Preoperative Statins and Acute Kidney Injury After Cardiac Surgery: Utilization of a Consensus Definition of Acute Kidney Injury

A wide scope, pan-comparative, systematic meta-analysis of the efficacy of prophylactic strategies for cardiac surgery-associated acute kidney injury

Acute kidney injury (AKI) is the most common complication of cardiac surgery. Cardiac surgery-associated AKI (CSA-AKI) is caused by systemic and renal hemodynamic impairment and parenchymal injury. Prophylaxis of CSA-AKI remains an unmet priority, for which preventive strategies based on drug therapies, hydration procedures, and remote ischemic preconditioning (RIPC) have been tested in pre-clinical and clinical studies, with variable success. Contradicting reports and scarce or insufficiently pondered information have blurred conclusions. Therefore, with an aim to contribute to consolidating the available information, we carried out a wide scope, pan-comparative meta-analysis including the accessible information about the most relevant nephroprotective approaches assayed. After a thorough examination of 1892 documents retrieved from PubMed and Web of Science, 150 studies were used for the meta-analysis. Individual odds ratios of efficacy at reducing AKI incidence, need for dialysis, and plasma creatinine elevation were obtained for each alleged protectant. Also, the combined class effect of drug families and protective strategies was also meta-analyzed. Our results show that no drug family or procedure affords substantial protection against CSA-AKI. Only, a mild but significant reduction in the incidence of CSA-AKI by preemptive treatment with dopaminergic and adrenergic drugs, vasodilators, and the RIPC technique. The integrated analysis suggests that single-drug approaches are unlikely to cope with the variety of individual pathophysiological scenarios potentially underlying CSA-AKI. Accordingly, a theragnostic approach involving the etiopathological diagnosis of kidney frailty is necessary to guide research towards the development of pharmacological combinations concomitantly and effectively addressing the key mechanisms of CSA-AKI.

Effect of preoperative moderate-dose statin and duration on acute kidney injury after cardiac surgery: a retrospective cohort study

BACKGROUND

The impact of preoperative statin use on postoperative acute kidney injury (AKI) is uncertain. We aimed to examine the association of statin therapy before cardiac surgery with postoperative AKI.

METHODS

The retrospective cohort study consisted of 1581 patients undergoing cardiac surgery. Postoperative AKI were identified by the modified KDIGO definition. Propensity-score matching was employed to control for selection bias, and logistic regression was used to control for confounders. Subgroup and interaction analyses were performed to evaluate the robustness of the findings.

RESULTS

The overall incidence of postoperative AKI and severe AKI were 42.19% and 12.27%, respectively. Preoperative moderate-dose statin was significantly associated with a reduced incidence of postoperative AKI (28.9% vs 43.0%, OR (95%CI): 0.54 (0.38, 0.77), p < 0.001) and severe AKI (6.9% vs 13.7%, OR (95%CI): 0.46 (0.26, 0.83), p = 0.009). The beneficial effect on postoperative AKI persisted after adjusting for major confounding factors (OR (95%CI): 0.47 (0.34, 0.66)). Decreased risk of postoperative AKI was observed in patients with preoperative statin duration of 7 ∼ 14 days (OR (95%CI): 0.41 (0.25, 0.65)) and over 14 days (OR (95%CI): 0.43 (0.28, 0.65)), but not in those with preoperative statin duration of <7 days. Similar favorable effects were noted in most subgroup patients, except for those with high-risk factors such as diabetes mellitus, previous congestive cardiac failure, arrhythmia, preoperative ACEI/ARB, aortic cross-clamping or IABP.

CONCLUSION

Preoperative moderate-dose statin was significantly related to a decreased risk of postoperative AKI, especially in patients who received statins for a longer duration. Further large-scale multicenter randomized controlled trials are needed to ascertain the impact of statin dose, duration, and timing on postoperative AKI in cardiac surgery patients.

The effect of preoperative statins on postoperative mortality, renal, and neurological complications in patients undergoing cardiac surgeries: a retrospective cohort study

BACKGROUND

Cardiac surgery is performed worldwide to treat severe cases of cardiovascular diseases. Statins have shown controversial effects on complications after cardiac surgeries. We aimed to investigate the effect of preoperative statin therapy on the frequency of postoperative mortality, renal, and neurological complications.

