Performing cardiac catheterization and heart surgery on different hospital admissions may reduce risk of kidney damage
Research Activities, May 2011, No. 369
Acute injury to the kidneys occurs frequently when cardiac catheterization and heart surgery are done during the same hospitalization. However, the risk of acute kidney injury (AKI) may be reduced by up to 45 percent if the surgery is done on a later hospital admission, according to a new study. AKI is thought to be caused in this case by the contrast dye used during diagnostic imaging via cardiac catheterization superimposed upon other preoperative events such as factors intrinsic to the patient and medications. Heart surgery patients with AKI have increased risk of complications and death.
Robert S. Kramer, M.D., Jeremiah R. Brown, Ph.D., M.S., and Dartmouth-Hitchcock Medical Center colleagues followed 668 patients admitted for nonemergency heart surgery at 1 hospital in 2008. They measured serum creatinine levels (mg/dL), an indicator of kidney function, before surgery (baseline), daily for 2 days after surgery, and according to the surgeon's judgment until hospital discharge. The incidence of AKI was 50.2 percent in patients who had catheterization and surgery in the same hospital admission, but was significantly less (33.7 percent) among surgical patients who had the imaging procedure during a previous admission.
After adjusting for patient age, presence of coronary artery disease, baseline serum creatinine concentration, pump time, and hematocrit levels before surgery, the researchers found that patients with same-admission catheterization and surgery were 54 percent more likely to develop AKI than those who had catheterization during a prior admission. Kidney injury was defined prior to hospital discharge as a 50 percent (0.3 mg/dL) or greater increase in serum creatinine from the baseline level. Although the researchers recognize that their study does not show the optimal time between cardiac catheterization and surgery, they feel confident that having the two procedures occur during separate hospital admissions will reduce AKI and potentially other heart surgery complications. The study was funded in part by the Agency for Healthcare Research and Quality (HS18443).
More details are in "Same admission cardiac catheterization and cardiac surgery: Is there an increased incidence of acute kidney injury?" by Dr. Kramer, Reed D. Quinn, M.D., Robert C. Groom, M.S., Dr. Brown, and others in the November 2010 The Annals of Thoracic Surgery 90(5) pp. 1418-1424.