Changes in cardiac parameters of renal allograft recipients: a compilation of clinical, laboratory, and echocardiographic observations

Left Ventricular Hypertrophy After Renal Transplantation: Systematic Review and Meta-analysis

Background

Left ventricular hypertrophy (LVH) in patients with end stage renal disease undergoing renal replacement is linked to an increased risk for cardiovascular diseases. Dialysis does not completely prevent or correct this abnormality, and the evidence for kidney transplantation (KT) varies. This analysis aims to explore the relationship between KT and LVH.

Methods

MEDLINE and Scopus were systematically searched in October 2023. All cross-sectional and longitudinal studies that fulfilled our inclusion criteria were included. Outcome was left ventricular mass index (LVMI) changes. We conducted a meta-analysis using a random effects model. Meta-regression was applied to examine the LVMI changes dependent on various covariates. Sensitivity analysis was used to handle outlying or influential studies and address publication bias.

Results

From 7416 records, 46 studies met the inclusion criteria with 4122 included participants in total. Longitudinal studies demonstrated an improvement of LVMI after KT -0.44 g/m2 (-0.60 to -0.28). Blood pressure was identified as a predictor of LVMI change. A younger age at the time of KT and well-controlled anemia were also associated with regression of LVH. In studies longitudinally comparing patients on dialysis and renal transplant recipients, no difference was detected -0.09 g/m2 (-0.33 to 0.16). Meta-regression using changes of systolic blood pressure as a covariate showed an association between higher blood pressure and an increase in LVMI, regardless of the modality of renal replacement treatment.

Conclusions

In conclusion, our results indicated a potential cardiovascular benefit, defined as the regression of LVH, after KT. This benefit was primarily attributed to improved blood pressure control rather than the transplantation itself.

Incidence, Clinical Correlates, and Outcomes of Pulmonary Hypertension After Kidney Transplantation: Analysis of Linked US Registry and Medicare Billing Claims

BACKGROUND

The incidence, risks, and outcomes associated with pulmonary hypertension (P-HTN) in the kidney transplant (KTx) population are not well described.

METHODS

We linked US transplant registry data with Medicare claims (2006-2016) to investigate P-HTN diagnoses among Medicare-insured KTx recipients (N = 35 512) using billing claims. Cox regression was applied to identify independent correlates and outcomes of P-HTN (adjusted hazard ratio [aHR] 95%LCLaHR95%UCL) and to examine P-HTN diagnoses as time-dependent mortality predictors.

RESULTS

Overall, 8.2% of recipients had a diagnostic code for P-HTN within 2 y preceding transplant. By 3 y posttransplant, P-HTN was diagnosed in 10.310.6%11.0 of the study cohort. After adjustment, posttransplant P-HTN was more likely in KTx recipients who were older (age ≥60 versus 18-30 y a HR, 1.912.403.01) or female (aHR, 1.151.241.34), who had pretransplant P-HTN (aHR, 4.384.795.24), coronary artery disease (aHR, 1.051.151.27), valvular heart disease (aHR, 1.221.321.43), peripheral vascular disease (aHR, 1.051.181.33), chronic pulmonary disease (aHR, 1.201.311.43), obstructive sleep apnea (aHR, 1.151.281.43), longer dialysis duration, pretransplant hemodialysis (aHR, 1.171.371.59), or who underwent transplant in the more recent era (2012-2016 versus 2006-2011: aHR, 1.291.391.51). Posttransplant P-HTN was associated with >2.5-fold increased risk of mortality (aHR, 2.572.843.14) and all-cause graft failure (aHR, 2.422.642.88) within 3 y posttransplant. Outcome associations of newly diagnosed posttransplant P-HTN were similar.

CONCLUSIONS

Posttransplant P-HTN is diagnosed in 1 in 10 KTx recipients and is associated with an increased risk of death and graft failure. Future research is needed to refine diagnostic, classification, and management strategies to improve outcomes in KTx recipients who develop P-HTN.

Comparison of left atrial deformation parameters between renal transplant and hemodialysis patients

Background

Renal transplantation (RT) has been demonstrated to improve left ventricular systolic function. However, only few studies have attempted to reveal the effects of transplantation on left atrial (LA) function. In our study, we aimed to compare LA function between RT and hemodialysis patients.

Methods

This cross-sectional study included 75 consecutive patients with RT, and 75 age- and gender-matched patients on maintenance hemodialysis. LA strain and strain rate (SR) analyzed by two-dimensional (2D) speckle tracking echocardiography (STE) were compared between the groups in addition to standard echocardiographic parameters.

