Effects of atorvastatin on systemic inflammatory response after coronary bypass surgery

Pathophysiological mechanisms of atrial fibrillation: a translational appraisal

Atrial fibrillation (AF) is an arrhythmia that can occur as the result of numerous different pathophysiological processes in the atria. Some aspects of the morphological and electrophysiological alterations promoting AF have been studied extensively in animal models. Atrial tachycardia or AF itself shortens atrial refractoriness and causes loss of atrial contractility. Aging, neurohumoral activation, and chronic atrial stretch due to structural heart disease activate a variety of signaling pathways leading to histological changes in the atria including myocyte hypertrophy, fibroblast proliferation, and complex alterations of the extracellular matrix including tissue fibrosis. These changes in electrical, contractile, and structural properties of the atria have been called "atrial remodeling." The resulting electrophysiological substrate is characterized by shortening of atrial refractoriness and reentrant wavelength or by local conduction heterogeneities caused by disruption of electrical interconnections between muscle bundles. Under these conditions, ectopic activity originating from the pulmonary veins or other sites is more likely to occur and to trigger longer episodes of AF. Many of these alterations also occur in patients with or at risk for AF, although the direct demonstration of these mechanisms is sometimes challenging. The diversity of etiological factors and electrophysiological mechanisms promoting AF in humans hampers the development of more effective therapy of AF. This review aims to give a translational overview on the biological basis of atrial remodeling and the proarrhythmic mechanisms involved in the fibrillation process. We pay attention to translation of pathophysiological insights gained from in vitro experiments and animal models to patients. Also, suggestions for future research objectives and therapeutical implications are discussed.

Usefulness of statins pretreatment for the prevention of postoperative atrial fibrillation in patients undergoing cardiac surgery

BACKGROUND

postoperative atrial fibrillation (AF) remains the most common arrhythmic complication following cardiac surgery. We performed a meta-analysis based on all currently available randomized controlled trials (RCTs) to confirm the hypothesis that statins pretreatment may lower the risk of postoperative AF in patients undergoing cardiac surgery.

METHODS AND RESULTS

the published literature was scanned by formal searches of electronic databases up through August 2010. RCTs were eligible for inclusion if they compared preoperative statins treatment versus control in patients scheduled for cardiac surgery and had the data of postoperative AF reported. Prespecified criteria were met by eight RCTs involving 841 patients. During the follow-up period, 80 of 422 patients (19.0%) in the statins pretreatment group developed postoperative AF, significantly less than 149 of 419 (35.6%) patients assigned to the control group ( P < 0.001). Postoperative hospital stay was significantly shortened in patients pretreated with statins compared with the control ( P < 0.01).

CONCLUSIONS

this meta-analysis supports the effectiveness of statins pretreatment on reducing the incidence of postoperative AF in patients undergoing cardiac surgery.

Steroids and statins: an old and a new anti-inflammatory strategy compared

OBJECTIVES

This study compared the anti-inflammatory effects of methylprednisolone (MP) and atorvastatin and analysed their influences on clinical variables in patients undergoing coronary revascularization.

METHODS

Ninety patients with compromised left ventricular ejection fraction (≤30%) undergoing elective coronary surgery were equally randomized to one of three groups: statin group, treatment with atorvastatin (20 mg/day) 3 weeks before surgery; methylprednisolone group, a single shot of methylpredniosolone (10mg/kg); and control group.

RESULTS

Postoperative IL-6 was higher in the control group when compared to the methylprednisolone and statin groups (p<0.01). IL-6 was higher in the statin-treated patients (p<0.05 versus methylprednisolone). Administration of methylprednisolone as well as statin treatment increased postoperative cardiac index, left ventricular stroke work index, decreased postoperative atrial fibrilation rate and reduced ICU stay (p<0.05 versus control). The number of patients requiring inotropic support was lower in the methylprednisolone group when compared with the other two groups (p<0.01). Tracheal intubation time was reduced in patients who received methylprednisolone (p<0.01 versus control).

CONCLUSIONS

Preoperative administration of either methylprednisolone or atorvastatin reduced pro-inflammatory cytokine release, improved haemodynamics, decreased postoperative atrial fibrilation rate and reduced ICU stay in patients with significantly impaired cardiac function undergoing coronary revascularization. Treatment with methylprednisolone was associated with less inotropic support requirements and reduced mechanical ventilation time.

Simvastatin attenuates cardiopulmonary bypass-induced myocardial inflammatory injury in rats by activating peroxisome proliferator-activated receptor γ

