Renal replacement therapy and conservative management

Selecting relevant studies

The recommendation for research on cardiac assessment sought to answer the following question: What is the clinical and cost effectiveness of cardiac assessment before transplantation?

Due to the scope of the existing review protocol (which included people considering renal replacement therapy) and the lack of existing evidence, we opted to include studies that either 1) included people before cardiac assessment and transplant listing, or 2) included people who had already undergone initial assessment and were identified as suitable candidates for transplant or were waitlisted for transplant and undergoing follow-up assessments. We also included studies where the patient population had non-invasive or invasive tests for cardiac assessment and was compared with patient populations where no screening test was used. Randomised controlled trials (RCTs) were prioritised, but non-randomised studies were considered where outcomes were adjusted for key confounders, such as age, health at baseline and comorbidities.

We found 3 studies in a search for RCTs, non-randomised studies and systematic reviews published between 1 December 2017 and 21 March 2023. One was a prospective and 2 were retrospective cohort studies.

No new evidence was available for cardiac assessment in children and young people. This remains an evidence gap.

UK study of up to 5-year post-transplant outcomes for transplant candidates with or without screening

A national prospective cohort study in England (Nimmo et al. 2020) investigated whether transplant candidate screening with a stress test or invasive coronary angiogram for asymptomatic coronary artery disease was associated with any difference in major adverse cardiac events (MACE) up to 5 years post-transplantation. Overall, 2,572 individuals were transplanted in 18 centres between 2011 to 2017. The incidence of MACE post-transplant at 90 days, 1 and 5 years was 0.9%, 2.1% and 9.4% respectively. Prior to propensity-score matching, patients undergoing screening had a higher incidence of MACE at 1 and 5 years (18 screening versus 34 no screening patients had an event at 1 year; 66 screening versus 133 no screening patients had an event at 5 years). No difference was observed at 90 days post-transplant.

After propensity-score matching based on age, sex, ethnicity, socioeconomic status, smoking history, history of diabetes, ischemic heart disease, peripheral vascular disease, and cerebrovascular disease, 1,760 individuals were examined (880 each in the screened and unscreened groups). There was no statistically significant association between screening and MACE at 90 days (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.31 to 2.05), 1 year (HR 1.12, 95% CI 0.51 to 2.47) or 5 years (HR 1.31, 95% CI 0.86 to 1.99). There was no association between screening for asymptomatic coronary artery disease and MACE up to 5 years post-transplant. An important limitation of this study is that it provides no information about individuals who had cardiac assessment but were then excluded from the transplant pathway.

US study #1 of 30-day post-transplant outcomes for transplant candidates with or without screening.

A national retrospective cohort study in the United States (Cheng et al. 2023) investigated whether invasive or non-invasive testing for coronary heart disease in asymptomatic kidney transplant candidates in the year of the kidney transplant is associated with reduced early post-transplant death or myocardial infarction (MI). An instrumental variable (IV) analysis was used, with the programme-level coronary heart disease (CHD) testing rate in the year of the transplant as the IV. Analyses were stratified by study period, as the rate of CHD testing varied over time. The primary outcome was a composite of death or acute MI within 30 days of after kidney transplant.

Using data from the US Renal Data System and Medicare claims from 2000 to 2014, the cohort comprised 79,334 adult, first-time kidney transplant recipients. The primary outcome occurred in 4,604 patients (5.3%; 2,063 [2.6%] death, 2,329 [2.9%] acute MI). In the main IV analysis, compared with no testing, CHD testing was not associated with a change in the rate of primary outcome (rate difference, 1.9%; 95% CI, 0% to 3.5%). The results were similar across study periods, except for 2000 to 2003, during which CHD testing was associated with a higher event rate (rate difference, 6.8%; 95% CI, 1.8% to 12.0%).

US study #2 of 30-day post-transplant outcomes for transplant candidates with or without screening.

A national retrospective cohort study in the United States (Dunn et al. 2019) sought to establish if cardiac stress testing after placement on the waitlist, prior to kidney transplantation would not reduce postoperative death, total MI or fatal MI. Data were extracted from the United States Renal Data System for end stage renal disease patients; they were over 40 years old with primary Medicare insurance and received their first kidney transplant between 2006 and 2013; patients who received coronary angiography without stress testing in the 18 months prior to transplant were excluded. Propensity matching created a 1:1 matched sample of patients with and without stress testing in the 18 months prior to kidney transplantation. Propensity matching eliminated differences in demographics, identified risk factors and comorbidities between groups.

In the propensity-matched cohort of 17,304 patients, death within 30 days occurred in 72 of 8,652 (0.83%) patients who underwent stress testing and in 65 of 8,652 (0.75%) patients who did not (odds ratio [OR] 1.07; 95% CI: 0.79 to 1.45; p=0.66). MI within 30 days occurred in 339 (3.9%) patients who had a stress test and in 333 (3.8%) patients who did not (OR 1.03; 95% CI: 0.89 to 1.21; p=0.68). Fatal MI occurred in 17 (0.20%) patients who underwent stress testing and 15 (0.17%) patients who did not (OR 0.97; 95% CI: 0.71 to 1.32; p=0.84).