Two-Dimensional Speckle Tracking Echocardiography in Heart Transplant Patients: Two-Year Follow-Up of Right and Left Ventricular Function

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.

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.

The 2-year postoperative left heart function in marginal donor heart recipients assessing by speckle tracking echocardiography

This study analyzed the differences and explored the donor/recipient factors between marginal and standard donor heart recipients after heart transplantation (HT) by speckle tracking echocardiography (STE). Seventy-two HT patients were enrolled: 25 standard and 47 marginal donor heart recipients. Thirty HT patients completed 2-year continuous follow-up (1, 6, 12, 24 months). Thirty healthy volunteers were controls. STE was used to track the strain characteristics of the left ventricle and atrium for detecting early changes in marginal donor heart recipients, including left ventricular global longitudinal, circumferential and radial strain (LVGLS, LVGCS, LVGRS) and left atrial strain in systole (LAS-S) and late diastole (LAS-A). The perioperative parameters were similar between the standard and marginal groups. No significant differences were found in left heart size, systolic and diastolic function parameters. Left ventricular systolic strain (LVGLS, LVGCS, LVGRS) and systolic and late diastolic left atrial strain (LAS-S, LAS-A) were lower in the HT recipients than the control group (P < 0.05), but there was no difference between the marginal and standard groups (P > 0.05). LVGLS, LVGCS, and LAS-S were low in the marginal group 1 month after surgery but recovered gradually at 6 months. The patients with donor/recipient body weight ratio < 0.8 group had lower LVGLS and LAS-S. STE showed no significant difference between marginal and standard donor recipients. The LVGLS and LAS-S were lower in those with a smaller donor/recipient body weight ratio. The cardiac function of HT patients was lower in the early postoperative period but gradually recovered over time.

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.

Tricuspid Annular Plane Systolic Excursion (TAPSE) correlates with mean pulmonary artery pressure especially 10 years after pediatric heart transplantation

Tricuspid annular plane systolic excursion (TAPSE) is important in the noninvasive echocardiographic assessment of right heart function. This retrospective observational study shows correlations of TAPSE with invasive right heart catheterization parameters after pediatric heart transplantation (HTx). The study included patients after pediatric HTx with cardiac catheterizations in 2018/2019 and measurement of TAPSE (n = 52 patients with 57 examinations; 50.9% adults, 52.6% female, median age: 18.54 years). TAPSE was compared with normal values. Stepwise, linear and multiple regression were used to show influencing variables on TAPSE. Mean TAPSE z-score was -3.48 (SD: 2.25) and 68.4% of HTx-recipients showed abnormally reduced TAPSE (z-score ←2) compared to normal values. Multiple regression (p-value <0.001; corrected R² = 0.338) showed significant correlations of time since HTx (p-value <0.001) and mPAP (p-value: 0.008) with TAPSE z-scores. Divided into subgroups (time since HTx <10 and ≥10 years), TAPSE and mPAP correlated only ≥10 years after HTx (p-value = 0.002). This study provides data of TAPSE even ≥10 years after pediatric HTx. Most patients showed a decreased TAPSE early after HTx, which improved over time. TAPSE z-scores correlated significantly with time since HTx and mPAP, especially ≥10 years post-HTx. Therefore, TAPSE must be used carefully in the early follow-up.

The quest for determination of standard reference values of right ventricular longitudinal systolic strain: a systematic review and meta-analysis

Right ventricular function is strongly associated with clinical outcomes in many conditions, and the evaluation of right ventricle (RV) structure and function in patients with cardiopulmonary disorders is an essential component of clinical management. The objective of this study was to determine the normal ranges of right ventricular longitudinal strain (RVLS) measurements derived by two-dimensional (2D) speckle tracking echocardiography (STE) through a systematic review and meta-analysis. A systematic review was performed using PubMed, Cochrane, ClinicalKey, and CINAHL. Search terms covered the concepts of right ventricle, strain, speckle-tracking, and 2D echocardiography with additional filtering for humans and adults over the last decade. The RV four-chamber longitudinal strain (RV4CLS), RV free wall longitudinal strain (RVFWLS), and free wall longitudinal segmental strain values of healthy individuals without cardiopulmonary diseases from 28 studies were assessed. Weighted means were estimated using random-effects models in a meta-analysis. The results show for RV4CLS -24,91%[CI  - 25.94;  - 23.88, I² 98%], for RVFWLS -27.63%[CI  - 28.78;  - 26.48, I² 98%], for basal RVFWLS -26.65%[CI  - 30.57;  - 22.73, I² 99%], mid RVFWLS -27.61%[CI  - 30.99;  - 24.22, I² 99%] and apical RVFWLS -24.54%[CI  - 26.70;  - 22.38, I² 98%]. This systematic review and meta-analysis showed longitudinal strain values of 2D STE derived RV. No clear reference value for RV strain can be distilled from the literature search due to high statistical heterogeneity between the studies. However, all results of our analysis suggest that the lower reference values for RVLS in the current recommendations with a cut-off value of  - 20% is underestimated.

