Usefulness of Two-Dimensional Strain Parameters to Diagnose Acute Rejection after Heart Transplantation

Rejection Surveillance: Integrating Cell-Free DNA and Gene Expression Panels to Decrease Invasiveness in Routine Monitoring of Heart Transplant Recipients

Post-transplant rejection surveillance remains a cornerstone of heart transplant care. Although endomyocardial biopsy has long been the gold standard for monitoring rejection, its invasiveness and limitations have driven innovations in noninvasive techniques. Molecular diagnostics, including gene expression profiling (GEP) and donor-derived cell-free DNA (dd-cfDNA), have emerged as promising alternatives with demonstrated utility. GEP excels in identifying immune activation with high negative predictive value, while dd-cfDNA provides insights into allograft injury, with sensitivity up to 81% and specificity of 85%. Complementary cardiac imaging such as echocardiography and cardiac magnetic resonance enhance graft assessment by providing structural and functional data. Together, these investigations offer a multimodal approach to rejection surveillance, reducing the frequency of endomyocardial biopsy and improving overall care for transplant recipients.

Speckle-tracking echocardiography of left and right ventricle and acute cellular rejection in orthotropic heart transplantation: a systematic review and meta-analysis

After a cardiac transplantation, the steering of immunosuppression requires an active search for acute cellular rejection (ACR). Surveillance with endomyocardial biopsy (EMB) is the gold standard. Given the costs and potential complications, there is growing interest in the use of non-invasive screening methods. Thus, we have conducted a systematic review and meta-analysis to evaluate the role of speckle-tracking echocardiography as a screening method for ACR. We searched PubMed (CENTRAL) and gray literature for studies presenting data on speckle tracking echocardiography in heart-transplant patients experiencing acute cellular rejection. The primary outcomes of the meta-analysis were left and right ventricular global longitudinal strain. We used random effects models for all our calculations. We pre-registered our meta-analysis with PROSPERO (CRD42024508654). By incorporating data from over 2000 biopsies included in 18 studies, we found that both left (LVGLS, MD -1.96, 95% CI -2.85 to -1.07, p < 0.0001), and right (RVGLS, MD -2.90, 95% CI -4.03 to -1.76, p < 0.00001) ventricular longitudinal strain were lower among patients without ACR. The change of LVGLS from baseline over time was also greater among patients experiencing ACR (MD -2.43, 95% CI -4.82 to -0.05, p = 0.045). Current data suggest that myocardial strain measured by speckle tracking echocardiography is affected in ACR and could potentially be used for early rejection detection as a rule-out strategy, leading to reduction of routine EMB in heart transplant follow-up.

Echocardiographic Evaluation of the Post-Heart Transplant Patient

PURPOSE OF REVIEW

Significant practice variability exists with respect to the role and frequency of echocardiography after heart transplantation. We sought to illustrate key studies relating to the utility and diagnostic accuracy of echocardiography for the post-heart transplant patient.

RECENT FINDINGS

Several echocardiographic parameters correlate with acute heart transplant rejection, but there is enough heterogeneity between study results or in diagnostic accuracy, such that it precludes parameter use in isolation to rule out rejection. Newer techniques such as strain echocardiography may have better sensitivity. Similarly, resting and stress echocardiography can be combined with modern techniques such as myocardial contrast echocardiography to diagnose and prognosticate cardiac allograft vasculopathy, but studies have again demonstrated variable accuracy. Echocardiography remains an accessible tool in the evaluation and management of patients after heart transplantation. This modality can guide clinical judgment with real-time data and several fairly sensitive parameters for the detection of rejection, cardiac allograft vasculopathy, and other abnormalities. Often, auxiliary diagnostic modalities need to be combined to optimize diagnostic accuracy.

Implications of Preoperative C-Reactive Protein Levels in Heart Transplant Patients-A Single-Center Retrospective Study

Background: Heart transplant is the final therapeutic option for end-stage heart failure patients. It has been used with increasing success as a surgical procedure, greatly influenced by advances in diagnostic and prognostic tools. The aim of this paper was to study potential implications of C-reactive protein (CRP) in patients who underwent heart transplants. Methods: Our cohort included 43 adult patients from the Emergency Institute for Cardiovascular Diseases and Transplant of Târgu Mureș who underwent heart transplants in our center between 2011 and 2023. Correlations between CRP levels and different characteristics of the patients were investigated, and the optimal cut-off value for CRP levels in relation to the 6-month mortality rate was determined. The central tendencies of the baseline characteristics of patients who had a CRP value lower than the cut-off and those with a value higher than it were compared using parametric or nonparametric tests. Results: Significant correlations between the preoperative CRP levels and 6-month mortality rate (r = 0.35; 95%CI: 0.05-0.60; p = 0.02), as well as previous cardiac resynchronization therapy (CRT) and preoperative CRP levels (r = -0.37; 95%CI: -0.61--0.07, p = 0.01) were highlighted. A value for CRP > 1.66 mg/dL was found to be associated with 6-month mortality (OR = 18.00; 95%CI: 1.90-170.33, p < 0.01). Moreover, the patients who received CRT before transplantation had significantly lower levels of CRP when compared to those who did not receive CRT (p = 0.01). Conclusions: Preoperative CRP levels could represent a valuable asset in the follow-up algorithm of heart transplant patients. The lower levels of CRP in patients who benefited from CRT before transplantation highlights the importance of understanding the complex mechanisms of inflammation and increasing focus on device therapy for future transplant recipients. Further prospective studies with larger cohorts are needed for validation.

Right ventricular dysfunction: pathophysiology, experimental models, evaluation, and treatment

Interest in the right ventricle has substantially increased due to advances in knowledge of its pathophysiology and prognostic implications across a wide spectrum of diseases. However, we are still far from understanding the multiple mechanisms that influence right ventricular dysfunction, its evaluation continues to be challenging, and there is a shortage of specific treatments in most scenarios. This review article aims to update knowledge about the physiology of the right ventricle, its transition to dysfunction, diagnostic tools, and available treatments from a translational perspective.

Histopathological Characteristics of Percutaneous Endomyocardial Biopsy in Heart Transplant Rejection Surveillance: A Single Center Experience

BACKGROUND

Heart transplantation (HT) remains the ultimate treatment for end-stage heart failure. An endomyocardial biopsy (EMB) is "the gold standard" diagnostic procedure used in HT rejection surveillance. The aim of this study is to provide a detailed analysis of the histopathological characteristics of the EMB and to investigate if there is a correlation between some histopathological changes, such as fibrosis, vasculitis, Quilty effect (Q.E.), myocytes damage, and the presence of episodes of acute rejection.

METHODS

In this retrospective study, 200 EMBs were included, coming from 65 patients transplanted in the Emergency Institute for Cardiovascular Diseases and Transplantation (ICvDT) Targu Mures between 2012 and 2024. Fibrosis, vasculitis, Q.E., myocyte damage, etc., were microscopically evaluated to see if these parameters correlate with rejection episodes.

RESULTS

The mean age was 38.18 years (SD 15.67), 25% of biopsies being recorded in the 41-50 age group. 77.14% of total acute cellular rejection (ACR) was of mild rejection, with most registered in the 11-20 age group; the cases of severe rejection being recorded in the 41-50 age group. Antibody-mediated rejection (AMR) was recorded more frequently in women with a representation of 23.4%, compared to 8.5% of men. 86.7% (39 cases) of the total number of EMBs with fibrosis score 3 and 71.4% (15 cases) of the total EMBs with fibrosis score 2 were recorded in men, compared to the 28.6% (6 cases) of fibrosis score 2 recorded in women (p = 0.013). 50.0% of all the EMB recorded in the 61-70 age group showed fibrosis score 3, compared to 34.8% of those from the 21-30 age group. The Q.E. was identified in 13% of the biopsies and, in some patients, it was observed across 3-4 successive biopsies. Mild vasculitis was associated in 34.9% of cases with ISHLT ≥ 1R and moderate vasculitis was associated in 87.5% of cases with ISHLT ≥ 1R.

CONCLUSIONS

Fibrosis was detected much more frequently in men and in the 61-70 age group. In addition to the histopathological changes specific to acute rejection, there are other pathological changes, such as the Q.E., and vasculitis and myocytes damage and disarray, that seem to suggest a close connection with rejection, but extensive studies are needed to confirm this.