Statins have been shown to downregulate the systemic inflammatory response after cardiopulmonary bypass. However, the role of statins as anti-inflammatory agents in heart tissue remains unknown. The aim of this study was to test whether statin pretreatment attenuates local inflammatory cytokines production in heart and to explore whether the underlying mechanism involves peroxisome proliferator-activated receptor (PPAR) γ. A rat model of cardiopulmonary bypass was established. The animals were pretreated with simvastatin 5 mg/kg/day or 10 mg/kg/day for 7 days before operation. The serum concentration and myocardial level of tumor necrosis factor (TNF)-α, interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1 was evaluated by enzyme linked immunosorbent assay. The polymorphonuclear neutrophils accumulation in heart tissue was determined by myeloperoxidase activity assay. The activity of nuclear factor (NF)-κB and PPARγ in the heart was determined by electrophoretic mobility shift assay. The myocardial PPARγ expression was also examined by immunohistochemistry. The systemic and local TNF-α, IL-6 and MCP-1 were all significantly elevated after cardiopulmonary bypass. In contrast, simvastatin pretreatment significantly decreases the serum and myocardial expression level of above cytokines, myocardial myeloperoxidase activity and myocardial NF-κB activity. However, there was an evident increase in the activity and expression of PPARγ. In conclusion, simvastatin pretreatment not only attenuates acute systemic and local inflammatory response induced by cardiopulmonary bypass. The anti-inflammatory effect of simvastatin in myocardium may be partly related to the activation of PPARγ and inhibition of NF-κB.

Evidence of pre-procedural statin therapy a meta-analysis of randomized trials

OBJECTIVES

The purpose of this study was to summarize the evidence of pre-procedural statin therapy to reduce periprocedure cardiovascular events.

BACKGROUND

Invasive procedures can result in adverse cardiovascular events, such as myocardial infarction (MI) and death. We hypothesized that statins might improve clinical outcomes when used before invasive procedures.

METHODS

We searched the MEDLINE, Cochrane, and clinicaltrials.gov databases from inception to February 2010 for randomized, controlled trials that examined statin therapy before invasive procedures. Invasive procedures were defined as percutaneous coronary intervention, coronary artery bypass grafting (CABG), and noncardiac surgery. We required that studies initiated statins before the procedure and reported clinical outcomes. A DerSimonian-Laird model was used to construct random-effects summary risk ratios.

RESULTS

Eight percent of the screened trials (21 of 270) met our selection criteria, which included 4,805 patients. The use of pre-procedural statins significantly reduced post-procedural MI (risk ratio [RR]: 0.57, 95% confidence interval [CI]: 0.46 to 0.70, p < 0.0001). This benefit was seen after both percutaneous coronary intervention (p < 0.0001) and noncardiac surgical procedures (p = 0.004), but not CABG (p = 0.40). All-cause mortality was nonsignificantly reduced by statin therapy (RR: 0.66, 95% CI: 0.37 to 1.17, p = 0.15). Pre-procedural statins also reduced post-CABG atrial fibrillation (RR: 0.54, 95% CI: 0.43 to 0.68, p < 0.0001).

CONCLUSIONS

Statins administered before invasive procedures significantly reduce the hazard of post-procedural MI. Additionally, statins reduce the risk of atrial fibrillation after CABG. The routine use of statins before invasive procedures should be considered.

Non-antiarrhythmic drugs to prevent atrial fibrillation

Atrial fibrillation (AF) is the most frequent arrhythmia found in clinical practice. The majority of patients with AF are still candidates for antiarrhythmic drug treatment, not only for acute reversion to sinus rhythm but also for long-term treatment to prevent recurrences of AF. Currently available antiarrhythmic drugs, however, are unable to provide complete efficacy in all patients, and present problematic risks of proarrhythmia. The progressively increasing prevalence of AF supports the need to develop improved therapeutic approaches for the clinical management of arrhythmia. Accordingly, new treatment techniques aimed at suppressing the origin of the arrhythmogenic foci have been developed in the last decade. However, ablative treatments are only available for selected patients. Because of these factors, and also because primary prevention of AF should be our goal, the introduction of non-antiarrhythmic agents that could prevent both new-onset AF and recurrences of AF may eventually improve patient outcomes and reduce the incidence of this epidemic disease. The potential clinical value of these non-antiarrhythmic options is currently under active investigation. There is now clinical and experimental evidence that many drugs may have beneficial effects in preventing AF through several possible mechanisms. Non-antiarrhythmic drugs, such as ACE inhibitors and angiotensin receptor blockers, HMG-CoA reductase inhibitors (statins), corticosteroids, and N-3 polyunsaturated fatty acids may have a positive effect in patients with AF or in preventing AF in patients at risk.

Atorvastatin pretreatment diminishes the levels of myocardial ischemia markers early after CABG operation: an observational study

Background

Statin pretreatment has been associated with a decrease in myocardial ischemia markers after various procedures and cardiovascular events. This study examined the potential beneficial effects of preoperative atorvastatin treatment among patients undergoing on-pump CABG operation.

Methods

Twenty patients that had received atorvastatin treatment for at least 15 days prior to the operation and 20 patients who had not received any antihyperlipidemic agent prior to surgery were included in this study. CK-MB and troponin I levels were measured at baseline and 24 hours after the operation. Perioperative variables were also recorded.

Results

Twenty-four hours after the operation, troponin I and CK-MB levels were significantly lower in the atorvastatin group: for CK-MB levels, 12.9 ± 4.3 versus 18.7 ± 7.4 ng/ml, p = 0.004; for troponin I levels, 1.7 ± 0.3 versus 2.7 ± 0.7 ng/ml, p < 0.001. In addition, atorvastatin use was associated with a decrease in the duration of ICU stay.

Conclusions

Preoperative atorvastatin treatment results in significant reductions in the levels of myocardial injury markers early after on-pump CABG operation, suggesting a reduction in perioperative ischemia in this group of patients. Further studies are needed to elucidate the mechanisms of these potential benefits of statin pretreatment.

