Introduction: Acute kidney injury (AKI) after cardiac surgery is associated with increased morbidity and mortality. Risk factors for AKI during off-pump coronary artery bypass grafting (OPCAB) are poorly understood. Our aim in this study is to identify the relationship between perioperative parameters and AKI following OPCAB.
Method: This prospective observational study was conducted in a single tertiary cardiac center. A total of 175 patients undergoing elective isolated CABG were included in this study over a 2-year period (March 2021 – February 2023). Out of 175 patients, 34 developed acute kidney injury after off-pump coronary artery bypass grafting surgery. Their preoperative, intraoperative, and postoperative findings were compared to identify the independent risk factors for developing postoperative acute kidney injury.
Result: The study was conducted on 175 patients: 113 males (64.5%) and 62 females (35.5%). Their age ranged from 61.81±8.30 years. In the AKI group patients, independent risk factors for developing postoperative AKI consisted of age>70 years (P<0.0001), BMI>30kg/m2 (P=0.015), diabetes, high HbA1c level (>6.5%) (P=<0.001), hypertension (P<0.001), no intake of calcium channel blockers for hypertension (P=<0.001), EF<30%, and timing of angiography before surgery (< 14days) (P=0.005).
Conclusion: Independent risk factors for developing postoperative AKI consist of age>70 years, BMI>30kg/m2, diabetes, high HbA1c level (>6.5%), hypertension, no intake of calcium channel blockers for hypertension, EF<30%, timing of angiography before surgery (<14 days), Acute MI (<30 days), High serum lactate level at 12 hours post-ICU admission, high vasoactive inotropic score, and requirement of blood transfusion due to various reasons. Among all these variables, mortality was found as a strong predictor in AKI group patients (p=0.016, OR=14.95, 95%CI 1.64-136.08).