Tricuspid Annular Plane Systolic Excursion-to-Systolic Pulmonary Artery Pressure Ratio as a Prognostic Factor in Heart Transplant Patients

Background and Objectives: Heart transplant is currently the final step in treating patients with heart failure. The success of this procedure is strongly connected to potential complications such as postoperative heart failure, infections, graft rejection, graft vasculopathy, and kidney failure. Thus, identifying potential prognostic factors for patients' outcome is of utmost importance. We investigated the prognostic role of the postoperative ratio between the tricuspid annular plane systolic excursion (TAPSE) and systolic pulmonary artery pressure (sPAP) in patients who underwent heart transplantation in our center. Materials and Methods: The study included 46 adult patients from the Emergency Institute for Cardiovascular Diseases and Transplant of Târgu Mureș, who underwent heart transplant between January 2011 and April 2023. By the use of receiver operating characteristic (ROC) analysis, we determined an optimal cut-off value for TAPSE/sPAP with regard to survival at 6 months. Differences in central tendencies of baseline characteristics in those who had a value lower than the cut-off value of TAPSE/sPAP and those who presented a value above it were investigated using the corresponding parametric or nonparametric tests. Results: A value for TAPSE/sPAP above 0.47 mm/mmHg was associated with 6-month survival (OR: 59.5, CI: 5.7-616.0). No significant differences in central tendencies for baseline characteristics were found between the patients who had a TAPSE/sPAP ratio below the cut-off and those who had a ratio above it. Conclusions: The TAPSE/sPAP ratio might prove to be valuable in the early identification of at-risk heart transplant patients. Further prospective studies with larger cohorts are required for validation.

A Comprehensive Excursus of the Roles of Echocardiography in Heart Transplantation Follow-Up

Current guidelines for the care of heart transplantation recipients recommend routine endomyocardial biopsy and invasive coronary angiography as the cornerstones in the surveillance for acute rejection (AR) and coronary allograft vasculopathy (CAV). Non-invasive tools, including coronary computed tomography angiography and cardiac magnetic resonance, have been introduced into guidelines without roles of their own as gold standards. These techniques also carry the risk of contrast-related kidney injury. There is a need to explore non-invasive approaches providing valuable information while minimizing risks and allowing their application independently of patient comorbidities. Echocardiographic examination can be performed at bedside, serially repeated, and does not carry the burden of contrast-related kidney injury and procedure-related risk. It provides comprehensive assessment of cardiac morphology and function. Advanced echocardiography techniques, including Doppler tissue imaging and strain imaging, may be sensitive tools for the detection of minor myocardial dysfunction, thus providing insight into early detection of AR and CAV. Stress echocardiography may offer a valuable tool in the detection of CAV, while the assessment of coronary flow reserve can unravel coronary microvascular impairment and add prognostic value to conventional stress echocardiography. The review highlights the role of Doppler echocardiography in heart transplantation follow-up, weighting advantages and limitations of the different techniques.

Feasibility Value of Right Ventricular Longitudinal Shortening Fraction and the Prognostic Implications in Patients With Heart Transplantation

BACKGROUND

Right ventricular longitudinal shortening fraction (RVLSF) is a 2-dimensional speckle tracking echocardiography parameter based on tricuspid annular displacement analysis that could be used to assess right ventricular (RV) systolic function. The value of RVLSF in the assessment of RV systolic function in recipients of heart transplantation (HT) and whether RVLSF can replace strain parameters remains unknown.

METHODS AND RESULTS

A total of 153 adult patients who underwent HT were consecutively enrolled in this prospective longitudinal study. All subjects were examined by conventional transthoracic 2-dimensional echocardiography and 2-dimensional speckle tracking echocardiography to evaluate the RV end-diastolic basal diameter, RV end-diastolic area, fractional area change, peak systolic velocity of tricuspid annulus, tricuspid annular plane systolic excursion, RV free wall strain, and RVLSF. Cox proportional hazards regression was used to test if the parameters of interest had independent prognostic value for adverse outcome prediction in patients who underwent HT. A significant positive correlation was found between the measurements of RVLSF and RV free wall strain (r=0.927, P<0.001). Compared with the event-free group, the adverse outcome group displayed reduced RVLSF and RV free wall strain and higher age (P<0.001, <0.001, =0.016, respectively) in patients who underwent HT. RVLSF and RV free wall strain were independently associated with poor prognosis in multivariable analysis (both P<0.001).

CONCLUSIONS

RVLSF assessment provides an effective evaluation of RV longitudinal systolic function in the transplanted hearts and has prognostic value for adverse outcomes in patients undergoing HT.

Early left ventricular systolic function is a more sensitive predictor of adverse events after heart transplant

BACKGROUND

First-phase ejection fraction (EF1) is a novel measure of early changes in left ventricular systolic function. This study was to investigate the prognostic value of EF1 in heart transplant recipients.

METHODS

Heart transplant recipients were prospectively recruited at the Union Hospital, Wuhan, China between January 2015 and December 2019. All patients underwent clinical examination, biochemistry measures [brain natriuretic peptide (BNP) and creatinine] and transthoracic echocardiography. The primary endpoint was a combined event of all-cause mortality and graft rejection.

RESULTS

In 277 patients (aged 48.6 ± 12.5 years) followed for a median of 38.7 [26.8-45.0] months, there were 35 (12.6%) patients had adverse events including 20 deaths and 15 rejections. EF1 was negatively associated with BNP (β = -0.220, p < 0.001) and was significantly lower in patients with events compared to those without. EF1 had the largest area under the curve in ROC analysis compared to other measures. An optimal cut-off value of 25.8% for EF1 had a sensitivity of 96.3% and a specificity of 97.1% for prediction of events. EF1 was the most powerful predictor of events with hazard ratio per 1% change in EF1: 0.628 (95%CI: 0.555-0.710, p < 0.001) after adjustment for left ventricular ejection fraction and global longitudinal strain.

CONCLUSIONS

Early left ventricular systolic function as measured by EF1 is a powerful predictor of adverse outcomes after heart transplant. EF1 may be useful in risk stratification and management of heart transplant recipients.

Serial electrocardiograms at follow-up for early detection of transplanted heart rejection: A viewpoint

This viewpoint proposed that serial electrocardiograms (ECG) could be used to monitor for heart transplantation (HT) rejection, based on the expected attenuation of the amplitude of ECG QRS complexes (attQRS) engendered by the rejection-induced decrease in electrical resistance due to the underlying myocardial edema (ME). Previous work in humans has shown attQRS in the setting of a diverse array of edematous states, affecting the myocardium (i.e, ME) and the body volume conductor "enveloping" the heart. Also, animal and human experience has revealed low electrical resistance during mild/moderate HT rejection. Studies with serial correlations of endomyocardial biopsy (EMB), echocardiography, cardiac magnetic resonance imaging, and ECG are recommended, which will merely require recording of an ECG, when EMB and imaging studies are carried out for monitoring of post-HT rejection.

Multimodality Imaging in Advanced Heart Failure for Diagnosis, Management and Follow-Up: A Comprehensive Review

Advanced heart failure (AHF) presents a complex landscape with challenges spanning diagnosis, management, and patient outcomes. In response, the integration of multimodality imaging techniques has emerged as a pivotal approach. This comprehensive review delves into the profound significance of these imaging strategies within AHF scenarios. Multimodality imaging, encompassing echocardiography, cardiac magnetic resonance imaging (CMR), nuclear imaging and cardiac computed tomography (CCT), stands as a cornerstone in the care of patients with both short- and long-term mechanical support devices. These techniques facilitate precise device selection, placement, and vigilant monitoring, ensuring patient safety and optimal device functionality. In the context of orthotopic cardiac transplant (OTC), the role of multimodality imaging remains indispensable. Echocardiography offers invaluable insights into allograft function and potential complications. Advanced methods, like speckle tracking echocardiography (STE), empower the detection of acute cell rejection. Nuclear imaging, CMR and CCT further enhance diagnostic precision, especially concerning allograft rejection and cardiac allograft vasculopathy. This comprehensive imaging approach goes beyond diagnosis, shaping treatment strategies and risk assessment. By harmonizing diverse imaging modalities, clinicians gain a panoramic understanding of each patient's unique condition, facilitating well-informed decisions. The aim is to highlight the novelty and unique aspects of recently published papers in the field. Thus, this review underscores the irreplaceable role of multimodality imaging in elevating patient outcomes, refining treatment precision, and propelling advancements in the evolving landscape of advanced heart failure management.