Preoperative statin therapy decreases risk of postoperative renal insufficiency

INTRODUCTION

Although current guidelines recommend withholding statins in perioperative patients, little information is available on whether perioperative statin use increases risk for postoperative renal failure.

AIMS

We examined the relation between preoperative statin therapy and postoperative risk for renal insufficiency in patients undergoing cardiac surgery.

METHODS

Retrospective cohort review from the Texas Heart Institute research database was performed. Patients were divided into two groups: those who received preoperative statins and those who did not. Primary outcome was the development of postoperative renal insufficiency (requiring dialysis or not). Outcomes were assessed in the entire cohort and in subgroups undergoing isolated coronary artery bypass grafting (CABG), isolated valve surgery, or combined CABG and valve surgery.

RESULTS

Of 3001 patients, 56% received preoperative statins. In multivariate logistic regression analysis, preoperative statins were associated with significant reductions in risk for postoperative renal insufficiency in the entire cohort (odds ratio [OR]= 0.60, 95% confidence interval [CI] 0.38-0.95) and in patients undergoing isolated CABG (OR = 0.34, 95% CI 0.17-0.68). In patients undergoing isolated valve surgery (OR = 1.35, 95% CI 0.61-2.96) or combined CABG and valve surgery (OR = 1.39, 95% CI 0.48-3.99), preoperative statins were not associated with decreased incidence of postoperative renal insufficiency. Age >65 years, preoperative renal insufficiency, history of congestive heart failure, preoperative intra-aortic balloon pump insertion, and total cardiopulmonary bypass time >80 min were also independent predictors associated with increased risk for postoperative renal insufficiency.

CONCLUSIONS

Preoperative statin therapy was associated with decreased incidence of postoperative renal insufficiency in patients undergoing cardiac surgeries, particularly in patients undergoing isolated CABG.

Endothelial activation after coronary artery bypass surgery: comparison between on-pump and off-pump techniques

BACKGROUND

The effects of off-pump coronary artery bypass (OPCAB) surgery on endothelial cell activation are poorly understood. Endothelial cell adhesion molecules (CAMs) are expressed and released when the endothelium is activated. We compared plasma CAMs (E-selectin, ICAM-1 and VCAM-1) and HUVEC expression of the same CAMs when exposed to plasma taken before, during and after OPCAB or on-pump coronary surgery (CABG).

METHODS

Patients undergoing first time CABG (n=10) or OPCAB (n=10) had 6 blood samples taken before surgery and up to 24h post-operatively. Plasma samples were assayed for E-selectin, ICAM-1 and VCAM-1. The same plasma samples were exposed to HUVEC cultures and cell-surface expression of E-selectin, ICAM-1 and VCAM-1 measured. Data are expressed as mean+/-SEM of n subjects.

RESULTS

Plasma E-selectin was unchanged. Plasma ICAM-1 and VCAM-1 were elevated 24h post-operatively in both groups (P<0.01), with no differences between the groups. Twenty-four hours post-OPCAB plasma increased basal and IL-1beta induced expression of endothelial VCAM-1 by 133+/-16% and 140+/-27% (P<0.05), respectively. Plasma taken 3h post-CABG decreased endothelial VCAM-1 expression by 76+/-10% (P<0.05). Peri-operative plasma had no effect on endothelial expression of E-selectin or ICAM-1 in either group.

CONCLUSIONS

OPCAB and CABG with CPB appear to generate qualitatively different inflammatory responses with respect to endothelial activation, which may have clinical implications.

Atorvastatin increases the number of endothelial progenitor cells after cardiac surgery: a randomized control study

Endothelial progenitor cells (EPCs) are a subtype of hematopoietic stem cells, which contribute to the repair of injured endothelium. Treatment with atorvastatin has been shown to increase EPC count in patients with coronary artery disease. Therefore, we investigated whether atorvastatin augments the number of EPCs after cardiopulmonary bypass (CPB) surgery. We conducted a randomized double-blind, placebo-controlled, 2-way crossover trial in 50 patients undergoing elective coronary surgery. Patients received either 3-week treatment with atorvastatin or placebo. EPCs were quantitated by flow cytometric phenotyping on blood samples. Levels of interleukin, IL-6 and IL-8; tumor necrosis factor alpha; SDF-1alpha; granulocyte colony-stimulating factor; and vascular endothelial growth factor were determined at recruitment, preoperatively, post-CPB, and 6, 12, and 24 hours postoperatively. The atorvastatin group showed a significantly higher amount of EPCs both pre- and postoperatively compared with the placebo, with a >4-fold increase compared with the baseline values. CPB induced an increase in all cytokines, but the levels of proinflammatory cytokines were significantly lower in the atorvastatin group (P < 0.05). Statin did not affect levels of SDF-1alpha, granulocyte colony-stimulating factor, and vascular endothelial growth factor. However, no correlation was found between plasma levels of any cytokine and number of EPCs, with the exception of SDF-1alpha. Pretreatment with atorvastatin significantly increases the amount of EPCs after CPB, by a mechanism independent of plasma levels of cytokines and cholesterol.

