Acute kidney injury after coronary artery bypass grafting: Does rhabdomyolysis play a role?

Benedetto, Umberto; Angeloni, Emiliano; Luciani, Remo; Refice, Simone; Stefanelli, Manuel; Comito, Cosimo; Roscitano, Antonino; Sinatra, Riccardo

doi:10.1016/j.jtcvs.2010.03.028

« Previous Next »The Journal of Thoracic and Cardiovascular Surgery
Volume 140, Issue 2 , Pages 464-470, August 2010

Acute kidney injury after coronary artery bypass grafting: Does rhabdomyolysis play a role?

Umberto Benedetto, MD
- Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy
- Address for reprints: Umberto Benedetto, MD, Cardiac Surgery Department, II School of Medicine, University of Rome “La Sapienza,” Via di Grottarossa 1035, 00100, Rome, Italy.
Emiliano Angeloni, MD
- Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy
Remo Luciani, MD
- Nephrology Unit, G. Rummo Hospital, Benevento, Italy
Simone Refice, MD
- Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy
Manuel Stefanelli, MD
- Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy
Cosimo Comito, MD
- Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy
Antonino Roscitano, MD
- Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy
Riccardo Sinatra, MD
- Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy

Received 3 December 2009; received in revised form 6 February 2010; accepted 20 March 2010. published online 23 April 2010.

Objective

In clinical situations in which rhabdomyolysis is common, renal dysfunction association with myoglobinemia is well described. After coronary artery bypass grafting, a rapid increase in serum myoglobin concentration is generally seen, but whether it might independently increase the risk of acute kidney injury remains to be determined.

Methods

The study population consisted of 731 consecutive patients undergoing coronary artery bypass grafting. Creatine kinase, myoglobin, and creatinine concentrations were assessed in each patient preoperatively and postoperatively. Acute kidney injury was defined as an absolute increase in serum creatinine concentration of 0.3 mg/dL or greater.

Results

Overall, 295 (40.3%) of 731 patients had acute kidney injury. Patients' risk profiles were significantly worse in those with acute kidney injury, and 31 (4.2%) of 731 patients required dialysis. Acute kidney injury was associated with a higher increase in serum myoglobin concentration after 1 hour from aortic declamping (534 μg/mL [interquantile range, 354–733 μg/mL] vs 377 μg/mL [interquantile range, 278–528 μg/mL], P < .0001), which persisted at 24 and at 48 hours. After adjusting for confounding factors, myoglobin concentration was found to independently predict postoperative acute kidney injury (odds ratio, 1.0011 [1 μg/mL increase]; 95% confidence interval, 1.0003–1.0019; P = .005), and this result persisted when patients with perioperative myocardial infarction were excluded from the analysis (odds ratio, 1.0007; 95% confidence interval, 1.0002–1.0009; P = .01). Myoglobin concentration had a better accuracy to discriminate patients having acute kidney injury than creatine kinase concentration at any time.

Conclusions

An increase in laboratory findings of muscle injury postoperatively, especially serum myoglobin concentration, predicts the incidence of acute kidney injury and renal replacement therapy requirement, as reported in other surgical settings. Perioperative myocardial injury cannot totally explain the occurrence of increased myoglobinemia. These results suggest an important role of skeletal muscle breakdown and necrosis in determining an increased myoglobinemia concentration after coronary artery bypass grafting.

CTSNet classification: 23

Abbreviations and Acronyms: ACEI/ARB, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, AKI, acute kidney injury, CABG, coronary artery bypass grafting, CI, confidence interval, CK, creatine kinase, CPB, cardiopulmonary bypass, cTnI, cardiac troponin I, GFR, glomerular filtration rate, IQR, interquantile range, LOS, low cardiac output syndrome, OR, odds ratio, RBC, red blood cell, ROC, receiver operating characteristic, RRT, renal replacement therapy