A case report of transthyretin amyloidosis following cardiac transplantation: thick ventricles that look alike

Background

Transthyretin (ATTR) amyloidosis is more prevalent than initially thought. As much as 13% of patients hospitalized with heart failure with preserved ejection fraction may have ATTR-cardiomyopathy (CM). Conversely, heart transplant patients may manifest left ventricular hypertrophy or diastolic dysfunction, especially late after transplantation.

Case summary

We present a case of a 82-year-old male heart transplant patient, 31 years following orthotopic heart transplantation. While he was satisfied with his exercise capacity as an octogenarian, several years before, he required pacemaker implantation due to third-degree atrioventricular block, had bilateral carpal tunnel syndrome treated with carpal tunnel release surgery, and experienced idiopathic sudden deafness. Based on increasing left ventricular wall thickness during routine follow-up, a diagnosis of ATTR amyloidosis was suspected. Ultimately, the diagnosis was confirmed non-invasively with a specific scintigraphic exam, while an additional physicochemical stain on an endomyocardial biopsy taken several years before provided pathological proof. We initiated tafamidis, yet stopped this treatment after 1 month because of gastrointestinal intolerance. Ultimately, our patient died 2 years later due to heart failure.

Discussion

Our case shows the long delay between the onset of ATTR deposition, the presence of clinical signs, and the final diagnosis. Echocardiographic findings suggestive for ATTR-CM include left ventricular hypertrophy and diastolic dysfunction, which are both common in heart transplant patients. Yet, ATTR-CM should be considered in the differential diagnosis, especially late after transplantation, in this closely monitored population.

Myocardial Work by Speckle-Tracking Echocardiography in Heart Transplant Recipients: Association Between Global Work Efficiency and Coronary Allograft Vasculopathy

Coronary allograft vasculopathy (CAV) is a leading cause of morbidity and mortality after heart transplantation. CAV is often diagnosed in later stages or during routine screening in asymptomatic subjects. Myocardial work (MW), calculated using left ventricular global longitudinal strain (LV-GLS) and systemic blood pressure, may be associated with the presence of CAV and outperform conventional echocardiographic parameters. In this retrospective observational study, heart transplant recipients who underwent regular follow-up at our institution between May 2022 and September 2023 were enrolled. All included patients underwent speckle-tracking echocardiography, including MW indexes. CAV was classified according to invasive coronary angiography or computed tomography performed within 12 months of index echocardiography. We collected all available clinical and echocardiographic parameters and evaluated the potential association with CAV. CAV was detected in 29 of 93 patients (31%) (CAV+). Of the MW indexes, the mean global work efficiency (GWE) was 90 ± 6% and was significantly lower in CAV+ than CAV- subjects (86 ± 7% vs 91 ± 4%, p <0.001). GWE (OR 0.86, CI 0.77 to 0.94, p = 0.002), E/e' ratio (OR 1.27, CI 1.08 to 1.52, p = 0.006), and left ventricular ejection fraction (OR 0.90; CI 0.81 to 0.98, p = 0.017) were independently associated with the presence of CAV. GWE (GWE vs LV-GLS, delta area under the curve 0.154, p = 0.047) and the proposed model (GWE+E/e' vs LV-GLS, delta area under the curve 0.198, p = 0.004) were significantly superior in stratifying the incremental risk for CAV compared with LV-GLS. In conclusion, GWE was observed to be independently associated with the presence of CAV. MW could represent a novel noninvasive screening method for CAV in heart transplant recipients. Larger and prospective studies are needed to confirm this hypothesis.

Temporal changes in CT-derived fractional flow reserve in patients after heart transplantation

BACKGROUND

Adding functional information by CT-derived fractional flow reserve (FFRct) to coronary CT angiography (CCTA) and assessing its temporal change may provide insight into the natural history and physiopathology of cardiac allograft vasculopathy (CAV) in heart transplantation (HTx) patients. We assessed FFRct changes as well as CAV progression over a 2-year period in HTx patients undergoing serial CT imaging.

METHODS

HTx patients from Erasmus MC and Mount Sinai Hospital, who had consecutive CCTAs 2 years apart were evaluated. FFRct analysis was performed for both scans. FFRct values at the most distal point in the left anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA) were measured after precisely matching the anatomical locations in both analyses. Also, the number of anatomical coronary stenoses of > 30% was scored.

RESULTS

In total, 106 patients (median age 57 [interquartile range 47-67] years, 67% male) at 9 [6-13] years after HTx at the time of the baseline CCTA were included. Median distal FFRct values significantly decreased from baseline to follow-up for the LAD from 0.85 [0.79-0.90] to 0.84 [0.76-0.90] (p = 0.001), LCX from 0.92 [0.88-0.96] to 0.91 [0.85-0.95] (p = 0.009), and RCA from 0.92 [0.86-0.95] to 0.90 [0.86-0.94] (p = 0.004). The number of focal anatomical stenoses of > 30% increased from a median of 1 [0-2] at baseline to 2 [0-3] at follow-up (p = 0.009).

CONCLUSIONS

The distal coronary FFRct values in post-HTX patients in each of the three major coronary arteries decreased, and the number of focal coronary stenoses increased over a 2-year period. Temporal FFRct change rate may become an additional parameter in the follow-up of HTx patients, but more research is needed to elucidate its role.

CLINICAL RELEVANCE STATEMENT

CT-derived fractional flow reserve (FFRct) is important post-heart transplant because of additional information on coronary CT angiography for cardiac allograft vasculopathy (CAV) detection. The decrease and degree of reduction in distal FFRct value may indicate progression in anatomic CAV burden.

KEY POINTS

CT-derived fractional flow reserve (FFRct) is important for monitoring cardiac allograft vasculopathy (CAV) in heart transplant patients. Over time, transplant patients showed a decrease in distal FFRct and an increase in coronary stenoses. Temporal changes in FFRct could be crucial for transplant follow-up, aiding in CAV detection.

Influence of donor age and donor-recipient age difference on intimal hyperplasia in pediatric patients with young and adult donors vs. adult patients after heart transplantation

AIM

Optimal selection and allocation of donor hearts is a relevant aspect in transplantation medicine. Donor age and cardiac allograft vasculopathy (CAV) affect post-transplant mortality. To what extent donor age impacts intimal hyperplasia (CAVIH) in pediatric and adult patients after heart transplantation (HTx) is understudied.

METHODS

In a cohort of 98 HTx patients, 58 pediatric (24.1% with adult donors) and 40 adult patients, we assessed the effect of donor age and donor-recipient age difference (D-R) on the continuous parameter of maximal intima thickness (mIT) in optical coherence tomography. We evaluated their predictive value regarding higher mIT and the prevalence of CAVIH, defined as mIT > 0.3 mm, and compared it to established CAV risk factors.

RESULTS

In the overall population, donor age correlated with mIT (p < 0.001), while in the pediatric subpopulation, both donor age and D-R correlated with mIT (p < 0.001 and p = 0.002, respectively). In the overall population, donor age was a main predictor of higher mIT and CAVIH (p = 0.001 and p = 0.01, respectively) in addition to post-transplant interval, arterial hypertension, and dyslipidemia. In the pediatric patients, dyslipidemia remained a main predictor of both higher mIT and CAVIH (p = 0.004 and p = 0.040, respectively), while donor age and D-R were not.