Preoperative statin therapy is not associated with a reduced incidence of postoperative acute kidney injury after cardiac surgery

BACKGROUND

Our objective was to examine the association between preoperative statin therapy and the prevalence of postoperative acute kidney injury (AKI) in patients undergoing cardiac surgery with the use of cardiopulmonary bypass.

METHODS

We performed a retrospective investigation of 10,648 consecutive patients undergoing coronary artery bypass grafting using cardiopulmonary bypass and/or valve surgery between January 2002 and December 2006. Patients were divided into 2 groups depending on preoperative therapy with statin drugs. The primary outcome was postoperative AKI based on the RIFLE (Risk, Injury, Failure, Loss, End-stage) criteria. Secondary outcomes included requirement for postoperative dialysis and hospital mortality. Multivariable logistic regression models were developed for the primary and secondary outcomes. To control for selection bias related to statin therapy, a propensity score was developed using a greedy matching technique.

RESULTS

The incidence of AKI was 12.1% (n = 1286). AKI occurred in 13.31% of patients receiving preoperative statins (819 of 6152 patients) versus 10.41% in the no statin group (467 of 4487 patients) (P < 0.001). The incidence of postoperative dialysis was 1.71% (n = 182). Postoperative dialysis was needed in 1.75% of patients in the statin group (108 of 6157 patients) compared with 1.65% of patients (74 of 4491 patients) in the no statin group (P = 0.68). Hospital mortality after surgery occurred in 1.71% (n = 182) of patients. The incidence of mortality for patients in the statin group was 1.71% (105 of 6157 patients) and this was not different from mortality in the no statin group of 1.71% (77 of 4491 patients) (P = 0.97). In multivariate logistic regression analysis, statin therapy was not associated with AKI (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.84-1.12; P = 0.68), postoperative dialysis (OR 0.80, 95% CI 0.55-118; P = 0.23), or hospital mortality (OR 0.803, 95% CI 0.56-1.16; P = 0.24). In 2646 propensity-matched pairs, the incidence of AKI was 12.0% in the statin group versus 12.8% in the no statin group (P = 0.38). The statin group had a 1.63% incidence of postoperative dialysis versus 2.08% in the no statin group (P = 0.22). In the same propensity-matched population, hospital mortality occurred in 1.63% of patients in the statin group compared with 2.1% in the no statin group (P = 0.19).

CONCLUSION

These results suggest that previously reported reductions in perioperative mortality for patients taking preoperative statins and undergoing cardiac surgery is likely not mediated through a reduction in postoperative AKI.

Role of polymorphonuclear neutrophils in atherosclerosis: current state and future perspectives

Contrary to the long-standing and widely accepted belief that polymorphonuclear neutrophils (PMN) are of marginal relevance in atherosclerosis, evidence revealing a previously unappreciated role of PMN in the process of atherosclerosis is being accumulating. Systemic inflammation involving activated PMN is clearly associated with unstable conditions of coronary artery disease and an increased number of circulating neutrophils is a well-known risk indicator of future cardiovascular outcomes. Furthermore, PMN are activated in a number of clinical conditions associated with high risk of developing atherosclerosis and are detectable into culprit lesions of patients with coronary artery disease. At present, pharmacological interventions aimed at blocking neutrophil emigration from the blood into the arterial wall and/or inhibiting neutrophil-mediated inflammatory functions are not an option for treating atherosclerosis. Nevertheless, several lines of evidence suggest that part of the atheroprotective effects of statins as well as HDL and HDL apolipoproteins may be related to their ability to modulate neutrophilic inflammation in the arterial wall. These hypotheses are not definitely established and warrant for further study. This Review describes the evidence suggesting that PMN may have a causative role in atherogenesis and atheroprogression and discusses the potential importance of modulating neutrophilic inflammation as part of a novel, improved strategy for preventing and treating atherosclerosis.

Statin prophylaxis and inflammatory mediators following cardiopulmonary bypass: a systematic review

Introduction

Induction of an inflammatory response is thought to have a significant role in the complications that follow cardiopulmonary bypass (CPB). The statin drugs are increasingly being recognized as having potent anti-inflammatory effects and hence have potential to influence an important mechanism of injury in CPB, although there is no current confirmation that this is indeed the case. Our objective was to systematically review if pre-operative prophylactic statin therapy, compared with placebo or standard of care, can decrease the inflammatory response in people undergoing heart surgery with CPB.

Methods

We performed a systematic and comprehensive literature search for all randomized controlled trials (RCTs) of open heart surgery with CPB in adults or children who received prophylactic statin treatment prior to CPB, with reported outcomes which included markers of inflammation. Two authors independently identified eligible studies, extracted data, and assessed study quality using standardized instruments. Weighted mean difference (WMD) was the primary summary statistic with data pooled using a random effects model. Descriptive analysis was used when data could not be pooled.

Results

Eight RCTs were included in the review, with the number of trials for each inflammatory outcome being even more limited. Pooled data demonstrated benefit with the use of statin to attenuate the post-CPB increase in interleukins 6 and 8 (IL-6, IL-8), peak high sensitivity C-reactive protein (hsCRP), and tumor necrosis factor-alpha (TNF-α) post-CPB (WMD [95% confidence interval (CI)] -23.5 pg/ml [-36.6 to -10.5]; -23.4 pg/ml [-35.8 to -11.0]; -15.3 mg/L [CI -26.9 to -3.7]; -2.10 pg/ml [-3.83 to -0.37] respectively). Very limited RCT evidence suggests that prophylactic statin therapy may also decrease adhesion molecules following CPB including neutrophil CD11b and soluble P (sP)-selectin.

