Non-dialysis-dependent renal dysfunction and cardiac surgery-an assessment of perioperative risk factors

In most reports, dialysis-dependent patients are known to be at increased risk for perioperative morbidity and mortality after cardiac surgical procedures.(1-7) However, the preoperative factors important for risk stratification of patients who have renal insufficiency but are not dialysis dependent are unclear. We set forth to ascertain preoperative risk factors important for predicting 2 endpoints: (1) dialysis at discharge and (2) hospital death.

A retrospective analysis.

A tertiary referral center.

From a database of patients undergoing cardiopulmonary bypass over a 6-year period, 150 patients were chosen for study based on their preoperative creatinine being greater than 1.5 mg/dl.

Routine monitoring and care of patients after their cardiac surgical procedures.

Many preoperative, perioperative, and postoperative variables were measured. Multivariable regression was used for data analysis. There were 21 (14%) hospital deaths and 7 (5%) patients who were not on preoperative dialysis who required dialysis at discharge. Preoperative risk factors for hospital death were the patients' New York Heart Association (NYHA) class (p = 0.004) and emergency status (p = 0.005). Preoperative risk factors for dialysis at discharge were female gender (p = 0.02), emergency status of procedure (p = 0.01), and preoperative creatinine (p = 0.03).

These data allow for a more accurate assessment of risk stratification in this group of patients with renal insufficiency but who are not dependent on dialysis. Given the data presented here and other studies that report good outcomes for patients with renal disease after cardiac surgical procedures,(8-10) earlier operative intervention for coronary disease in this subset of patients might be warranted.