CONCLUSION

While there was an effect of the non-modifiable parameter of donor age regarding maximal intimal thickness, a stronger association was seen between the modifiable risk factor dyslipidemia and higher maximal intimal thickness and CAVIH in both the overall population and the pediatric subpopulation.

Speckle-Tracking Echocardiography in Right Ventricular Function of Clinically Well Patients with Heart Transplantation

Heart transplantation (HT) is the mainstream therapy for end-stage heart disease. However, the cardiac graft function can be affected by several factors. It is important to monitor HT patients for signs of graft dysfunction. Transthoracic echocardiography is a simple, first-line, and non-invasive method for the assessment of cardiac function. The emerging speckle-tracking echocardiography (STE) could quickly and easily provide additive information over traditional echocardiography. STE longitudinal deformation parameters are markers of early impairment of ventricular function. Although once called the "forgotten ventricle", right ventricular (RV) assessment has gained attention in recent years. This review highlights the potentially favorable role of STE in assessing RV systolic function in clinically well HT patients.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

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.

Right Ventricular Function on Cardiovascular Magnetic Resonance Imaging and Long-Term Outcomes in Stable Heart Transplant Recipients

BACKGROUND

In heart transplant recipients, right ventricular (RV) dysfunction may occur for a variety of reasons. Whether RV dysfunction in the stable phase after heart transplantation is associated with long-term adverse outcomes is unknown. We aimed to determine the long-term prognostic significance of RV dysfunction identified on cardiovascular magnetic resonance imaging (CMR) at least 1 year after heart transplantation.

METHODS

In consecutive heart transplant recipients who underwent CMR for surveillance, we assessed 2 CMR measures of RV function: RV ejection fraction and RV global longitudinal strain (RVGLS). We investigated associations between RV dysfunction and a composite end point of death or major adverse cardiac events, including retransplantation, nonfatal myocardial infarction, coronary revascularization, and heart failure hospitalization.

RESULTS

A total of 257 heart transplant recipients (median age, 59 years; 75% men) who had CMR at a median of 4.3 years after heart transplantation were included. Over a median follow-up of 4.4 years after the CMR, 108 recipients experienced death or major adverse cardiac events. In a multivariable Cox regression analysis adjusted for age, time since transplantation, indication for transplantation, cardiac allograft vasculopathy, history of rejection, and CMR covariates, RV ejection fraction was not associated with the composite end point, but RVGLS was independently associated with the composite end point with a hazard ratio of 1.08 per 1% worsening in RVGLS ([95% CI, 1.00-1.17]; P=0.046). RVGLS provided incremental prognostic value over other variables in multivariable analyses. The association was replicated in subgroups of recipients with normal RV ejection fraction and recipients with late gadolinium enhancement imaging. A similar association was seen with a composite end point of cardiovascular death or major adverse cardiac events.

CONCLUSIONS

CMR feature tracking-derived RVGLS assessed at least 1 year after heart transplantation was independently associated with the long-term risk of death or major adverse cardiac events. Future studies should investigate its role in guiding clinical decision-making in heart transplant recipients.

Feasibility and prognostic value of tissue motion annular displacement in patients with heart transplantation

BACKGROUND

Tissue motion of mitral annular displacement (TMAD) assessment has proved to be an effective method for several cardiovascular diseases including hypertrophic cardiomyopathy, heart failure, non-ST-elevation myocardial infarction, etc. However, there are no studies exploring the feasibility of TMAD in heart transplantation (HT) recipients, and the predictive value of this parameter for adverse outcomes in these patients remains unknown. Consequently, this study aimed to evaluate the feasibility of TMAD in the evaluation of left ventricular (LV) systolic function in clinically well adult HT patients, and further investigate the prognostic value of TMAD.

METHODS

Echocardiography was performed in 155 adult HT patients and 49 healthy subjects. All the subjects were examined by conventional transthoracic two-dimensional echocardiography and two-dimensional speckle tracking echocardiography (2D-STE) with evaluation of the LV end-diastolic diameter, LV end-diastolic volume index, LV end-systolic volume index, interventricular septal thickness, left atrial diameter, mitral annular plane systolic excursion (MAPSE), LV ejection fraction (LVEF), TMAD and LV global longitudinal strain (LVGLS). The end point was defined as all-causes mortality or posttransplant related hospitalization during follow up. Cox proportional hazards regression was performed to evaluate the prognostic value of the parameters for predicting poor outcomes in HT patients.

RESULTS

A significant positive correlation was found between the measurements of TMAD and LVGLS (r = .714, p < .001). TMAD obtained by 2D-STE had good reproducibility. The LVGLS and TMAD were significantly lower in HT group than in control group (both p < .001). In HT patients, compared with event free group, adverse outcome group displayed reduced TMAD and LVGLS, and elevated age (p < .001, < .001, = .017, respectively). Patients with higher TMAD (> 9.1 mm) had comparatively better survival when stratified by cutoff value (log-rank p < .001). LVGLS and TMAD were independently associated with adverse outcomes in multivariable analysis (both p < .001).

CONCLUSION

Assessment of TMAD is effective for evaluating LV longitudinal systolic function and predicting adverse outcomes in clinically well adult HT patients.

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.

Routine screening for HLA Antibodies in Heart Transplant patients-Does it affect clinical decision making?

BACKGROUND

We aimed to assess outcomes in patients with and without donor specific antibodies (DSA) and to evaluate the relationship between DSA presence and graft function, cardiac allograft vasculopathy (CAV), and mortality.

METHODS

The study population comprises 193 consecutive long-term heart transplanted (HTx) patients who underwent DSA surveillance between 2016 and 2022. The patients were prospectively screened for CAV through serial coronary angiograms, graft function impairment through serial echocardiograms, and cardiac biomarkers. The patients were followed from the first DSA measurement until death, 5 years follow-up or right censuring on the 30th of June 2023.

RESULTS

DSAs were detected in 50 patients using a cut-off at MFI ≥1000 and 45 patients using a cut-off at ≥2000 MFI. The median time since HTx was 9.0 years [3.0-14.4]. DSA positive patients had poorer graft function and higher values of NT-proBNP and troponin T, and more prevalent CAV than DSA negative patients. In total, 25 patients underwent endomyocardial biopsies due to DSA presence while another eight patients underwent endomyocardial biopsies for other reasons. Histological antibody mediated rejection (AMR) signs were seen in three biopsies. During a median follow-up of five years [4.7-5], a total of 41 patients died. Mortality rates did not differ between DSA positive and DSA negative patients (HR 1.2, 95% CI .6-2.4). DSA positive patients were more likely to experience CAV progression than DSA negative patients (HR 2.7, 95% CI 1.5-4.8) CONCLUSIONS: Routine screening reveals DSA in approximately 25% of long-term HTx patients but is rarely related to histopathological AMR signs. DSA presence was associated with poorer graft function and more prevalent and progressive CAV. However, DSA positive patients had similar survival rates to DSA negative patients.