Results

LA strain during reservoir phase (29.88 ± 5.76% vs 26.11 ± 5.74%, P < .001), LA strain during conduit phase (− 15.28 ± 5.00% vs − 12.92 ± 4.38%, P = .003), and LA strain during contraction phase (− 14.60 ± 3.32% vs − 13.19 ± 3.95%, P = .020) were higher in the transplantation group. Similarly, LA peak SR during reservoir phase (1.54 ± 0.33 s^− 1 vs 1.32 ± 0.33 s^− 1, P < .001), LA peak SR during conduit phase (− 1.47 ± 0.49 s^− 1 vs − 1.12 ± 0.42 s^− 1, P < .001), and LA peak SR during contraction phase (− 2.13 ± 0.46 s^− 1 vs − 1.83 ± 0.58 s^− 1, P = .001) were higher in the transplantation group as well.

Conclusions

LA function assessed by 2D STE was better in RT patients than hemodialysis patients. This may suggest favorable effects of RT on LA function.

Pulmonary Hypertension in Chronic Kidney Disease

There is a high prevalence of pulmonary hypertension in chronic kidney disease (CKD), with rates increasing as glomerular filtration rate declines. Pulmonary hypertension is associated with a higher risk of cardiovascular events and mortality in non-dialysis-dependent CKD stages 3 to 5, dialysis-dependent CKD, as well as kidney transplant recipients. The pathophysiology of pulmonary hypertension in CKD is multifactorial and includes higher pulmonary capillary wedge pressure caused by ischemic heart disease and cardiomyopathy, higher cardiac output caused by anemia and arteriovenous access used for hemodialysis, as well as potentially higher pulmonary vascular resistance. Treatment should focus on the underlying cause.

Kidney Transplantation Confers Survival Benefit for Candidates With Pulmonary Hypertension

Kidney transplantation (KT) is controversial in patients with pretransplant pulmonary hypertension (PtPH). We aimed to quantify post-KT graft and patient survival as well as survival benefit in recipients with PtPH.

Methods

Using UR Renal Data System (2000-2018), we studied 90 819 adult KT recipients. Delayed graft function, death-censored graft failure, and mortality were compared between recipients with and without PtPH using inverse probability weighted logistic and Cox regression. Survival benefit of KT was determined using stochastic matching and stabilized inverse probability treatment Cox regression.

Results

Among 90 819 KT recipients, 2641 (2.9%) had PtPH. PtPH was associated with higher risk of delayed graft function (odds ratio, 1.23; 95% CI, 1.10-1.36; P < 0.01), death-censored graft failure (hazard ratio [HR], 1.23; 95% CI, 1.11-1.38; P < 0.01), and mortality (HR, 1.56; 95% CI, 1.44-1.69; P < 0.01). However, patients with PtPH who received a KT had a 46% reduction in mortality (HR, 0.54; 95% CI, 0.48-0.61; P < 0.01) compared with those who remained on the waitlist.

Conclusions

Although PtPH is associated with inferior post-KT outcomes, KT is associated with better survival compared with remaining on the waitlist. Therefore, KT is a viable treatment modality for appropriately selected patients with PtPH.

Changes in left ventricular structure and function associated with renal transplantation: a systematic review and meta-analysis

Aims

This study aimed to examine if the cardiac changes associated with uraemic cardiomyopathy are reversed by renal transplantation.

Methods and results

MEDLINE, Embase, OpenGrey, and the Cochrane Library databases were searched from 1950 to March 2020. The primary outcome measure was left ventricular mass index. Secondary outcome measures included left ventricular dimensions and measures of diastolic and systolic function. Studies were included if they used any imaging modality both before and after successful renal transplantation. Data were analysed through meta‐analysis approaches. Weight of evidence was assessed through the Grading of Recommendations Assessment, Development and Evaluation system. Twenty‐three studies used echocardiography, and three used cardiac magnetic resonance imaging as their imaging modality. The methodological quality of the evidence was generally poor. Four studies followed up control groups, two using cardiac magnetic resonance imaging and two using echocardiography. Meta‐analysis of these studies indicated that there was no difference in left ventricular mass index between groups following transplantation {standardized mean difference −0.07 [95% confidence interval (CI) −0.41 to 0.26]; P = 0.67}. There was also no difference observed in left ventricular ejection fraction [mean difference 0.39% (95% CI −4.09% to 4.87%); P = 0.86] or left ventricular end‐diastolic volume [standardized mean difference −0.24 (95% CI −0.94 to 0.45); P = 0.49]. Inconsistent reporting of changes in diastolic dysfunction did not allow for any meaningful analysis or interpretation.