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.

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.

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.

Validation of mitral regurgitation reversibility in patients with HeartMate 3 implantation

The resolution of functional mitral valve regurgitation (MR) in patients awaiting left ventricular assist device (LVAD) implantation is discussed controversially. The present study analyzed MR and echocardiographic parameters of the third-generation LVAD HeartMate 3 (HM3) over 3 years. Of 135 LVAD patients (with severe MR, n = 33; with none, mild, or moderate MR, n = 102), data of transthoracic echocardiography were included preoperatively to LVAD implantation, up to 1 month postoperatively, and at 1, 2, and 3 years after LVAD implantation. Demographic data and clinical characteristics were collected. Severe MR was reduced immediately after LVAD implantation in all patients. The echocardiographic parameters left ventricular end-diastolic diameter (P < .001), right ventricular end-diastolic diameter (P < .001), tricuspid annular plane systolic excursion (P < .001), and estimated pulmonary artery pressure (P < .001) decreased after HM3 implantation independently from the grade of MR prior to implantation and remained low during the 2 years follow-up period. Following LVAD implantation, right heart failure, ventricular arrhythmias, ischemic stroke as well as pump thrombosis and bleeding events were comparable between the groups. The incidences of death and cardiac death did not differ between the patient groups. Furthermore, the Kaplan-Meier analysis showed that survival was comparable between the groups (P = .073). HM3 implantation decreases preoperative severe MR immediately after LVAD implantation. This effect is long-lasting in most patients and reinforces the LVAD implantation without MR surgery. The complication rates and survival were comparable between patients with and without severe MR.

Right Ventricular Remodeling in Hypoplastic Left Heart Syndrome is Minimally Impacted by Cardiopulmonary Bypass: A Comparison of Norwood vs. Hybrid

Right ventricular (RV) remodeling in hypoplastic left heart syndrome (HLHS) begins prenatally and continues through staged palliations. However, it is unclear if the most marked observed remodeling post-Norwood is secondary to cardiopulmonary bypass (CPB) exposure or if it is an adaptation intrinsic to the systemic RV. This study aims to determine the impact of CPB on RV remodeling in HLHS. Echocardiograms of HLHS survivors undergoing stage 1 Norwood (n = 26) or Hybrid (n = 20) were analyzed at pre- and post-stage 1, pre- and post-bidirectional cavo-pulmonary anastomosis (BCPA), and pre-Fontan. RV fractional area change (FAC), vector velocity imaging for longitudinal & derived circumferential deformation (global radial shortening (GRS) = peak radial displacement/end-diastolic diameter), and deformation ratio (longitudinal/ circumferential) were assessed. Both groups had similar age, clinical status and functional parameters pre-stage 1. No difference in RV size and sphericity at any stage between groups. RVFAC was normal (> 35%) throughout for both groups. Both Norwood and Hybrid patients had increased GRS (p = 0.0001) post-stage 1 and corresponding unchanged longitudinal strain, resulting in decreased deformation ratio (greater relative RV circumferential contraction), p = 0.0001. Deformation ratio remained decreased in both groups in subsequent stages. Irrespective of timing of the first CPB exposure, both Norwood and Hybrid patients underwent similar RV remodeling, with relative increase in circumferential to longitudinal contraction soon after stage 1 palliation. The observed RV remodeling in HLHS survivors were minimally impacted by CPB.

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).

Heart transplantation ten-year follow-ups: Deformation differentiation comparison of myocardial performance in left ventricle and right ventricle

BACKGROUND

We try to investigate whether the values of three-dimensional principal longitudinal strain present differently between the left and right ventricles in patients with long-time follow-ups after heart transplantation (HTx).