Echocardiographic assessment of pediatric heart transplantation: A single-center experience in China

BACKGROUND

Pediatric heart transplant (HT) has become the standard of care for end-stage heart failure in children worldwide. Serial echocardiographic evaluations of graft anatomy and function during follow-up are crucial for post-HT management. However, evolution of cardiac structure and function after pediatric HT has not been well described, especially during first year post-HT. This study aimed to characterize the evolution of cardiac structure and function after pediatric HT and investigate the correlation between biventricular function with adverse clinical outcomes.

METHODS

A single-center retrospective study of echocardiographic data obtained among 99 pediatric HT patients was conducted. Comprehensive echocardiographic examination was performed in all patients at 1-, 3-, 6-, 9- and 12-months post-HT. We obtained structural, functional and hemodynamic parameters from both left- and right-side heart, such as left ventricular stroke volume (LVSV), left ventricular ejection fraction (LVEF), right ventricular fractional area change (RVFAC), etc. The cardiac evolution of pediatric HT patients during first post-HT year was described and compared between different time points. We also explored the correlation between cardiac function and major adverse transplant events (MATEs).

RESULTS

1) Evolution of left heart parameters: left atrial length, mitral E velocity, E/A ratio, LVSV and LVEF significantly increased while mitral A velocity significantly decreased over the first year after HT (P < .05). Compared with 1 month after HT, interventricular septum (IVS) and left ventricular posterior wall (LVPW) decreased at 3 months but increased afterwards. (2) Evolution of right heart parameters: right ventricular base diameter and mid-diameter; right ventricular length diameter, tricuspid E velocity, E/A ratio, tricuspid annular velocity e' at free wall, and RVFAC increased, while tricuspid A velocity decreased over the first year after HT (P < .05). (3) Univariate logistic regression model suggests that biventricular function parameters at 1-year post-HT (LVEF, RVFAC, tricuspid annular plane systolic excursion and tricuspid lateral annular systolic velocity) were associated with MATEs.

CONCLUSION

Gradual improvement of LV and RV function was seen in pediatric HT patients within the first year. Biventricular function parameters associated with MATEs. The results of this study pave way for designing larger and longer follow-up of this population, potentially aiming at using multiparameter echocardiographic prediction of adverse events.

CVIT 2023 clinical expert consensus document on intravascular ultrasound

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

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.

Multiparametric assessment of right ventricular function in heart transplant recipients by echocardiography and relations with pulmonary hemodynamics

OBJECTIVE

Right ventricular (RV) dilatation and dysfunction are usually present in heart transplant (HTx) patients and worsened with residual pulmonary hypertension (PH). We aimed to determine the ability of different echocardiographic modalities to evaluate RV function in comparison with cardiac magnetic resonance (CMR) and their relations with pulmonary hemodynamics in HTx patients.

METHODS

A total of 62 data sets [echocardiographic, hemodynamic, and CMR] were acquired from 35 HTx patients. Comprehensive echocardiography, including two-dimensional (2D) transthoracic echocardiography, speckle tracking echocardiography, and three-dimensional (3D) echocardiography, was performed. Mean pulmonary artery pressure (mPAP) was obtained invasively from right heart catheterization. The correlations between all echocardiographic parameters and CMR imaging data and the differences between patients with and without residual PH were evaluated.

RESULTS

Diastolic and systolic RV volumes and RV ejection fraction (RVEF) by 3D echocardiography correlated strongly with CMR-derived volumes and RVEF (r = .91, r = .79, r = .64; p < .0001 for each, respectively). Among other parameters, RV fractional area change (r = .439; p < .001) and RV free wall longitudinal strain (RVFW-LS) (r = -.34; p < .05) correlated moderately with CMR-RVEF, whereas tricuspid annulus S' velocity (r = .29; p < .05) and tricuspid annular systolic plane excursion (r = .27; p < .05) correlated weakly with CMR-RVEF. Additionally, 3D-RVEF and RVFW-LS were significantly decreased in studies with mPAP ≥ 20 mm Hg in comparison to those with mPAP < 20 mm Hg (47.7 ± 3.7 vs. 50.9 ± 5.3, p = .04 and -15.5 ± 3.1 vs. -17.5 ± 3, p = .03, respectively).

CONCLUSION

The best method for the evaluation of RV function in HTx recipients is 3D echocardiography. Besides, the subclinical impact of residual PH on RV function can be best determined by RVFW-LS and 3D-RVEF in these patients.

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.

New Non-Invasive Imaging Technologies in Cardiac Transplant Follow-Up: Acquired Evidence and Future Options

Heart transplantation (HT) is the established treatment for end-stage heart failure, significantly enhancing patients' survival and quality of life. To ensure optimal outcomes, the routine monitoring of HT recipients is paramount. While existing guidelines offer guidance on a blend of invasive and non-invasive imaging techniques, certain aspects such as the timing of echocardiographic assessments and the role of echocardiography or cardiac magnetic resonance (CMR) as alternatives to serial endomyocardial biopsies (EMBs) for rejection monitoring are not specifically outlined in the guidelines. Furthermore, invasive coronary angiography (ICA) is still recommended as the gold-standard procedure, usually performed one year after surgery and every two years thereafter. This review focuses on recent advancements in non-invasive and contrast-saving imaging techniques that have been investigated for HT patients. The aim of the manuscript is to identify imaging modalities that may potentially replace or reduce the need for invasive procedures such as ICA and EMB, considering their respective advantages and disadvantages. We emphasize the transformative potential of non-invasive techniques in elevating patient care. Advanced echocardiography techniques, including strain imaging and tissue Doppler imaging, offer enhanced insights into cardiac function, while CMR, through its multi-parametric mapping techniques, such as T1 and T2 mapping, allows for the non-invasive assessment of inflammation and tissue characterization. Cardiac computed tomography (CCT), particularly with its ability to evaluate coronary artery disease and assess graft vasculopathy, emerges as an integral tool in the follow-up of HT patients. Recent studies have highlighted the potential of nuclear myocardial perfusion imaging, including myocardial blood flow quantification, as a non-invasive method for diagnosing and prognosticating CAV. These advanced imaging approaches hold promise in mitigating the need for invasive procedures like ICA and EMB when evaluating the benefits and limitations of each modality.

Effects of high-intensity interval training on cardiac remodelling, function and coronary microcirculation in de novo heart transplant patients: a substudy of the HITTS randomised controlled trial

Objectives

High-intensity interval training (HIT) improves peak oxygen consumption (VO2peak) in de novo heart transplant (HTx) recipients. It remains unclear whether this improvement early after HTx is solely dependent on peripheral adaptations, or due to a linked chain of central and peripheral adaptations. The objective of this study was to determine whether HIT results in structural and functional adaptations in the cardiovascular system.

Methods

Eighty-one de novo HTx recipients were randomly assigned to participate in either 9 months of supervised HIT or standard care exercise-based rehabilitation. Cardiac function was assessed by echocardiogram and the coronary microcirculation with the index of microcirculatory resistance (IMR) at baseline and 12 months after HTx.

