Presence of peripheral artery disease in renal transplant outcomes – Don’t throw the baby out with the bath water

Abstract

/home/vmjGuidelines for the evaluation of renal transplant candidates are well established and comprehensive, including assessment of an individual's cardiovascular function and comorbidities. 1 Regarding the evaluation, treatment, and follow-up of peripheral artery disease (PAD) in renal transplant candidates, the American Society of Transplantation recommends that angioplasty or surgical intervention for PAD be reserved for patients with symptomatic disease. 1 However, these guidelines do not specify which patients should or should not be considered for renal transplant in the presence of PAD.Given the high prevalence of PAD in this population, an understanding of its impact on outcomes, including graft failure and mortality, is important.In order to examine this relationship, Patel and colleagues performed a retrospective analysis investigating the ability of pre-transplant ankle-brachial index (ABI) measurements to predict graft failure and mortality in kidney transplant recipients. 2 The authors analyzed the medical records of all kidney transplant recipients from 1994 to 2014 at three Mayo Clinic campuses and included 819 patients with ABI measurements within 5 years of the renal transplant. ABI measurements were ultimately grouped into normal ABI (0.90-1.39), low ABI (≤ 0.89), and high ABI (≥ 1.40). A predictive model of graft failure and mortality after adjustment for known cardiovascular risk factors (age, sex, smoking history, hypertension, diabetes, stroke, known coronary artery disease or heart failure, and years of dialysis) was then performed. Using multivariate logistic regression and Cox proportional hazard models, the authors report that low ABI was a significant predictor of graft failure (odds ratio (OR) 2.77, 95% confidence interval (CI) 1.68-4.58, p < 0.001) and secondary endpoints, including myocardial infarction, cerebrovascular accident and limb ischemia/gangrene/amputation (hazard ratio (HR) 1.39, 95% CI 0.97-1.99, p < 0.076), and death (HR 1.84, 95% CI 1.26-2.68, p = 0.002).We commend the authors for their important work in bringing to attention the prognostic importance of pretransplant ABI to potentially predict graft failure and mortality in these high-risk patients. 2 Their results, if reproducible when performed prospectively, could potentially lead to routine screening for PAD with an ABI in all patients undergoing renal transplant evaluation. However, the study has a number of limitations that merit further consideration. The population included patients from three Mayo Clinic sites: Florida (606 patients, 74%), Arizona (73 patients, 9%), and Rochester, Minnesota (140 patients, 17%). The authors explain that patients at the Arizona and Rochester sites were selected for ABI measurements based upon clinicians' suspicion of significant PAD, while the patients in Florida underwent routine ABI testing as part of pre-transplant evaluation. Over one-quarter (26%) of patients in this study had a clinical presentation that warranted ABI measurement, such as limb ischemia, gangrene, or ulc...

Simultaneous recipient external iliac endarterectomy and renal transplant – a propensity score matched analysis

“…Our center does not perform routine screening with angiography. Screening of potential renal transplant candidates with the ABI, supplemented with toe‐brachial pressures has been shown to be just as effective . In fact, worse outcomes have been reported in patients with low ABIs following renal transplant .…”