Cardiac Output Values and Correlation of Renal Injury with Neutrophil Gelatinase-Associated Lipocalin Levels in Off-Pump Coronary Artery Bypass Patients

Abstract Objective: To investigate the correlation between cardiac output values and renal neutrophil gelatinase-associated lipocalin (NGAL) levels as a biomarker of renal ischemia. Methods: Forty patients, who underwent off-pump coronary artery bypass (OPCAB) surgery and in whom the positioning of the heart was fixed with simple suspension sutures without a mechanical stabilizer, were included in the study. Continuous cardiac output (CO) measurements were recorded using the arterial pressure waveform analysis method (FloTrac sensor system) in the perioperative period. CO was recorded every minute during non-anatomical cardiac positioning for left anterior descending artery (LAD), diagonal artery (D), circumflex artery (Cx), and right coronary artery (RCA) bypasses. Serum NGAL samples were analyzed in the preoperative, perioperative, and postoperative periods. Results: The CO values measured at various non-anatomical cardiac positions during distal anastomosis for LAD, D, Cx, and RCA were significantly lower than pre- and postoperative values measured with the heart in normal anatomical position (3.45±0.78, 2.9±0.71, 3.11±0.56, 3.19±0.81, 5.03±1.4, and 4.85±0.78, respectively, P=0.008). There was no significant difference between CO values measured at various non-anatomical cardiac positions during distal anastomosis. Although there was no significant correlation between NGAL levels and age, duration of surgery, preoperative CO, D-CO, RCA-CO, and postoperative CO measurements, there was a significant correlation between NGAL levels and LAD-CO (P=0.044) and Cx-CO (P=0.018) at the postoperative 12th hour. Conclusion: Full revascularization may be achieved by employing the OPCAB technique while using simple suspension sutures without a mechanical stabilizer and by providing safe CO levels and low risk of renal ischemia.摘要 研究目的：探讨心输出量（cardiac output, CO）与作为肾缺血生物标志物的肾型中性粒细胞明胶酶相关脂质运载蛋白（NGAL）水平之间的相关性。 研究方法：本研究纳入40例行非体外循环冠状动脉旁路移植术（off-pump coronary artery bypass, OPCAB）的患者，术中采用单纯悬吊缝线固定心脏位置，未使用机械稳定器。围手术期采用动脉压力波形分析法（FloTrac传感器系统）持续监测并记录心输出量（CO）。在左前降支（left anterior descending artery, LAD）、对角支（diagonal artery, D）、回旋支（circumflex artery, Cx）及右冠状动脉（right coronary artery, RCA）旁路移植术中的心脏非解剖位摆放期间，每分钟记录一次CO值。分别于术前、围手术期及术后时段采集血清NGAL样本进行检测分析。 研究结果：左前降支、对角支、回旋支及右冠状动脉远端吻合期间，不同非解剖位心脏对应的CO值均显著低于心脏处于正常解剖位时的术前及术后CO值（分别为3.45±0.78、2.9±0.71、3.11±0.56、3.19±0.81、5.03±1.4及4.85±0.78，P=0.008）。各冠状动脉远端吻合期间的不同非解剖位心脏对应的CO值之间无显著差异。尽管NGAL水平与患者年龄、手术时长、术前CO、对角支CO（D-CO）、右冠状动脉CO（RCA-CO）及术后CO均无显著相关性，但术后12小时时，NGAL水平与左前降支CO（LAD-CO）及回旋支CO（Cx-CO）呈显著相关（P=0.044、P=0.018）。 研究结论：采用单纯悬吊缝线而非机械稳定器的非体外循环冠状动脉旁路移植术技术，维持安全的心输出量水平，可实现完全血管重建，且降低肾缺血风险。