Results

Cardiac function as assessed by global longitudinal strain was significantly better in the HIT group than in the standard care group (16.3±1.2% vs 15.6±2.2%, respectively, treatment effect = -1.1% (95% CI -2.0% to -0.2%), p=0.02), as was the end-diastolic volume (128.5±20.8 mL vs 123.4±15.5 mL, respectively, treatment effect=4.9 mL (95% CI 0.5 to 9.2 mL), p=0.03). There was a non-significant tendency for IMR to indicate improved microcirculatory function (13.8±8.0 vs 16.8±12.0, respectively, treatment effect = -4.3 (95% CI -9.1 to 0.6), p=0.08).

Conclusion

When initiated early after HTx, HIT leads to both structural and functional cardiovascular adaptations.

Trial registration number

NCT01796379.

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.

The Use of Stress Cardiovascular Imaging in Pediatric Population

Although not frequent in the pediatric population, ischemia could occur in children due to several congenital and acquired disease. Stress imaging is key for the non-invasive evaluation of myocardial abnormalities and perfusion defect in this clinical setting. Moreover, beyond ischemia assessment, it can provide complementary diagnostic and prognostic information in valvular heart disease and cardiomyopathies. When performed using cardiovascular magnetic resonance, it could detect, in addition, myocardial fibrosis and infarction, increasing the diagnostic yield. Several imaging modalities are currently available for the evaluation of stress myocardial perfusion. Advances in technologies have also increased the feasibility, safety and availability of these modalities in the pediatric age group. However, despite the established role of stress imaging and its increasing use in daily clinical practice, there are currently no specific guidelines, and little data are available in the literature on this topic. The aim of this review is to summarize the most recent evidence on pediatric stress imaging and its clinical application with a focus on the advantages and limitations of each imaging modality currently available.

Review of Postoperative Care for Heart Transplant Recipients

The early postoperative management strategies after heart transplantation include optimizing the function of the denervated heart, correcting the causes of hemodynamic instability, and initiating and maintaining immunosuppressive therapy, allograft rejection surveillance, and prophylaxis against infections caused by immunosuppression. The course of postoperative support is influenced by the quality of allograft myocardial protection prior to implantation and reperfusion, donor-recipient heart size matching, surgical technique of orthotopic heart transplantation, and patient factors (eg, preoperative condition, immunologic compatibility, postoperative vasomotor tone, severity and reversibility of pulmonary vascular hypertension, pulmonary function, mediastinal blood loss, and end-organ perfusion). This review provides an overview of the early postoperative care of recipients and includes a brief description of the surgical techniques for orthotopic heart transplantation.

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.

Comparing Cardiac Mechanics and Myocardial Fibrosis in DBD and DCD Heart Transplant Recipients

BACKGROUND

Heart transplantation (HTx) after donation after circulatory death (DCD) is an expanding practice but is associated with increased warm ischemic time. The impact of DCD HTx on cardiac mechanics and myocardial fibrosis has not been reported. We aimed to compare cardiac mechanics and myocardial fibrosis using cardiovascular magnetic resonance (CMR) imaging in donation after brain death (DBD) and DCD HTx recipients and healthy controls.

METHODS AND RESULTS

Consecutive HTx recipients between March 2015 and March 2021 who underwent routine surveillance CMR imaging were included. Cardiac mechanics were assessed using CMR feature tracking to compute global longitudinal strain, global circumferential strain, and right ventricular free-wall longitudinal myocardial strain. Fibrosis was assessed using late gadolinium enhancement imaging and estimation of extracellular volume. There were 82 (DBD n = 42, DCD n = 40) HTx recipients (aged 53 years, interquartile range 41-59 years, 24% female) who underwent CMR imaging at median of 9 months (interquartile range 6-14 months) after transplantation. HTx recipients had increased extracellular volume (29.7 ± 3.6%) compared with normal ranges (25.9%, interquartile range 25.4-26.5). Myocardial strain was impaired after transplantation compared with controls (global longitudinal strain -12.6 ± 3.1% vs -17.2 ± 1.8%, P < .0001; global circumferential strain -16.9 ± 3.1% vs -19.2 ± 2.0%, P = .002; right ventricular free-wall longitudinal strain -15.7 ± 4.5% vs -21.6 ± 4.7%, P < .0001). There were no differences in fibrosis burden (extracellular volume 30.6 ± 4.4% vs 29.2 ± 3.2%; P = .39) or cardiac mechanics (global longitudinal strain -13.1 ± 3.0% vs -12.1 ± 3.1%, P = .14; global circumferential strain -17.3 ± 2.9% vs -16.6 ± 3.1%, P = .27; right ventricular free-wall longitudinal strain -15.9 ± 4.9% vs -15.5 ± 4.1%, P = .71) between DCD and DBD HTx.

CONCLUSIONS

HTx recipients have impaired cardiac mechanics compared with controls, with increased myocardial fibrosis. There were no differences in early CMR imaging characteristics between DBD and DCD heart transplants, providing further evidence that DCD and DBD HTx outcomes are comparable.

Peripheral Blood Mononuclear Cells Mitochondrial Respiration and Superoxide Anion after Heart Transplantation

INTRODUCTION

The mitochondrial function of circulating peripheral blood mononuclear cells (PBMCs) is an interesting new approach to cardiac diseases. Thus, PBMC's mitochondrial respiration decreases in relation to heart failure severity. However, no data are available on heart-transplanted patients (Htx).

POPULATION AND METHODS

We determined PBMCs mitochondrial respiration by high-resolution respirometry (Oroboros Instruments) and superoxide anion production using electron paramagnetic resonance (Bruker-Biospin) in 20 healthy subjects and 20 matched Htx and investigated clinical, biological, echocardiographic, coronarography and biopsy characteristics.

RESULTS

PBMCs mitochondrial respiratory chain complex II respiration was decreased in Htx (4.69 ± 0.84 vs. 7.69 ± 1.00 pmol/s/million cell in controls and Htx patients, respectively; p = 0.007) and complex IV respiration was increased (24.58 ± 2.57 vs. 15.68 ± 1.67 pmol/s/million cell; p = 0.0035). Superoxide anion production was also increased in Htx (1.47 ± 0.10 vs. 1.15 ± 0.10 µmol/min; p = 0.041). The leucocyte-to-lymphocyte ratio was increased in Htx, whom complex II correlated with leucocyte number (r = 0.51, p = 0.02) and with the left ventricular posterior wall peak early diastolic myocardial velocity (r = -0.62, p = 0.005). Complex IV was increased in the two patients with acute rejection and correlated negatively with Htx's isovolumetric relation time (r = -0.45, p = 0.045).

DISCUSSION

Although presenting with normal systolic function, Htx demonstrated abnormal PBMC's mitochondrial respiration. Unlike immunosuppressive therapies, subclinical diastolic dysfunction might be involved in these changes. Additionally, lymphopenia might reduce complex II, and acute rejection enhances complex IV respirations.

CONCLUSION

PBMC's mitochondrial respiration appears modified in Htx, potentially linked to cellular shift, mild diastolic dysfunction and/or acute rejection.