De Novo Donor-Specific Antibodies after Heart Transplantation: A Comprehensive Guide for Clinicians

Antibodies directed against donor-specific human leukocyte antigens (HLAs) can be detected de novo after heart transplantation and play a key role in long-term survival. De novo donor-specific antibodies (dnDSAs) have been associated with cardiac allograft vasculopathy, antibody-mediated rejection, and mortality. Advances in detection methods and international guideline recommendations have encouraged the adoption of screening protocols among heart transplant units. However, there is still a lack of consensus about the correct course of action after dnDSA detection. Treatment is usually started when antibody-mediated rejection is present; however, some dnDSAs appear years before graft failure is detected, and at this point, damage may be irreversible. In particular, class II, anti-HLA-DQ, complement binding, and persistent dnDSAs have been associated with worse outcomes. Growing evidence points towards a more aggressive management of dnDSA. For that purpose, better diagnostic tools are needed in order to identify subclinical graft injury. Cardiac magnetic resonance, strain techniques, or coronary physiology parameters could provide valuable information to identify patients at risk. Treatment of dnDSA usually involves plasmapheresis, intravenous immunoglobulin, immunoadsorption, and ritxumab, but the benefit of these therapies is still controversial. Future efforts should focus on establishing effective treatment protocols in order to improve long-term survival of heart transplant recipients.

The utilization of molecular microscope in management of heart transplant recipients in the era of noninvasive monitoring

INTRODUCTION

Monitoring for graft rejection is a fundamental tenet of post-transplant follow-up. In heart transplantation (HT) in particular, rejection has been traditionally assessed with endomyocardial biopsy (EMB). EMB has potential complications and noted limitations, including interobserver variability in interpretation. Additional tests, such as basic cardiac biomarkers, cardiac imaging, gene expression profiling (GEP) scores, donor-derived cell-free DNA (dd-cfDNA) and the novel molecular microscope diagnostic system (MMDx) have become critical tools in rejection surveillance beyond standard EMB.

METHODS

This paper describes an illustrative case followed by a review of MMDx within the context of other noninvasive screening modalities for rejection.

CONCLUSIONS

We suggest MMDx be used to assist with early detection of rejection in cases of discordance between EMB and other noninvasive studies.

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Heart transplantation and anti-HLA antibodY: myocardial dysfunction and prognosis - HeartLAy study

AIMS

The presence of anti-human leucocyte antigen (HLA) antibodies has been implicated in a higher incidence of complications as well as mortality rate in heart transplantation. The aim of the study was to identify through non-invasive parameters early signs of myocardial dysfunction in the presence of anti-HLA antibodies but without evidence of antibody-mediated rejection (AMR) and its possible prognostic impact.

METHODS AND RESULTS

A total of 113 heart-transplanted patients without acute cellular rejection (ACR) and AMR or cardiac allograft vasculopathy (CAV) were prospectively enrolled and divided into two groups ['HLA+' (50 patients) and 'HLA-' (63 patients)], based on the presence of anti-HLA antibodies. Each patient was followed for 2 years after the enrolment, recording episodes of AMR, ACR, CAV, and mortality. Clinical characteristics were similar between the two groups. Among laboratory data, N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin values were significantly higher in the presence of anti-HLA antibodies (P < 0.001 and P = 0.003, respectively). The echocardiographic parameters that showed a statistically significant difference between the two groups were deceleration time of E wave (DecT E, P < 0.001), left ventricular global longitudinal strain (P < 0.001), tricuspid annular plane systolic excursion (P = 0.011), tricuspid S' wave (P = 0.002), and free wall right ventricular longitudinal strain (fwRVLS, P = 0.027), whereas left atrial strain did not differ significantly (P = 0.408). Univariate analysis showed that anti-HLA antibodies were associated with the development of CAV at both 1 and 2 year follow-up [odds ratio (OR) 11.90, 95% confidence interval (CI) 1.43-90.79, P = 0.022 and OR 3.37, 95% CI 1.78-9.67, P = 0.024, respectively]. Bivariate analysis demonstrated that both fwRVLS and DecT E were predictors of CAV development independently from HLA status.

CONCLUSIONS

The presence of circulating anti-HLA antibodies is correlated with a mild cardiac dysfunction, even in the absence of AMR, and CAV development. Interestingly, reduced values of DecT E and fwRVLS were predictors of future development of CAV, independently from anti-HLA antibody.

Prognostic value of right ventricular three-dimensional speckle-tracking strain in adult heart transplantation patients

We aimed to investigate the prognostic value of three-dimensional right ventricular free wall longitudinal strain (3D-RV FWLS) in adult heart transplantation (HTx) patients, taking three-dimensional left ventricular global longitudinal strain (3D-LV GLS) into account. We prospectively enrolled 155 adult HTx patients. Conventional right ventricular (RV) function parameters, two-dimensional (2D) RV FWLS, 3D-RV FWLS, RV ejection fraction (RVEF), and 3D-LV GLS were obtained in all patients. All patients were followed for the endpoint of death and major adverse cardiac events. After a median follow-up of 34 months, 20 (12.9%) patients had adverse events. Patients with adverse events had higher incidence of previous rejection, lower hemoglobin, and lower 2D-RV FWLS, 3D-RV FWLS, RVEF and 3D-LV GLS (P < 0.05). In multivariate Cox regression, Tricuspid annular plane systolic excursion (TAPSE), 2D-RV FWLS, 3D-RV FWLS, RVEF and 3D-LV GLS were independent predictors of adverse events. The Cox model using 3D-RV FWLS (C-index = 0.83, AIC = 147) or 3D-LV GLS (C-index = 0.80, AIC = 156) was observed to predict adverse events more accurately than that with TAPSE, 2D-RV FWLS, RVEF or traditional risk model. Moreover, when added in nested models including previous ACR history, hemoglobin levels, and 3D-LV GLS, the continuous NRI (0.396, 95% CI 0.013 ~ 0.647; P = 0.036) of 3D-RV FWLS was significant. 3D-RV FWLS is a stronger independent predictor of adverse outcomes, and provides additive predictive value over 2D-RV FWLS and conventional echocardiographic parameters in adult HTx patients, taking 3D-LV GLS into account.

Serial changes of right ventricular function assessed by three-dimensional speckle-tracking echocardiography in clinically well adult heart transplantation patients

PURPOSE

The present study aimed to evaluate serial changes of right ventricular (RV) function in clinically well adult heart transplantation (HT) patients using three-dimensional speckle-tracking echocardiography (3D-STE).

METHODS

We included 58 adult HT patients, who were free from severe valvular insufficiency, severe coronary artery disease, acute rejection, or multiple organ transplantation, and 58 healthy controls. The healthy controls were matched by the distribution of age and sex with HT group. Conventional and three-dimensional (3D) echocardiography was performed in all HT patients at 1-, 3-, 6-, 9- and 12-months post-HT. And all the healthy controls underwent conventional and 3D echocardiography when recruited. Tricuspid annular plane systolic excursion (TAPSE), S' and RV fractional area change (RV FAC) were measured. Two-dimensional RV free wall longitudinal strain (2D-RV FWLS) was derived from two-dimensional speckle-tracking echocardiography (2D-STE). 3D RV free wall longitudinal strain (3D-RV FWLS) and RV ejection fraction (RVEF) were assessed by 3D-STE.

RESULTS

TAPSE, S', RV FAC, 2D-RV FWLS, 3D-RV FWLS, and RVEF increased significantly from 1 to 6 months post-HT (P < 0.05). TAPSE, S', RV FAC and 2D-RV FWLS showed no significant changes from 6 to 12 months post-HT (P > 0.05), while 3D-RV FWLS and RVEF were still significantly increased: 3D-RV FWLS (17.9 ± 1.0% vs. 18.7 ± 1.4%, P < 0.001) and RVEF (45.9 ± 2.2% vs. 46.8 ± 2.0%, P = 0.025). By 12 months post-HT, TAPSE, S', RV FAC, 2D-RV FWLS, 3D-RV FWLS and RVEF were significantly lower than the healthy controls: TAPSE (15.1 ± 2.1 mm vs. 23.5 ± 3.0 mm, P < 0.001), s' (10.3 ± 1.9 cm/s vs. 12.9 ± 2.0 cm/s, P < 0.001), RV FAC (45.3 ± 1.8% vs. 49.2 ± 3.8%, P < 0.001), 2D-RV FWLS (19.9 ± 2.3% vs. 23.5 ± 3.8%, P < 0.001), 3D-RV FWLS (18.7 ± 1.4% vs. 22.4 ± 2.3%, P < 0.001) and RVEF (46.8 ± 2.0% vs. 49.9 ± 5.7%, P < 0.001).

CONCLUSION

RV systolic function improved significantly over time in clinically well adult HT patients even up to 12 months post-HT. By 12 months post-HT, the patient's RV systolic function remained lower than the control. 3D-STE may be more suitable to assess RV systolic function in HT patients.

