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

The Treatment of Coronary Artery Disease in Patients with Chronic Kidney Disease: Gaps, Challenges, and Solutions

Background

Chronic kidney disease (CKD) is associated with a high burden of coronary artery disease (CAD), which remains the leading cause of death in CKD patients. Despite the high cardiovascular risk, ACS patients with renal dysfunction are less commonly treated with guideline-based medical therapy and are less frequently referred for coronary revascularization.

Summary

The management of CAD is more challenging in patients with CKD than in the general population due to concerns regarding side effects and renal toxicity, as well as uncertainty regarding clinical benefit of guideline-based medical therapy and interventions. Patients with advanced CKD and especially those receiving dialysis have not traditionally been represented in randomized trials evaluating either medical or revascularization therapies. Thus, only scant data from small prospective studies or retrospective analyses are available. Recently published studies suggest that there are significant opportunities to substantially improve both cardiovascular and renal outcomes of patients with CAD and CKD, including new medications and interventions. Thus, the objective of this review is to summarize the current evidence regarding the management of CAD in CKD patients, in particular with respect to improvement of both cardiovascular and renal outcomes.

Key Messages

Adequate medical therapy and coronary interventions using evidence-based strategies can improve both cardiac and renal outcomes in patients with CAD and CKD.

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.

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 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.

Effects of statins on the incidence and outcomes of acute kidney injury in critically ill patients: a systematic review and meta-analysis

INTRODUCTION

In critically ill patients, acute kidney injury (AKI) is a common complication with very high mortality rates. Several studies indicated that statin therapy, primarily due to its so-called pleiotropic effects, may beneficially affect the course of the disease, otherwise leading to significant clinical complications. However, both the original research as well as available meta-analyses on these associations report equivocal results. This leaves open a question whether pre- and perioperative statins might prevent AKI and improve overall prognosis in patients undergoing surgery.

MATERIAL AND METHODS

Following a systematic search of the literature, we performed a meta-analysis of selected clinical studies investigating the impact of statin treatment on the development and the clinical outcomes of AKI among subjects undergoing surgeries. The pooled odds ratios (OR) with 95% confidence intervals (CI) for the development of AKI and AKI-associated mortality, as well as the pooled mean differences (MD) and 95% CI for mean intensive care unit (ICU) stay and overall hospital length of stay were calculated for statin users compared to non-users.

RESULTS

Our results showed a highly significant association between statin use and the decrease in mortality of patients with AKI (OR = 0.73, 95% CI: 0.69-0.77; p<0.001). The development of AKI (OR = 0.92, 95% CI: 0.63-1.33; p = 0.659) as well as the ICU stay (MD = -0.02, 95% CI: -0.06 - 0.02; p = 0.321) were not significantly affected, while the overall hospital length of stay (MD = -0.49, 95% CI: -0.91 -0.07; p = 0.020) was reduced. Subgroup analysis showed that both pre- and postoperative statin use were not associated with the risk of AKI.

CONCLUSIONS

Our analysis showed a significant association between statin therapy and overall mortality of critically ill surgical patients diagnosed with AKI, while at the same time the use of statins did not affect the length of their stay in ICU.

Chronic kidney disease, risk of readmission, and progression to end-stage renal disease in 519,387 patients undergoing coronary artery bypass grafting

Objective

The association between chronic kidney disease and adverse outcomes after coronary artery bypass grafting is well established; in contrast, the association between chronic kidney disease and readmission has been less thoroughly investigated. We hypothesized that patients at higher chronic kidney disease stages have greater risk of readmission, poorer operative outcomes, and greater hospitalization cost.

Methods

Using the 2016-2018 Nationwide Readmissions Database, we identified 519,387 patients who underwent isolated coronary artery bypass grafting. Patients were stratified by chronic kidney disease stage based on International Classification of Diseases 10^th Revision classification. Multivariable logistic regression was used to assess risk factors for in-hospital mortality and 90-day readmission.

