Noninvasive Assessment of Left Ventricular Function Prior to and 6 Months After Renal Transplantation

Cardiac evaluation in patients awaiting kidney transplant-position statement of the Cardiological Society of India and Indian Society of Nephrology

Cardiovascular diseases are a major cause of death after kidney transplantation. This statement addresses preoperative cardiac decision-making and management with the aim of assessing and reducing the risk of the kidney transplant surgery. Important issues from a clinician's perspective include the basic cardiovascular workup of these patients, coronary evaluation and management of coronary artery disease, valvular heart disease and left ventricular systolic dysfunction. Recovery left ventricular function after kidney transplant is discussed. In addition, the use of cardiovascular drugs in patients with special emphasis on antiplatelets and anticoagulants in patients planned for kidney transplant is also discussed.

Improvement in Echocardiographic Indexes of Systolic Heart Failure Post-Kidney Transplantation: A Retrospective Analysis

INTRODUCTION

End-stage renal disease is a major risk factor for cardiovascular morbidity and mortality, which can be partially eliminated by kidney transplantation. Systolic heart failure might be considered contraindication for kidney transplant, although some patients demonstrate myocardial recovery post-transplant. We aimed to identify and characterize the phenomenon of reverse myocardial remodeling in kidney transplanted patients.

METHODS

The study is a retrospective cohort of patients undergoing kidney transplants between 2016 and 2019 (n = 604) at Rabin Medical Center. Patients were assessed according to availability of two echocardiographic examinations: pre- and post-kidney transplant. The change in estimated ejection fraction (EF) and possible predictors of myocardial recovery were examined.

RESULTS

Data of 293 patients was available for the final analysis. Eighty-one (28%) patients had a LVEF improvement equal to or above 5%, whereas 36 (12%) patients had a LVEF improvement of 10% or more post-transplantation. Twenty-five patients (8.5%) had moderate or severe systolic heart failure with LVEF reduced to 40% or less at baseline. 13 of them (52%) had a LVEF improvement of ≥5%, and 10 patients (40%) had an improvement of ≥10% in their EF. Cox regression analyses identified female gender as the only independent variable associated with LVEF improvement of at least 10%.

CONCLUSION

Renal transplantation might lead to improved LV systolic function in some patients.

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.

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.

The effect of renal transplantation on left ventricular function, electrocardiography, and mechanical synchrony by gated myocardial perfusion imaging

BACKGROUND

Depressed left ventricular ejection fraction (LVEF), LV mechanical dyssynchrony (LVMD), and prolonged QTc interval predict poor outcomes in end-stage renal disease (ESRD). Renal transplantation improves mortality in ESRD patients but the effects of transplantation on these indices remain undefined.

METHODS

We identified patients with myocardial perfusion imaging (MPI) before and after renal transplantation. A control group consisted of ESRD patients who underwent 2 MPIs but did not receive a transplant. Changes in LVEF, LVMD indices [phase standard deviation (SD) and bandwidth (BW)] by MPI, and electrocardiogram (ECG) indices were determined.

RESULTS

The study population consisted of 32 ESRD patients (53% male, 50 ± 11 years, 59% African American, 65% diabetic). The second MPI was performed 31 months (13-59 months) after renal transplantation. LVEF (72 ± 10% vs. 67 ± 10%, P < 0.001) but not SD (22 ± 15° vs. 22 ± 11°, P = 0.9) or BW (58 ± 35° vs. 57 ± 29°, P = 0.9) improved after transplantation. There were no changes in these indices in the control group. QTc (425 ± 30 ms vs. 447 ± 32 ms, P = <0.001) but not QRS (90 ± 21 ms vs. 90 ± 21 ms, P = 0.9) improved significantly after renal transplantation.

CONCLUSIONS

LVEF and QTc improved after renal transplantation but LVMD indices and QRS did not change, which suggests that LVMD and electrical dyssynchrony may be irreversible in ESRD.

Study of Echocardiographic Changes After Kidney Transplantation in End-stage Renal Disease Patients

Background

Cardiovascular complications are the leading cause of mortality in end-stage renal disease (ESRD) patients. This study aimed to evaluate the efficacy of kidney transplantation on the cardiovascular status in ESRD patients.

Methods

During 2012 to 2014 and in a cross-sectional study, 181 patients were randomly selected for this study. All patients were followed for periods of 6 and 12 months after kidney transplantation. The patients with ESRD and kidney transplant recipients; the patients with left ventricle ejection fraction<50%, left ventricular hypertrophy, mitral valve regurgitation and tricuspid valve regurgitation were included to study and the patients with kidney transplant rejection, myocardial infarction, high blood pressure with treatment-resistant, high blood pressure and addicted patients were censored.

Results

one hundred and eighty-one patients had the mean age of 38.52 (range, 16-69 years) that 54.7% were men and the mean duration of dialysis was 3.74 years. There were significant differences after 6 and 12 months compared with before and also 6 months compared with 12 months from kidney transplantation for all echocardiographic findings. The echocardiographic findings improved after 12 months compared with 6 months and also these times compared with before kidney transplantation.