Diastolic function in heart transplant: From physiology to echocardiographic assessment and prognosis

Heart transplant (HTx) still represents the most effective therapy for end-stage heart failure, with a median survival time of 10 years. The transplanted heart shows peculiar physiology due to the profound alterations induced by the operation, which inevitably influences several echocardiographic parameters assessed during these patients’ follow-ups. With these premises, the diastolic function is one of the main aspects to take into consideration. The left atrium (LA) plays a key role in this matter, and that same chamber is significantly impaired with the transplant, with different degrees of altered function based on the surgical technique. Therefore, the traditional echocardiographic evaluation of diastolic function applied to the general population might not properly reflect the physiology of the graft. This review attempts to provide current evidence on diastolic function in HTx starting from defining its different physiology and how the standard echocardiographic parameters might be affected to its prognostic role. Furthermore, based on the experience of our center and the available evidence, we proposed an algorithm that might help clinicians distinguish from actual diastolic dysfunction from a normal diastolic pattern in HTx population.

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.

Fibrotic plaques in heart transplanted patients and their association with insulin resistance syndrome and Lp(a)

BACKGROUND

Angiographic evidence of cardiac allograft vasculopathy (CAV_angio) is a major limiting factor to survival after heart transplantation (HTx). Prevention of CAV_angio is therefore most relevant. Whether modifiable risk factors could be targeted for the prevention of fibrotic plaques, that are common and related to CAV_angio, is not clear.

METHODS AND RESULTS

In a cohort of 74 consecutive HTx patients (median post-transplant interval 9.2 [4.1-15.5] years), we used the high resolution of optical coherence tomography (OCT) to quantify angulation parameters (maximal and mean arc) and plaque load (mean arc*relative plaque length) of fibrotic plaques. Mean arc was defined as the mean value of all angulation measurements per patient. We assessed the association between cardiovascular risk factors and OCT findings. Linear regression analysis showed a significant association of TG/HDL-c with mean fibrotic arc (12.7 [3.9-21.5], p = 0.006) and fibrotic plaque load (2298 [617-3979], p = 0.009) after adjustment for recipient age and sex. We used the median value of fibrotic plaque load to define high fibrotic plaque load. In binary logistic regression analysis, TG/HDL-c (odds ratio [OR] 1.81 with 95% CI [1.09-3.03], p = 0.02) and Lp(a) (OR 1.02 [1.00-1.05], p = 0.02) were associated with high fibrotic plaque load. Multivariable logistic regression analysis confirmed Lp(a) as significant predictor of high fibrotic plaque load (OR 1.03 [1.01-1.05], p = 0.02).

CONCLUSION

TG/HDL-c ratio, a surrogate of insulin resistance syndrome, and Lp(a) were significantly associated with fibrotic plaque in HTx patients. Insulin resistance syndrome and Lp(a) might therefore represent additional targets for CAV prevention.

Sodium-glucose cotransporter-2 (SGLT2) expression in diabetic and non-diabetic failing human cardiomyocytes

This study aimed at investigating the SGLT2 expression in human cardiomyocytes. Human studies evaluating cardiomyocyte SGLT2s expression are limited. To better clarify this issue, SGLT2 protein expression was assessed in human hearts of diabetic and non-diabetic patients, and in AC16 human cardiomyocyte cell line. A prospective study with a follow-up of patients who underwent their first heart transplant (HTX) was performed. Explanted heart, basal (1 week after HTX), and final (48 weeks after HTX) endomyocardial biopsies (EMBs) from patients were evaluated for SGLT2 occurrence in cardiomyocyte with immunohistochemistry, immunofluorescence and SGLT2 quantization with both real-time reverse transcription-polymerase chain reaction and Western blot analysis. The immunofluorescence co-localization of SGLT2 in cardiomyocyte evidenced that an increased expression in the explanted heart from diabetic patients compared to non-diabetic (p < 0.001). In all final EMBs from diabetic patients, the expression of SGLT2 in cardiomyocyte was increased compared to non-diabetic (p < 0.01). This evidence was confirmed by Western blot analysis of SGLT2 protein. In addition, PCR analysis revealed very low mRNA levels in basal EMBs from diabetic and non-diabetic patients (p = NS), whereas final EMBs from diabetic patients showed higher SGLT2 mRNA levels in diabetic compared to non-diabetic patients (p < 0.05). Cultured human cardiomyocytes exposed to high-glucose showed increased expression of SGLT2 protein compared to cells exposed to normal glucose (p < 0.05). The presence of SGLT2 in cardiomyocytes supports the hypothesis of SGLT2i-mediated impact on metabolic pathways within cardiomyocytes. Moreover, metabolic disorders linked to diabetes may lead promptly to upregulation of SGLT2 levels in human cardiomyocytes.

Incremental value of preoperative right ventricular function in predicting moderate to severe acute kidney injury after heart transplantation

Background

Acute kidney injury (AKI) commonly occurs after heart transplantation (HTx), but its association with preoperative right ventricular (RV) function remains unknown. Consequently, we aimed to determine the predictive value of preoperative RV function for moderate to severe AKI after HTx.

Materials and methods

From 1 January 2016 to 31 December 2019, all the consecutive HTx recipients in our center were enrolled and analyzed for the occurrence of postoperative AKI staged by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Conventional RV function parameters, including RV fractional area change (RVFAC) and tricuspid annular plane systolic excursion (TAPSE), were obtained. The primary endpoint was moderate to severe AKI (the KDIGO stage 2 or 3). The secondary endpoints included the impact of AKI on intensive care unit (ICU) mortality, in-hospital mortality, and 1-year mortality.

Results

A total of 273 HTx recipients were included in the study. Postoperative AKI occurred in 209 (77%) patients, including 122 (45%) patients in stage 1 AKI, 49 (18%) patients in stage 2 AKI, and 38 (14%) patients in stage 3 AKI. Patients with higher AKI stage had lower baseline estimated glomerular filtration rate (eGFR), more frequent diabetes, higher right atrial pressure (RAP), longer cardiopulmonary bypass (CPB) duration, more perioperative red blood cell (RBC) transfusions, and worse preoperative RV function. A multivariate logistic regression model incorporating previous diabetes mellitus [odds ratio (OR): 2.21; 95% CI: 1.06–4.61; P = 0.035], baseline eGFR (OR: 0.99; 95% CI: 0.97–0.10; P = 0.037), RAP (OR: 1.05; 95% CI: 1.00–1.10; P = 0.041), perioperative RBC (OR: 1.18; 95% CI: 1.08–1.28; P < 0.001), and TAPSE (OR: 0.84; 95% CI: 0.79–0.91; P < 0.001) was established to diagnose moderate to severe AKI more accurately [the area under the curve (AUC) = 79.8%; Akaike information criterion: 274].

Conclusion

Preoperative RV function parameters provide additional predicting value over clinical and hemodynamic parameters, which are imperative for risk stratification in patients with HTx at higher risk of AKI.