Results

Hospital readmission, in-hospital mortality, and cost progressively increased with worsening chronic kidney disease stage; patients with end-stage renal disease had the highest in-hospital mortality rate (7.2%), hospitalization costs ($59,616) (P < .001), and 90-day readmission rate (40%) (P < .001). Chronic kidney disease stage greater than 3 was associated with in-hospital mortality (odds ratio, 1.56, 95% confidence interval, 1.40-1.73; P < .001) and 90-day readmission (odds ratio, 1.66, 95% confidence interval, 1.56-1.76; P < .001). At 30 days after discharge, new-onset dialysis dependence was more frequent in patients readmitted with chronic kidney disease 4 to 5 (8.9%; n = 1495) than in patients with chronic kidney disease 1 to 3 (1.4%; n = 8623) and patients without chronic kidney disease (0.3%; n = 38,885). At 90 days after discharge, dialysis dependence increased to 11.1% (n = 1916) in readmitted patients with chronic kidney disease 4 to 5 but remained stable for patients with chronic kidney disease 1 to 3 (1.4%; n = 10,907) and patients without chronic kidney disease (0.3%; n = 50,200).

Conclusions

Chronic kidney disease stage is strongly associated with mortality, new-onset dialysis dependence, readmission, and higher cost after coronary artery bypass grafting. Patients with chronic kidney disease 4 and 5 and patients with end-stage renal disease are readmitted at the highest rates. Although further research is needed, a targeted approach may reduce costly readmissions and improve outcomes after coronary artery bypass grafting in patients with chronic kidney disease.

Impact of baseline body mass index on the efficacy and safety of tofacitinib in patients with psoriatic arthritis

OBJECTIVES

This post-hoc analysis explored the impact of body mass index (BMI) on tofacitinib efficacy/safety in patients with active psoriatic arthritis (PsA).

METHODS

Data were pooled from two phase 3 studies (NCT01877668; NCT01882439). Analyses included patients randomised to tofacitinib 5/10 mg twio times a day or placebo, stratified by baseline BMI: <25 kg/m2, ≥25-<30 kg/m2, ≥30-<35 kg/m2 or ≥35 kg/m2. Endpoints (month 3): American College of Rheumatology (ACR20/50/70), Health Assessment Questionnaire-Disability Index (HAQ-DI) and Psoriasis Area and Severity Index (PASI) 75 response rates; dactylitis/enthesitis resolution rates; changes from baseline Short Form-36 Health Survey version 2 (SF-36v2) Physical/Mental Component Summary (PCS) scores and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) total score. Safety was also reported.

RESULTS

Analysis included 710 patients; 43.8% were obese (BMI ≥30 kg/m2). Tofacitinib demonstrated higher efficacy response rates at month 3, compared with placebo, regardless of baseline BMI. Generally, ACR20/50/70 and HAQ-DI response rates, enthesitis resolution rates and changes from baseline in SF-36v2 PCS score and FACIT-F total score (month 3) were reduced in patients with baseline BMI ≥35 kg/m2 versus patients with lower BMIs. Elevated alanine aminotransferase/aspartate aminotransferase levels were reported in patients with baseline BMI ≥35 kg/m2 receiving tofacitinib 5 mg but not 10 mg two times a day.

CONCLUSION

Tofacitinib demonstrated greater efficacy than placebo in patients with PsA, regardless of baseline BMI. For all treatment arms, reduced efficacy was observed in patients with baseline BMI ≥35 kg/m2. Safety was generally comparable across BMI categories, although the effect of tofacitinib on liver enzymes in patients with baseline BMI ≥35 kg/m2 was inconclusive.

Body Mass Index (BMI) and Its Influence on the Cardiovascular and Operative Risk Profile in Coronary Artery Bypass Grafting Patients: Impact of Inflammation and Leptin

Background

Obesity is related to coronary artery disease (CAD) and worse outcomes in coronary artery bypass graft (CABG) patients. Adipose tissue itself is an endocrine organ that secretes many humoral mediators, such as adipokines, which can induce or reduce inflammation and oxidative stress.

Objectives

We investigate the relationship between the body mass index (BMI), inflammation, and oxidative stress by measuring serum levels of leptin, interleukin-6, and 3-nitrotyrosine in CABG patients and correlate their levels to the cardiovascular and operative risk profiles.

