Cardiac risk assessment for end-stage renal disease patients on the renal transplant waiting list

Standardized risk-stratified cardiac assessment and early posttransplant cardiovascular complications in kidney transplant recipients

Introduction

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in kidney transplant recipient (KTR). There is a dearth of standardized guidelines on optimal cardiovascular evaluation of transplant candidates.

Methods

This single-center cohort study aims to determine the effectiveness of our standardized risk-stratified pretransplant cardiovascular screening protocol, which includes coronary angiography (CAG), in identifying advanced CVD, the proper pretransplant management of which could lead to a reduction in the incidence of major cardiac events (MACE) in the early posttransplant period.

Results

Out of the total 776 KTR transplanted between 2017 and 2019, CAG was performed on 541 patients (69.7%), of whom 22.4% were found to have obstructive coronary artery disease (CAD). Asymptomatic obstructive CAD was observed in 70.2% of cases. In 73.6% of cases, CAG findings resulted in myocardial revascularization. MACE occurred in 5.6% (N = 44) of the 23 KTR with pretransplant CVD and 21 without pretransplant CVD. KTR with posttransplant MACE occurrence had significantly worse kidney graft function at the first year posttransplant (p = 0.00048) and worse patient survival rates (p = 0.0063) during the 3-year follow-up period compared with KTR without MACE. After adjustment, the independent significant factors for MACE were arrhythmia (HR 2.511, p = 0.02, 95% CI 1.158-5.444), pretransplant history of acute myocardial infarction (HR 0.201, p = 0.046, 95% CI 0.042-0.970), and pretransplant myocardial revascularization (HR 0.225, p = 0.045, 95% CI 0.052-0.939).

Conclusion

Asymptomatic CVD is largely prevalent in KTR. Posttransplant MACE has a negative effect on grafts and patient outcomes. Further research is needed to assess the benefits of pretransplant myocardial revascularization in asymptomatic kidney transplant candidates.

Association of frailty with postoperative outcomes following thoracic transplantation: A national analysis

Objective

Frailty has been repeatedly associated with inferior outcomes after surgical hospitalizations. However, a thorough evaluation of the impact of frailty on the clinical and financial outcomes of patients undergoing solid-organ thoracic transplantation is sparse in the literature. We evaluated the association of frailty, as determined by an administrative tool, with postoperative outcomes and healthcare resource use after heart or lung transplantation.

Methods

The Nationwide Readmissions Database was used to identify all adult hospitalizations for heart or lung transplant from 2014 to 2020. Patients were grouped as frail or nonfrail using International Classification of Diseases codes associated with conditions in the Johns Hopkins Adjusted Clinical Groups cluster. Multivariable regression models were developed to evaluate the association of frailty status on in-hospital mortality, complications, length of stay, costs, and unplanned readmissions.

Results

Of an estimated 35,862 heart or lung transplant recipients, 7316 (20.4%) were considered frail. After multivariable adjustment, frailty in heart transplantation was associated with greater odds of in-hospital mortality (adjusted odds ratio, 1.54; 95% CI, 1.19-1.99) and infectious complications (adjusted odds ratio, 1.77; 95% CI, 1.45-2.15; P < .001). Frailty in lung transplantation was also associated with higher odds of in-hospital mortality (adjusted odds ratio, 1.38; 95% CI, 1.11-1.69) and infectious complications (adjusted odds ratio, 1.93; 95% CI, 1.60-2.31). In addition, frailty in both heart transplantation and lung transplantation was associated with increased postoperative length of stay and greater costs.

Conclusions

Among transplant recipients, those classified as frail were associated with increased in-hospital mortality, perioperative complications, and resource use.

Cardiac Imaging and Management of Cardiac Disease in Asymptomatic Renal Transplant Candidates: A Current Update

Given the high cardiovascular risk accompanying end-stage kidney disease, it would be of paramount importance for the clinical nephrologist to know which screening method(s) identify high-risk patients and whether screening asymptomatic transplant candidates effectively reduces cardiovascular risk in the perioperative setting as well as in the longer term. Within this review, key studies concerning the above questions are reported and critically analyzed. The lack of unified screening criteria and of a prognostically sufficient screening cardiovascular effect for renal transplant candidates sets the foundation for a personalized patient approach in the near future and highlights the need for well-designed studies to produce robust evidence which will address the above questions.

