The effect of statins on perioperative inflammation in cardiac and thoracic surgery

2024 EACTS/EACTAIC/EBCP Guidelines on cardiopulmonary bypass in adult cardiac surgery

Clinical practice guidelines consolidate and evaluate all pertinent evidence on a specific topic available at the time of their formulation. The goal is to assist physicians in determining the most effective management strategies for patients with a particular condition. These guidelines assess the impact on patient outcomes and weigh the risk-benefit ratio of various diagnostic or therapeutic approaches. While not a replacement for textbooks, they provide supplementary information on topics relevant to current clinical practice and become an essential tool to support the decisions made by specialists in daily practice. Nonetheless, it is crucial to understand that these recommendations are intended to guide, not dictate, clinical practice, and should be adapted to each patient's unique needs. Clinical situations vary, presenting a diverse array of variables and circumstances. Thus, the guidelines are meant to inform, not replace, the clinical judgement of healthcare professionals, grounded in their professional knowledge, experience and comprehension of each patient's specific context. Moreover, these guidelines are not considered legally binding; the legal duties of healthcare professionals are defined by prevailing laws and regulations, and adherence to these guidelines does not modify such responsibilities. The European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) and the European Board of Cardiovascular Perfusion (EBCP) constituted a task force of professionals specializing in cardiopulmonary bypass (CPB) management. To ensure transparency and integrity, all task force members involved in the development and review of these guidelines submitted conflict of interest declarations, which were compiled into a single document available on the EACTS website (https://www.eacts.org/resources/clinical-guidelines). Any alterations to these declarations during the development process were promptly reported to the EACTS, EACTAIC and EBCP. Funding for this task force was provided exclusively by the EACTS, EACTAIC and EBCP, without involvement from the healthcare industry or other entities. Following this collaborative endeavour, the governing bodies of EACTS, EACTAIC and EBCP oversaw the formulation, refinement, and endorsement of these extensively revised guidelines. An external panel of experts thoroughly reviewed the initial draft, and their input guided subsequent amendments. After this detailed revision process, the final document was ratified by all task force experts and the leadership of the EACTS, EACTAIC and EBCP, enabling its publication in the European Journal of Cardio-Thoracic Surgery, the British Journal of Anaesthesia and Interdisciplinary CardioVascular and Thoracic Surgery. Endorsed by the EACTS, EACTAIC and EBCP, these guidelines represent the official standpoint on this subject. They demonstrate a dedication to continual enhancement, with routine updates planned to ensure that the guidelines remain current and valuable in the ever-progressing arena of clinical practice.

Interpretable machine learning models for early prediction of acute kidney injury after cardiac surgery

OBJECTIVE

Postoperative acute kidney injury (PO-AKI) is a common complication after cardiac surgery. We aimed to evaluate whether machine learning algorithms could significantly improve the risk prediction of PO-AKI.

METHODS

The retrospective cohort study included 2310 adult patients undergoing cardiac surgery in a tertiary teaching hospital, China. Postoperative AKI and severe AKI were identified by the modified KDIGO definition. The sample was randomly divided into a derivation set and a validation set based on a ratio of 4:1. Exploiting conventional logistic regression (LR) and five ML algorithms including decision tree, random forest, gradient boosting classifier (GBC), Gaussian Naive Bayes and multilayer perceptron, we developed and validated the prediction models of PO-AKI. We implemented the interpretation of models using SHapley Additive exPlanation (SHAP) analysis.