Methods and Results

45 men (<75 years) with a median BMI of 29 (21-51) kg/m², who were diagnosed with CAD and scheduled for elective CABG, were included after applying the following exclusion criteria: prior myocardial infarction, reoperation, female gender, and smoking. Patients' blood samples were taken preoperatively. Several markers were measured. We found significant correlations between leptin and BMI (p < 0.0001) as well as between leptin and 3-nitrotyrosine (p = 0.006). Interleukin-6 was correlated with C-reactive protein (p < 0.0001) and with the incidence of insulin-dependent diabetes mellitus (p = 0.036), arterial hypertension (p = 0.044), reduced left ventricular function (p = 0.003), and severe coronary calcification (p = 0.015). It was also associated with significantly longer extracorporeal bypass time (p = 0.009). Postoperative deep sternal wound infections could be predicted by a higher BMI (p = 0.003) and leptin level (p = 0.001).

Conclusions

There seems to be a correlation between inflammatory processes and cardiovascular morbidity in our cohort. Further, the incidence of deep sternal wound infections is related to a higher BMI and leptin serum level.

Effects of Preoperative Statin on Acute Kidney Injury After Off-Pump Coronary Artery Bypass Grafting

Background

Although many patients with coronary artery disease are using statins before off‐pump coronary artery bypass grafting (OPCAB) following current guidelines, recent studies have raised concerns regarding adverse effects of preoperative statins on postoperative kidney function. We evaluated the effects of preoperative statins on acute kidney injury (AKI) after OPCAB.

Methods and Results

We enrolled 1783 consecutive OPCAB patients in either a statin or nonstatin group based on preoperative use of statins. Propensity scores were used to adjust the differences between the groups. The primary outcome was incidence of postoperative AKI according to Kidney Disease: Improving Global Outcomes criteria. To evaluate the dose‐related renal effects of statins, the statin group was divided into low‐ and moderate‐ or higher dose groups based on preoperative statin dose. The incidence of postoperative AKI was 15.7% and 13.5% in the nonstatin and statin groups, respectively, and preoperative statins did not increase the incidence of postoperative AKI (odds ratio: 0.84; 95% CI, 0.61–1.15; P=0.27). In dose‐related analysis, the moderate‐ or higher dose group showed lower incidence of postoperative AKI in comparison with the nonstatin group (odds ratio: 0.61; 95% CI, 0.39–0.95; P=0.03). However, no difference was found between low‐dose and nonstatin groups (odds ratio: 1.17; 95% CI, 0.75–1.84; P=0.49) or between moderate‐ or higher dose and low‐dose statin groups (odds ratio: 0.84; 95% CI, 0.5–1.41; P=0.51) in the incidence of postoperative AKI.

Conclusions

Neither preoperative statin use nor statin dose increased the risk of AKI after OPCAB. Preoperative statin therapy is not harmful in patients receiving OPCAB.

The Impact of Statins before High-Risk CABG on Postoperative Multiple Organ Function

Background

The purpose of this cohort study was to investigate the independent relationship between preoperative statin therapy (PST) and postoperative severe multiorgan failure, measured by the Sequential Organ Failure Assessment (SOFA) maximum greater than 11, in high-risk patients undergoing isolated coronary artery bypass grafting (CABG).

Methods

The present study is a perspective, single-center, cohort analysis enrolling high-risk patients undergoing CABG from Jan 1, 2018, to Dec 31, 2018, in Beijing Anzhen hospital.

Results

Among a total of 880 high-risk patients undergoing isolated CABG included in this study, 503 (57.2%) experienced statin therapy before CABG. The SOFA maximum was significantly lower in the PST group compared with the control group (7.8 ± 3.0 v 9.2 ± 3.4, P < 0.0001). Multivariate logistic regression analysis demonstrated the incidence of the severe multiorgan dysfunction, measured by SOFA maximum ≥11, was dramatically reduced in the PST group (OR, 0.68, 95% CI 0.50-0.92, P=0.013). Furthermore, preoperative statin therapy (PST) might be associated with a decreased risk of postoperative major adverse cardiovascular and cerebral events and acute kidney injury, but an increased risk of postoperative hepatic inadequacy.

Conclusion

SOFA maximum was significantly lower in the PST group compared with the control group and the incidence of the severe multiorgan dysfunction was dramatically reduced in the PST group. The findings of this study might shed new light on questions of positive or negative effects of PST on multiple organ function after high-risk CABG, so as to ultimately improve high-risk patient in-hospital outcomes from CABG.