Kidney transplant candidacy evaluation and waitlisting practices in the United States and their association with access to transplantation

There are limited data on the degree of variability in practices surrounding prioritization of referrals for transplant evaluation and criteria for transplant candidacy and their association with transplantation rates. We surveyed transplant programs across the United States between January 2020 and May 2020 to determine current pre-transplantation practices. We examined the relation between these reported practices and the outcomes of waitlisted patients at responding programs between January 2015 and March 2021 using Scientific Registry of Transplant Recipients data. We used adjusted Cox models with random effects to accommodate clustering by program. Primary outcomes included living or deceased donor transplantation. Of 172 surveyed programs, 90 participated. Substantial variations were noted in when the candidacy evaluation began (13% reported when eGFR was <30 mL/min/1.73 m² and 17% reported no set policy) and the approach to pre-transplantation cardiac workup (multi-modality [58%], stress echocardiogram [20%]). Using adjusted models, a program policy of using other measures of body habitus to determine transplant candidacy rather than requiring patients to meet a body mass index (BMI) threshold of ≤35 kg/m² (reference group) for candidacy was associated with a higher hazard of living donor transplantation (HR 1.83 [95% CI 1.10-3.03]). Pre-transplant practices vary substantially across the United States, and select practices were associated with transplantation rates.

Global longitudinal strain by feature-tracking cardiovascular magnetic resonance imaging predicts mortality in patients with end-stage kidney disease

Background

Patients with end-stage kidney disease (ESKD) are at increased risk of premature death, with cardiovascular disease being the predominant cause of death. We hypothesized that left ventricular global longitudinal strain (LV-GLS) measured by feature-tracking cardiovascular magnetic resonance imaging (CMRI) would be associated with all-cause mortality in patients with ESKD.

Methods

A pooled analysis of CMRI studies in patients with ESKD acquired within a single centre between 2002 and 2016 was carried out. CMR parameters including LV ejection fraction (LVEF), LV mass index, left atrial emptying fraction (LAEF) and LV-GLS were measured. We tested independent associations of CMR parameters with survival using a multivariable Cox model.

Results

Among 215 patients (mean age 54 years, 62% male), mortality was 53% over a median follow-up of 5 years. The median LVEF was 64.7% [interquartile range (IQR) 58.5-70.0] and the median LV-GLS was -15.3% (IQR -17.24 to -13.6). While 90% of patients had preserved LVEF (>50%), 58% of this group had abnormal LV-GLS (>-16%). On multivariable Cox regression, age {hazard ratio [HR] 1.04 [95% confidence interval (CI) 1.02-1.05]}, future renal transplant [HR 0.29 (95% CI 0.17-0.47)], LAEF [HR 0.98 (95% CI 0.96-1.00)] and LV-GLS [HR 1.08 (95% CI 1.01-1.16)] were independently associated with mortality.

Conclusions

In this cohort of patients with ESKD, LV-GLS on feature-tracking CMRI and LAEF was associated with all-cause mortality, independent of baseline clinical variables and future renal transplantation. This effect was present even when >90% of the cohort had normal LVEF. Using LV-GLS instead of LVEF to diagnose cardiac dysfunction in patients with ESKD could result in a major advance in our understanding of cardiovascular disease in ESKD.

Cardiovascular outcomes after simultaneous pancreas kidney transplantation compared to kidney transplantation alone: a propensity score matching analysis

Background

Coronary heart disease due to arteriosclerosis is the leading cause of death in type 1 diabetic patients with end-stage renal disease (ESRD). The aim of this study was to evaluate the effect of simultaneous pancreas kidney transplantation (SPKT) compared to kidney transplantation alone (KTA) on survival, cardiovascular function and metabolic outcomes.

Methods

A cohort of 127 insulin-dependent diabetes mellitus (IDDM) patients with ESRD who underwent either SPKT (n = 100) or KTA (n = 27) between 1998 and 2019 at the University Hospital of Leipzig were retrospectively evaluated with regard to cardiovascular and metabolic function/outcomes as well as survival rates. An additional focus was placed on the echocardiographic assessment of systolic and diastolic cardiac function pretransplant and during follow-up. To avoid selection bias, a 2:1 propensity score matching analysis (PSM) was performed.

