Does hybrid imaging have a role in cardiac risk evaluation of the pre-renal transplant patient?

Screening and risk stratification of coronary artery disease in end-stage renal disease

End-stage renal disease (ESRD) is a growing global health problem with major health and economic implications. Cardiovascular complication is the major cause of morbidity and mortality in this population. Clustering of traditional atherosclerotic risk factors, such as diabetes, systemic inflammation, and altered mineral metabolism, contributes to enhanced systemic atherosclerosis in patients with ESRD. Prevalence of obstructive coronary artery disease (CAD) on coronary angiography exceeds 50% in this population. Despite having extensive CAD and vascular disease, patients with ESRD often do not present with classic symptoms because of impaired exercise capacity and diabetes. Furthermore, clinical trial data are exceedingly lacking in this population, resulting in considerable clinical equipoise regarding the optimal approach to the identification and subsequent management of CAD in these patients. Traditional clinical screening tools, including conventional risk prediction models, are significantly limited in their predictive accuracy for cardiovascular events in patients with ESRD. Noninvasive cardiac stress imaging modalities, such as nuclear perfusion and echocardiography, have been shown to improve the traditional clinical model in identifying the presence of CAD. Furthermore, they add incremental prognostic information to angiographic data. Novel imaging techniques and biomarker assays hold significant promise in further improving the ability to identify and risk-stratify for CAD. This review focuses on the current understanding of the clinical risk profile of asymptomatic patients with ESRD with an emphasis on the strengths and limitations of various noninvasive cardiovascular imaging modalities, including the role of novel methods in refining risk prediction. In addition, issues and challenges pertaining to the optimal timing of initial risk assessment ("screening") and possible repeat screening ("surveillance") are addressed. We also summarize the current data on the approach to the patient with ESRD being evaluated for transplantation in the context of recent guidelines and position statements by various professional societies.

Coronary Artery Calcium Assessment in CKD: Utility in Cardiovascular Disease Risk Assessment and Treatment?

Coronary artery calcification (CAC) is a strong predictor of cardiovascular event rates in the general population, and scoring with multislice computed tomography commonly is used to improve risk stratification beyond clinical variables. CAC is accelerated in chronic kidney disease, but this occurs as a result of 2 distinct pathologic processes that result in medial (arteriosclerosis) and intimal (atherosclerosis) deposition. Although there are data that indicate that very high CAC scores may be associated with increased risk of death in hemodialysis, average CAC scores in most patients are elevated at a level at which discriminatory power may be reduced. There is a lack of data to guide management strategies in these patients based on CAC scores. There are even fewer data available for nondialysis patients, and it is uncertain whether CAC score confers an elevated risk of premature cardiovascular morbidity and mortality in such patients. In this article, we review the evidence regarding the utility of CAC score for noninvasive cardiovascular risk assessment in individuals with chronic kidney disease, using a clinical vignette that highlights some of the limitations in using CAC score and considerations in risk stratification.