Lipid profile and statin use in critical care setting: implications for kidney outcome

Objective:

To determine whether pre-hospital statin use is associated with lower renal replacement therapy requirement and/or death during intensive care unit stay.

Methods:

Prospective cohort analysis. We analyzed 670 patients consecutively admitted to the intensive care unit of an academic tertiary-care hospital. Patients with ages ranging from 18 to 80 years admitted to the intensive care unit within the last 48 hours were included in the study.

Results:

Mean age was 66±16.1 years old, mean body mass index 26.6±4/9kg/m² and mean abdominal circumference was of 97±22cm. The statin group comprised 18.2% of patients and had lower renal replacement therapy requirement and/or mortality (OR: 0.41; 95%CI: 0.18-0.93; p=0.03). The statin group also had lower risk of developing sepsis during intensive care unit stay (OR: 0.42; 95%CI: 0.22-0.77; p=0.006) and had a reduction in hospital length-of-stay (14.7±17.5 days versus 22.3±48 days; p=0.006). Statin therapy was associated with a protective role in critical care setting independently of confounding variables, such as gender, age, C-reactive protein, need of mechanical ventilation, use of pressor agents and presence of diabetes and/or coronary disease.

Conclusion:

Statin therapy prior to hospital admission was associated with lower mortality, lower renal replacement therapy requirement and sepsis rates.

Association between statin use and perioperative mortality after aortobifemoral bypass in patients with aortoiliac occlusive disease

OBJECTIVE

The benefit of statins in reducing perioperative cardiovascular events in patients undergoing suprainguinal bypass is still controversial. The purpose of this study was to evaluate the association between statin use and perioperative mortality in patients undergoing aortobifemoral bypass (ABFB) for aortoiliac occlusive disease.

METHODS

We retrospectively analyzed all patients who had ABFB in the American College of Surgeons National Surgical Quality Improvement Program data set from 2011 to 2016. Univariable (t-test, χ² test, or Fisher exact test) and multivariable logistic regression analyses were used to compare patients' characteristics and the primary outcome (30-day mortality) between statin users and nonstatin users. Propensity score matching between statin users and nonusers was also performed on the basis of variables that were different between the two groups.

RESULTS

A total of 4445 patients underwent ABFB. Of those, 3032 (68.2%) were taking statins. Compared with nonstatin users, statins users were older (median [interquartile range], 67 years [59-74 years] vs 63 years [56-72 years]; P < .01) and more likely to be diabetic (31% vs 16%) and hypertensive (84% vs 63%) and to have a history of chronic obstructive pulmonary disease (20% vs 17%; all P < .05). Statin users had lower rates of 30-day mortality (3.4% vs 4.7%; P = .03) and renal complications (2.5% vs 3.7%; P = .04) compared with nonstatin users. After adjustment for patients' demographics (age, sex, race), comorbidities (diabetes, hypertension, congestive heart failure, chronic obstructive pulmonary disease, chronic kidney disease, dialysis, bleeding disorder), smoking, clinical presentation (claudication vs critical limb ischemia), and elective surgery status, statin use was associated with 32% reduction in 30-day mortality (odds ratio, 0.68; 95% confidence interval, 0.47-0.96; P = .03). Propensity score matching showed similar results (odds ratio, 0.63; 95% confidence interval, 0.41-0.95; P = .03).

CONCLUSIONS

This is the largest study to date demonstrating an association between preoperative statin use and lower 30-day mortality after ABFB for aortoiliac occlusive disease. This study highlights an area of potential quality improvement as one-third of the patients undergoing this procedure are not receiving statins.

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.

