Impact of cardiopulmonary bypass on acute kidney injury following coronary artery bypass grafting: a matched pair analysis.
BACKGROUND
Postoperative Acute Kidney Injury (AKI) after coronary artery bypass grafting (CABG) is a common complication associated with significant morbidity and mortality. Cardiopulmonary bypass (CPB) is accepted to contribute to the occurrence of AKI and is of particular importance as it can be avoided by using the off-pump technique. However the renoprotective properties of off-pump (CABG) are controversial. This analysis evaluates the impact of cardiopulmonary bypass on renal function.


METHODS
A matched-pair analysis of 1428 patients undergoing coronary artery bypass grafting was conducted. The patients were stratified according to their preoperative renal function and to risk factors for postoperative AKI. The development of the glomerular filtration rate (GFR) from before surgery until hospital discharge was analyzed. Incidence of AKI were analyzed. Furthermore the impact of CPB duration on postoperative GFR was assessed.


RESULTS
The occurrence of AKI increases the risk of thirty-day mortality (odds ratio of 4.3). The postoperative GFR decreases significantly after coronary artery bypass grafting but does not differ between onpump and offpump CABG (60.2 ± 24.5 vs 60.7 ± 24.8; p=0.54). No difference regarding the incidence (26.6% vs 25%) and severity of AKI between cardiopulmonary bypass and the off-pump technique could be found. Duration of cardiopulmonary bypass does not correlate with the decline in postoperative glomerular filtration rate (Pearson Product Moment Correlation; p>0.050).


CONCLUSIONS
Neither the mere use nor duration of cardiopulmonary bypass proofed to be a risk factor for developing postoperative AKI in CABG patients with a comparable preoperative risk profile for postoperative renal dysfunction. Furthermore, the severity of postoperative AKI is not affected by the use of cardiopulmonary bypass.
Department of Cardiothoracic Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 57, 93057 Regensburg, Germany. simon.schopka@klinik.uni-regensburg.de.
Simon
S
Schopka
Claudius
C
Diez
Daniele
D
Camboni
Bernhard
B
Floerchinger
Christof
C
Schmid
Michael
M
Hilker
D058186:Acute Kidney Injury / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D003324:Coronary Artery Disease / Q000601:surgery*; D003404:Creatinine / Q000097:blood; D005260:Female; D005858:Germany / Q000453:epidemiology; D005919:Glomerular Filtration Rate; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D015994:Incidence; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D016017:Odds Ratio; D011183:Postoperative Complications / Q000453:epidemiology*; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome
D003404:Creatinine