METHODS AND RESULTS

Transthoracic echocardiography with three-dimensional speckle tracking was performed at one-, five- and ten-year follow-ups in 62 "healthy" HTx patients together with routine echocardiographic evaluation in 32 control group (CG) individuals. Longitudinal strain was applied in all subjects assessing without myocardium wall motion abnormality. Firstly, left ventricular ejection fraction preserved in HTx and had no significant difference in comparison with the controls (p > .05). 3D measurement showed obvious reduction in global (%: CG: -20.5 ± 3.5 vs. HT1y: -13.7 ± 4.6, HT5y: -14.4 ± 4.5, HT10y: -14.6 ± 4.7. p < .01) and horizontal segmental (basal, mid, apical, CG vs. HTx: all p < .01) strain values of the left compared HTx with control subjects. Secondly, tissue Doppler imaging s' velocity and tricuspid annular plane systolic excursion reduced in HTx as compared to the controls in right ventricle (p < .01). Longitudinal strain presented a more distinctive reduction in global (%: CG: -24.5 ± 4.6 vs. HT1y:-14.8 ± 7.5, HT5y: -15.5 ± 6.4, HT10y: -15.9 ± 6.8. p < .01) and horizontal segmental (basal, mid, apical, CG vs. HTx: all p < .01) average values of the right compared HTx with control subjects. Thirdly, there weren't any significant changes between one-, five- and ten-year of all the values with HTx inter-group comparison in both the left and right ventricles (p > .05). Fourthly, the global and segmental strain of the right ventricle decreased more than that of the left ventricle in all HTx groups, with the global decreased differentiation rates of 7%, 7%, 6%, respectively.

CONCLUSIONS

Compared HTx with control subjects in both ventricles, conventional evaluation showed preserved or decreased functions in the left and right separately. Myocardial function evaluating by 3D longitudinal strain reduced after HTx, but the deformation of the right ventricle reduced more than those of the left ventricle. Additionally, 3D strain values almost remained with stable decreased differentiation rates during the long-time follow-ups.

Left and right ventricular function detection and myocardial deformation analysis in heart transplant patients with long-time follow-ups

OBJECTIVE

We try to investigate whether the values of longitudinal strain present differences between the left and right ventricles in long-time follow-ups after heart transplantation (HTx) with dynamic changes in function.

METHODS AND RESULTS

Follow-up transthoracic echocardiography was performed in 1- and 3-month and 1- and 5-year follow-ups in 50 "healthy" HTx patients and compared with 26 control subjects. The left ventricle with preserved ejection fraction evaluated by biplane Simpson (control group [CG] vs HT; P > .05) had an obvious reduction in global (CG: -20.49 ± 2.38 vs heart transplant 1 month [HT1m]: -13.06 ± 2.86, heart transplant 3 month [HT3m]: -13.61 ± 2.61, heart transplant 1 year [HT1y]: -13.69 ± 4.56, heart transplant 5 year [HT5y]: -14.41 ± 4.54; P < .001) and horizontal segmental (basal, mid, apical) (P < .001) together with chamber segmental (apical 4-chamber, apical 3-chamber, apical 2-chamber) (P < .001) average strain values. The right ventricle with reduced ventricular function measured by tissue Doppler imaging S' and tricuspid annular plane systolic excursion had a more distinctive reduction in global (CG: -24.53 ± 4.20 vs HT1m: -12.94 ± 5.03, HT3m: -13.68 ± 4.35, HT1y: -14.95 ± 7.50, HT5y: -15.20 ± 6.15; P < .001) with segmental lateral (P < .001) strain values. There were not any significant changes between 1- and 3-month follow-ups of all the values (P > .05). But it could be seen that values increased in 1- and 5-year follow-ups compared with the baseline of 1- and 3-month follow-ups (P < .05). The global and segmental strain of the right ventricle decreased more than that of the left ventricle in all HTx groups, and the strain values were decreased in the HTx groups compared with the CG, with the global decreased change rates being 11%, 10%, 6%, and 8%, respectively.

CONCLUSIONS

The strain values decreased after HTx and almost remained stable in the long-time follow-ups. Compared with the CG in both ventricles, they were with preserved or reduced functions. In addition, the deformation values of the right ventricle decreased more than those of the left.

Left ventricular adaptation following orthotopic heart transplantation in children: A speckle tracking echocardiographic imaging study

BACKGROUND

Evolution of left ventricle (LV) function in the pediatric OHT population has not been well described. Our hypothesis was that, in children following OHT without any rejection, there would be progressive normalization of LV size and function over 2 years.