Conclusions

Although the RCT evidence may suggest a reduction in post-CPB inflammation by statin therapy, the evidence is not definitive due to significant limitations. Several of the trials were not methodologically rigorous and statin intervention was highly variable in this small number of studies. This systematic review demonstrates that there is a significant gap that exists in the current literature in regards to the potential anti-inflammatory effect of statin therapy prior to CPB.

Factors associated with the development of anemia after subarachnoid hemorrhage

INTRODUCTION

Anemia is common after subarachnoid hemorrhage (SAH) and may exacerbate the reduction in oxygen delivery that underlies delayed cerebral ischemia. Fall in hemoglobin may relate to blood loss as well as inflammatory suppression of erythropoiesis. Identifying factors associated with anemia may facilitate targeted interventions, such as the use of erythropoiesis-stimulating agents, which could minimize the burden of anemia and reduce red blood cell (RBC) transfusion requirements.

METHODS

We analyzed a cohort of patients with spontaneous SAH admitted over a 3-year period who survived at least 4 days. All patients had daily hematocrit values drawn while in the ICU. Multivariate regression was performed to determine baseline and early post-admission variables associated with development of anemia (defined as hematocrit < 30%).

RESULTS

Anemia developed in 47% of 243 patients with SAH after a mean of 3.5 days (median 2 days). Admission variables independently associated with anemia were female gender (OR 3.7, 95% CI 1.8-7.6), baseline hematocrit < 36% (OR 3.9, 1.5-10.1 compared to 36-45%), history of hypertension (OR 2.1, 1.05-4.2), and poor clinical grade (OR 5.9, 2.3-15.0). Surgical aneurysm treatment (OR 13.5, 6.0-30.3) and greater admission SIRS score (OR 5.7, 1.7-19.2 if 3-4 criteria for systemic inflammatory response syndrome were met on day of admission compared to none) were also associated with fall in hematocrit.

CONCLUSIONS

It may be possible to predict those most likely to develop anemia using simple baseline clinical variables. Anemia was strongly related to surgery, likely through greater blood loss, and greater systemic inflammatory response on admission, possibly explained by cytokine-mediated inhibition of RBC production.

A clinician's perspective on rating the strength of evidence in a systematic review

Systematic review is a means of reviewing clearly formulated questions by using an explicit methodology to minimize bias in the location, selection, critical evaluation, and synthesis of research evidence from existing studies. It is not enough, however, to simply know that the best evidence available was captured in a systematic review. Rather, health care decision makers also need to understand what the strength of that evidence is. Strong evidence of a therapy's benefits and harms facilitates sound judgment in clinical practice, compared with weak evidence. In the absence of an organized method, different clinicians may review the same data and differ on their impression of the strength of evidence but not understand why they differ. A wide variety of grading systems are available to rate the strength of evidence, but different organizations may weigh features or domains of these systems differently. Also, the published articles written on how to grade the strength of evidence are not likely to penetrate to the clinician's level and are not written so that practicing clinicians can understand them. In this article, we provide a better understanding of the key criteria or domains that should be considered when rating the strength of a body of evidence, why they are important, and the domains included in some of the validated and commonly used scales. This not only will enable clinicians and health care decision makers to personally grade the strength of evidence and be able to extend it to their clinical practices, but also will allow them to understand which domains are and which are not covered, and how different grading scales can provide different results and still be accurate based on the domains they include.

Recent advances in perioperative medicine: highlights from the literature for the cardiothoracic and vascular anesthesiologist

There have been major advances in perioperative cardiothoracic and vascular medicine. Because of promising data, steroids, statins, and endothelin antagonists are being clinically tested in randomized trials with adult cardiac surgical patients. In vascular surgical patients, recent meta-analysis has revealed that interventions such as beta-blockade or endovascular stenting for peripheral vascular lesions may not improve outcome overall. Furthermore, a landmark trial has shown that anesthetic technique does not affect outcome after carotid endarterectomy. The surgical Apgar score may become part of routine clinical care of the vascular surgical patient because it predicts outcome and can be calculated at the bedside. Recent studies confirm that the serious perioperative risks of hyperglycemia also apply to nondiabetic and pediatric cardiac surgical patients. This has been highlighted in the new guidelines from the Society of Thoracic Surgeons. Perioperative myocardial protection is possible with ischemic preconditioning and omega-3 fatty acids. Pneumonia after lung resection may be reduced significantly by broadening antibiotic prophylaxis. Transfusion-related acute lung injury has immediate and delayed presentations that highlight the dangers of blood transfusion. Perioperative renal dysfunction after adult cardiac surgery is significantly reduced by the infusion of sodium bicarbonate. Although promising, further trials are required. Taken together, these recent advances will have significant influence on the future practice of cardiovascular and thoracic anesthesia as the ongoing search for perioperative outcome improvement achieves results.