RESULTS

Postoperative AKI and severe AKI occurred in 1020 (44.2%) and 286 (12.4%) patients, respectively. Compared with the five ML models, LR model for PO-AKI exhibited the largest AUC (0.812, 95%CI: 0.756, 0.860, all P < 0.05), sensitivity (0.774, 95%CI: 0.719, 0.813), accuracy (0.753, 95%CI: 0.719, 0.781) and Youden index (0.513, 95%CI: 0.451, 0.573). Regarding severe AKI, GBC algorithm showed a significantly higher AUC than the other four ML models (all P < 0.05). Although no significant difference (P = 0.173) was observed in AUCs between GBC (0.86, 95%CI: 0.808, 0.902) and conventional logistic regression (0.803, 95%CI: 0.746, 0.852), GBC achieved greater sensitivity, accuracy and Youden index than conventional LR. Notably, SHAP analyses showed that preoperative serum creatinine, hyperlipidemia, lipid-lowering agents and assisted ventilation time were consistently among the top five important predictors for both postoperative AKI and severe AKI.

CONCLUSION

Logistic regression and GBC algorithm demonstrated moderate to good discrimination and superior performance in predicting PO-AKI and severe AKI, respectively. Interpretation of the models identified the key contributors to the predictions, which could potentially inform clinical interventions.

The pathophysiology and management of depression in cardiac surgery patients

Background

Depression is common in the cardiac surgery population. This contemporary narrative review aims to explore the main pathophysiological disturbances underpinning depression specifically within the cardiac surgery population. The common non-pharmacological and pharmacological management strategies used to manage depression within the cardiac surgery patient population are also explored.

Methods

A total of 1291 articles were identified through Ovid Medline and Embase. The findings from 39 studies were included for qualitative analysis in this narrative review.

Results

Depression is associated with several pathophysiological and behavioral factors which increase the likelihood of developing coronary heart disease which may ultimately require surgical intervention. The main pathophysiological factors contributing to depression are well characterized and include autonomic nervous system dysregulation, excessive inflammation and disruption of the hypothalamic-pituitary-adrenal axis. There are also several behavioral factors in depressed patients associated with the development of coronary heart disease including poor diet, insufficient exercise, poor compliance with medications and reduced adherence to cardiac rehabilitation. The common preventative and management modalities used for depression following cardiac surgery include preoperative and peri-operative education, cardiac rehabilitation, cognitive behavioral therapy, religion/prayer/spirituality, biobehavioral feedback, anti-depressant medications, and statins.

Conclusion

This contemporary review explores the pathophysiological mechanisms leading to depression following cardiac surgery and the current management modalities. Further studies on the preventative and management strategies for postoperative depression in the cardiac surgery patient population are warranted.

Anti-inflammatory effects of non-statin low-density lipoprotein cholesterol-lowering drugs: an unused potential?

Objectives. Inflammatory responses are closely knit with low-density lipoprotein (LDL)-cholesterol in driving atherosclerosis. Even if LDL-cholesterol is causative to atherosclerotic diseases and LDL-cholesterol lowering reduces hard clinical endpoints, there is a residual risk for clinical events, possibly driven by inflammatory processes, in accordance with its role in autoimmune diseases. Design. As LDL-cholesterol treatment targets are reduced, the use of non-statin lipid-lowering drugs will probably increase. Atherosclerotic plaques evolve through lipid infiltration and modification in the intima, furthermore infiltration of cells including monocytes, macrophages, T-lymphocytes and neutrophils initiating inflammatory signaling. Here we briefly review inflammation in atherosclerosis and the effects of the non-statin lipid-lowering drugs on inflammation. The review is limited to the most common non-statin lipid lowering drugs, i.e. proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors, bile acid sequestrants (BAS) and cholesterol absorption inhibitors. Results. PCSK9 inhibition is mostly studied together with statins and is associated with a reduction of pro-inflammatory cytokines. Furthermore, PCSK9 inhibitors seem to have an effect on monocyte migration trough CCR2. They also have an interaction with sirtuins, possibly offering a therapeutic target. BAS have several interesting effects on inflammation, including reduction of pro-inflammatory cytokines and a reduction of the number of infiltrating macrophages, however there are relatively few reports considering that these drugs have been on the market for decades. Ezetimibe also has effects on inflammation including reduction of pro-inflammatory cytokines and adhesion molecules, however these effects are usually accomplished in tandem with statins. Conclusion. This topic adds an interesting piece to the puzzle of atherosclerosis, indicating that PCSK9 inhibition, BAS and ezetimibe all affect thromboinflammation.