Results

After PSM, a total of 63 patients were identified; 42 patients underwent SPKT, and 21 patients received KTA. Compared with the KTA group, SPKT recipients received organs from younger donors (p < 0.05) and donor BMI was higher (p = 0.09). The risk factor-adjusted hazard ratio for mortality in SPKT recipients compared to KTA recipients was 0.63 (CI: 0.49–0.89; P < 0.05). The incidence of pretransplant cardiovascular events was higher in the KTA group (KTA: n = 10, 47% versus SPKT: n = 10, 23%; p = 0.06), but this difference was not significant. However, the occurrence of cardiovascular events in the SPKT group (n = 3, 7%) was significantly diminished after transplantation compared to that in the KTA recipients (n = 6, 28%; p = 0.02). The cardiovascular death rate was higher in KTA recipients (19%) than in SPK recipients with functioning grafts (3.3%) and comparable to that in patients with failed SPKT (16.7%) (p = 0.16).

In line with pretransplant values, SPKT recipients showed significant improvements in Hb1ac values (p = 0.001), blood pressure control (p =  < 0.005) and low-density lipoprotein/high-density lipoprotein (LDL/HDL) ratio (p =  < 0.005) 5 years after transplantation. With regard to echocardiographic assessment, SPKT recipients showed significant improvements in left ventricular systolic parameters during follow-up.

Conclusions

Normoglycaemia and improvement of lipid metabolism and blood pressure control achieved by successful SPKT are associated with beneficial effects on survival, cardiovascular outcomes and systolic left ventricular cardiac function. Future studies with larger samples are needed to make predictions regarding cardiovascular events and graft survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02522-8.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

A propensity score-matched analysis indicates screening for asymptomatic coronary artery disease does not predict cardiac events in kidney transplant recipients

Screening for asymptomatic coronary artery disease prior to kidney transplantation aims to reduce peri- and post-operative cardiac events. It is uncertain if this is achieved. Here, we investigated whether pre-transplant screening with a stress test or coronary angiogram associated with any difference in major adverse cardiac events (MACE) up to five years post-transplantation. We examined a national prospective cohort recruited to the Access to Transplant and Transplant Outcome Measures study who received a kidney transplant between 2011-2017, and linked patient demographics and details of cardiac screening investigations to outcome data extracted from the Hospital Episode Statistics dataset and United Kingdom Renal Registry. Propensity score matched groups were analyzed using Kaplan-Meier and Cox survival analyses. Overall, 2572 individuals were transplanted in 18 centers; 51% underwent screening and the proportion undergoing screening by center ranged from 5-100%. The incidence of MACE at 90 days, one and five years was 0.9%, 2.1% and 9.4% respectively. After propensity score matching based on the presence or absence of screening, 1760 individuals were examined (880 each in screened and unscreened groups). There was no statistically significant association between screening and MACE at 90 days (hazard ratio 0.80, 95% Confidence Interval 0.31-2.05), one year (1.12, 0.51-2.47) or five years (1.31, 0.86-1.99). Age, male sex and history of ischemic heart disease were associated with MACE. Thus, there is no association between screening for asymptomatic coronary artery disease and MACE up to five years post-transplant. Practices involving unselected screening of transplant recipients should be reviewed.

The assessment of coronary artery disease in patients with end-stage renal disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality among patients with end-stage renal disease (ESRD). Clustering of traditional atherosclerotic and non-traditional risk factors drive the excess rates of coronary and non-coronary CVD in patients with ESRD. Coronary artery disease (CAD) is a key disease process, present in ∼50% of the haemodialysis population ≥65 years of age. Patients with ESRD are more likely to be asymptomatic, posing a challenge to the correct identification of CAD, which is essential for appropriate risk stratification and management. Given the lack of randomized clinical trial evidence in this population, current practice is informed by observational data with a significant potential for bias. For this reason, the most appropriate approach to the investigation of CAD is the subject of considerable discussion, with practice patterns largely varying between different centres. Traditional imaging modalities are limited in their diagnostic accuracy and prognostic value for cardiac events and survival in patients with ESRD, demonstrated by the large number of adverse cardiac outcomes among patients with negative test results. This review focuses on the current understanding of CAD screening in the ESRD population, discussing the available evidence for the use of various imaging techniques to refine risk prediction, with an emphasis on their strengths and limitations.