The renoprotective effects of simvastatin and atorvastatin in patients with acute coronary syndrome undergoing percutaneous coronary intervention: An observational study

Some statins, such as atorvastatin, have proven renoprotective effects. The comparative renoprotective potential of simvastatin is less clear. This study aimed to compare the renoprotective effects of simvastatin with atorvastatin in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). This observational study examined the medical records of 271 patients who were treated at the Guangdong Cardiovascular Institute from April 2004 to February 2008. Patients had received either 40 mg simvastatin (n = 128) or 20 mg atorvastatin (n = 143), daily, for a period of at least 6 months following PCI. Declined renal function (DRF) was defined at the occurrence of chronic kidney disease (CKD) or elevated CKD stages at 6-months post-PCI. Results showed that the incidence of DRF was similar among patients taking simvastatin or atorvastatin (25.00% vs 26.57%, respectively). Kaplan-Meier survival analysis showed that patients who developed DRF had a higher incidence of mortality and major adverse cardiovascular events (MACEs) than those without DRF (17.41% vs 28.57%, P = .0308). Multivariate logistic regression analysis identified diabetes and baseline estimated glomerular filtration rate as independent risk factors for DRF. Collectively, our results indicate that simvastatin has comparable renoprotective effects to atorvastatin in ACS patients undergoing PCI. Further studies are warranted to confirm the comparative renoprotective effects of statins.

Evaluation of the Effect of Statins on Post-Surgical Patients with Acute Kidney Injury

INTRODUCTION

Acute kidney injury is the sudden and almost complete loss of renal function with reduced glomerular filtration rate, and it occurs whenever the kidneys are unable to excrete metabolic waste products.

METHOD

This randomized double-blinded clinical trial was performed in an intensive care unit (ICU) of a university educational hospital. After randomization with a random assigning table of numbers, patients were divided into two groups: an intervention group and a control group. The patients' daily blood urea nitrogen and creatinine levels were measured and changes were recorded. The statin group received a tablet of atorvastatin 40 mg daily (Abidi Pharmacy Production). Moreover, patients' baseline vital signs and changes in serum blood urea nitrogen, creatinine, mechanical ventilation requirement, need for dialysis, ICU stays, and mortality were recorded in both groups. SPSS version 20 software was used for data analysis. P value <0.05 was considered significant.

RESULTS

The mean intubation time for the intervention and control groups was 4.44±1.8 and 3.46±2.02, respectively, and the mean mechanical ventilation time was 2.14±2.15 and 2.34±2.07 days, respectively. The mean ICU stay was 4.91±3.3 days for the intervention group and 4.67±2.67 days for the control group. Throughout the study duration, the mean dialysis requirement frequency was 4.66±1.2 times in the intervention group and 5.54 ±1.75 times in the control group. Two patients in the intervention group and three patients in the control group died. There was no statistically significant difference in mortality between the two groups (P >0.05).

DISCUSSION AND CONCLUSION

The effects of statins on the different stages of acute kidney injury and its outcomes are yet challengeable, so we recommend conducting further studies with larger sample sizes.

Recent Perioperative Pharmacological Prevention of Acute Kidney Injury after Cardiac Surgery: A Narrative Review

Acute kidney injury (AKI) is a common and severe complication of cardiac surgery, and related rates of both hospitalization and long-term mortality are increasing. A number of studies have explored the preventive effects of perioperative pharmacological therapy on AKI after cardiac surgery. However, the mechanisms of AKI are multifaceted, and no universal treatment has been confirmed as beneficial. We review and analyze several current perioperative pharmacological therapies for AKI after cardiac surgery to identify promising preventive strategies.

Perioperative Statin Therapy for Patients Undergoing Coronary Artery Bypass Grafting

Coronary artery bypass grafting is associated with an intense systemic inflammatory response, which is linked to postoperative complications. Beyond lipid lowering, statins exert a constellation of beneficial actions, including an antiinflammatory role, known as pleiotropic effects. There is increasing evidence that perioperative statin therapy improves outcomes in patients undergoing coronary artery bypass grafting. Statins are underused in the coronary artery bypass grafting population, because perioperative discontinuation remains a common practice. This article provides an extensive review of the available literature on the effect of perioperative statin therapy on post–coronary artery bypass grafting outcomes and weighs the evidence for the concerns about increased incidence of statin-related adverse effects in this setting.

Prevention and Treatment of Cardiac Surgery Associated Acute Kidney Injury

AIM OF REVIEW

Acute kidney injury (AKI) after cardiac surgery is a relatively common postoperative complication and is independently related to increased mortality and morbidity.

