Impact of Preoperative Impact of Preoperative Renal Dysfunction in Renal Dysfunction in Patients Undergoing Off-Patients Undergoing Off-pumppump vs vs On-pump On-pump Coronary Artery BypassCoronary Artery Bypass

Heart Failure and Renal DysfunctionHeart Failure and Renal Dysfunction

Impact of Preoperative Renal Dysfunction in Impact of Preoperative Renal Dysfunction in Patients Undergoing Off-pumpPatients Undergoing Off-pump vs vs On-pump On-pump Coronary Artery BypassCoronary Artery Bypass

Source

Boulton BJ, Kilgo P, Guyton RA, et al. Impact of preoperative renal dysfunction in patients undergoing off-pump vs on-pump coronary artery bypass. Ann Thorac Surg. 2011;92:595–602.

Background

There is an intimate association between cardiovascular diseases and renal dysfunction. Patients with end-stage renal disease undergoing hemodialysis (HD) are at high risk for adverse outcomes after coronary artery bypass grafting (CABG) and present with a spectrum of preoperative renal dysfunction (RD). Though studies have utilized serum creatinine as the preoperative variable to determine degrees of renal failure, estimated glomerular filtration rate (eGFR) has been noted as the most reliable index of renal function according to the National Kidney Foundation guidelines. The impact of the degree of RD in patients undergoing CABG ranging from normal to dialysis dependence is still not well defined.

Aim

To evaluate the short- and long-term outcomes in patients undergoing coronary revascularization with varying degrees of preoperative renal dysfunction and to compare surgical outcomes in patients undergoing CABG with or without the use of cardiopulmonary bypass.

Methods

Summary of key results Out of the total, 57% underwent off-pump coronary artery bypass (OPCAB), while 43% underwent on-pump CAB.

1. Preoperative RD was common comprising 75.3% (n=10,696 of 14,199) of the study population.

2. Increased incidence of other known preoperative risk factors for coronary artery disease associated with poorer outcomes such as diabetes mellitus (P<0.001), prior stroke (P<0.001), and New York Heart Association class III or IV heart failure (P<0.001) observed in patients with severe RD and preoperative HD.

3. Moderate to severe RD or preoperative dialysis was associated with worse adjusted in-hospital mortality.

4. OPCAB patients with moderate-to-severe RD had worse long-term survival than on-pump CAB patients.

Conclusion

Mortality and morbidity increases with renal dysfunction. In patients with normal or mild renal dysfunction or dialysis, long-term all-cause survival was not significantly different between OPCAB and ONCAB, whereas in patients with moderate or severe RD, long-term all-cause survival was significantly improved in the ONCAB group.

In CABG population, preoperative RD is common and often associated with diminished long-term survival. The early improvement seen in

patients with RD undergoing OPCAB diminished with worsening RD.