Statin therapy is associated with decreased mortality in patients with infection

OBJECTIVES

The objective was to investigate the association between statin therapy and mortality in emergency department (ED) patients with suspected infection.

METHODS

A secondary analysis of a prospective, observational cohort study was conducted at an urban, academic ED with approximately 50,000 annual visits. Data were collected between December 2003 and September 2004. Inclusion criteria consisted of age > or = 18 years, clinical suspicion of infection, and hospital admission. Patients were divided by those receiving statin therapy and those not receiving statins while hospitalized. Medication data were collected from an inpatient pharmacy database. Comparisons were conducted with Fisher's exact test or Wilcoxon rank sum test. To adjust for baseline differences, multivariable logistic regression analysis controlling for gender, severity of illness (Mortality in Emergency Department Sepsis [MEDS] score), Charlson Comorbidity Index, and duration of statin therapy was performed.

RESULTS

Of 2,132 patients with suspected infection, 2,036 (95%) had interpretable pharmacy data and were analyzed. The cohort had a median age of 61 years (interquartile range [IQR] = 46-78 years) and a mortality of 3.9% (95% confidence interval [CI] = 3.1% to 4.8%). Patients who received statins (n = 474) had a lower unadjusted crude mortality (1.9%; 95% CI = 0.6% to 3.3%) compared to those who did not (4.5%; 95% CI = 3.4% to 5.4%; p </= 0.01). When adjusting for gender, MEDS score, Charlson Comorbidity Index, and duration of statin therapy, the odds of death for statin patients was 0.27 (95% CI = 0.1 to 0.72; p < or = 0.01).

CONCLUSIONS

Patients who were admitted to the hospital with infection and received statin therapy while hospitalized had a significantly lower in-hospital mortality compared to patients who did not receive a statin.

Statin use is associated with lower risk of atrial fibrillation in women with coronary disease: the HERS trial

OBJECTIVE

To determine the efficacy of statin treatment in atrial fibrillation (AF) prevention in women.

DESIGN

Cohort study using data obtained in the Heart and Estrogen/Progestin Replacement Study (HERS).

SETTING

Secondary analysis of a multicentre, randomised controlled clinical trial.

PATIENTS

2673 Postmenopausal women with coronary disease.

MAIN OUTCOME MEASURES

AF prevalence at baseline and incident AF over a mean follow-up of 4.1 years.

RESULTS

88 Women with AF were identified: 29 at baseline and 59 during follow-up. Women with AF were significantly less likely to be taking a statin at study enrollment than those without AF (22% vs 37%, p = 0.003). Baseline statin use was associated with a 65% lower odds of having AF at baseline after controlling for age, race, history of myocardial infarction or revascularisation and history of heart failure (odds ratio 0.35, 95% confidence interval (CI) 0.13 to 0.93, p = 0.04). The risk of developing AF during the study among those free from AF at baseline, adjusted for the same covariates, was 55% less for those receiving statin treatment (hazard ratio 0.45, 95% CI 0.26 to 0.78, p = 0.004).

CONCLUSIONS

Statin treatment is associated with a lower prevalence and incidence of AF after adjustment for potential confounders in postmenopausal women with coronary disease.

Atrial fibrillation following cardiac surgery: clinical features and preventative strategies

Atrial fibrillation (AF) is a common complication of cardiac surgery, with an increasing incidence. Post-operative AF results in many complications and increased healthcare resources. Despite substantial interest in the prediction and prevention of post-operative AF, as well as guidelines for the management of this common arrhythmia, there is still some uncertainty about appropriate risk stratification and management. The aim of this review article is to provide an overview of clinical predictive features for the development of AF following cardiac surgery and suitable preventive measures, using both antiarrhythmic and non-antiarrhythmic strategies.

Pre-Operative Atorvastatin Therapy to Decrease the Systemic Inflammatory Response after Coronary Artery Bypass Grafting

The effect of pre-operative atorvastatin on systemic inflammatory response syndrome (SIRS), often seen after coronary artery bypass grafting (CABG) was evaluated in 40 patients undergoing elective CABG. Patients were divided into two groups: group I (pre-operative LDL cholesterol ≤ 100 mg/dl; n = 20) received 20 mg/day atorvastatin for at least 15 days pre-operatively; group II (pre-operative LDL cholesterol < 100 mg/dl; n = 20) did not receive antihyperlipidaemic agents. All patients underwent CABG with cardiopulmonary bypass. Blood samples were taken pre-operatively and 24 h post-operatively. There were no significant differences between the two groups in terms of demographic, pre-operative or operative parameters. At 24 h post-operatively, median high-sensitivity C-reactive protein and mean interleukin-6 levels were significantly lower in group I compared with group II. There were no other significant differences in postoperative parameters between the two groups, except for duration of stay in the intensive care unit, which was shorter in group I patients. In conclusion, pre-operative atorvastatin treatment in patients undergoing elective CABG decreased inflammation parameters and could be effective in preventing SIRS.