METHODS

In a retrospective cohort study, the database of patients operated on in two hospitals in southern Iran during 2008-2019 was used to compare preoperative statin use with no use on the composite outcome of mortality, renal, and neurological complications as well as on each component of the composite, separately. Effects of low dose (<40 mg simvastatin equivalence) vs. high dose (≥40 mg) statins were also evaluated. Confounders that could affect the outcomes were considered in the logistic regression model, and multiple imputation techniques were used to categorize patients with unknown statin dose use as either high or low-dose users.

RESULTS

Of total 7329 patients, 17.6% of statin users and 17% of non-statin users developed the composite outcome (P=0.51). Statin use had no statistically significant association with the composite outcome (aRR 1.01 [95% CI: 0.88-1.16]). There was no significant association with mortality [aRR: 0.75 (95% CI: 0.34-1.69)], neurological [aRR: 1.25 (95% CI: 0.77-2.12)], or renal complications [aRR: 1.03 (95% CI 0.90-1.19)] after surgery. Neither low nor high doses had any statistically significant effect on the composite or any of its components.

CONCLUSIONS

In this large study, preoperative statin use, either high dose or low dose, did not affect short-term postoperative mortality, neurological, or renal complications.

Long-Term Preoperative Atorvastatin or Rosuvastatin Use in Adult Patients before CABG Does Not Increase Incidence of Postoperative Acute Kidney Injury: A Propensity Score-Matched Analysis

Background: Acute kidney injury (AKI) is among the expected complications of cardiac surgery. Statins with pleiotropic anti-inflammatory and antioxidant effects may be effective in the prevention of AKI. However, the results of studies on the efficacy and safety of statins are varied and require further study. Methods: We conducted a retrospective cohort study to evaluate long-term preoperative intake of atorvastatin and rosuvastatin on the incidence of AKI, based on the “Kidney Disease: Improving Global Outcomes” (KDIGO) criteria in the early postoperative period after coronary artery bypass graft surgery (CABG). We performed propensity score matching to compare the findings in our study groups. The incidence of AKI was assessed on day 2 and day 4 after the surgery. Results: The analysis included 958 patients after CABG. After 1:1 individual matching, based on propensity score, the incidence of AKI was comparable both on day 2 after the surgery (7.4%) between the atorvastatin group and rosuvastatin group (6.5%) (OR: 1.182; 95%Cl 0.411–3.397; p = 0.794), and on postoperative day 4 between the atorvastatin group (3.7%) and the rosuvastatin group (4.6%) (OR: 0.723, 95%Cl 0.187–2.792; p = 0.739). Additionally, there were no statistically significant differences in terms of incidence of AKI after 1:1 individual matching, based on propensity score, between the rosuvastatin group and the control group both on postoperative day 2 (OR: 0.692; 95%Cl 0.252–1.899; p = 0.611) and day 4 (OR: 1.245; 95%Cl 0.525–2.953; p = 0.619); as well as between the atorvastatin group and the control group both on postoperative day 2 (OR: 0.549; 95%Cl 0.208–1.453; p = 0.240) and day 4 (OR: 0.580; 95%Cl 0.135–2.501; p = 0.497). Conclusion: Long-term statin use before CABG did not increase the incidence of postoperative AKI. Further, we revealed no difference in the incidence of post-CABG AKI between the atorvastatin and rosuvastatin groups.

Postoperative Cardiac Surgery Outcomes in a Statin-Native Population

Background

Statin utilization had been associated with improved survival after cardiac surgery. We aim to study whether perioperative treatment with statin could be associated with increased postoperative complications.

Design

This was a retrospective, descriptive, single-center study.

Settings

We analyzed morbidity after cardiac surgery as well as the outcome related to statin therapy in a tertiary cardiac center.

Patients

A total of 202 consecutive patients were enrolled over 1 year after cardiac surgery.

Intervention

Patients were divided into two groups; Group I - statin users and Group II - nonusers.

Measurements

Measurements were baseline and follow-up laboratory markers for muscular injury including cardiac muscle and hepatic injuries and renal injuries.

Results

The incidence of rhabdomyolysis and elevation of liver enzymes did not differ between both groups. Postoperative atrial fibrillation was significantly lower in the statin group (P = 0.02). In addition, peak cardiac troponin and creatine kinase-MB did not differ significantly in the statin group. Statin-treated group had significant lower length of mechanical ventilation, and length of stay in the Intensive Care Unit and hospital (P = 0.036, 0.04, and 0.027, respectively).

Conclusions

Therapy with statin before cardiac surgeries was not associated with high incidence of adverse events.