METHOD

In this review, we will focus on risk factors of developing AKI, early detection by biomarkers and preventive strategies for AKI after adult cardiac surgery.

RECENT FINDINGS

Many perioperative factors affect renal function and acute AKI following cardiac surgery. Novel biomarkers of kidney injury such as neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), cystatin C (CysC), have the potential to facilitate the early diagnosis of cardiac surgery associated AKI (CSA-AKI). Pharmacological interventions have been inconsistent to their efficacy, and to date, there is no compelling pharmacologic agent known to reduce the risk of AKI or treat established AKI.

SUMMARY

Preventive strategies of AKI focus on optimal perioperative management.

Levosimendan for Prevention of Acute Kidney Injury After Cardiac Surgery: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Levosimendan has been shown to confer direct renoprotection in renal endotoxemic and ischemia-reperfusion injury and could increase renal blood flow in patients with low-cardiac-output heart failure. Results from clinical trials of levosimendan on acute kidney injury (AKI) following cardiac surgery are controversial.

STUDY DESIGN

A random-effect meta-analysis was conducted based on evidence from PubMed, EMBASE, and Cochrane Library.

SETTINGS & POPULATION

Adult patients undergoing cardiac surgery.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials comparing the renal effect of levosimendan versus placebo or other inotropic drugs during cardiac surgery.

INTERVENTION

Perioperative levosimendan continuous infusion at a rate of 0.1 to 0.2μg/kg/min following a loading dose (6-24μg/kg) for 24 hours or only 1 loading dose (24μg/kg) within 1 hour.

OUTCOMES

AKI, need for renal replacement therapy, mechanical ventilation duration, intensive care unit stay during hospitalization, and postoperative mortality (in-hospital or within 30 days).

RESULTS

13 trials with a total of 1,345 study patients were selected. Compared with controls, levosimendan reduced the incidence of postoperative AKI (40/460 vs 78/499; OR, 0.51; 95% CI, 0.34-0.76; P=0.001; I(2)=0.0%), renal replacement therapy (22/492 vs 49/491; OR, 0.43; 95% CI, 0.25-0.76; P=0.002; I(2)=0.0%), postoperative mortality (35/658 vs 94/657; OR, 0.41; 95% CI, 0.27-0.62; P<0.001; I(2)=0.0%), mechanical ventilation duration (in days; n=235; weighted mean difference, -0.34; 95% CI, -0.58 to -0.09; P=0.007], and intensive care unit stay (in days; n=500; weighted mean difference, -2.2; 95% CI, -4.21 to -0.13; P=0.04).

LIMITATIONS

Different definitions for AKI among studies. Small sample size for some trials.

CONCLUSIONS

Perioperative administration of levosimendan in patients undergoing cardiac surgery may reduce complications. Future trials are needed to determine the dose effect of levosimendan in improving outcomes, especially in patients with decreased baseline kidney function.

Prevention of renal dysfunction in postoperative elderly patients

PURPOSE OF REVIEW

To describe the effect of ageing on kidney function and to summarize the benefits of advocated measures to prevent perioperative acute kidney injury (AKI) in elderly patients.

RECENT FINDINGS

Given a reduced renal reserve and the burden of comorbidities, the senescent kidney is susceptible to develop perioperative AKI and is less able to recover when injury occurs. Current evidence suggests that preoperative statin therapy, tight glycemic control or urine alkalinization with bicarbonate do not protect the kidneys from harm. The theoretical kidney protective effect of preoperative aspirin therapy or renal vasodilatation with atrial natriuretic peptide or fenoldopam is only supported by low-quality evidence that needs further evaluation. Although questions regarding the amount and timing of fluid resuscitation during surgery are seeking answers in ongoing multicenter studies, the harmful effect of hydroxyethyl starches (HES) and hyperchloremic solutions is now surrounded by strong evidence.

SUMMARY

The future increase in elderly patients being exposed to surgery calls for improved perioperative management to prevent collaterally increased AKI. Although pharmacological therapies aiming to protect the kidneys from harm are under evaluation, hemodynamic optimization and avoidance of nephrotoxic drugs, including HES and hyperchloremic solutions, are critical for the elderly perioperative patient.

