As a general internist practicing hospital-based internal medicine, I found the recent article by O'Meara and Dehmer [1] informative and clinically applicable. As the authors point out, clinicians caring for patients who have recently undergone a percutaneous coronary procedure need to be alert for myriad potential complications. Some of these complications may involve the kidneys and lead to electrolyte derangements and acute renal failure. The authors note that therapy with certain drugs may need to be discontinued before the procedure to minimize the risk for renal injury. Drugs that are known to affect potassium homeostasis and may lead to hyperkalemia include trimethoprim, heparin, potassium-sparing diuretics, angiotensin-converting enzyme inhibitors, and ß-adrenergic antagonists [2]. Patients with underlying chronic renal insufficiency or diabetic nephropathy could experience hyperkalemia if these drugs are used, especially in the setting of dye nephropathy [2].

Another renal complication of percutaneous coronary artery interventions not mentioned by the authors is the cholesterol embolism syndrome, or diffuse atheroembolism. This syndrome, characterized by diffuse embolization of disrupted atherosclerotic plaques, typically occurs after manipulation of the aorta during catheter-based or surgical procedures and may occur in up to 26% of patients undergoing coronary angiography [3-5]. Clinical clues to the cholesterol embolism syndrome include fever, livedo reticularis, and blue toes, often with eosinophilia, an elevated erythrocyte sedimentation rate, and hypocomplementemia [3, 5]. This syndrome frequently leads to renal failure, usually a few weeks after the predisposing procedure. Thus, clinicians must consider diffuse atheroembolism in patients with worsening renal function after a percutaneous coronary artery procedure.