The impact of statin use on atrial fibrillation

The aim of the present systematic review is to present an overview of the evidence linking atrial fibrillation (AF), inflammation and oxidative stress, with emphasis on the potential of statins to decrease the incidence of different types of AF, including new-onset AF, after electrical cardioversion (EC) and after cardiac surgery. Observational and clinical trials have studied the impact of statin therapy on new-onset, post-EC or postoperative AF. Data from different observational trials have shown that treatment with statins significantly reduces the incidence of new-onset AF in the primary and secondary prevention. The data are insufficient to recommend the use of statins before EC. Finally, perioperative statin therapy may represent an important non-antiarrhythmic adjunctive therapeutic strategy for the prevention of postoperative AF.

Does preoperative statin therapy improve outcomes in patients undergoing isolated cardiac valve surgery?

Preoperative statins have been associated with decreased mortality after coronary artery bypass grafting. Data are limited on whether these benefits extend to patients undergoing cardiac valve surgery. We examined whether preoperative statins decrease morbidity and mortality in patients undergoing isolated cardiac valve surgery. In a retrospective cohort analysis of consecutive patients who underwent surgical valve repair or replacement (excluding concomitant coronary artery bypass grafting, aortic root replacement, or ventricular assist device placement) at St. Luke's Episcopal Hospital, the primary outcome was 30-day mortality. Secondary outcomes included 30-day major adverse events (composite of early mortality, postoperative myocardial infarction, or stroke). Of 825 patients, 31% received preoperative statins (n = 255). Logistic regression analysis revealed that age >65 years (p = 0.02), history of congestive heart failure (p = 0.001), and total bypass time >80 minutes (p = 0.01) were independent predictors of increased 30-day mortality. Preoperative statin therapy was not associated with decreased 30-day mortality (odds ratio 0.89, 95% confidence interval 0.38 to 2.03), major adverse events (odds ratio 1.09, 95% confidence interval 0.61 to 1.96), postoperative myocardial infarction (p = 0.70), or stroke (p = 0.57). At a mean follow-up of 1.57 years, preoperative statin therapy was not associated with decreased mortality (p = 0.81). In the analysis using propensity score matching (354 propensity-matched patients, 177 in each group), preoperative statin was not associated with improved primary or secondary outcomes. In conclusion, preoperative statin therapy was not associated with a decrease in morbidity or mortality in patients undergoing isolated cardiac valve surgery.

The inflammatory response to colloids and crystalloids used for pump priming during cardiopulmonary bypass

BACKGROUND

Systemic inflammatory response frequently occurs after coronary artery bypass surgery and is strongly correlated with the risk of postoperative morbidity and mortality. This study tests the hypothesis that the priming of the extracorporeal circuit with colloid solutions results in less inflammation in patients undergoing cardiac surgery than priming with crystalloid solutions.

METHODS

A prospective, randomized study was designed. Forty-four patients undergoing elective coronary artery bypass grafting were randomly allocated to one of two groups: 22 patients primed with Ringer's lactate (RL) solution and 22 patients primed with gelatin-containing solution during the surgery. Plasma levels of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha, C-reactive protein (CRP) and, complement 4 were measured during the surgical intervention and over the following 48 postoperative hours. Cytokine levels were measured by enzyme-linked assays from plasma samples obtained at specific time points pre- and post-operatively.

RESULTS

In both groups the serum levels of the pro-inflammatory cytokines (IL-6, IL-8, TNF-alpha), CRP, complement 4, and leukocytes increased significantly over the baseline, although no significant differences were observed between the two groups. The operation time, blood loss, need for inotropic support, extubation time, and length of intensive care unit stay did not differ significantly between the two groups.

CONCLUSION

Priming with gelatin vs. RL produces no significant differences in the inflammatory response in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

The burden of the systemic inflammatory response predicts vasospasm and outcome after subarachnoid hemorrhage

INTRODUCTION

Subarachnoid hemorrhage (SAH) can trigger immune activation sufficient to induce the systemic inflammatory response syndrome (SIRS). This may promote both extra-cerebral organ dysfunction and delayed cerebral ischemia, contributing to worse outcome. We ascertained the frequency and predictors of SIRS after spontaneous SAH, and determined whether degree of early systemic inflammation predicted the occurrence of vasospasm and clinical outcome.

METHODS

Retrospective analysis of prospectively collected data on 276 consecutive patients admitted to a neurosciences intensive care unit with acute, non-traumatic SAH between 2002 and 2005. A daily SIRS score was derived by summing the number of variables meeting standard criteria (HR >90, RR >20, Temperature >38 degrees C, or <36 degrees C, WBC count <4,000 or >12,000). SIRS was considered present if two or more criteria were met, while SIRS burden over the first four days was calculated by averaging daily scores. Regression modeling was used to determine the relationship among SIRS burden (after controlling for confounders including infection, surgery, and corticosteroid use), symptomatic vasospasm, and outcome, determined by hospital disposition.

RESULTS

SIRS was present in over half the patients on admission and developed in 85% within the first four days. Factors associated with SIRS included poor clinical grade, thick cisternal blood, larger aneurysm size, higher admission blood pressure, and surgery for aneurysm clipping. Higher SIRS burden was independently associated with death or discharge to nursing home (OR 2.20/point, 95% CI 1.27-3.81). All of those developing clinical vasospasm had evidence of SIRS, with greater SIRS burden predicting increased risk for delayed ischemic neurological deficits (OR 1.77/point, 95% CI 1.12-2.80).