Cardiac surgery-associated acute kidney injury

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a well-recognized complication resulting with the higher morbid-mortality after cardiac surgery. In its most severe form, it increases the odds ratio of operative mortality 3-8-fold, length of stay in the Intensive Care Unit and hospital, and costs of care. Early diagnosis is critical for an optimal treatment of this complication. Just as the identification and correction of preoperative risk factors, the use of prophylactic measures during and after surgery to optimize renal function is essential to improve postoperative morbidity and mortality of these patients. Cardiopulmonary bypass produces an increased in tubular damage markers. Their measurement may be the most sensitive means of early detection of AKI because serum creatinine changes occur 48 h to 7 days after the original insult. Tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 are most promising as an early diagnostic tool. However, the ideal noninvasive, specific, sensitive, reproducible biomarker for the detection of AKI within 24 h is still not found. This article provides a review of the different perspectives of the CSA-AKI, including pathogenesis, risk factors, diagnosis, biomarkers, classification, postoperative management, and treatment. We searched the electronic databases, MEDLINE, PubMed, EMBASE using search terms relevant including pathogenesis, risk factors, diagnosis, biomarkers, classification, postoperative management, and treatment, in order to provide an exhaustive review of the different perspectives of the CSA-AKI.

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.

The effects of preoperative statins on the incidence of postoperative acute kidney injury in patients undergoing cardiac surgeries

OBJECTIVES

Recent evidence has emphasized multifunctional therapeutic effects of statins on renal protection after cardiac surgeries. We aimed to assess the effects of preoperative administration of statins on lowering the incidence of postoperative acute kidney injury in patients undergoing cardiac surgeries.

METHODS

In a retrospective study, the preoperative, intraoperative and postoperative data of 1064 consecutive patients who underwent different forms of cardiovascular surgeries were reviewed. According to whether patients had received statins preoperatively, the patients were categorized into no statin (n = 620), low-dose statin (n = 262) or high-dose statin (n = 182) administration groups.

RESULTS

No difference was seen in postoperative incidence of acute kidney injury between the three groups (11.1, 9.9 and 11.5%, respectively, P = 0.887). The multivariate logistic regression analysis showed that advanced age [odds ratio (OR) = 1.043, P < 0.001], recent myocardial infarction within 90 days of surgery (OR = 1.935, P = 0.002) and longer intubation time (OR = 1.001, P = 0.001) could predict occurrence of kidney injury after cardiac surgery. The preoperative use of angiotensin converting enzyme (ACE) inhibitor could effectively prevent occurrence of this postoperative event (OR = 0.552, P = 0.008). After adjusting for propensity score only, statin treatment, at low or high doses, was not associated with lower postoperative acute kidney injury (OR = 1.010, P = 0.971 for low dose and OR = 1.108, P = 0.745 for high dose versus no statin). After further adjustment for propensity score, statin treatment with the different dosages was not associated with acute kidney injury (OR = 0.869, P = 0.633 for low dose and OR = 1.051, P = 0.885 for high dose versus no statin).

CONCLUSIONS

Preoperative statin use may not inhibit acute kidney injury after operation.

Pharmacological and nonpharmacological treatment after cardiac surgery

Open-heart surgery has become a common procedure. Postcardiac surgery management is a critical issue and represents a crucial period in terms of physical recovery. Cardiac rehabilitation is increasingly considered as an integral component of the continuum of care for patients with cardiovascular disease. Its usefulness is now widely accepted, and therefore, it is recommended in most contemporary cardiovascular clinical practice guidelines. Similarly, early pharmacological management can modulate the pathophysiological alterations after cardiac surgery, leading to an improvement in the early and long-term outcome. In this review, we will present recent advances in postcardiac surgery management, focusing on the pathophysiology of the perioperative period and on recent evidences in pharmacological and rehabilitative strategies.

