Frequency, time course, and possible causes of right ventricular systolic dysfunction after cardiac transplantation: a single center experience

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.

Epidemiological Study of Tricuspid Regurgitation After Cardiac Transplantation. Does it Influence Survival?

Background: Tricuspid valve disease is the most frequent valvulopathy after heart transplantation (HTx). Evidence for the negative effect of post-transplant tricuspid regurgitation (TR) on survival is contradictory. The aim of this study was to analyze the causes of post-transplant TR and its effect on overall mortality. Methods: This is a retrospective observational study of all transplants performed in two Spanish centers (1009 patients) between 2000 and 2019. Of the total number of patients, 809 had no TR or mild TR and 200 had moderate or severe TR. The etiology of TR was analyzed in all cases. Results: The prevalence of moderate and severe TR was 19.8%. The risk of mortality was greater when TR was caused by early primary graft failure (PGF) or rejection (p < 0.05). TR incidence was related to etiology: incidence of PGF-induced TR was higher in the first period, while TR due to rejection and undefined causes occurred more frequently in three periods: in the first year, in the 10-14-year period following HTx, and in the long term (16-18 years). In the multivariable analysis, TR was significantly associated with mortality/retransplantation (HR:1.04, 95% CI:1.01-1.07, p:0.02). Conclusion: The development of TR after HTx is relatively frequent. The annual incidence depends on TR severity and etiology. The risk of mortality is greater in severe TR due to PGF or rejection.

Impact of increased donor distances following adult heart allocation system changes: A single center review of 1-year outcomes

BACKGROUND

On October 18, 2018, several changes to the donor heart allocation system were enacted. We hypothesize that patients undergoing orthotopic heart transplantation (OHT) under the new allocation system will see an increase in ischemic times, rates of primary graft dysfunction, and 1-year mortality due to these changes.

METHODS

In this single-center retrospective study, we reviewed the charts of all OHT patients from October 2017 through October 2019. Pre- and postallocation recipient demographics were compared. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

A total of 184 patients underwent OHT. Recipient demographics were similar between cohorts. The average distance from donor increased by more than 150 km (p = .006). Patients in the postallocation change cohort demonstrated a significant increase in the rate of severe left ventricle primary graft dysfunction from 5.4% to 18.7% (p = .005). There were no statistically significant differences in 30-day mortality or 1-year survival. Time on the waitlist was reduced from 203.8 to 103.7 days (p = .006).

CONCLUSIONS

Changes in heart allocation resulted in shorter waitlist times at the expense of longer donor distances and ischemic times, with an associated negative impact on early post-transplantation outcomes. No significant differences in 30-day or 1-year mortality were observed.

Donor-recipient predicted heart mass ratio and right ventricular-pulmonary arterial coupling in heart transplant

OBJECTIVES

Right ventricular-pulmonary arterial (RV-PA) coupling interactions are largely unexplored in heart transplant patients. The outcome of this study was RV-PA coupling at 7 and 30 days after heart transplant and its association with donor-recipient size matching.

METHODS

Clinical, echocardiographic and haemodynamic data from a retrospective cohort of heart transplant recipients and respective donors were reviewed. Coupling between RV-PA was examined by assessing the RV fractional area change and pulmonary artery systolic pressure ratio. Donor-recipient size matching was assessed by the predicted heart mass (PHM) ratio, and groups with a PHM ratio <1 and ≥1 were compared.

RESULTS

Forty-four heart transplant recipients were included in this study (50 years, 57% male sex). Postoperative RV-PA coupling improved from 7 to 30 days (RV fractional area change/pulmonary artery systolic pressure 0.9 ± 0.3 vs 1.2 ± 0.3; P < 0.001). A positive association was found between an adequate PHM ratio and improvement of RV fractional area change/pulmonary artery systolic pressure at 30 days, independent of graft ischaemic time and pre-existent pulmonary hypertension (B coefficient 0.54; 95% confidence interval 0.11-0.97; P = 0.016; adjusted R2 = 0.24).

CONCLUSIONS

These findings highlight the role of PHM as a metric to help donor selection and suggest its impact in RV-PA coupling interactions post-heart transplant.

Anesthetic protocol for right ventricular dysfunction management in heart transplantation: systematic review, development and validation

BACKGROUND

Right Ventricular Dysfunction (RVD) is the most frequent intraoperative hemodynamic complication in Heart Transplantation (HTx). RVD occurs in 0.04-1.0% of cardiac surgeries with cardiotomy and in 20-50% of HTx, with mortality up to 75%. No consensus has been established for how anesthesiologists should manage RVD, with management methods many times remaining unvalidated.

METHODS

We conducted a systematic review, following PRISMA guidelines, to create an anesthetic protocol to manage RVD in HTx, using databases that include PubMed and Embase, until September 2018 based on inclusion and exclusion criteria. The articles screening for the systematic review were done two independent reviewers, in case of discrepancy, we consulted a third independent reviewer. Based on the systematic review, the anesthetic protocol was developed. The instrument selected to perform the validation of the protocol was AGREE II, for this purpose expert anesthetists were recruited to do this process. The minimum arbitration score for domains validation cutoff of AGREE II is arbitered to 70%. This study was registered at PROSPERO (115600).

RESULTS

In the systematic review, 152 articles were included. We present the protocol in a flowchart with six steps based on goal-directed therapy, invasive monitoring, and transesophageal echocardiogram. Six experts judged the protocol and validated it.

CONCLUSION

The protocol has been validated by experts and new studies are needed to assess its applicability and potential benefits on major endpoints.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Altered Biatrial Phasic Function after Heart Transplantation in Children

PURPOSE

We used two-dimensional echocardiographic speckle-tracking to investigate whether left and right atrial (LA and RA) phasic function in pediatric heart transplantation (HT) patients is altered and explored the relationship to HT-related clinical variables.