Glycated ACE2 reduces anti-remodeling effects of renin-angiotensin system inhibition in human diabetic hearts

BACKGROUND

High glycated-hemoglobin (HbA1c) levels correlated with an elevated risk of adverse cardiovascular outcomes despite renin-angiotensin system (RAS) inhibition in type-2 diabetic (T2DM) patients with reduced ejection fraction. Using the routine biopsies of non-T2DM heart transplanted (HTX) in T2DM recipients, we evaluated whether the diabetic milieu modulates glycosylated ACE2 (GlycACE2) levels in cardiomyocytes, known to be affected by non-enzymatic glycosylation, and the relationship with glycemic control.

OBJECTIVES

We investigated the possible effects of GlycACE2 on the anti-remodeling pathways of the RAS inhibitors by evaluating the levels of Angiotensin (Ang) 1-9, Ang 1-7, and Mas receptor (MasR), Nuclear-factor of activated T-cells (NFAT), and fibrosis in human hearts.

METHODS

We evaluated 197 first HTX recipients (107 non-T2DM, 90 T2DM). All patients were treated with angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) at hospital discharge. Patients underwent clinical evaluation (metabolic status, echocardiography, coronary CT-angiography, and endomyocardial biopsies). Biopsies were used to evaluate ACE2, GlycACE2, Ang 1-9, Ang 1-7, MasR, NAFT, and fibrosis.

RESULTS

GlycACE2 was higher in T2DM compared tonon-T2DM cardiomyocytes. Moreover, reduced expressions of Ang 1-9, Ang 1-7, and MasR were observed, suggesting impaired effects of RAS-inhibition in diabetic hearts. Accordingly, biopsies from T2DM recipients showed higher fibrosis than those from non-T2DM recipients. Notably, the expression of GlycACE2 in heart biopsies was strongly dependent on glycemic control, as reflected by the correlation between mean plasma HbA1c, evaluated quarterly during the 12-month follow-up, and GlycACE2 expression.

CONCLUSION

Poor glycemic control, favoring GlycACE2, may attenuate the cardioprotective effects of RAS-inhibition. However, the achievement of tight glycemic control normalizes the anti-remodeling effects of RAS-inhibition.

TRIAL REGISTRATION

https://clinicaltrials.gov/ NCT03546062.

Multimodality Imaging to Detect Rejection, and Cardiac Allograft Vasculopathy in Pediatric Heart Transplant Recipients—An Illustrative Review

The three most common modalities of graft surveillance in pediatric heart transplant (HT) recipients include echocardiography, coronary angiography, and endomyocardial biopsy (EMB). The survival outcomes after HT in children have improved considerably in recent years. However, allograft rejection and cardiac allograft vasculopathy remain the leading cause of death or re-transplantation. The routine surveillance by EMB and coronary angiography are invasive and risky. Newer noninvasive echocardiographic techniques, including tissue Doppler imaging (TDI), 2-D speckle tracking echocardiography, CT coronary angiography (CTCA), cardiovascular magnetic resonance (CMR), single-photon emission computed tomography (SPECT), and positron emission tomography (PET) and invasive techniques such as intravascular ultrasound (IVUS), functional flow reserve (CFR) of coronary arteries, optical coherence tomography (OCT), have emerged as powerful tools which may help early recognition of sub-clinical rejection, response to treatment, early detection, and progression of CAV. The multimodality imaging approach, including noninvasive and invasive tests, is the future for the transplanted heart to detect dysfunction, rejections, and early CAV. This review illustrates noninvasive and invasive imaging techniques currently used or could be considered for clinical use in detecting heart transplant rejection, dysfunction, and CAV in children.

Detection of cardiac allograft vasculopathy on dual source computed tomography in heart transplant recipients: comparison with invasive coronary angiography

OBJECTIVE

We aimed to evaluate the diagnostic accuracy (DA) of dual-source CT coronary angiography (DSCTCA) against invasive coronary angiography (ICA) in assessing stenotic cardiac allograft vasculopathy (CAV) in heart transplant (HTX) recipients.

METHODS

Consecutive HTX recipients(n = 38) on annual surveillance, underwent DSCTCA prior to ICA on a 192-detector 384-slice DSCT scanner. Cases were classified as no CAV (no stenosis), any CAV (any degree of stenosis) or significant CAV (>50% stenosis).

RESULTS

Mean age was 33.66 ± 11.45 years (M:F = 27:11, median time from HTX-23.5 months). Prevalence of any CAV on DSCTCA and ICA was 44.7%(n = 17) and 39.5%(n = 15), respectively and that of significant CAV was 21.1%(n = 8) and 15.8%(n = 6), respectively. 557 (96.7%) segments were interpretable on DSCTCA. Mean radiation dose was 4.24 ± 2.15 mSv. At patient-level, the sensitivity, specificity, positive-predictive value, negative-predictive value (NPV), and DA of DSCTCA for detection of any CAV and significant CAV were 100%, 91.3%, 88.2%, 100%, 94.73% and 100%, 94%, 75%, 100%, 95% respectively. The same on segment-based analysis were 96%, 97.6%, 80%, 99.6%, 97.5% and 100%, 99.6%,86.7%,100%, 99.6%, respectively. There was excellent agreement between the two modalities for detection of any CAV and significant CAV [κ = 0.892 and 0.826 (patient-level), 0.859 and 0.927 (segment-level)]. CAC score correlated significantly with the presence of any CAV on both modalities. A diagnosis of rejection on biopsy did not correlate with any/significant CAV on DSCTCA or ICA.

CONCLUSION

High sensitivity and NPV of DSCTCA in the evaluation of stenotic CAV suggests that it can be an accurate and non-invasive alternative to ICA for routine surveillance of HTX recipients.

ADVANCES IN KNOWLEDGE

DSCTCA detects the stenotic CAV non-invasively in transplant recipients with high sensitivity, specificity and NPV when compared with catheter coronary angiography, at lower radiation doses. There is excellent agreement between CT angiography and catheter coronary angiography for detection of any CAV and significant CAV. A diagnosis of rejection on biopsy does not correlate with any/significant CAV on CT angiography or catheter angiography.

Cardiac allograft vasculopathy: A review

BACKGROUND

Heart transplantation has become the standard of care for pediatric patients with end-stage heart disease, and outcomes have consistently improved over the last few decades. CAV, however, remains a leading cause of morbidity and mortality in heart transplantation and is the leading cause of death beyond 3 years post-transplantation. We sought out to provide an in-depth overview of CAV in the pediatric heart transplant population.

METHODS

Database searches were conducted in both Medline and Embase on the topic of cardiac vasculopathy in pediatric heart transplant recipients. The search used five broad concept terms: heart transplant; pediatric; CAV; diagnosis, prognosis, and risk factors; and guidelines and reviews. References were captured if there was at least one term in each of the concepts. The search was limited to articles in the English language.

RESULTS

A total of 148 articles were identified via the literature search with further articles identified via review of references. Pediatric data regarding the etiology and development of CAV remain limited although knowledge about the immune and non-immune factors playing a role are increasing. CAV continues to be difficult to detect with many invasive and non-invasive methods available, yet their effectiveness in the detection of CAV remains suboptimal. There remains no proven medical intervention to treat or reverse established CAV disease, and CAV is associated with high rates of graft loss once detected. However, several medications are used in hopes of preventing, slowing progression, or modifying the outcomes.