Prognostic value of feature-tracking right ventricular longitudinal strain in heart transplant recipients

OBJECTIVES

The prognostic value of cardiac magnetic resonance feature tracking (CMR-FT)-derived right ventricular longitudinal strain (RVLS) post-heart transplantation has not been studied. This study aimed to evaluate the prognostic significance of CMR-FT-derived RVLS, in patients post- heart transplantation and to directly compare its value with that of conventional RV ejection fraction (RVEF).

METHODS

In a cohort of consecutive heart transplantation recipients who underwent CMR for surveillance, RVLS from the free wall was measured by CMR-FT. The composite endpoint was all-cause death or major adverse cardiac events. The Cox regression model was used to examine the independent association between RVLS and the endpoint.

RESULTS

A total of 96 heart transplantation recipients were retrospectively included. Over a median follow-up of 41 months, 20 recipients reached the composite endpoint. The multivariate Cox analysis showed that the model with RVLS (hazard ratio [HR]:1.334; 95% confidence interval [CI]:1.148 to 1.549; p < 0.001; Akaike information criterion [AIC] = 140, C-index = 0.831) was better in predicting adverse events than the model with RVEF (HR:0.928; 95% CI: 0.868 to 0.993; p = 0.030; AIC = 149, C-index = 0.751). Furthermore, receiver operating characteristic curves revealed that the accuracy for predicting adverse events was greater for RVLS than RVEF (area under the curve: 0.85 vs 0.76, p = 0.03).

CONCLUSIONS

CMR-FT-derived RVLS is an independent predictor of adverse events in post-heart transplantation, and its predictive value was better than RVEF. Therefore, our study highlighted the importance of evaluating RVLS for risk stratification after heart transplantation.

KEY POINTS

• CMR-RVLS is an independent predictor of adverse events post-heart transplantation and provides greater predictive value. • CMR-RVLS may help clinicians to risk stratification in heart transplantation recipients.

Echocardiography strain: why is it used more and more?

In the last decade, speckle tracking echocardiography (STE) has acquired a fundamental role in the evaluation of the systolic function of the left ventricle, with several advantages over the Doppler method, including angle independence, greater reproducibility, and rapidity of image acquisition. Speckle tracking finds application in various pathologies, ranging from ischaemic heart disease, to cardiomyopathies, to heart failure, both with reduced and preserved ejection fraction (EF), in which the EF is not a reliable prognostic marker and the estimate of left ventricular function by means of ‘strain’ is of crucial utility. In addition, the strain of the left atrium finds application in many clinical contexts as an early index of diastolic dysfunction and left ventricular filling pressures. Finally, the strain of the right ventricle is of particular prognostic importance in the evaluation of heart failure, particularly in its advanced form, becoming an indispensable index in the evaluation of patients who are candidates for advanced therapeutic strategies. This document aims to describe the various fields of clinical application of STE, with particular emphasis on its diagnostic and prognostic role, so much that it is now integrated into the algorithms for managing multiple pathologies in daily clinical practice.

Evaluation of the myocardial deformation in the diagnosis of rejection after heart transplantation

Introduction

Heart transplantation represents main therapy for end-stage heart failure. However, survival after transplantation is limited by development of graft rejection. Endomyocardial biopsy, an invasive and expensive procedure, is gold standard technique for diagnosis of rejection. Most of biopsy complications are observed using echocardiography. Novel echocardiographic techniques, such as myocardial strain and three-dimensional reconstruction, can be useful in heart transplant patients.

Purpose

To evaluate ventricular strain in heart transplant patients and association with rejection, cellular or humoral, as well as two- and three-dimensional echocardiographic parameters.

Methods

Cohort of patients from heart transplant program taken to echocardiography after endomyocardial biopsy, from December 2017 to January 2020. Ventricular strain and three-dimensional left ventricle parameters were studied. Rejection results were retrieved from medical record. Qualitative variables were expressed by absolute frequency and percentages, while continuous variables by means and standard deviations. Association between rejection and variables of interest was measured by odds ratio and confidence interval of 95%, with p-value < 0.05.

Results

123 post-endomyocardial biopsy echocardiographic exams were performed in 54 patients. Eighteen exams were excluded, lasting 105 exams to be evaluated for conventional and advanced echocardiographic parameters. Male patients were 60.4%. Prevalence of cellular rejection was 8.6%, humoral rejection 12.4%, and rejection of any type 20%. There was no association between right ventricular strain and rejection, whether cellular (p = 0.118 and p = 0.227 for septum and free wall, respectively), humoral (p = 0.845 and p = 0.283, respectively), or of any type (0.504 and 0.446). There was no correlation between rejection and left ventricle global longitudinal strain, three-dimensional ejection fraction or desynchrony index. Conventional parameters associated to rejection were left ventricle posterior wall thickness [OR 1.660 (1.163; 2.370), p = 0.005] and left ventricle mass index [OR 1.027 (1.011; 1.139), p = 0.001]. Left ventricle posterior wall thickness remained significant after analysis of cellular and humoral rejection separately [OR 1.825 (1.097; 3.036), p = 0.021 and OR 1.650 (1.028; 2.648), p = 0.038, respectively].

Conclusions

There was no association between ventricular strain, three-dimensional left ventricular ejection fraction and the desynchrony index and rejection, cellular or humoral. Evidence of association of graft rejection with left ventricle posterior wall thickness and left ventricle mass index was observed.

Rationale and Protocol of the Multimodality Evaluation of Antibody-Mediated Injury in Heart Transplantation (LEONE-HT) Observational Cross-Sectional Study

Introduction: Heart transplant (HT) survival has barely improved in the last decades, which is unsatisfactory for many HT recipients. The development of anti-human leukocyte antigen (anti-HLA) antibodies in HT patients is associated with a cardiac allograft dysfunction. The mechanisms leading to this damage are unclear. The Multimodality Evaluation Of Antibody-Mediated Injury In Heart Transplantation (LEONE-HT) study aimed to thoroughly describe the damage inflicted on the myocardium by anti-HLA antibodies. Methods and analysis: The LEONE-HT study is a cohort study with a cross-sectional approach in which HT patients with positive anti-HLA antibodies are compared with coetaneous HT patients with negative anti-HLA antibodies. All patients will undergo a state-of-the-art multimodal assessment, including imaging techniques, coronary anatomy and physiology evaluations and histological and immunological analyses. The individual and combined primary outcomes of structural graft injuries and longitudinal secondary outcomes are to be compared between the exposed and non-exposed groups with univariate and multivariable descriptive analyses. Ethics and dissemination: The LEONE-HT study is carried out in accordance with the principles set out in the Declaration of Helsinki and the International Conference on Harmonization guidelines for good clinical practice and following national laws and regulations. The study design, objectives and participant centers have been communicated to clinicaltrials.gov (NCT05184426). The LEONE-HT study counts on the support of patient associations to disseminate the objectives and results of the research. This study was funded by the Spanish Ministry of Science and Innovation and the Spanish Society of Cardiology.

The Assessment of Myocardial Longitudinal Strain in a Paediatric Spanish Population Using a New Software Analysis

BACKGROUND

Two-dimensional speckle-tracking echocardiography (2DSTE) has been present for years. However, it is underutilized due to the expertise and time requirements for its analysis. Our aims were to provide strain values in a paediatric Spanish population and to assess the feasibility and reproducibility of a new strain software analysis in our environment.

METHODS

A cross-sectional study of 156 healthy children aged 6 to 17 years. Longitudinal strain (LS) analysis of the left ventricle, right ventricle, and left atrium was performed. Feasibility and reproducibility were assessed. The associations of clinical and echocardiographic variables with strain values were investigated by multivariate analysis.

RESULTS

Mean age was 11 ± 3 years (50% female). Feasibility of LS measurement ranged from 94.2% for left ventricle global LS (LVGLS) to 98.1% for other chamber strain parameters. Strain values were 26.7 ± 2.3% for LVGLS; 30.5 ± 4.4% and 26.9 ± 4% for right ventricle free wall LS (RVFWLS) and four chambers view LS (RV4CLS) respectively; and 57.8 ± 10.5%, 44.9 ± 9.5%, and 12.9 ± 5.5% for left atrium LS reservoir phase (LALSr), conduct phase (LALScd) and contraction phase (LALSct), also respectively. Body surface area (BSA) and age presented a negative correlation with strain values. Higher values were found in females than in males, except for LALScd. Excellent intra- and inter-observer reproducibility were found for right and left ventricular strain measurement, with intraclass correlation coefficients (ICC) ranging from 0.88 to 0.98, respectively. In conclusion, we described strain values in a healthy Spanish paediatric population. LS assessment by this new strain analysis software by semi-automatic manner was highly feasible and reproducible.