Effect of preoperative statin therapy on postoperative acute kidney injury in patients undergoing major surgery: systemic review and meta-analysis

We aimed to examine the association between preoperative use of statins and postoperative acute kidney injury (AKI) in patients undergoing major surgery by performing a systemic review and meta-analysis. MEDLINE and EMBASE, from inception to April 2013, and the reference lists of related articles were searched for relevant studies. Trials comparing preoperative statin therapy with no preoperative statin in patients undergoing major surgery were included. Outcome measures of interest were the risk of cumulative postoperative AKI and postoperative AKI requiring renal replacement therapy (RRT). Fixed or random effect meta-analysis was performed to derive summary effect estimates. In five randomized controlled trials (RCTs) and 19 observational studies, comprising a total of 989 173 patients undergoing major surgery, 112 840 patients (11.41%) received preoperative statin therapy. The specific type, dosage, and duration of statin therapy were not available in most studies. Preoperative statin therapy was associated with a significant risk reduction for cumulative postoperative AKI (weighted summary odds ratio (OR) 0.87, 95% CI 0.79 to 0.95). The effect of risk reduction was also significant when considering postoperative AKI requiring RRT (OR 0.80, 95% CI 0.72 to 0.90). When restricting the analysis to the five RCTs, preoperative statin therapy did not show significant protective effect on postoperative AKI (OR 0.49, 95% CI 0.22 to 1.09). In patients undergoing major surgery, preoperative statin therapy could associate with a reduced risk for postoperative AKI. However, considerable heterogeneity existed among included studies. Future randomized trials were warranted for this critical clinical question.

Preoperative statin therapy is associated with lower requirement of renal replacement therapy in patients undergoing cardiac surgery: a meta-analysis of observational studies

OBJECTIVES

Acute kidney injury (AKI) following cardiac surgery is a common complication associated with serious morbidity and mortality. Activation of inflammatory cascade and vascular endothelial dysfunction plays a vital role during the perioperative period leading to AKI. Statins are known to suppress inflammation and improve endothelial dysfunction over and above the cholesterol lowering efficacy.

METHODS

Observational studies with a defined population in terms of preoperative statin therapy and no preoperative statin therapy undergoing cardiac surgery (CABG, isolated valve surgery or both) and with reported data on the incidence of acute renal failure/injury and/or mortality were identified and analysed for inclusion in the analysis. Outcomes evaluated were occurrence of postoperative acute kidney injury/failure, requirement of any postoperative renal replacement therapy and short-term all-cause mortality rate. A meta-analysis was conducted and a pooled estimate of odds ratio (OR) was calculated using the inverse variance method.

RESULTS

A total of 17 studies with a total population of 24 998 statin users and 22 082 non-statin users were included in the final analysis. PST resulted in a significantly lower incidence of renal replacement therapy in patients undergoing CABG (OR: 0.56 [0.41-0.76]) but not in isolated valve surgery (OR: 1.80 [0.73-4.44]). Also preoperative statin therapy resulted in a significantly lower postoperative mortality (0.72 [0.61-0.84]) irrespective of the type of surgery. There was no effect of preoperative statin therapy on the incidence of AKI in any of the sub-group of the patients.

CONCLUSIONS

Patients undergoing CABG might derive benefit from preoperative statin therapy in terms of reducing the need for postoperative renal replacement therapy and mortality. However, the uncertainty concerning the reno-protective efficacy of preoperative statin therapy in patients undergoing isolated valve surgery needs further investigation.

Preoperative statin therapy in cardiac surgery: a meta-analysis of 90,000 patients

The objective of this systematic literature review with meta-analysis was to determine the strength of evidence for a preoperative statin on the reduction of adverse postoperative outcomes in patients undergoing cardiac surgery. Randomized controlled (RCT) and observational trials were searched in online databases that reported about the effects of preoperative statin therapy on major adverse clinical outcomes after cardiac surgery. Analysed outcomes included early all-cause mortality, myocardial infarction, atrial fibrillation (AF), stroke and renal failure using a priori-defined criteria. Effect estimates were calculated and are given as odds ratio (OR) with 95% confidence intervals (95% CI) using fixed- or random-effect models. Literature search of all major databases retrieved 2371 studies. After screening, a total of 54 trials were identified (12 RCT, 42 observational) that reported outcomes of 91 491 cardiac surgery patients with (n = 46 614; 51%) or without (n = 44 877; 49%) preoperative statin therapy. Preoperative statin use resulted in a 0.9% absolute risk (2.6 vs 3.5%) and a 31% odds reduction for early all-cause mortality (OR 0.69; 95% CI 0.59-0.81; P < 0.0001). In addition, statin treatment before surgery was associated with a substantial reduction (P < 0.01) in the postoperative end-points AF (OR 0.71; 95% CI 0.61-0.82), new-onset AF (OR 0.68; 95% CI 0.54-0.85), stroke (OR 0.83; 95% CI 0.74-0.93), stay on intensive care unit (weighted mean difference [WMD] -0.14; 95% CI -0.23 to -0.03; P < 0.01) and in-hospital stay (WMD -0.57; 95% CI -0.76 to -0.38; P < 0.01). No statistical differences were found between groups with regard to myocardial infarction or renal failure. In conclusion, the current systematic review strengthens the evidence that preoperative statin therapy extends substantial clinical benefit to early postoperative outcomes in cardiac surgery patients.

