Cardiac catheterization in the dialysis population in 2012: we know more, but much remains unknown.

Chronic kidney disease is now widely accepted as an independent risk factor for coronary disease and the dialysis population may represent the highest risk subgroup. Among all dialysis patients, a cardiac cause of mortality has been estimated at 40%. In addition, prior studies have demonstrated that when cardiac catheterization is obtained in a consecutive series of asymptomatic diabetic patients on dialysis the rates of coronary disease can approach 50%. However, the ability to define the problem continues to be greater than the ability to treat or prevent it. Coronary revascularization strategies have limitations in the general population which are amplified in the dialysis population. The ability to accurately diagnose an acute coronary syndrome is more difficult, clinical outcomes have a smaller margin of benefit, and technical challenges result in higher complication rates. Recent data demonstrate an inverse relationship between glomerular filtration rate and the risk of presenting with an acute myocardial infarction rather than unstable angina suggesting that patients with CKD may have a unique pathophysiologic profile that is more prone to plaque rupture. However, these "vulnerable" plaques typically are associated with stenoses <50% prior to rupture and are thus poor targets for revascularization and perhaps best treated with medical therapy. Although the benefits of revascularization may continue to outweigh the risks in the context of acute coronary syndromes, preventive strategies would have to overcome the lower margin of benefit and higher complication rates.