Conclusions

The evidence does not support the notion that uraemic cardiomyopathy is reversible by renal transplantation. However, the evidence is limited by methodological weaknesses, which should be considered when interpreting these findings.

Kidney transplantation in valvular heart disease and pulmonary hypertension: Consensus in waiting

Kidney transplantation induces a lesser anesthetic, surgical, and physiological alterations than other solid organ transplantation. Concomitant valvular pathologies expose these patients to poor postoperative outcome. There is a critical gap in knowledge and lack of coherence in the guidelines related to the management in patients with end-stage renal disease with valvular heart disease. The individualized diagnostic and management plan should be based on the assessment of perioperative outcomes. Similarly, pulmonary hypertension in end-stage renal disease poses a unique challenge, it can manifest in isolation or may be associated with other cardiac lesions, namely left-sided valvular heart disease and left ventricular systolic and diastolic dysfunction. Quantification and stratification according to etiology are needed in pulmonary hypertension to ensure an adequate management plan to minimize the adverse perioperative outcomes. Lack of randomized controlled trials has imposed hindrance in proposing a unified approach to clinical decision-making in these scenarios. In this review, we have described the magnitude of the problems, pathophysiologic interactions, impact on clinical outcomes and have also proposed a management algorithm for both the scenarios.

To ligate or not to ligate hemodialysis arteriovenous fistulas in kidney transplant patients

There is significant disagreement about maintenance or ligation of arteriovenous fistulas (AVFs) in kidney transplant patients (KTPs). Potential harms from maintaining AVFs are their impact on cardiac function, cosmetic concerns and complications such as bleeding and rupture. High flow AVFs can place a strain on the heart and cause or exacerbate pre-existing cardiac dysfunction. There is an improvement in cardiac function after kidney transplantation independent of vascular access status. Studies comparing cardiac parameters in patients with and without AVFs after renal transplantation have shown conflicting results. Ligation of high flow AVFs in KTPs resulted in improvement in cardiac function and prevention of heart failure. In KTPs with deteriorating renal function and high flow AVFs, banding of the AVFs to reduce flow is an option. Patients who retain AVFs after renal transplant have the advantage of immediate, optimal access should the transplant fail and may have preserved kidney function. The patient's post-transplant kidney function, risk factors for transplant loss, AVF blood flow, and cardiac function play an important role when making the decision to ligate or preserve AVFs.

The effect of kidney transplantation on speckled tracking echocardiography findings in patients on hemodialysis

Introduction: Cardiac dysfunction is a major cause of morbidity and mortality in patients with end-stage renal disease (ESRD). Previous studies have shown that kidney transplantation can reverse some of the gross changes in the myocardial structure such as left ventricular ejection fraction (LVEF) and volumes. Whether kidney transplantation can reverse the subtle and early myocardial changes in ESRD patients who do not suffer from gross alternations in myocardial function is not yet studied. The aim of this study was to answer this question. Methods: We followed 25 patients with ESRD at baseline that all of them had a kidney transplant and were reassessed 1 month after the transplantation. Conventional and speckle tracking echocardiography (STE)was done at baseline and 1 month after kidney transplantation in patients. Results: LV hypertrophy was the most prevalent finding at baseline (58%), followed by diastolic dysfunction (53%). Kidney transplantation significantly improved the ejection fraction (EF) (treatment effect = 4.23 ± 2.06%; P = 0.046) and apical 4-chamber strain (treatment effect = -0.89 ± 0.37%; P = 0.021) in the patients. It also reduced the LV mass index (treatment effect = -73.82 ± 11.6; P < 0.001) and relative wall thickness (treatment effect = -0.056±0.023; P = 0.021). Other variables including global longitudinal strain and diastolic dysfunction were not improved significantly. Conclusion: STE may show early improvements in myocardial function 1 month after renal transplantation.

Regression of left atrial diameter after kidney transplantation is associated with prolonged survival: an observational study

Renal transplantation reduces the dramatically elevated risk of cardiovascular death in dialysis patients. We previously showed that left atrial diameter before transplantation predicts cardiovascular and overall mortality. Now, we investigated the association of changes in cardiac morphology after transplantation and mortality. We retrospectively analyzed data from the Austrian transplant repository using multivariable Cox and competing risk models and multivariable logistic regression for the prediction of changes in cardiac morphology. We identified 414 patients with a median follow-up of 8 years and observed a significant progression of mean diameter of left atrium (LA), right atrium and right ventricle and a significant regression of left ventricle. Complete case analysis of 243 patients with a regression of initially enlarged LA diameter had a significantly lower risk of adjusted overall and cardiovascular mortality; hazard ratio (HR 0.45, 95% CI 0.30-0.69, P < 0.001, 124 deaths), and HR of 0.43 [95% CI 0.21-0.92, P = 0.029, 48 cardiovascular (CV) deaths], respectively. Only age at transplantation was significantly associated with regression of LA (OR 0.75, 95% CI 0.60-0.93, P = 0.007). Patients with regression of LA after kidney transplantation exhibited a lower overall and CV mortality risk. Besides age, peritoneal dialysis and antihypertensive therapy were mediators of LA regression.