Preoperative Statin Use Not Associated With Improved Outcomes After Ascending Aortic Repair

Statins have potent pleiotropic effects that have been correlated with improved perioperative cardiovascular surgery outcomes. We hypothesize that statins may improve morbidity and mortality after ascending aortic surgery. Within a statewide database consisting of 19 centers a total of 1804 patients had ascending aortic repair with or without aortic valve replacement (2004-2016). Patients were stratified by preoperative statin therapy for analysis. To account for baseline differences, patients were propensity matched in a 1:1 fashion by baseline characteristics. Patient characteristics and outcomes were analyzed by paired analysis. Of 1804 patients undergoing ascending aortic repair, 35% took statins preoperatively. After matching, 386 patients in each group were well matched with no statistically significant baseline or operative differences. There was no statistically significant difference in outcomes between patients taking statins preoperatively and those not taking statins, including operative mortality (3.6% vs 3.1%, P = 0.68) and major morbidity (18.4% vs 17.1%, P = 0.62). Postoperative atrial fibrillation (27.2% vs 28.5%, P = 0.71) and acute kidney injury (3.1% vs 4.2%, P = 0.41) also showed no statistically significant difference. Statins have no apparent clinical impact on perioperative outcomes after ascending aortic aneurysm repair. Considering recent evidence suggesting statins may increase perioperative risk of acute kidney injury, there is insufficient evidence to recommend starting preoperative statin before ascending aortic repair.

Preoperative Statin Treatment for the Prevention of Acute Kidney Injury in Patients Undergoing Cardiac Surgery: A Meta-Analysis of Randomised Controlled Trials

BACKGROUND

The effect of preoperative statin treatment (PST) on the risk of postoperative acute kidney injury (AKI) after cardiac surgery remains controversial. We performed a meta-analysis of randomised controlled trials (RCT) to investigate whether PST could improve the renal outcomes in patients undergoing cardiac surgery.

METHODS

We conducted a comprehensive search on PubMed, Embase and Cochrane Central Register of Controlled Trials. Randomised controlled trials which reported incidence of AKI and renal replacement treatment (RRT), mean change of serum creatine (SCr) and C-reactive protein (CRP), length of stay in intensive care unit (LOS-ICU) and hospital (LOS-HOS) were included.

RESULTS

A total of nine RCTs, covering 3,201 patients were included. Based on the results of our meta-analysis, PST could not reduce the incidence of AKI (risk ratio (RR) 1.12, 95% confidence interval (CI) 0.97 to 1.29, p=0.37), and RRT (RR 1.13, 95% CI 0.45 to 2.85, p=0.80). Furthermore, SCr was not likely to be improved by PST (weighted mean difference (WMD) 0.03, 95% CI 0.00 to 0.06, p=0.055). However, the level of CRP (WMD -5.93, 95% CI 11.71 to 0.15, p=0.044) in patients treated with PST was significantly lower than that of patients administered with placebo. In addition, no significant difference was observed in LOS-ICU and LOS-HOS between PST and control groups.

CONCLUSION

Our meta-analysis suggests that PST cannot provide any benefit for improving renal complications and clinical outcomes, but may slightly reduce postoperative inflammation in patients undergoing cardiac surgery. In the future, more powerful RCTs will be needed to confirm these findings.

Perioperative statin therapy in cardiac surgery: a meta-analysis of randomized controlled trials

BACKGROUND

Several studies suggest beneficial effects of perioperative statin therapy on postoperative outcome after cardiac surgery. However, recent randomized controlled trials (RCTs) show potential detrimental effects. The objective of this systematic review is to examine the association between perioperative statin therapy and clinical outcomes in cardiac surgery patients.

