/m2; RVEDVi 74.5±17.5 vs 90.3±12.1ml/m2, p<0.05),stroke volumes (p<0.05) and higher LVMi (67.6±14.4 vs 57.2±11g/m2, p<0.05). CMR based strain analysis of the HTX pts showed hyperkinetic GCS (−40,5±6.3% vs −35.2±4.8%, p<0.05), increased SD of peak LS and more pronounced mechanical dispersion (p<0.001) compared to the controls. Examining temporal changes in HTX pts we found a decrease in LVMi (69.57±16.4 vs 61.7±9.8g/m2, p<0.05) already at three months, normalization of GCS (−37.7±5.5% vs −32.6±4.9%, p<0.05) and decrease in SD of peak LS (13.5±2.3 vs 11.4±2.4, p<0.05) at 6 months. Oedema was present in all pts at one month after HTX, and disappeared after three months. LGE with aspecific pattern was present in 42%.

LGE with aspecific pattern in HTX pts

Conclusions

Understanding the temporal changes of LV mechanics, function and tissue characteristics, furthermore the establishment of physiological values may help in the early, noninvasive identification of pathological changes in HTX pts.

NCT number: NCT03499197

Acknowledgement/Funding

Project no. NVKP_16-1-2016-0017 has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary

The aspartimide problem in Fmoc-based SPPS. Part II

The sequence dependence of base-catalysed aspartmide formation during Fmoc-based SPPS was systematically studied employing the peptide models H-Val-Lys-Asp-Xaa-Tyr-Ile-OH. The extent of formation of aspartimide and related by-products was determined by RP-HPLC. Considerable amounts of by-products were formed in the case of Xaa = Asp(OtBu), Arg(Pbf), Asn(Mtt), Cys(Acm) and unprotected Thr. Aspartimide formation could be diminished by incorporation of Asp(OMpe) or by employing milder methods for Fmoc cleavage, e.g. hexamethyleneimine/N-methylpyrrolidine/HOBt/NMP/DMSO 4:50:4:71:71 (v/v/w/v/v).

The aspartimide problem in Fmoc-based SPPS. Part I

A variety of Asp beta-carboxy protecting groups, Hmb backbone protection and a range of Fmoc cleavage protocols have been employed in syntheses of the model hexapeptide H-VKDGYI-OH to investigate the aspartimide problem in more detail. The extent of formation of aspartimide and aspartimide-related by-products was determined by RP-HPLC. This study included three new Fmoc-Asp-OH derivatives: the beta-(4-pyridyl-diphenylmethyl) and beta-(9-phenyl-fluoren-9-yl) esters and also the orthoester Fmoc-beta-(4-methyl-2,6,7-trioxabicyclo[2.2.2]-oct-1-yl)-alanine. 3-Methylpent-3-yl protection of the Asp side chain resulted in significant improvements with respect to aspartimide formation. Complete suppression was achieved using the combination OtBu side chain protection and Hmb backbone protection for the preceding Gly residue.

Synthesis and application of Fmoc-His(3-Bum)-OH

This paper presents a reevaluation of the synthesis and properties of Fmoc-His(3-Bum)-OH regarding its application in SPPS with minimal racemization of histidine residues during coupling and esterification reactions. By-product formation during the deprotection of the test peptides could be significantly reduced by scavenging the concomitantly formed HCHO, e.g. with methoxyamine.

Improved labelling of no-carrier-added 123I-MIBG and preliminary clinical evaluation in patients with ventricular arrhythmias

Meta-[123I]iodobenzylguanidine (123I-MIBG) is currently used to assess myocardial sympathetic innervation by single photon emission tomography (SPET). In recent studies, an enhanced cardiac uptake of 123I-MIBG with high specific activity has been reported, suggesting the clinical potential of no-carrier-added (n.c.a.) 123I-MIBG in the assessment of abnormalities in cardiac sympathetic function. This paper describes the preparation of n.c.a. 123I-MIBG by non-isotopic Cu(I)-assisted [123I]iododebromination and by [123I]iododestannylation, both resulting in n.c.a. 123I-MIBG with radiochemical yields of 88 +/- 6% and high specific activity (> or = 6.3 TBq.mumol-1) in a total synthesis time of less than 50 min. The diagnostic potential of n.c.a. 123I-MIBG (> 6.3 TBq.mumol-1) was studied in 13 patients (nine patients with malignant ventricular arrhythmias and four patients suspected of phaeochromocytoma) and compared to commercial 123I-MIBG (approximately 75 MBq.mumol-1) using a dual-headed SPET camera (MULTISPECT II). High specific activity results in higher 123I-MIBG uptake in the heart and in the liver in all patients. The calculated heart-to-lung and heart-to-liver count ratios 4.5 h post-injection increased by 22 +/- 6% and 10 +/- 5% with n.c.a. 123I-MIBG compared to commercial 123I-MIBG respectively. In contrast, no significant correlation between the specific activity of 123I-MIBG and lung uptake could be established in this study. Analysis of radioactivity in blood after the intravenous injection of n.c.a. and commercially available 123I-MIBG showed an initial rapid clearance of radioactivity from blood, followed by a plateau from 60 min onwards. Within the first 24 h, more than 85% of the plasma activity was unchanged 123I-MIBG. The free 123I-iodide concentration determined 24 h post-injection was 2 +/- 1% with commercial 123I-MIBG and 3 +/- 2% with n.c.a. 123I-MIBG. In conclusion, the results of this investigation indicate that n.c.a. 123I-MIBG is a promising clinical tool for imaging myocardial sympathetic dysfunction by SPET. High specific activity n.c.a. 123I-MIBG can now be prepared by simple one-step methods giving high radiochemical yields and high purity suitable for clinical application. This encourages the further clinical validation of n.c.a. 123I-MIBG on a large scale.

[Pregnancy and hyperthyroidism]

Because the coincidence of hyperthyroidism and pregnancy is rare, there is come uncertainty in the management of these patients. In order to avoid complications during the course of pregnancy, it is important to know--besides etiology and pathogenesis--the particularities in diagnosis and start of the appropriate therapy in time.

4-Methyltrityl (Mtt): a new protecting group for the side chain protection of Asn and Gln in solid-phase peptide synthesis

The trityl group was recently introduced for the protection of the side chain carboxamide function of asparagine and glutamine. The 4-methyltrityl (Mtt) group, a structural modification of trityl, is presented here and allows more rapid cleavage from the protected peptides. Procedures for the introduction of the group and comparative cleavage reactions are also presented.