Conclusions

The results of this study appeared that kidney transplantation had a positive effect on the cardiovascular status of patients with ESRD and improved the cardiac function of these patients.

Exercise limitation following transplantation

Organ transplantation is one of the medical miracles or the 20th century. It has the capacity to substantially improve exercise performance and quality of life in patients who are severely limited with chronic organ failure. We focus on the most commonly performed solid-organ transplants and describe peak exercise performance following recovery from transplantation. Across all of the common transplants, evaluated significant reduction in VO2peak is seen (typically renal and liver 65%-80% with heart and/or lung 50%-60% of predicted). Those with the lowest VO2peak pretransplant have the lowest VO2peak posttransplant. Overall very few patients have a VO2peak in the normal range. Investigation of the cause of the reduction of VO2peak has identified many factors pre- and posttransplant that may contribute. These include organ-specific factors in the otherwise well-functioning allograft (e.g., chronotropic incompetence in heart transplantation) as well as allograft dysfunction itself (e.g., chronic lung allograft dysfunction). However, looking across all transplants, a pattern emerges. A low muscle mass with qualitative change in large exercising skeletal muscle groups is seen pretransplant. Many factor posttransplant aggravate these changes or prevent them recovering, especially calcineurin antagonist drugs which are key immunosuppressing agents. This results in the reduction of VO2peak despite restoration of near normal function of the initially failing organ system. As such organ transplantation has provided an experiment of nature that has focused our attention on an important confounder of chronic organ failure-skeletal muscle dysfunction.

Left Ventricle Hypertrophy, Dilatation and Ejection Fraction Changes Before and After Kidney Transplantation

Background

Patients with end stage renal disease (ESRD) are at risk of complications in different organs including cardiovascular system. Renal transplantation is the best choice in these patients which diminishes these complications. It is observed that after renal transplantation, cardiac parameters have appropriate improvement. Current study evaluates echocardiographic findings in renal transplant recipients before and after kidney transplantation.

Methods

In an analytic cross sectional study, 30 patients (50% male, mean age of 45.57 ± 13.32 years) with ESRD who underwent renal transplantation were studied. All patients had echocardiographic studies after the last dialysis before and 6 months after transplantation. Echocardiographic study was done by Color Doppler two dimension methods and left ventricle ejection fraction was measured by Simpson method. All echocardiograms before and after transplantation were interpreted by the same cardiologist.

Results

Mean left ventricle ejection fraction before and after renal transplantation was 53.83±10.14% and 57.33±4.49%, respectively (P = 0.09). Left ventricle hypertrophy, mitral regurgitation and tricuspid regurgitation existed in 46.7%, 76.7% and 33.3% respectively, which was improved in 30%, 50% and 33.3% after renal transplantation.

Conclusion

According to the results of current study it is suggested that renal transplantation could improve left ventricle parameters in patients with end stage renal disease.

Reversible cardiomyopathies--a review

End-stage renal disease, cirrhosis, obesity, tachycardia, and extreme stress have all been shown to result in impaired left ventricular function. It is becoming clear, however, that the cardiomyopathies associated with these states are reversible after resolution of the underlying process. In this article, we present the current data demonstrating that renal transplantation, liver transplantation, and bariatric surgery can lead to reversal of uremic, cirrhotic, and obesity cardiomyopathies, respectively. We also discuss the reversibility of tachycardia-induced cardiomyopathy after radiofrequency ablation or pharmacologic therapy for rate or rhythm control and the reversibility of stress-induced cardiomyopathy with supportive care.

The impact of kidney transplantation on heart failure risk varies with candidate body mass index

BACKGROUND

The relationship of body mass index (BMI) with heart failure (HF) risk before and after kidney transplant is not well described.

METHODS

We examined United States Renal Data System records for 67,591 kidney transplant candidates (1995-2004) with Medicare insurance and BMI data at listing. Heart failure diagnoses were ascertained from Medicare billing claims. Body mass index was categorized per World Health Organization criteria. We modeled time-dependent associations (adjusted hazard ratio, aHR) of transplant with HF risk after listing compared with waiting in each BMI group by multivariable, stratified Cox regression. The time-dependent exposure variables partitioned relative risk of HF after transplant versus waiting into early (90 days) posttransplant periods.

RESULTS

The BMI distribution of listed candidates was as follows: 3.7% under, 40.4% normal, 32.0% over, 16.2% obese, and 7.7% morbidly obese weight. The prevalence of HF among patients awaiting transplant reached 57.4% by 3 years. Deceased-donor transplant was associated with increased early HF risk compared with continued waiting-aHRs ranged from 2.23 for normal-BMI to 2.82 for morbidly obese patients. However, transplant reduced the risk of HF in the late posttransplant period from 54% (aHR 0.46) in normal-BMI to 32% (aHR 0.68) for morbidly obese patients. Relative benefits were largest for normal-weight candidates who received live-donor transplants (aHR 0.31).

CONCLUSIONS

Heart failure risk improves in obese patients in the long term after kidney transplant, but not as much as for nonobese patients. There is need for close monitoring and for new strategies to reduce HF risk in obese patients before and after transplant.