CONCLUSION

This review provides a comprehensive overview of CAV, discusses its clinical presentation, risk factors, diagnostic tools used to identify CAV in the pediatric population, and highlights the current therapeutic options and the need for ongoing research.

Left Heart Chamber Volumetric Assessment by Automated Three-Dimensional Echocardiography in Heart Transplant Recipients

Background

Recently, a new automated software (Heart Model) was developed to obtain three-dimensional (3D) left heart chamber volumes. The aim of this study was to verify the feasibility and accuracy of the automated 3D echocardiographic algorithm in heart transplant (HTx) patients. Conventional manual 3D transthoracic echocardiographic (TTE) tracings and cardiac magnetic resonance (CMR) images were used as a reference for comparison.

Methods

This study enrolled 103 healthy HTx patients prospectively. In protocol 1, left ventricular end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), left atrial max volume (LAVmax), LA minimum volume (LAVmin) and LV ejection fraction (LVEF) were obtained using the automated 3D echocardiography (3DE) and compared with corresponding values obtained through the manual 3DE. In protocol 2, 28 patients’ automated 3DE measurements were compared with CMR reference values. The impacts of contour edit and surgical technique were also tested.

Results

Heart Model was feasible in 97.1% of the data sets. In protocol 1, there was strong correlation between 3DE and manual 3DE for all the parameters (r = 0.77 to 0.96, p<0.01). Compared to values obtained through manual measurements, LV volumes and LVEF were overestimated by the automated algorithm and LA volumes were underestimated. All the biases were small except for that of LAVmin. After contour adjustment, the biases reduced and all the limits of agreement were clinically acceptable. In protocol 2, the correlations for LV and LA volumes were strong between automated 3DE with contour edit and CMR (r = 0.74 to 0.93, p<0.01) but correlation for LVEF remained moderate (r = 0.65, p < 0.01). Automated 3DE overestimated LV volumes but underestimated LVEF and LA volumes compared with CMR. The limits of agreement were clinically acceptable only for LVEDV and LAVmax.

Conclusion

Simultaneous quantification of left heart volumes and LVEF with the automated Heart Model program is rapid, feasible and to a great degree it is accurate in HTx recipients. Nevertheless, only LVEDV and LAVmax measured by automated 3DE with contour edit seem applicable for clinical practice when compared with CMR. Automated 3DE for HTx recipients is a worthy attempt, though further verification and optimization are needed.

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.

Estimating filling pressures in paediatric heart transplant recipients using echocardiographic parameters and B-type natriuretic peptide

BACKGROUND

Longitudinal evaluation of allograft diastolic function in paediatric heart transplant recipients is important for early detection of acute rejection, cardiac allograft vasculopathy, and graft dysfunction. Mean diastolic right atrial and pulmonary capillary wedge pressures obtained at catheterisation are the reference standards for assessment. Echocardiography is non-invasive and more suitable for serial surveillance, but individual parameters have lacked accuracy. This study aimed to identify covariates of post-transplant mean right atrial and pulmonary capillary wedge pressures, including B-type natriuretic peptide and certain echocardiographic parameters.

METHODS

A retrospective review of 143 scheduled cardiac catheterisations and echocardiograms from 56 paediatric recipients transplanted from 2007 to 2011 was performed. Samples with rejection were excluded. Univariate and multivariate linear regression models using backward selection were applied to a database consisting of B-type natriuretic peptide, haemodynamic, and echocardiographic data.

RESULTS

Ln B-type natriuretic peptide, heart rate z-score, left ventricular end-diastolic dimension z-score, mitral E/e', and percent interventricular septal thickening in systole were independently associated with mean right atrial pressure. Ln B-type natriuretic peptide, heart rate z-score, left ventricular end-diastolic dimension z-score, left ventricular mass (observed/predicted), and mitral E/e' were independently associated with mean pulmonary capillary wedge pressure. Covariates of B-type natriuretic peptide included mean pulmonary artery and pulmonary capillary wedge pressures, height, haemoglobin, fractional shortening, percent interventricular septal thickening in systole, and pulmonary vascular resistance index.

CONCLUSIONS

B-type natriuretic peptide and echocardiographic indices of diastolic function were independently related to post-transplant mean right atrial and pulmonary capillary wedge pressures in paediatric heart transplant recipients without rejection.

Clinical Utility of SPECT in the Heart Transplant Population: Analysis From a Single Large-volume Center

BACKGROUND

Survival after heart transplant has greatly improved, with median survival now over 12 years. Cardiac allograft vasculopathy (CAV) has become a major source of long-term morbidity and mortality. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is used for CAV surveillance, but there is limited data on its prognostic utility.

METHODS

We retrospectively identified patients undergoing SPECT MPI for CAV surveillance at a single, large-volume center. Images were assessed with semiquantitative visual scoring (summed stress score [SSS] and summed rest score) and quantitatively with total perfusion defect (TPD).

RESULTS

We studied 503 patients (mean age 62.5, 69.3% male) at a median of 9.0 years post-transplant. During mean follow-up of 5.1 ± 2.5 years, 114 (22.6%) patients died. The diagnostic accuracy for significant CAV (ISHLT grade 2 or 3) was highest for SSS with an area under the curve of 0.650 and stress TPD (area under the curve, 0.648), with no significant difference between SSS and stress TPD (P = 0.061). Stress TPD (adjusted hazard ratio, 1.07; P = 0.018) was independently associated with all-cause mortality, while SSS was not (P = 0.064). The prognostic accuracy of quantitative assessment of perfusion tended to be higher compared with semiquantitative assessment, with the highest accuracy for stress TPD (area under the receiver operating curve 0.584).

CONCLUSIONS

While SPECT MPI identified a cohort of higher risk patients, with quantitative analysis of perfusion demonstrating higher prognostic accuracy. However, the overall prognostic accuracy was modest and alternative noninvasive modalities may be more suitable for CAV surveillance.

Sodium/glucose cotransporter 2 (SGLT2) inhibitors improve cardiac function by reducing JunD expression in human diabetic hearts

BACKGROUND

The pathogenesis of experimental diabetic cardiomyopathy may involve the activator protein 1 (AP-1) member, JunD. Using non-diabetic heart transplant (HTX) in recipients with diabetes, we examined the effects of the diabetic milieu (hyperglycemia and insulin resistance) on cardiac JunD expression over 12 months. Because sodium/glucose cotransporter-2 inhibitors (SGLT2i) significantly reverse high glucose-induced AP-1 binding in the proximal tubular cell, we investigated JunD expression in a subgroup of type 2 diabetic recipients receiving SGLT2i treatment.