Update on clinical trials for the prevention of acute kidney injury in patients undergoing cardiac surgery

BACKGROUND

Effective therapeutic agents for the prevention and treatment of acute kidney injury (AKI) after cardiac surgery remain elusive despite the tremendous advances in surgical techniques, technology, and understanding of disease processes. Recent developments and their effect on the incidence of AKI after cardiac surgery are discussed.

DATA SOURCES

Published clinical trials in PubMed, strength of evidence assessed by the guidelines of the American Family Physicians.

CONCLUSIONS

The definition of AKI has changed, and the focus of interventions has shifted from treatment to prevention to recovery from AKI. Antioxidants and biological agents have been added to classic armaments of hydration and diuretics in addition to tighter metabolic control to prevent AKI. Although the treatment options remain unsatisfactory, a lot of progress nevertheless continues to be made in the prevention and treatment of AKI.

Preoperative statin use and postoperative acute kidney injury

BACKGROUND

Acute kidney injury is a frequent postoperative complication that confers increased mortality, morbidity, and costs. The purpose of this study was to evaluate whether preoperative statin use is associated with a decreased risk of postoperative acute kidney injury.

METHODS

We assembled a retrospective cohort of 98,939 patients who underwent a major open abdominal, cardiac, thoracic, or vascular procedure between 2000 and 2010. Statin users were pair-matched to nonusers on the basis of surgery type, baseline kidney function, days from admission until surgery, and propensity score based on demographics, comorbid conditions, and concomitant medications. Acute kidney injury was defined based on changes in serum creatinine measurements applying Acute Kidney Injury Network and Risk-Injury-Failure staging systems, and on the need for renal replacement therapy. Associations between statin use and acute kidney injury were estimated by conditional logistic regression.

RESULTS

Across various acute kidney injury definitions, statin use was consistently associated with a decreased risk: adjusted odds ratios (95% confidence intervals) varied from 0.74 (0.58-0.95) to 0.80 (0.71-0.90). Associations were similar among diabetics and nondiabetics, and across strata of baseline kidney function. The protective association of statins was most pronounced among patients undergoing vascular surgery and least among patients undergoing cardiac surgery.

CONCLUSIONS

Preoperative statin use is associated with a decreased risk of postoperative acute kidney injury. Future randomized clinical trials are needed to determine causality.

Pilot double-blind, randomized controlled trial of short-term atorvastatin for prevention of acute kidney injury after cardiac surgery

AIM

To test whether short-term perioperative administration of oral atorvastatin could reduce incidence of postoperative acute kidney injury (AKI) in cardiac surgical patients.

METHODS

We conducted a double-blind, randomized controlled trial in 100 cardiac surgical patients at increased risk of postoperative AKI. Patients were randomized to atorvastatin (40 mg once daily for 4 days starting preoperatively) or identical placebo capsule. Primary outcome was to detect a smaller absolute rise in postoperative creatinine with statin therapy. Secondary outcomes included AKI defined by the creatinine criteria of RIFLE consensus classification (RIFLE R, I or F), change in urinary neutrophil gelatinase-associated lipocalin (NGAL) concentration, requirement for renal replacement therapy, length of stay in intensive care, length of stay in hospital and hospital mortality.

RESULTS

Study groups were well matched. For each patient maximal increase in creatinine during the 5 days after surgery was assessed; median maximal increase was 28 µmol/L in the atorvastatin group and 29.5 µmol/L in the placebo group (P = 0.62). RIFLE R or greater occurred in 26% of patients with atorvastatin and 32% with placebo (P = 0.65). Postoperatively urine NGAL changes were similar (median NGAL : creatinine ratio at intensive care unit admission: atorvastatin group 1503 ng/mg, placebo group 1101 ng/mg; P = 0.22). Treatment was well tolerated and adverse events were similar between groups.

CONCLUSION

Short-term perioperative atorvastatin use was not associated with a reduced incidence of postoperative AKI or smaller increases in urinary NGAL. (ClinicalTrials.gov NCT00910221).