METHODS

LV function was evaluated using STE and conventional echo parameters at five time points in pediatric OHT patients without any rejection in the first 2 years following OHT and normal controls. LV global peak systolic longitudinal strain (LVPLS) and strain rate, LV peak systolic radial and circumferential strain (LVRS and LVCS), and strain rate were analyzed.

RESULTS

We had twenty two patients with median age at OHT of 1.27 years ( IQR 0.19, 5.6 years). The LVPLS (mean ± SD) was abnormal in the post-OHT echocardiograms at 1 week (-12.4 ± 3.7) and 1 month (-13.9 ± 3.7) and significantly improved at 6 months (-15.8 ± 3.2), 1 year (-15.7 ± 3.1), and 2 years (-17.8 ± 2.8). However, LVPLS remained below the normal group even at 2 years following OHT (-21.3 ± 1.76).

CONCLUSION

In children following OHT, despite the absence of rejection, strain values are significantly impaired in the initial months, improve progressively over the first 2 years but remain abnormal compared with healthy controls.

Serial Changes in Right Ventricular Systolic Function Among Rejection-Free Children and Young Adults After Heart Transplantation

BACKGROUND

Evolution of right ventricular (RV) systolic function after pediatric heart transplantation (HT) has not been well described.

METHODS

We analyzed echocardiograms performed over the first year after HT among children and young adults who remained rejection-free. Ninety-six patients (median age 7.1 [0.1-24.4] years at HT) were included: 22 infants (≤1 year) and 74 noninfants (>1 year). Two-dimensional tricuspid annular plane systolic excursion (TAPSE), tissue Doppler-derived tricuspid annular systolic velocity (S'), fractional area change (FAC), myocardial performance index (MPI), and two-dimensional speckle-tracking-derived RV global longitudinal (GLS) and free wall strain (FWS) were assessed.

RESULTS

All measures of RV function were impaired immediately after HT and significantly improved over the first year: TAPSE z-score (-8.15 ± 1.88 to -3.94 ± 1.65, P < .0001), S' z-score (-4.30 ± 1.36 to -2.28 ± 1.33, P < .0001), FAC (24.37% ± 7.71% to 42.02% ± 7.09%, P < .0001), MPI (0.96 ± 0.47 to 0.41 ± 0.22, P < .0001), GLS (-10.37% ± 3.86% to -21.05% ± 3.41%, P < .0001), and FWS (-11.2% ± 4.08% to -23.66% ± 4.13%, P < .0001). By 1 year post-HT, TAPSE, S', GLS, and FWS, remained abnormal, whereas FAC and MPI nearly normalized. Patients transplanted during infancy demonstrated better recovery of RV systolic function.

CONCLUSIONS

Although RV systolic function improved over the first year after HT in children and young adults without rejection, measures that assess longitudinal contractility remained abnormal at 1 year post-HT. These findings contribute to our understanding of RV myocardial contractility after HT in children and young adults and improve our ability to assess function quantitatively in this population.

Right ventricular function during exercise in children after heart transplantation

Aims

Right ventricular (RV) dysfunction is a common problem after heart transplant (HTx). In this study, we used semi-supine bicycle ergometry (SSBE) stress echocardiography to evaluate RV systolic and diastolic reserve in paediatric HTx recipients.

Methods and results

Thirty-nine pediatric HTx recipients and 23 controls underwent stepwise SSBE stress echocardiography. Colour tissue doppler imaging (TDI) peak systolic (s') and peak diastolic (e') velocities, myocardial acceleration during isovolumic contraction (IVA), and RV free wall longitudinal strain were measured at incremental heart rates (HR). The relationship with increasing HR was evaluated for each parameter by plotting values at each stage of exercise versus HR using linear and non-linear regression models. At rest, HTx recipients had higher HR with lower TDI velocities (s': 5.4 ± 1.7 vs. 10.4 ± 1.8 cm/s, P < 0.001; e': 6.4 ± 2.2 vs.12 ± 2.4 cm/s, P < 0.001) and RV IVA values (IVA: 1.2 ± 0.4 vs. 1.6 ± 0.8 m/s2, P = 0.04), while RV free wall longitudinal strain was similar between groups. At peak exercise, HR was higher in controls and all measurements of RV function were significantly lower in HTx recipients, except for RV free wall longitudinal strain. When assessing the increase in each parameter vs. HR, the slopes were not significantly different between patients and controls except for IVA, which was lower in HTx recipients.

