WASHINGTON— A simple urine test before heart surgery can predict which patients may develop kidney-related complications, according to a study published online Dec.8 in the Journal of the American Society Nephrology (JASN).
Loss of protein in the urine puts heart surgery patients at increased risk of kidney injury following their procedure, and performing the urine test prior to surgery provides an early warning sign to patients and physicians.
Impaired kidney function affects more than 12 percent of individuals in the general population and puts them at substantial risk of developing complications—such as kidney injury— when they undergo invasive medical procedures such as heart bypass surgery. The association between the loss of protein in the urine (proteinuria), which is a marker of kidney dysfunction, and kidney injury following heart surgery has not been thoroughly examined.
Kwan-Dun Wu, MD, PhD; Vin-Cent Wu, MD; Wen-Je Ko, MD, PhD (National Taiwan University Hospital and College of Medicine, in Taipei, Taiwan); Tao-Min Huang, MD (National Taiwan University Hospital Yun-Lin Branch, in Douliou City, Taiwan) and their colleagues studied 1,052 adult patients undergoing heart bypass surgery at a medical center and its two affiliate hospitals between 2003 and 2007.
Kidney injury associated with the surgery arose in 183 (17.4 percent) of the patients. Compared with patients who did not have proteinuria, patients with mild proteinuria were 1.66 times more likely to experience surgery-associated kidney injury. Those with more severe proteinuria were 2.30 times more likely to experience surgery-associated kidney injury and 7.29 times more likely to need dialysis or a kidney transplant.
“We have found that proteinuria is potentially a risk factor of postoperative acute kidney injury; however, this simple test is usually neglected in current practice. These findings should motivate clinicians to become more concerned about the presence of low quantities of protein in the urine,” said Wu.