Novel left and right ventricular strain analysis to detect subclinical myocardial dysfunction in cardiac allograft rejection

Early detection of acute cellular rejection (ACR) by echocardiography shows potential clinical benefit as ACR remains a significant contributor to morbidity and mortality. This retrospective, longitudinal study sought to investigate the use of novel left (LV) and right ventricular (RV) strain analysis to detect biopsy proven ACR. 46 heart transplant patients (Mean age 46 ± 16 years) with biopsy proven ACR were grouped according to biopsy results: 1R-ACR (n = 36) and 2R-ACR (n = 10). Serial two-dimensional transthoracic echocardiography with strain analysis was performed. Echocardiographic parameters were serially measured: (1) rejection free period (0R-ACR); (2) pre-ACR period (pre-ACR); (3) during ACR (1R-ACR or 2R-ACR) and (4) post-ACR (Post-ACR). Significant reductions for LV Global Longitudinal Strain (LV GLS) and LV Early diastolic Strain rate (LV ESr) were observed between 0R-ACR and pre-ACR (LV GLS 0R-ACR: 17.3% vs Pre-2R ACR: 15.4%, p = 0.016; LV ESr 0R-ACR: 1.00/s vs Pre-2R ACR: 0.74/s, p = 0.007) with LV ESr demonstrating the highest sensitivity (92%) and specificity (81%) to predict ACR. LV ESr and the E/LV ESr ratio were significantly different (p = 0.0001; p = 0.016) during pre-1R ACR period vs 0R whereas LV GLS showed no significant differences for grade 1R-ACR. Diastolic mechanical dispersion showed significant increases in dispersion during ACR for the 1R-ACR group and early significant increases pre-2R ACR. Systolic and diastolic RV strain parameters showed a similar trend for both ACR groups. Systolic and diastolic strain parameters can detect myocardial dysfunction before biopsy confirmed 2R-ACR. Early diastolic strain rate parameters are most sensitive detecting subclinical myocardial dysfunction pre-ACR. Novel strain parameters are potentially useful clinical tool for prediction of early ACR in heart transplant.

Acute Cellular Rejection in Heart Transplant Patients: Insights of Global Longitudinal Strain, Myocardial Work, and an Exclusive Group of Chagas Disease

Background

Echocardiographic markers associated with asymptomatic acute cellular rejection (ACR) in patients with orthotopic heart transplant (HT) are still under investigation. The aim of our study was to determine clinical and myocardial strain imaging (MSI) variables evaluated by echocardiography associated with ACR in the first year of HT. A separate analysis was performed to compare variables during the first 6 months of HT, when ACR has a prevalence in 60% of patients. Another analysis evaluated an exclusive population with Chagas disease as the cause of HT.

Methods

We prospectively studied 67 patients with less than 1 year of HT, 36 patients without ACR (41% men, age 49 ± 12 years, 52% Chagas disease as the cause of heart failure), and 31 patients with ACR (59% men, age 55 ± 8 years, 74% Chagas disease as the cause of heart failure). Conventional echocardiographic measurements and MSI by global longitudinal strain (GLS) from the left ventricle (LV) and right ventricle free wall (RV-FWLS) and myocardial work (MW) from the left ventricle were obtained by experienced echocardiologists. Clinical variables, such as the presence of diabetes, hypertension, and immunosuppressant drugs, were compared between groups.

Results

HT patients with ACR were older and used more cyclosporine for immunosuppression. The positive ACR group had an increased relative wall thickness and LV mass index and similar LVGLS and RV-FWLS compared to the negative ACR group. Nevertheless, MW analysis observed increased global work efficiency (GWE) in positive ACR. Multivariate analysis identified older age, cyclosporine use, LV mass index, and GWE as independent predictors for detecting rejection. A separate analysis was performed for patients with less than 6 months of HT. Similar MSI was observed in both groups, with a trend for increased GWE in patients with ACR and significantly increased LV mass index in the ACR group. An exclusive group of Chagas patients as the primary cause of HT was analyzed, and similar MSI results for LVGLS, RV-FWLS, and MW were observed for both ACR and the no rejection groups. Additionally, the survival rates at 2 years were similar between the Chagas disease groups.

Conclusion

LVGLS and RV-FWLS were similar between patients with or without ACR in the first year after HT. Conversely, GWE, a derivative of LVGLS, and LV mass index were increased in positive ACR and could be markers for rejection. Increased LV mass index was also found in a subgroup analysis of patients less than 6 months after HT; however, MSI was similar regardless of ACR. For chagasic patients, rejection in the first year did not increase mortality at the 2-year follow-up, and MSI parameters were similar between patients with or without ACR. In a multivariate analysis to predict ACR, the independent parameters in this study were older age, cyclosporine use, LV mass index, and GWE.

Assessment of Acute Rejection by Global Longitudinal Strain and Cardiac Biomarkers in Heart-Transplanted Patients

Aims

The aim of this study was to evaluate left ventricular global longitudinal strain (LVGLS), N-terminal pro brain natriuretic peptide (Nt-ProBNP), and Troponin T as non-invasive markers for acute cellular rejection (ACR) diagnosis and severity assessment after heart transplantation (HTx).

Methods

We retrospectively included all HTx patients transplanted from 2013 to 2019. At each visit, the patients were subjected to endomyocardial biopsy (EMB), measurement of Nt-ProBNP and Troponin T, and protocoled echocardiography with assessment of LVGLS. Sudden drop in graft function (SDGF) was defined as a drop in LVGLS ≥-2% in combination with either an increase in Troponin T ≥20% or Nt-ProBNP ≥30% compared with levels at the latest visit.

Results

We included 1,436 EMBs from 83 HTx patients. The biopsies were grouped as 0R (n = 857), 1R (n = 538), and ≥2R (n = 41). LVGLS was lower and Troponin T and Nt-ProBNP higher in the 2R group than in the 0R and 1R groups (LVGLS: -12.9 ± 3.8% versus -16.9 ± 3.1% and -16.1 ± 3.3%; Troponin T: 79 [33;230] ng/l versus 27 [13;77] ng/l and 27 [14;68] ng/l; Nt-ProBNP: 4,174 [1,095;9,510] ng/l versus 734 [309;2,210] ng/l and 725 [305;2,082], all p < 0.01). A SDGF was seen at 45 visits of which 19 had ≥2R ACR. EMBs showed ACR in 20 cases without SDGF. Finally, neither was SDGF seen nor did the EMB show rejection in 1,136 cases. Thus, the sensitivity of SDGF for ≥2R ACR detection was 49% (32–65) and specificity 98% (97–99). The positive predictive value (PPV) was 42% (31–55) and the negative predictive value (NPV) 98% (98–99). The diagnostic value improved in a sub-analysis excluding EMBs within 3 months after HTx, clinically interpreted false positive ≥2R ACR cases, and cases with ≥2R ACR who recently (<2 weeks) were treated with intravenous methylprednisolone due to ≥2R ACR (sensitivity 75% (48–93), specificity 97% (96–98), NPV 99% (99–100), and PPV 39% (27–52).

Conclusions

Patients with ≥2R ACR have lower LVGLS and higher Troponin T and Nt-ProBNP than patients without 2R rejection. A non-invasive model combining changes in LVGLS and Troponin T or Nt-ProBNP showed excellent negative predictive value and moderate sensitivity and may be used as a gatekeeper to invasive biopsies after HTx.

Changes in circumferential strain can differentiate pediatric heart transplant recipients with and without graft rejection

BACKGROUND

Routine surveillance protocols rely heavily on endomyocardial biopsy (EMB) for detection of rejection in pediatric heart transplant recipients. More sensitive echocardiographic tools to assess rejection may help limit the number of EMBs. This study compared changes in left ventricular (LV) strain in patients who had rejection versus those who did not.

METHODS

A single center retrospective review was conducted between 2013 and 2020. Patients were categorized based on rejection history. Echocardiograms were evaluated at the time of 2 consecutive EMBs; in the rejection group, the second echocardiogram was collected at the time of a rejection episode. Conventional measures of LV function and speckle-tracking echocardiography-derived longitudinal (LS) and circumferential strain (CS) were measured.

RESULTS

17 patients were in the non-rejection group and 17 were in the rejection group (30 total rejection episodes). The rejection group was older at the time of transplant (12.5 vs. 1.3 years, p = .01). A decline in CS was seen in the rejection group at the second echocardiogram [-18.5 (IQR -21.5, -14.6) to -15.7 (IQR -19.8, -13.2)] while CS improved in the non-rejection group [-20.8 (IQR -23.9, -17.8) to -23.9 (IQR -24.9, -20.1)]. This difference in change reached significance (p = .02). A similar pattern was seen in LS that neared significance (p = .06). There was no significant difference in ejection fraction change (p = .24).