Conclusion

In pediatric HTx recipients RV systolic and diastolic functional response to exercise is preserved with a normal increase in TDI velocities and strain values with increasing HR. The blunted IVA response possibly indicates a mildly decreased RV contractile response but it requires further investigation.

Early assessment of right ventricular systolic function after pediatric heart transplant

RV systolic function is important early after HT; however, it has not been critically assessed in children using quantitative measures. The aim of this study was to describe the most validated and commonly used quantitative echocardiographic measures of RV systolic function early after pediatric HT and to assess associations with qualitative function evaluation and clinical factors. RV systolic function was quantified on the first post-HT echocardiogram >24 hours after cardiopulmonary bypass using two-dimensional TAPSE, Tricuspid annular S', FAC, and MPI. In 145 patients (median age 7.6 years), quantitative RV systolic function was markedly abnormal: mean TAPSE z-score -8.43 ± 1.89; S' z-score -4.36 ± 1.22; FAC 24.4 ± 8.34%; and MPI 0.86 ± 0.51. Few patients had normal quantitative function: TAPSE (0%), S' (1.2%), FAC (9.4%), and MPI (28.4%). In contrast, 48.3% were observed as normal by qualitative assessment. Most clinical factors, including diagnosis, pulmonary vascular resistance, posttransplant hemodynamics, inotropic support, and rejection, were not associated with RV function. In this large pediatric HT population, TAPSE, S', FAC, and MPI were strikingly abnormal early post-HT despite reassuring qualitative assessment and no significant association with clinical factors. This suggests that the accepted normal values of these quantitative measures may not apply in the early post-HT period to accurately grade RV systolic function, and there may be utility in adapting a concept of normal reference values after pediatric HT.

Long-term prognostic value of invasive and non-invasive measures early after heart transplantation

BACKGROUND

Invasively assessed coronary microvascular resistance early after heart transplantation predicts worse long-term outcome; however, little is known about the relationship between microvascular resistance, left ventricular function and outcomes in this setting.

METHODS

A total of 100 cardiac transplant recipients had fractional flow reserve (FFR) and the index of microcirculatory resistance (IMR) measured in the left anterior descending artery and echocardiographic assessment of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) at 1 year after heart transplantation. The primary endpoint was the composite of death and retransplantation occurring beyond the first post-operative year.

RESULTS

The mean FFR, IMR, LVEF, and GLS values at 1 year were 0.87 ± 0.06, 21.3 ± 17.3, 60.4 ± 5.4%, and 14.2 ± 2.4%, respectively. FFR and IMR had no significant correlation with LVEF and GLS. During a mean follow-up of 6.7 ± 4.2 years, the primary endpoint occurred in 24 patients (24.0%). By ROC curve analysis, IMR = 19.3 and GLS = 13.3% were the best cutoff values for predicting death or retransplantation. Cumulative event-free survival was significantly lower in patients with higher IMR (log-rank p = 0.02) and lower GLS (log-rank p < 0.001). Cumulative event-free survival can be further stratified by the combination of IMR and GLS (long-rank p < 0.001). By multivariable Cox proportional hazards model, higher IMR and lower GLS were independently associated with long-term death or retransplantation (elevated IMR, hazard ratio = 2.50, p = 0.04 and reduced GLS, hazard ratio = 3.79, p = 0.003, respectively).

CONCLUSION

Invasively assessed IMR does not correlate with GLS at 1 year after heart transplantation. IMR and GLS determined at 1 year may be used as independent predictors of late death or retransplantation.

Noninvasive monitoring of acute and chronic rejection in heart transplantation

PURPOSE OF REVIEW

Recent years have seen advances in the early detection of cardiac graft rejection.

RECENT FINDINGS

We review the possibilities offered by tissue Doppler imaging and speckle tracking echocardiography, cardiac magnetic resonance, cardiac computed tomography, single positron emission tomography, gene expression profiling, and quantitation of donor-derived cell-free DNA, and microRNAs.

SUMMARY

Noninvasive monitoring of acute and chronic rejection after cardiac transplantation is an unmet need and remains a challenge. Imaging techniques and peripheral blood biomarkers are the most commonly used approaches, and in recent years there has been great progress. Gene expression profiling seems to be useful for ruling out the presence of a moderate to severe acute cellular rejection in stable, low-risk patients. Newer monitoring tools, like donor-derived cell-free DNA or microRNA, seem to be promising for individualizing immunosuppressive therapies and better understanding the mechanisms of rejection.