METHODS

Eighty-six subjects (36 HT and 50 normal children) were prospectively enrolled in two centers. Clinical data included age at HT, bypass time, ischemia time, donor age, and incidence of rejection. Atrial deformation indices including strain and strain rates (SRs) were measured using two-dimensional echocardiographic speckle-tracking. Components of phasic atrial function-reservoir (ε_r, SR_r), conduit (ε_cd, SR_cd), and booster (ε_ct, SR_ct) were calculated. Comparisons with controls were made using t test or Kruskal-Wallis test, and correlations to clinical variables were explored.

RESULTS

The mean age and body surface area of HT subjects were 10.2 ± 6.2 years and 1.2 ± 0.6 m², respectively. The mean heart rates were higher in HT (96 ± 18 vs 88 ± 21 in controls). There were reductions in RA and LA reservoir (ε_r, SR_r), conduit (ε_cd, SR_cd), and booster (ε_ct, SR_ct) function in HT compared with controls. There was no relationship of LA and RA deformation indices with mean age at HT, bypass time, or ischemia time. The LA ε_cd correlated weakly with donor age (r = -0.49, P = .04) and RA SR_r, and SR_cd showed association with duration of HT (P < .05). Nineteen HT recipients had follow-up studies 0.24 ± 0.18 years after the first examination, and deformational indices were not significantly changed.

CONCLUSIONS

Atrial strain determination is feasible in pediatric HT recipients and demonstrates disruption of reservoir, conduit, and booster function of both atria in this population; we speculate this may be a consequence of ventricular diastolic dysfunction.

Cardiac Magnetic Resonance Feature Tracking Global Longitudinal Strain and Prognosis After Heart Transplantation

OBJECTIVES

This study determined the long-term prognostic significance of GLS assessed using CMR-FT in a large cohort of heart transplant recipients.

BACKGROUND

In heart transplant recipients, global longitudinal strain (GLS) assessed using echocardiography has shown promise in the prediction of clinical outcomes. We hypothesized that CMR feature tracking (CMR-FT) GLS is independently associated with long-term outcomes in heart transplant recipients.

METHODS

In a cohort of consecutive heart transplant recipients who underwent routine CMR for clinical surveillance, CMR-FT GLS was calculated from 3 long-axis cine CMR images. Associations between GLS and a composite endpoint of death or major adverse cardiac events (MACE), including retransplantation, nonfatal myocardial infarction, coronary revascularization, and heart failure hospitalization, were investigated.

RESULTS

A total of 152 heart transplant recipients (age 54 ± 15 years; 29% women; 5.0 ± 5.4 years after heart transplantation) were included. The median GLS was -11.6% (interquartile range: -13.6% to -9.2%). Over a median follow-up of 2.6 years, 59 recipients reached the composite endpoint. On Kaplan-Meier analyses, recipients with GLS worse than the median had a higher estimated cumulative incidence of the composite endpoint compared with recipients with GLS better than the median (log rank p = 0.004). On multivariate Cox proportional hazards regression, GLS was independently associated with the composite endpoint after adjustment for cardiac allograft vasculopathy, history of rejection, left ventricular ejection fraction (LVEF), right ventricular EF, and presence of myocardial fibrosis, with a hazard ratio of 1.15 for every 1% worsening in GLS (95% confidence interval: 1.06 to 1.24; p < 0.001). Similar results were seen in subgroups of recipients with LVEF >50% and with no myocardial fibrosis. GLS provided incremental prognostic value over other variables in the multivariate model as determined by the log-likelihood chi-squared test.

CONCLUSIONS

In a large cohort of heart transplant recipients, CMR-FT GLS was independently associated with the long-term risk of death or MACE.

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.

Tricuspid Valve Regurgitation Immediately After Heart Transplant and Long-Term Outcomes

BACKGROUND

Tricuspid valve regurgitation (TR) is a common finding immediately after cardiac transplantation. However, there is a scarcity of data regarding its implication if left untreated on long-term outcomes and the role of early surgical repair.

METHODS

We retrospectively reviewed the Duke University Medical Center transplant database from January 2000 to June 2012 and identified 542 patients who underwent orthotropic heart transplantation. Patients were excluded if they underwent surgical repair for TR during the transplant or if the transplant was part of a multiorgan transplant or redo heart transplantation. TR was assessed intraoperatively after weaning from cardiopulmonary bypass. Independent variables were grade of TR and changes in TR grade during follow-up. TR grades were classified as insignificant (none or mild) versus significant (moderate or severe). Survival and need for posttransplant valve repair during follow-up were assessed.

RESULTS

Significant TR was detected in 114 patients (21%) after weaning from cardiopulmonary bypass, with no significant difference in preoperative recipient pulmonary vascular resistance. Significant TR was associated with increased maximum postoperative plasma creatinine (median [interquartile range], 2.2 [1.5 to 3.2] mg/dL vs 1.8 [1.4 to 2.6] mg/dL, p = 0.008), prolonged postoperative stay (median [interquartile range], 12 [9 to 21] days vs 10 [8 to 14] days; p < 0.001), and decreased adjusted survival. Significant TR regressed to insignificant in 91% of recipients by 1 year after transplant. Six recipients (1%) who had significant TR after cardiopulmonary bypass underwent delayed tricuspid valve repair for significant TR during follow-up.

CONCLUSIONS

Significant TR is a common finding immediately after transplant and is associated with early morbidity and reduced adjusted survival. Most significant TR resolves by 1 year after transplant. Optimal algorithms for follow-up and treatment of significant TR after heart transplantation need to be defined.

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.