Statins for the Prevention of Contrast-Induced Nephropathy After Coronary Angiography/Percutaneous Interventions: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Statins have been demonstrated to prevent the development of contrast-induced nephropathy (CIN). Nevertheless, clinical research has indicated conflicting results. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the protective effects of statins on CIN and the requirement of renal replacement therapy (RRT) in patients undergoing coronary angiography/percutaneous interventions.

METHODS

PubMed, MEDLINE, Web of Science, EMBASE, ClinicalTrials.gov, and the Cochrane Central RCTs were searched for RCTs from inception to February 2014 to compare statins with placebo treatment for preventing CIN in patients undergoing coronary angiography/percutaneous interventions.

RESULTS

Nine RCTs were identified and analyzed in a total of 5143 patients involving 2560 patients with statin pretreatment and 2583 patients as control. Patients who received statin therapy had a 53% lower risk of CIN with different definitions (within 48 or 72 hours) compared to the control group based on a fixed effect model (risk ratio = 0.47, 95% confidence interval = 0.37-0.60, P < .0001) and were less likely to require RRT based on Peto fixed effect. Subgroup analysis showed that statin pretreatment could decrease the incidence of CIN in patients with preexisting renal dysfunction or diabetes mellitus. In addition, patients on rosuvastatin had a similar reduced incidence of CIN compared to patients on atorvastatin.

CONCLUSION

This updated meta-analysis demonstrated that preprocedural statin treatment could reduce the risk of CIN and the need for RRT in patients undergoing coronary angiography/percutaneous interventions. Moreover, statin therapy would be helpful in reducing the incidence of CIN in high-risk patients with preexisting renal dysfunction or diabetes mellitus. Additionally, rosuvastatin and atorvastatin had similar efficacies in preventing CIN development.

A patient with AKI after cardiac surgery

Up to 30% of patients undergoing cardiac surgery develop AKI, with 1% requiring RRT. AKI is an independent risk factor for morbidity and mortality. Postoperatively, even minimal changes in serum creatinine are associated with a substantial increase in mortality. No intervention has been definitely proven effective in reducing kidney injury. The successful prevention and management of AKI involves identifying patients at risk for AKI, recognizing subtle abnormalities in a timely manner, performing basic clinical assessments, and responding appropriately to data obtained. With that in mind, in this Attending Rounds, a woman with AKI in the setting of cardiac surgery is presented to highlight the use of history, physical exam, hemodynamic monitoring, laboratory data trends, and urine indices in establishing the correct diagnosis and appropriate management.

Effects of atorvastatin on plasma matrix metalloproteinase-9 concentration after glial tumor resection; a randomized, double blind, placebo controlled trial

Background

Neurosurgical procedures such as craniotomy and brain tumor resection could potentially lead to unavoidable cerebral injuries. Matrix metalloproteinase-9 (MMP-9) is up-regulated in neurological injuries. Statins have been suggested to reduce MMP- 9 level and lead to neuroprotection. Atorvastatin preoperatively administered to evaluate its neuroprotective effects and outcome assessment in neurosurgical-induced brain injuries after glial tumor resection. In this prospective, randomized, double-blind, placebo-controlled trial, 42 patients undergoing glial tumor surgery randomly received 40 mg atorvastatin or placebo twice daily from seven days prior to operation and continued for a 3 weeks period. Plasma MMP-9 concentration measured 4 times, immediately before starting atorvastatin or placebo, immediately before surgery, 24 hours and two weeks after the surgery. Karnofsky performance score was assessed before first dose of atorvastatin as a baseline and 2 months after the surgery.

Results

Karnofsky performance scale after surgery raised significantly more in Atorvastatin group (11.43 +/- 10.62 vs. 4.00 +/- 8.21) (p = 0.03). Atorvastatin did not significantly reduce MMP-9 plasma concentration 24 hours after surgery in comparison to placebo. No statistical significance detected regarding length of hospital stay among the groups. Significant reduction in MMP-9 plasma concentration was recorded in atorvastatin group two weeks after surgery (p = 0.048).

Conclusions

Significant statistical differences detected with atorvastatin group regarding MMP-9 plasma concentration, clinical outcome and Karnofsky performance score. Consequently, atorvastatin use may lead to better outcome after neurosurgical procedures.