CONCLUSIONS

Patients in the non-rejection group displayed improvement in CS between echocardiograms while patients in the rejection group showed subsequent decline. Worsening of LV CS may help identify acute rejection in the early post-transplant period.

Prognostic Value of Left and right ventricular deformation strain analysis on Acute Cellular rejection in Heart Transplant recipients: A 6-year outcome study

PURPOSE

Two-dimensional (2D) strain analysis is a sensitive method for detecting myocardial dysfunction in acute cellular rejection (ACR) from post-transplant complications. This study aims to evaluate the utility of novel left (LV) and right ventricular (RV) strain parameters for prognostic risk stratification associated with ACR burden at 1-year post transplantation.

METHODS

128 Heart transplant patients, assessed between 2012 and 2018, underwent transthoracic echocardiography and endomyocardial biopsy. 2D strain analysis was performed and history of rejection burden was assessed and grouped according to ACR burden at 1-year post transplantation. The primary endpoint was all-cause mortality at 6-years follow up.

RESULTS

21 patients met primary the endpoint. Multivariate analysis of 6-year all-cause mortality showed LV global longitudinal strain (LV GLS) (Hazard Ratio [HR] = 1.21, CI = 1.06-1.49), LV early diastolic strain rate (LV ESr) (HR = 1.31, CI = 1.12-1.54), RV GLS (HR = 1.12, CI = 1.02-1.25) and RV ESr (HR = 1.26, CI = 1.12-1.47) were significant predictors of outcome. Univariate analysis also showed LV GLS, LV ESr, RV GLS and RV ESr were significant predictors of outcome. Optimal cut-off for predicting 6-year mortality for LV GLS by receive operator characteristic was 15.5% (sensitivity: 92%, specificity: 79%). Significant reductions (p < 0.05) in LV GLS, RV GLS and LV and RV ESr between rejection groups were seen.

CONCLUSIONS

Non-invasive LV and RV strain parameters are predictors of mortality in post-transplant patient with ACR. LV GLS and LV ESr are superior to other strain and conventional echo parameters.

The Role of Echocardiography in the Management of Heart Transplant Recipients

Transthoracic echocardiography is the primary non-invasive modality for the investigation of heart transplant recipients. It is a versatile tool that provides comprehensive information on cardiac structure and function. Echocardiography is also helpful in diagnosing primary graft dysfunction and evaluating the effectiveness of therapeutic approaches for this condition. In acute rejection, echocardiography is useful with suspected cellular or antibody-mediated rejection, with findings confirmed and quantified by endomyocardial biopsy. For identifying chronic rejection, ultrasound has a more significant role and, in some specific patients (e.g., patients with renal failure), it may offer a role comparable to coronary angiography to identify cardiac allograft vasculopathy. This review highlights the usefulness of echocardiography in evaluating normal graft function and its role in the management of heart transplant recipients.

Speckle-tracking-based global longitudinal and circumferential strain detect early signs of antibody-mediated rejection in heart transplant patients

AIMS

Acute rejection is an important cause of mortality after heart transplant (HTx), but symptoms develop only when myocardial damage is already extensive. We sought to investigate if echocardiographic parameters can detect and predict an acute cellular rejection (ACR) or antibody-mediated rejection (AMR) episode in HTx patients.

METHODS AND RESULTS

Data of 403 consecutive HTx recipients between 2003 and 2020 from our centre were reviewed. Patients with severe ACR (n = 10) and AMR (n = 7) were identified. Each HTx patient presenting with rejection was matched to a control HTx patient. Echocardiographic variables from the moment of rejection and 3, 6, and 12 months before were analysed and compared among groups. At acute rejection episode, patients with rejection had lower values of global longitudinal strain (GLS), global circumferential strain (GCS), and left ventricular ejection fraction (LVEF) compared to controls. HTx patients with AMR showed a progressive decline of GLS and GCS in the months preceding acute rejection, while controls and ACR patients had stable strain values except for the moment of rejection. In our cohort, a GLS cut-off lower than 15.5% and a GCS cut-off lower than 15.2% could distinguish with a sensitivity and specificity of 100.0% AMR from controls 3 months before rejection. LVEF and other conventional echo parameters could not differentiate among groups.

CONCLUSION

GLS and GCS show a progressive decrease months before AMR becomes clinically apparent. Our data suggest that global strain assessment by echocardiography allows an early detection of a developing AMR, which could improve the clinical management of HTx patients.

Insight into Noninvasive Radiological Modalities to Detect Heart Transplant Rejection

Purpose  Patients with end-stage heart failure who remain symptomatic even with exemplary medical and device therapy are treated with heart transplantation. Multitudes of endeavor have been contrived during the last decennium in the field of noninvasive tests to rule out heart transplant rejection (HTR). In spite of having supportive literature, noninvasive imaging techniques lack acceptable documentation of clinical robustness, and endomyocardial biopsy (EMB) still remains the gold standard. The aim of this review is to shed light on the existing noninvasive radiological modalities to detect rejection among heart transplant recipients. Methods  A comprehensive search was conducted for this review article on the basis of literature available including scientific databases of PubMed, Embase, and Google Scholar, using keywords of "Heart transplantation," "Acute allograft rejection," "Arrhythmias," "Echocardiography," "Speckle tracking echocardiography," and "Cardiac magnetic resonance imaging" from inception until September 2020. Results  After preliminary screening of the databases, details regarding existent noninvasive radiological modalities to detect HTR were gathered and compiled in this review article. Currently, deformation imaging using speckle tracking and T2 time using cardiac magnetic resonance imaging can serve as screening tools based on which further invasive investigations can be planned. Standardization of blood-based and imaging modalities as screening and possible diagnostic tools for rejection would have obvious clinical and financial benefits in the care of growing number of post heart transplant recipients in our country. Conclusion  Diagnosis of allograft rejection in heart transplant recipients through noninvasive techniques is demanding. To unravel the potential of noninvasive radiological modalities that can serve as a standard-of-care test, a prospective multicentric study randomizing noninvasive modality as first strategy versus current EMB-based gold standard of care is the need of the hour.

Global longitudinal strain in heart transplantation recipients using different vendors: reliability and validity in a tertiary hospital in Colombia

Global Longitudinal Strain (GLS) is a useful tool to follow-up heart transplant (HT) recipients. Important inter-vendor variability of GLS measurements has been reported in healthy subjects and different conditions, but there is still limited evidence among HT patients. We assessed the reliability and validity of GLS using two vendors (General Electric and Philips) in a group of consecutive and stable adult HT recipients. Patients underwent two concurrent GLS analyses during their echocardiographic follow-up. We evaluated GLS inter-vendor reliability using Bland-Altman's limits of agreement (LOA) plots, computing its coverage probability (CP) and the intraclass correlation coefficient (ICC). Validity was assessed though receiver operating characteristics (ROC) curves, predictive values, sensitivity and specificity of GLS for each vendor to detect a normal left ventricle function. 78 pairs of GLS studies in 53 stable HT patients were analyzed. We observed a modest inter-vendor reliability with a broad LOA (less than 50% of values falling out our CP of 2% and an ICC of 0.49). ROC analyses (areas under the curve of 0.824 Vs. 0.631, p < 0.05) and diagnosis test indices (Sensitivity of 0.73 Vs. 0.64; and Specificity of 0.79 Vs. 0.50) favored GE over Philips. Inter-vendor variability for GLS analysis exceeded clinically acceptable limits in HT recipients. GLS from GE software seemed to show higher validity as compared to Philips'. The present study provides evidence to consider caution for the interpretation of GLS for clinical management in the follow-up of HT patients, especially when GLS is measured by different vendors.

Integration of imaging and circulating biomarkers in heart failure: a consensus document by the Biomarkers and Imaging Study Groups of the Heart Failure Association of the European Society of Cardiology

Circulating biomarkers and imaging techniques provide independent and complementary information to guide management of heart failure (HF). This consensus document by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) presents current evidence-based indications relevant to integration of imaging techniques and biomarkers in HF. The document first focuses on application of circulating biomarkers together with imaging findings, in the broad domains of screening, diagnosis, risk stratification, guidance of treatment and monitoring, and then discusses specific challenging settings. In each section we crystallize clinically relevant recommendations and identify directions for future research. The target readership of this document includes cardiologists, internal medicine specialists and other clinicians dealing with HF patients.

