The Neutrophil to Lymphocyte Ratio and Serum Albumin as Predictors of Acute Kidney Injury After Coronary Artery Bypass Grafting

Postoperative acute kidney injury (AKI) is a highly prevalent and serious complication after cardiac surgery. The aim of this study is to identify the predictors of AKI and the cut-off values after isolated off-pump coronary artery bypass grafting (OPCAB). A total of 329 adult patients, who underwent isolated OPCAB between December 2008 and February 2021, were retrospectively analyzed. The patients were divided into three groups: non-AKI, early AKI and late AKI groups. The early AKI group or the late AKI group were defined as ‘having AKI that occurred before or after 48 hours postoperatively’, respectively. Multivariate logistic regression analysis was performed to identify the predictors of AKI. Receiver operating characteristic (ROC) curve analysis was used to evaluate the cutoff value, the sensitivity, and the specificity of the predictors. On the multivariate analysis, the emergency surgery, the preoperative serum albumin, and the postoperative day 1 neutrophil to lymphocyte ratio (NL ratio) were identified as the independent predictors of AKI. However, neither albumin nor the NL ratio predicted late AKI. The present study showed the preoperative albumin and the postoperative day 1 NL ratio were the robust and independent predictors of postoperative early AKI in isolated OPCAB.

Microcirculatory Response to Blood vs. Crystalloid Cardioplegia During Coronary Artery Bypass Grafting With Cardiopulmonary Bypass

Background: Blood cardioplegia attenuates cardiopulmonary bypass (CPB)-induced systemic inflammatory response in patients undergoing cardiac surgery, which may favorably influence the microvascular system in this cohort. The aim of this study was to investigate whether blood cardioplegia would offer advantages over crystalloid cardioplegia in the preservation of microcirculation in patients undergoing coronary artery bypass grafting (CABG) with CPB.Methods: In this prospective observational cohort study, 20 patients who received crystalloid (n = 10) or blood cardioplegia (n = 10) were analyzed. The microcirculatory measurements were obtained sublingually using incident dark-field imaging at five time points ranging from the induction of anesthesia (T0) to discontinuation of CPB (T5).Results: In the both crystalloid [crystalloid cardioplegia group (CCG)] and blood cardioplegia [blood cardioplegia group (BCG)] groups, perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV) were reduced after the beginning of CPB. The observed reduction in microcirculatory parameters during CPB was only restored in patients who received blood cardioplegia and increased to baseline levels as demonstrated by the percentage changes from T0 to T5 (%Δ)T0−T5 in all the functional microcirculatory parameters [%ΔTVDT0−T5(CCG): −10.86 ± 2.323 vs. %ΔTVDT0−T5(BCG): 0.0804 ± 1.107, p < 0.001; %ΔPVDT0−T5(CCG): −12.91 ± 2.884 vs. %ΔPVDT0−T5(BCG): 1.528 ± 1.144, p < 0.001; %ΔPPVT0−T5(CCG): −2.345 ± 1.049 vs. %ΔPPVT0−T5(BCG): 1.482 ± 0.576, p < 0.01].Conclusion: Blood cardioplegia ameliorates CPB-induced microcirculatory alterations better than crystalloid cardioplegia in patients undergoing CABG, which may reflect attenuation of the systemic inflammatory response. Future investigations are needed to identify the underlying mechanisms of the beneficial effects of blood cardioplegia on microcirculation.

Perioperative Application of Diltiazem in Patients Undergoing On-Pump Coronary Artery Bypass Grafting

Diltiazem is frequently applied during the perioperative period of coronary artery bypass grafting with cardiopulmonary bypass (on-pump CABG) to prevent arterial graft spasm; however, the short- and long-term outcome effects are unclear. In this retrospective cohort study, from October 2008 to October 2018, adult patients who underwent isolated CABG with cardiopulmonary bypass (CPB) were identified. Patients in the perioperative diltiazem (DILT) and non-intervention (non-DILT) cohorts were matched based on propensity scores. Logistic regression was fitted to evaluate the impact on short-term outcomes. Long-term outcome was investigated by survival analyses. Total of 1004 patients were included. There were no statistically significant differences between the cohorts in perioperative outcomes, although at 24 hours postoperatively, patients in DILT were more likely to be on hemodynamic support from inotropic and/or vasoactive agents. The overall long-term survival was similar between the cohorts; however, in the subgroup of patients who received more than one arterial graft, perioperative diltiazem may be associated with higher long-term all-cause mortality. Based on these data, the perioperative and long-term outcome benefits of continuous iv infusion of diltiazem in patients who underwent on-pump CABG.

Predictors of perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting

Background Perioperative myocardial infarction (PMI) increases morbidity and mortality after off-pump coronary artery bypass grafting (CABG). The objective of the current study was to characterize patients with PMI after off-pump CABG and identify its predictors. Results We included 1181 patients who had off-pump CABG from 2010 to 2020; 59 patients (5%) had PMI. We compared patients with PMI to those without PMI. Patients with PMI were older (57 (25th–75th percentiles: 51–63) vs. 54 (48–60) years; P = 0.01) and had higher NYHA class (28 (47.46%) vs. 326 (29.06%): P = 0.01). The distal anastomosis time was longer in patients with PMI (28 (23–35) vs. 24 (16–30) min; P ˂ 0.001). Patients with PMI had higher postoperative low cardiac output (10 (18.18%) vs. 1 (0.1%): P ˂ 0.001), prolonged ventilation (12 (8–39) vs. 8 (6–10) h, P ˂ 0.001), ICU (71 (46–138) vs. 24 (23–42) h; P ˂ 0.001), and hospital stay (9 (6–15) vs. 7 (6–8) days; P ˂ 0.001). Mortality was significantly higher in patients with PMI (20 (33.9%) vs. 6 (0.53%); P ˂ 0.001). Older age (OR: 1.05 (95% CI: 1.01–1.1); P = 0.02), increased number of distal anastomoses (OR: 1.74 (95% CI: 1.20–2.50); P = 0.003), preoperative congestive heart failure (OR: 10.27 (95% CI: 2.58–40.95); P = 0.001), and thrombolysis within 24 h of surgery (OR: 15.34 (1.93–121.9); P = 0.01) were associated with increased PMI, while PMI was lower in male patients (OR: 0.42 (95% CI: 0.19–0.93); P = 0.03) and with higher body surface area (BSA) (OR: 0.08 (95% CI: 0.07–0.86); P = 0.04). Conclusions Post-off-pump CABG PMI was associated with increased morbidity and mortality. Risk factors for PMI were older age, lower BSA, females, increased distal anastomoses, preoperative heart failure, and thrombolysis.