Impact of renal transplantation on cardiac morphological and functional characteristics in children and adults

AIM

To compare the effects of renal transplantation on cardiac functions in children and adults.

METHODS

One hundred and ten patients attending the nephrology outpatient clinic were enrolled in this study and were divided into six groups. The first two groups consisted each of 30 renal transplant patients who had a successful renal transplantation more than six months, but less than one year. Group I were less than 18 years and group II were more than 18 years. The third and fourth groups, each were 20 chronic renal failure patients on regular hemodialysis. Again, group III were less than 18 years and group IV were more than 18 years. Group V and VI (The control Groups) consisted each of 5 subjects below and above 18 years of age, respectively with normal kidney functions. All patients were subjected to history and examination. The kidney functions and the hemoglobin were analyzed. After obtaining informed consent, echocardiography was done to all patients.

RESULTS

There was a statistically significant improvement (P < 0.0001) in all cardiac parameters. A regression in left ventricular end diastolic volume (LVED) both in children (4.7 ± 0.8 to 4.2 ± 0.5) and in adults (5.9 ± 0.7 to 4.9 ± 0.6) were found. There was a regression in left ventricular end systolic volume (LVES) both in children (3.1 ± 0.6 to 2.4 ± 0.4) and in adults (4.1 ± 0.9 to 3.1 ± 0.5). Fractional shortening improves both in children (32.6 ± 5.3 to 41.7 ± 7.6) and in adults (29.0 ± 6.6 to 36.5 ± 4.1). The improvement in ejection fraction (EF) was higher in children (59.7 ± 7.0 to 71.9 ± 6.1) than in adults (52.0 ± 12.5 to 64.8 ± 5.9). However, this degree of improvement (in children: 12.2 ± 5.1) did not show statistical difference (P-value 0.8), when compared to adults (12.7 ± 9.8).

CONCLUSION

After renal transplantation cardiac functions and morphology (EF/LVED/LVES) do improve markedly and rapidly in both children and adults.

Relationship between fragmented QRS complex and left ventricular systolic and diastolic function in kidney transplant patients

BACKGROUND

Kidney transplant is a most important replacement therapy. It reduces cardiovascular mortality and morbidity but does not fully correct impairments in cardiac function. Fragmented QRS (fQRS) complex includes various RSR' patterns with different QRS complex morphologies on electrocardiograms.

OBJECTIVE

To analyze fQRS frequency and the relationship between fQRS and left ventricular function in kidney transplant patients.

METHOD

-After demographic data on 39 kidney transplant patients were recorded and biochemical parameters were investigated, electrocardiograms were evaluated for the presence of fQRS. Left ventricular ejection fraction, mitral annular plane systolic excursion, peak early diastolic mitral annular velocities, late diastolic mitral annular velocities, and systolic mitral annular velocity were analyzed.

RESULTS

Fragmented QRS was detected in 16 patients. A history of hypertension was associated with the presence of fQRS. Patients with fQRS had significantly lower systolic and peak early diastolic mitral annular velocities, mitral annular plane systolic excursion, and left ventricular ejection fraction than did patients without fQRS (P= .03, .01, <.001, and .03, respectively).

CONCLUSION

Detection of fQRS on electrocardiograms may be useful in predicting systolic and diastolic dysfunction of the left ventricle in kidney transplant patients.

Insertion/deletion polymorphism of the angiotensin-converting enzyme predicts left ventricular hypertrophy after renal transplantation

BACKGROUND

Kidney transplant recipients show a higher risk for cardiovascular complications, such as left ventricular hypertrophy and heart failure, leading to the premature death in many cases.

METHODS

We investigated the contribution of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism to the development of left ventricular hypertrophy (LVH), an indicator of heart disease progression among kidney transplant recipients.

RESULTS

We observed a significant correlation between graft function and left ventricular mass index. The occurrence of LVH or severe LVH was significantly greater among patients with at least one D-allele (ID or DD).

CONCLUSION

The use of ACE inhibitors or angiotensin receptor blockers seemed to be advantageous for patients with the ID and especially, the DD genotype.