Echocardiographic Longitudinal Strain Analysis in Heart Failure: Real Usefulness for Clinical Management Beyond Diagnostic Value and Prognostic Correlations? A Comprehensive Review

Heart failure (HF) is a highly prevalent clinical syndrome characterized by considerable phenotypic heterogeneity. The traditional classification based on left ventricular ejection fraction (LVEF) is widely accepted by the guidelines and represents the grounds for patient enrollment in clinical trials, even though it shows several limitations. Ejection fraction (EF) is affected by preload, afterload, and contractility, it being problematic to express LV function in several conditions, such as HF with preserved EF (HFpEF), valvular heart disease, and subclinical HF, and in athletes. Over the last two decades, developments in diagnostic techniques have provided useful tools to overcome EF limitations. Strain imaging analysis (particularly global longitudinal strain (GLS)) has emerged as a useful echocardiographic technique in patients with HF, as it is able to simultaneously supply information on both systolic and diastolic functions, depending on cardiac anatomy and physiology/pathophysiology. The use of GLS has proved helpful in terms of diagnostic performance and prognostic value in several HF studies. Universally accepted cutoff values and variability across vendors remain an area to be fully explored, hence limiting routine application of this technique in clinical practice. In the present review, the current role of GLS in the diagnosis and management of patients with HF will be discussed. We describe, by critical analysis of the pros and cons, various clinical settings in HF, and how the appropriate use and interpretation of GLS can provide important clues.

Basic and advanced echocardiography in advanced heart failure: an overview

Advanced chronic heart failure (ACHF) is the last phase in the evolution of heart failure and is characterized by high hospitalization and mortality rates and is refractory to medical therapy, therefore requiring more aggressive therapies, such as mechanical circulatory support or heart transplantation. Over the last years, the incidence of ACHF was continuously growing, together with the increase in population survival rates. Therefore, the early recognition of the transition to ACHF is of crucial importance in HF patients, which also helps in prognostication of such patients, since advanced therapeutic options are limited to selected patients and they also have some important risk implications. Echocardiography is the gold standard tool for the evaluation of patients with HF; moreover, the recent technological advances provided new structural and functional indices of the four cardiac chambers that showed to be comparable to advanced imaging or invasive hemodynamic parameters. This allows us to operate an accurate study of ACHF with first- and second-level echocardiographic techniques, which are now being integrated in daily clinical practice. The present review presents an overview of the currently available tools for the echocardiographic examination of patients with ACHF, with its advantages and limitations, based on the latest supporting evidences.

Impaired left atrial function in clinically well heart transplant patients

Left atrial (LA) enlargement is present in the majority of adult heart transplant (HT) recipients. We used speckle-tracking echocardiography to investigate whether LA phasic function in HT patients is altered and explored its relationship to HT-related clinical variables. This study evaluated LA function in 112 clinically well HT patients and 40 healthy controls. Clinical data included recipient age at HT, donor age, ischemia time, left ventricular function, and biochemical indicators. Atrial deformation and volume indices were measured with two-dimensional and three-dimensional speckle-tracking echocardiography, respectively. Components of phasic atrial function were calculated and correlations to clinical variables were explored. Compared with controls, HT patients had worse LA reservoir, conduit, and pump function. LA reservoir function of the bicaval group was better than the biatrial group, but differences did not persist after adjustment for potential confounders. Among patients with HT, those with lower LAS-peak had an older recipient age, larger LA volume, as well as worse left ventricular systolic function than those patients with higher LAS-peak. However, E/e', biochemical indicators and donor-related information were similar across the quartiles of LA function. In HT cohort, we observed impairment in all phases of LA function, and LA reservoir function was decreased independent of surgical technique. LAS-peak was associated with worse left ventricular systolic function, which suggested that LA function may play an important role in HT patients.

Imaging of Cardiac Transplantation: An Overview

Heart transplantation (HTx) remains the optimal treatment for selected patients with end-stage advanced heart failure. However, survival is limited early by acute rejection and long term by cardiac allograft vasculopathy (CAV). Even though the diagnosis of rejection is based on histology, cardiac imaging provides a pivotal role for early detection and severity assessment of these hazards. The present review focuses on the use and reliability of different invasive and non-invasive imaging modalities to detect and monitor CAV and rejection after HTx. Coronary angiography remains the corner stone in routine CAV surveillance. However, angiograms are invasive and underestimates the CAV severity especially in the early phase. Intravascular ultrasound and optical coherence tomography are invasive methods for intracoronary imaging that detects early CAV lesions not evident by angiograms. Non-invasive imaging can be divided into myocardial perfusion imaging, anatomical/structural imaging and myocardial functional imaging. The different non-invasive imaging modalities all provide clinical and prognostic information and may have a gatekeeper role for invasive monitoring. Acute rejection and CAV are still significant clinical problems after HTx. No imaging modality provides complete information on graft function, coronary anatomy and myocardial perfusion. However, a combination of invasive and non-invasive modalities at different stages following HTx should be considered for optimal personalized surveillance and risk stratification.

Detection of cardiac allograft vasculopathy by multi-layer left ventricular longitudinal strain in heart transplant recipients

Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse type of coronaropathy that develops in the transplanted human heart, representing a major cause of graft failure and mortality. Nowadays the gold standard for the diagnosis of CAV is coronary angiography (CA). Non-invasive CAV detection, especially in the early stages of the disease, is still challenging. Our study aimed to investigate the role of speckle tracking echocardiography (STE), in particular three-layer STE, in predicting CAV at early stages, and if other traditional echocardiographic, clinical or biochemical parameters could relate to CAV. The study population was composed of a total of 33 heart transplanted patients, divided accordingly to the presence or absence of CAV (12 CAV+ , 22 CAV-). All subjects underwent a complete transthoracic echocardiographic examination on the same day of the CA, and all conventional parameters of myocardial function were obtained, including strain values assessed by STE. Strain values were significantly reduced in presence of CAV, at each myocardial layer but in particular the endocardial-epicardial gradient (- 4.15 ± 1.6 vs - 1.7 ± 0.4% < .0001) that was also highly predictive of CAV (AUC at ROC curve 0.97). Among diastolic parameters, the E wave deceleration time (DT) and the mean E/e' ratio were strongly positively associated with CAV. In our population, left ventricular global longitudinal strain (GLS), layer-specific GLS and the endocardial-epicardial LS gradient, E wave DT and E/e' ratio were the best independent non-invasive predictors of CAV.

Usefulness of speckle tracking echocardiography and biomarkers for detecting acute cellular rejection after heart transplantation

BACKGROUND

Acute cellular rejection (ACR) is a major complication after heart transplantation. Endomyocardial biopsy (EMB) remains the gold standard for its diagnosis, but it has concerning complications. We evaluated the usefulness of speckle tracking echocardiography (STE) and biomarkers for detecting ACR after heart transplantation.

METHODS

We prospectively studied 60 transplant patients with normal left and right ventricular systolic function who underwent EMB for surveillance 6 months after transplantation. Sixty age- and sex-matched healthy individuals constituted the control group. Conventional echocardiographic parameters, left ventricular global longitudinal, radial and circumferential strain (LV-GLS, LV-GRS and LV-GCS, respectively), left ventricular systolic twist (LV-twist) and right ventricular free wall longitudinal strain (RV-FWLS) were analyzed just before the procedure. We also measured biomarkers at the same moment.

RESULTS

Among the 60 studied patients, 17 (28%) had severe ACR (grade ≥ 2R), and 43 (72%) had no significant ACR (grade 0 - 1R). The absolute values of LV-GLS, LV-twist and RV-FWLS were lower in transplant patients with ACR degree ≥ 2 R than in those without ACR (12.5% ± 2.9% vs 14.8% ± 2.3%, p=0.002; 13.9° ± 4.8° vs 17.1° ± 3.2°, p=0.048; 16.6% ± 2.9% vs 21.4%± 3.2%, p < 0.001; respectively), while no differences were observed between the LV-GRS or LV-GCS. All of these parameters were lower in the transplant group without ACR than in the nontransplant control group, except for the LV-twist. Cardiac troponin I levels were significantly higher in patients with significant ACR than in patients without significant ACR [0.19 ng/mL (0.09-1.31) vs 0.05 ng/mL (0.01-0.18), p=0.007]. The combination of troponin with LV-GLS, RV-FWLS and LV-Twist had an area under curve for the detection of ACR of 0.80 (0.68-0.92), 0.89 (0.81-0.93) and 0.79 (0.66-0.92), respectively.