METHODS

Electronic databases were searched up to 1 November 2016 for RCTs of preoperative statin therapy versus placebo or no treatment in adult cardiac surgery. Postoperative outcomes were acute kidney injury, atrial fibrillation, myocardial infarction, stroke, infections, and mortality. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using fixed-effects meta-analyses. Primary analysis was restricted to trials with low risk of bias according to Cochrane methodology, and sensitivity analyses examined whether the risk of bias of included studies was associated with different results. We performed trial sequential analysis (TSA) to test the strength of the results.

RESULTS

We included data from 23 RCTs involving 5102 patients. Meta-analysis of trials with low risk of bias showed that statin therapy was associated with an increase in acute kidney injury (314 of 1318 (23.82%) with statins versus 262 of 1319 (19.86%) with placebo; OR 1.26 (95%CI 1.05 to 1.52); p = 0.01); these results were supported by TSA. No difference in postoperative atrial fibrillation, myocardial infarction, stroke, infections, or mortality was present. On sensitivity analysis, statin therapy was associated with a slight increase in hospital mortality. Meta-analysis including also trials with high or unclear risk of bias showed no beneficial effects of statin therapy on any postoperative outcomes.

CONCLUSIONS

There is no evidence that statin therapy in the days prior to cardiac surgery is beneficial for patients' outcomes. Particularly, statins are not protective against postoperative atrial fibrillation, myocardial infarction, stroke, or infections. Statins are associated with a possible increased risk of acute kidney injury and a detrimental effect on hospital survival could not be excluded. Future RCTs should further evaluate the safety profile of this therapy in relation to patients' outcomes and assess the more appropriate time point for discontinuation of statins before cardiac surgery.

Neuromuscular electrical stimulation may attenuate muscle proteolysis after cardiovascular surgery: A preliminary study

OBJECTIVE

To explore the efficacy of postoperative neuromuscular electrical stimulation (NMES) on muscle protein degradation and muscle weakness in patients after cardiovascular surgery.

METHODS

Sixty-one patients underwent NMES daily from postoperative days (PODs) 1 to 5 in addition to postoperative mobilization program (NMES group), and 41 patients underwent postoperative mobilization program only (non-NMES group). The primary outcome was the concentration of 3-methylhistidine (3-MH) in 24-hour urine corrected for urinary creatinine content (3-MH/Cre) from PODs 1 to 5. The secondary outcomes were knee extensor isometric strength (KEIS) and handgrip strength at POD 7.

RESULTS

Baseline characteristics such as age, sex, preoperative body mass index, hemoglobin, handgrip strength, KEIS, surgery type, cardiopulmonary bypass time, and immediate postoperative interleukin-6 were not different between the groups. Urinary 3-MH/Cre was increased significantly in both groups; however, urinary 3-MH/Cre in the NMES group peaked earlier compared with that in the non-NMES group. KEIS at POD 7 was significantly greater in the NMES group (median [interquartile range], 0.40 kg/weight [0.33-0.45] in the NMES group vs 0.23 kg/weight [0.15-0.36] in the non-NMES group; P < .01). Handgrip strength at POD 7 was also significantly greater in the NMES group (median [interquartile range], 32 kg [24.5-35.3] in the NMES group vs 24 kg [16.0-30.0] in the non-NMES group; P < .01).

CONCLUSIONS

This study demonstrated that NMES might attenuate skeletal muscle protein degradation and muscle weakness after cardiovascular surgery. A cause-effect relationship between NMES and functional preservation would be a future challenging issue.

Indications, algorithms, and outcomes for coronary artery bypass surgery in patients with acute coronary syndromes

For patients with a non-ST-segment elevation acute coronary syndrome (NSTE-ACS), guideline recommendations and treatment pathways focus on revascularization for definitive treatment if the patient is an appropriate candidate. Despite the widespread use of revascularization for NSTE-ACS, most patients undergo a percutaneous coronary intervention, whereas a minority of patients undergo coronary artery bypass grafting. Focusing specifically on the USA, the contemporary utilization, preoperative and perioperative considerations, and outcomes of NSTE-ACS patients undergoing coronary artery bypass grafting have not been comprehensively reviewed.