The Impact of Pre- and Postoperative Renal Dysfunction on Outcome of Patients Undergoing Coronary Artery Bypass Grafting (CABG)[*]

Abstract

Objective: Acute changes in renal function after elective coronary bypass surgery represent a challenging clinical problem. In this study, we evaluated perioperative risk factors for the development of postoperative renal dysfunction (PRD), and the impact of such an event on the perioperative course. Additionally, we investigated the influence of preoperatively mildly increased serum creatinine on perioperative mortality and morbidity. Methods: We retrospectively analyzed data of 2511 patients undergoing isolated CABG between 2004 and 2007 with a preoperative serum creatinine ≤ 2.2 mg/dL. There were 592 patients with a preoperative serum creatinine of between 1.4 and 2.2 mg/dl (mild renal dysfunction group) and 1919 patients with a serum creatinine < 1.4 mg/dl. Perioperative risk factors for PRD were analyzed by multivariate regression analysis. Results: Global in-hospital mortality was 3.1 %.The incidence of PRD was 6.2 %. Mortality for patients who had PRD was 7.8 vs. 2.9 % for patients who did not (p < 0.05). PRD increased the length of hospital stay by 3.7 days (12.2 vs. 15.9; p < 0.05). Multivariate logistic regression identified the following variables as independent predictors of PRD: age, angina class III/IV, diabetes mellitus, prolonged cardiopulmonary bypass time, and preoperative serum creatinine. With regard to preoperative renal function, we found that operative mortality was higher in the mild renal dysfunction group (5.7 % vs. 2.5 %; p < 0.05). New dialysis/hemofiltration (5.1 % vs. 1.2 %; p < 0.05) and postoperative stroke (5.1 % vs. 1.6 %; p < 0.05) were also more common in these patients. Conclusions: Mild renal dysfunction preoperatively is an important predictor of outcome after CABG. In these patients, PRD dramatically increases mortality, morbidity and length of hospital stay.

Key words

coronary bypass surgery - renal dysfunction - patient outcome

1 The content of this paper was presented during the 38th annual meeting of the German Society of Thoracic- and Cardiovascular Surgery on Feb. 15th–18th, 2009 in Stuttgart/ Germany.

References

• 1 Maganti M, Rao V, Armstrong S, Feindel C M, Scully H E, Daid T E. Redo valve surgery in elderly patients.  Ann Thorac Surg. 2009;  87 521-525
• 2 Sun X, Hill P C, Bafi A S, Garcia J M, Haile E, Corso P J, Boyce S W. Is cardiac surgery safe in extremely obese patients (body mass index 50 or greater)?.  Ann Thorac Surg. 2009;  87 546-547
• 3 Peivandi A A, Kasper-Koenig W, Quinkenstein E. Risk factors influencing the outcome after surgical treatment of complicated deep sternal wound infections.  Cardiovasc Surg. 2003;  11 207-212
• 4 Gummert J F, Barten M J, Hans C, Kluge M, Doll N, Walther T, Hentschel B, Schmitt D V, Mohr F W, Diegeler A. Mediastinitis and cardiac surgery – an updated risk factor analysis in 10373 consecutive adult patients.  Thorac Cardiovasc Surg. 2002;  50 87-91
• 5 Hirose H, Amano A, Yoshida S, Takahashi A, Nagano N. Coronary artery bypass grafting in elderly.  Chest. 2000;  117 1262-1270
• 6 Herlitz J, Brandrup-Wognsen G, Karlsson T, Karlson B, Haglid M, Sjoland H. Predictors of death and other cardiac events within 2 years after coronary artery bypass grafting.  Cardiology. 1998;  90 110-114
• 7 Chertow G M, Lazarus J M, Christiansen C L. Preoperative renal risk stratification.  Circulation. 1997;  95 878-884
• 8 Corwin H L, Sprague S M, De Laria G A, Norusis M J. Acute renal failure associated with cardiac operations.  J Thorac Cardiovasc Surg. 1989;  98 1107-1112
• 9 Frost L, Pedersen R S, Lund O, Hansen O K, Hansen H E. Prognosis and risk factors in acute, dialysis requiring renal failure after open heart surgery.  Scand J Thorac Cardiovasc Surg. 1991;  25 161-166
• 10 Paganini E P, Bosworth C R. Acute renal failure following cardiac surgery: newer concepts and current therapy.  Sem Thorac Cardiovasc Surg. 1991;  3 63-70
• 11 Zanardo G, Michielon P, Paccagnella A, Rosi P, Calo M, Saladin V, Da Ros A, Miechieletto F, Simini G. Acute renal failure in the patient undergoing cardiac operation. Prevalence, mortality rate and main risk factors.  J Thorac Cardiovasc Surg. 1994;  107 1489-1495
• 12 Andersson G L, Ekroth R, Bratteby L E, Hallhagen S, Wesslen O. Acute renal failure after coronary surgery – a study of incidence and risk factors in 2009 consecutive patients.  Thorac Cardiovasc Surg. 1993;  41 237-241
• 13 Bastien O, Saroul C, Hercule C, George M, Estanove S. Continuous veno-venous hemofiltration after cardiac surgery.  Contrib Nephrol. 1991;  93 76-78
• 14 Glenn W W L. Glenn's thoracic and cardiovascular surgery. 6th edition. Stamford; Appleton & Lange 1995: 1788-1789
• 15 Lopart T, Lombardi R, Forselledo M, Andrade R. Acute renal failure in open heart surgery.  Renal Failure. 1997;  7 45-49
• 16 Quanini E, Colombo T, Russo C, Vitali E, Pellegrini A. Hospital morbidity and mortality after myocardial revascularization surgery: current changes in risk factors.  Eur J Cardiothorac Surg. 1995;  9 275-282
• 17 Chertow G M, Levy E M, Hammermeister K E, Grover F, Daley J. Independent association between acute renal failure and mortality following cardiac surgery.  Am J Med. 1998;  104 343-348
• 18 Kumbhani D J, Healey N A, Thatte H S, Nawas S, Crittenden M D, Birjiniuk V, Treanor P R, Khuri S F. Patients with diabetes mellitus undergoing cardiac surgery are at greater risk of developing intraoperative myocardial acidosis.  J Thorac Cardiovasc Surg. 2007;  133 1566-1572
• 19 Elahi M, Asopa S, Pflueger A, Hakim N, Matata B. Acute kidney injury following cardiac surgery: impact of early versus late haemofiltration on morbidity and mortality.  Eur J Cardiothorac Surg. 2009;  35 854-863
• 20 Elahi M, Lim M Y, Joseph R N, Dhannapueni R R, Spyt T J. Early hemofiltration improves survival in post-cardiotomy patients with acute renal failure.  Eur J Cardiothorac Surg. 2004;  26 1027-1031

1 The content of this paper was presented during the 38th annual meeting of the German Society of Thoracic- and Cardiovascular Surgery on Feb. 15th–18th, 2009 in Stuttgart/ Germany.