CONCLUSION

Heart transplant patients have altered left ventricular dynamics compared with control individuals. The combination of troponin with strain parameters had higher accuracy for the detection of ACR than the isolated variables and this association might select patients with a higher risk for ACR who will benefit from an EMB procedure in the first year after heart transplantation.

Predictive Parameters of Decreased Left Ventricular Global Longitudinal Strain at 1 Month After Pediatric Heart Transplantation

Previous reports indicate that the decreased left ventricular global longitudinal strain (LVGLS) seen in the early postoperative period of pediatric heart transplant patients generally recovers over the course of 1-2 years. In this study, we investigate the predictive capacity of preoperative parameters on the LVGLS decline seen at 1 month post transplant. Forty-six transplant subjects with 2D echocardiographic images sufficient for speckle tracking echocardiography were enrolled. We excluded patients diagnosed with cardiac allograft vasculopathy or with an episode of rejection 1 month before or after their echocardiographic examinations. The mean LVGLS was significantly reduced at 1 month when compared to 1 year following transplant (- 15.5% vs. - 19.4%, respectively, p < 0.001). The predictors of LVGLS that decline at 1 month were the LV mass z-score [odds ratio (OR) 1.452; 95% confidence interval (CI) 1.007-2.095, p = 0.046], recipient age (OR 1.124; 95% CI 1.015-1.245, p = 0.025), and donor age (OR 1.081; 95% CI 1.028-1.136, p = 0.002) in the univariate logistic regression analyses. Although multivariate analysis yielded no significant predictors, higher LV mass z-scores showed a trend associated with the decline of LVGLS (p = 0.087). The donor/recipient weight ratio was associated with the LV mass z-score (R² = 0.412, p < 0.001).

C-Reactive protein level and left ventricular mass are associated with acute cellular rejection after heart transplant

OBJECTIVES

Acute cellular rejection (ACR) remains a major complication of heart transplant (HT). The gold standard for its diagnosis is endomyocardial biopsy (EMB), whereas the role of non-invasive biomarkers for detecting ACR is unclear. This study aimed to identify non-invasive biomarkers for the diagnosis of ACR in patients undergoing HT and presenting with normal left ventricular function.

METHODS

We evaluated patients who underwent HT at a single center between January 2010 and June 2019. Patients were enrolled after HT, and those with left ventricular (LV) systolic dysfunction before EMB were excluded. We included only the results of the first EMB performed at least 30 days after HT (median, 90 days). Troponin, B-type natriuretic peptide (BNP), and C-reactive protein (CRP) levels were measured and echocardiography was performed up to 7 days before EMB. ACR was defined as International Society for Heart and Lung Transplantation grade 2R or 3R on EMB. We performed logistic regression analysis to identify the non-invasive predictors of ACR (2R or 3R) and evaluated the accuracy of each using area under the receiver operator characteristic curve analysis.

RESULTS

We analyzed 72 patients after HT (51.31±13.63 years; 25 [34.7%] women); of them, 9 (12.5%) developed ACR. Based on multivariate logistic regression analysis, we performed forward stepwise selection (entry criteria, p<0.05). The only independent predictors that remained in the model were CRP level and LV mass index. The optimal cut-off point for CRP level was ≥15.9 mg/L (odds ratio [OR], 11.7; p=0.007) and that for LV mass index was ≥111 g/m2 (OR, 13.6; p=0.003). The area under the receiver operating characteristic curve derived from this model was 0.87 (95% confidence interval [CI], 0.75-0.99), with sensitivity of 85.7% (95% CI, 42.1%-99.6%), specificity of 78.4% (95% CI, 64.7%-88.7%), positive predictive value of 35.3% (95% CI, 14.3%-61.7%), and negative predictive value of 97.6% (95% CI, 87.1%-99.9%).

CONCLUSIONS

Among patients undergoing HT, CRP level and LV mass were directly associated with ACR, but troponin and BNP levels were not.

Ventricular systolic dysfunction with and without altered myocardial contractility: Clinical value of echocardiography for diagnosis and therapeutic decision-making

The inability of one of the two or both ventricles to contract normally and expel sufficient blood to meet the functional demands of the body results from a complex interplay between intrinsic abnormalities and extracardiac factors that limit ventricular pump function and is a major cause for heart failure (HF). Even if impaired myocardial contractile function was the primary cause for ventricular dysfunction, with the progression of systolic dysfunction, additionally developed diastolic dysfunction can also contribute to the severity of HF. Although at the first sight, the diagnosis of systolic HF appears quite easy because it is usually defined by reduction of the ejection fraction (EF), in reality this issue is far more complex because ventricular pumping performance depends not only on myocardial contractility, but also largely on loading conditions (preload and afterload), being also influenced by valvular function, ventricular interdependence, pericardial constraint, synchrony of ventricular contrac-tion and heart rhythm. Conventional echocardiography (ECHO) combined with new imaging techniques such as tissue Doppler and tissue tracking can detect early subclinical alteration of ventricular systolic function. However, no single ECHO parameter reveals alone the whole picture of systolic dysfunction. Multiparametric ECHO evaluation and the use of integrative approaches using ECHO-parameter combinations which include also the ventricular loading conditions appeared particularly useful especially for differentiation between primary (myocardial damage-induced) and secondary (hemodynamic overload-induced) systolic dysfunction. This review summarizes the available evidence on the usefulness and limitations of comprehensive evaluation of LV and RV systolic function by using all the currently available ECHO techniques.

Assessment of biventricular function by three-dimensional speckle-tracking echocardiography in clinically well pediatric heart transplantation patients

BACKGROUND

The biventricular function plays an important role in the prognosis of pediatric heart transplantation (HTx) patients. Therefore, in this study, we aimed to evaluate the biventricular function of pediatric HTx patients by three-dimensional (3D) speckle-tracking echocardiography (3D-STE).

METHODS

We enrolled 30 clinically well pediatric HTx patients and 30 healthy controls with a similar distribution of sex and age to the HTx. All participants underwent comprehensive two-dimensional (2D) and 3D echocardiography. Left ventricular (LV) global longitudinal strain (GLS), global circumferential strain (GCS), left and right ventricular ejection fraction (LVEF and RVEF, respectively), and right ventricular free wall longitudinal strain (RV FWLS) were acquired by 3D-STE. Moreover, the correlations between strains and clinical data were explored.

RESULTS

Compared with controls, LV GLS was decreased in pediatric HTx patients (P < .05), while LV GCS and LVEF showed no difference. LV GLS showed a weak correlation with cold ischemic time in HTx group (r = 0.396, P < .05). Meanwhile, RVEF and RV FWLS were significantly lower in the HTx group (P < .05). In the HTx group, RV FWLS showed a weak correlation with the preoperative mean pulmonary artery pressure (r = 0.420, P < .05) and postoperative pulmonary artery systolic pressure (r = 0.465, P < .05).

CONCLUSION

The 3D-biventricular mechanical functions were decreased in clinically well pediatric HTx patients. The provided characteristics and appropriate normal values of biventricular mechanical functions can be the basis in subsequent studies in the pediatric HTx patients.

Non-invasive cardiac allograft rejection surveillance: reliability and clinical value for prevention of heart failure

Allograft rejection-related acute and chronic heart failure (HF) is a major cause of death in heart transplant recipients. Given the deleterious impact of late recognized acute rejection (AR) or non-recognized asymptomatic antibody-mediated rejection on short- and long-term allograft function improvement of AR surveillance and optimization of action strategies for confirmed AR can prevent AR-related allograft failure and delay the development of cardiac allograft vasculopathy, which is the major cause for HF after the first posttransplant year. Routine non-invasive monitoring of cardiac function can improve both detection and functional severity grading of AR. It can also be helpful in guiding the anti-AR therapy and timing of routine surveillance endomyocardial biopsies (EMBs). The combined use of EMBs with non-invasive technologies and methods, which allow detection of subclinical alterations in myocardial function (e.g., tissue Doppler imaging and speckle-tracking echocardiography), reveal alloimmune activation (e.g., screening of complement-activating donor-specific antibodies and circulating donor-derived cell-free DNA) and help in predicting the imminent risk of immune-mediated injury (e.g., gene expression profiling, screening of non-HLA antibodies, and circulating donor-derived cell-free DNA), can ensure the best possible surveillance and management of AR. This article gives an overview of the current knowledge about the reliability and clinical value of non-invasive cardiac allograft AR surveillance. Particular attention is focused on the potential usefulness of non-invasive tools and techniques for detection and functional grading of early and late ARs in asymptomatic patients. Overall, the review aimed to provide a theoretical and practical basis for those engaged in this particularly demanding up-to-date topic.