New Insights Into Mechanisms of Acute Kidney Injury in Heart Disease

Acute kidney injury is a frequent occurrence in patients with heart disease, and is associated with higher risk of adverse outcomes, including mortality. In the setting of decompensated heart failure, acute kidney injury can occur from hemodynamic and neurohormonal activation, venous congestion, and nephrotoxic medications. Certain medications, such as loop diuretics, renin angiotensin system blockers, and mineralocorticoid antagonists can seemingly cause acute kidney injury. However, this increase in creatinine level is not always associated with adverse outcomes and should be carefully differentiated so as to allow deliberate continuation of these cardio- and nephroprotective agents. In other settings such as cardiac surgery, acute kidney injury can occur from factors related to the cardiopulmonary bypass, renal hypoperfusion, or other perioperative factors. Last, patients with heart disease commonly undergo imaging procedures that require contrast administration. Contrast can indeed cause acute kidney injury, but these interventional procedures also can result in kidney injury from atheroembolic phenomena. This is well documented by the recent data reporting a higher risk of acute kidney injury from femoral compared with radial access. The advent of biomarkers of kidney injury present an opportunity for early detection, accurate differential diagnosis, as well as potentially designing innovative biomarker-enriched adaptive clinical trials.