METHODS

We evaluated 77 first HTX recipients (40 and 37 patients with and without diabetes, respectively). Among the recipients with diabetes, 17 (45.9%) were receiving SGLT2i treatment. HTX recipients underwent standard clinical evaluation (metabolic status, echocardiography, coronary computed tomography angiography, and endomyocardial biopsy). In the biopsy samples, we evaluated JunD, insulin receptor substrates 1 and 2 (IRS1 and IRS2), peroxisome proliferator-activated receptor-γ (PPAR-γ), and ceramide levels using real-time polymerase chain reaction and immunofluorescence. The biopsy evaluations in this study were performed at 1-4 weeks (basal), 5-12 weeks (intermediate), and up to 48 weeks (final, end of 12-month follow-up) after HTX.

RESULTS

There was a significant early and progressive increase in the cardiac expression of JunD/PPAR-γ and ceramide levels, along with a significant decrease in IRS1 and IRS2 in recipients with diabetes but not in those without diabetes. These molecular changes were blunted in patients with diabetes receiving SGLT2i treatment.

CONCLUSION

Early pathogenesis in human diabetic cardiomyopathy is associated with JunD/PPAR-γ overexpression and lipid accumulation following HTX in recipients with diabetes. Remarkably, this phenomenon was reduced by concomitant therapy with SGLT2i, which acted directly on diabetic hearts.

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.

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.

Analysis of Fibrotic Plaques in Angiographic Manifest Cardiac Allograft Vasculopathy in Long-term Heart Transplanted Patients Using Optical Coherence Tomography

Supplemental Digital Content is available in the text.

Background.

The development and progression of cardiac allograft vasculopathy documented by coronary angiography (CAV_angio) after heart transplantation (HTx) has prognostic relevance. Yet there are limited data regarding the role of concomitant intracoronary imaging in the presence CAV_angio. In particular, atherosclerotic plaques might represent a potential target for prevention, but their impact on stenosis is understudied.

Methods.

We used high-resolution intracoronary optical coherence tomography (OCT) to quantify and compare findings of intimal hyperplasia (IH) and plaque morphologies in HTx patients (fibrotic plaque, lipid plaque, and calcified plaque). OCT findings were related to the presence of CAV_angio as well as to the severity of stenosis.

Results.

We included 65 consecutive patients into analysis (66% with CAV_angio, posttransplant interval 9.9 ± 7.6 y). Fibrotic, lipid, and calcified plaques were present in 41 (63.1%), 39 (60%), and 18 (27.7%) patients, respectively. In addition to IH, the presence of fibrotic, lipid, and calcified plaques was found to be associated with CAV_angio. The prevalence of lipid plaque and quantitative measurements of fibrotic plaque increased with stenosis severity (lipid plaque, P < 0.001, maximal and mean fibrotic arc, P = 0.05 and P = 0.001, respectively). Receiver operating characteristic analysis showed that area under the curve of the fibrotic plaque parameter mean fibrotic arc (0.87, 95% confidence interval [0.76-0.99]; P = 0.002) was superior to area under the curve of intima parameters regarding CAV_angio. The effect of mean fibrotic arc (r = 0.52, P < 0.001) was relevant regarding stenosis severity.

Conclusions.

After a longer posttransplant interval, CAV findings in OCT included a combination of IH and atherosclerotic plaques. In addition to IH, the presence of fibrotic, lipid, and calcified plaques is associated with CAV_angio. Further studies are warranted to evaluate if the in vivo screening for plaque progress, particularly of fibrotic plaque, could improve individual secondary prevention and outcome in HTx patients.

Association Between 2D- and 3D-Speckle-Tracking Longitudinal Strain and Cardiovascular Magnetic Resonance Evidence of Diffuse Myocardial Fibrosis in Heart Transplant Recipients

Objective: This study aimed to: (1) evaluate the association between myocardial fibrosis (MF) quantified by extracellular volume fraction (ECV) and myocardial strain measured by two-dimensional (2D)- and three-dimensional speckle-tracking echocardiography (3D-STE) and (2) further investigate which strain parameter measured by 2D- and 3D-STE is the more robust predictor of MF in heart transplant (HT) recipients.

Methods: A total of 40 patients with HT and 20 healthy controls were prospectively enrolled. Left ventricular (LV)-global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) were measured by 2D- and 3D-STE. LV diffuse MF was defined by cardiovascular magnetic resonance (CMR)-ECV.

Results: The HT recipients had a significantly higher native T1 and ECV than healthy controls (1043.8 ± 34.0 vs. 999.7 ± 19.7 ms, p < 0.001; 26.6 ± 2.7 vs. 24.3 ± 1.8%, p = 0.02). The 3D- and 2D-STE-LVGLS and LVGCS were lower (p < 0.005) in the HT recipients than in healthy controls. ECV showed a moderate correlation with 2D-LVGLS (r = 0.53, p = 0.002) and 3D-LVGLS (r = 0.60, p < 0.001), but it was not correlated with 2D or 3D-LVGCS, or LVGRS. Furthermore, 3D-LVGLS and 2D-LVGLS had a similar correlation with CMR-ECV (r = 0.60 vs. 0.53, p = 0.670). A separate stepwise multivariate linear analysis showed that both the 2D-LVGLS (β = 0.39, p = 0.019) and 3D-LVGLS (β = 0.54, p < 0.001) were independently associated with CMR-ECV.

Conclusion: CMR marker of diffuse MF was present in asymptomatic patients with HT and appeared to be associated with decreased myocardial strain by echocardiography. Both the 2D- and 3D-LVGLS were independently correlated with diffuse LVMF, which may provide an alternative non-invasive tool for monitoring the development of adverse fibrotic remodeling during the follow-up of HT recipients.

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.

Exercise training in heart transplantation

Heart transplantation remains the gold standard in the treatment of end-stage heart failure (HF). Heart transplantation patients present lower exercise capacity due to cardiovascular and musculoskeletal alterations leading thus to poor quality of life and reduction in the ability of daily self-service. Impaired vascular function and diastolic dysfunction cause lower cardiac output while decreased skeletal muscle oxidative fibers, enzymes and capillarity cause arteriovenous oxygen difference, leading thus to decreased peak oxygen uptake in heart transplant recipients. Exercise training improves exercise capacity, cardiac and vascular endothelial function in heart transplant recipients. Pre-rehabilitation regular aerobic or combined exercise is beneficial for patients with end-stage HF awaiting heart transplantation in order to maintain a higher fitness level and reduce complications afterwards like intensive care unit acquired weakness or cardiac cachexia. All hospitalized patients after heart transplantation should be referred to early mobilization of skeletal muscles through kinesiotherapy of the upper and lower limbs and respiratory physiotherapy in order to prevent infections of the respiratory system prior to hospital discharge. Moreover, all heart transplant recipients after hospital discharge who have not already participated in an early cardiac rehabilitation program should be referred to a rehabilitation center by their health care provider. Although high intensity interval training seems to have more benefits than moderate intensity continuous training, especially in stable transplant patients, individualized training based on the abilities and needs of each patient still remains the most appropriate approach. Cardiac rehabilitation appears to be safe in heart transplant patients. However, long-term follow-up data is incomplete and, therefore, further high quality and adequately-powered studies are needed to demonstrate the long-term benefits of exercise training in this population.

Clinical expert consensus document on intravascular ultrasound from the Japanese Association of Cardiovascular Intervention and Therapeutics (2021)

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.