CONCLUSIONS

Systemic inflammatory activation is common after SAH even in the absence of infection; it is more frequent in those with more severe hemorrhage and in those who undergo surgical clipping. Higher burden of SIRS in the initial four days independently predicts symptomatic vasospasm and is associated with worse outcome.

The effects of atorvastatin on the occurrence of postoperative atrial fibrillation after off-pump coronary artery bypass grafting surgery

BACKGROUND

Atrial fibrillation (AF) after coronary artery bypass graft (CABG) surgery is still the most common arrhythmic complication. This study evaluated whether pretreatment with atorvastatin protects against AF after off-pump CABG.

METHODS

One hundred twenty-four patients without a history of AF or previous statin use, who were scheduled to undergo elective off-pump CABG, were enrolled. Patients were randomized to control group (n = 62) or to atorvastatin group (n = 62) who were administered atorvastatin 20 mg/d for 3 days before the surgery. Primary outcome was the incidence of postoperative AF. Secondary outcomes were major adverse cardiac and cerebrovascular events, persistent AF at 1 month, and identification of the markers to predict inhospital postoperative AF.

RESULTS

The incidence of AF was significantly lower in the atorvastatin group than in the control group (13% vs 27%, P = .04). The incidence of major adverse cardiac and cerebrovascular events and persistent AF at 1 month was similar in comparisons between the groups. Postoperative peak N-terminal pro-brain natriuretic peptide levels were significantly higher in the patients with AF (P = .03). Multivariate analysis identified pretreatment with atorvastatin as an independent factor associated with a significant reduction in postoperative AF (odds ratio 0.34, P = .04). Higher postoperative peak N-terminus pro-B-type natriuretic peptide levels were associated with the development of postoperative AF (odds ratio 1.02 per 100 pg/mL, P = .03).

CONCLUSIONS

Pretreatment with atorvastatin significantly reduced the occurrence of postoperative AF after off-pump CABG.

Medical countermeasures for radiation combined injury: radiation with burn, blast, trauma and/or sepsis. report of an NIAID Workshop, March 26-27, 2007

Non-clinical human radiation exposure events such as the Hiroshima and Nagasaki bombings or the Chernobyl accident are often coupled with other forms of injury, such as wounds, burns, blunt trauma, and infection. Radiation combined injury would also be expected after a radiological or nuclear attack. Few animal models of radiation combined injury exist, and mechanisms underlying the high mortality associated with complex radiation injuries are poorly understood. Medical countermeasures are currently available for management of the non-radiation components of radiation combined injury, but it is not known whether treatments for other insults will be effective when the injury is combined with radiation exposure. Further research is needed to elucidate mechanisms behind the synergistic lethality of radiation combined injury and to identify targets for medical countermeasures. To address these issues, the National Institute of Allergy and Infectious Diseases convened a workshop to make recommendations on the development of animal models of radiation combined injury, possible mechanisms of radiation combined injury, and future directions for countermeasure research, including target identification and end points to evaluate treatment efficacy.

Impact of preoperative statin therapy on adverse postoperative outcomes in patients undergoing cardiac surgery: a meta-analysis of over 30,000 patients

AIMS

To determine the strength of evidence for preoperative statin use for prevention of adverse postoperative outcomes in patients undergoing cardiac surgery.

METHODS AND RESULTS

After literature search in major databases, 19 studies were identified [three RCT (randomized prospective clinical trials), 16 observational] that reported outcomes of 31 725 cardiac surgery patients with (n = 17 201; 54%) or without (n = 14 524; 46%) preoperative statin therapy. Outcomes that were analysed included early all-cause mortality (30-day mortality), myocardial infarction (MI), atrial fibrillation (AF), stroke and renal failure. Odds ratio (OR) with 95% confidence intervals (95%CI) were reported using fixed or random effect models and publication bias was assessed. Preoperative statin therapy resulted in a 1.5% absolute risk reduction (2.2 vs. 3.7%; P < 0.0001) and 43% odds reduction for early all-cause mortality (OR 0.57; 95%CI: 0.49-0.67). A significant reduction (P < 0.01) in statin pretreated patients was also observed for AF (24.9 vs. 29.3%; OR 0.67, 95%CI: 0.51-0.88), stroke (2.1 vs. 2.9%, OR 0.74, 95%CI: 0.60-0.91), but not for MI (OR 1.11; 95%CI: 0.93-1.33) or renal failure (OR 0.78, 95%CI: 0.46-1.31). Funnel plot and Egger's regression analysis (P = 0.60) excluded relevant publication bias.

CONCLUSION

Our meta-analysis provides evidence that preoperative statin therapy exerts substantial clinical benefit on early postoperative adverse outcomes in cardiac surgery patients, but underscores the need for RCT trials.

Simvastatin reduces platelet–endocardium adhesion in atrial fibrillation

OBJECTIVES

To evaluate the relationship between CD40/CD40L system and increased thrombogenesis in AF, and to test the effects of simvastatin treatment.

METHODS

In vitro study using human tissue, University Hospital (tertiary referral center). Experiments on right atrial segments obtained before the onset of cardiopulmonary bypass were done in either presence or absence of 5 microM simvastatin. Two groups of patients in either chronic atrial fibrillation or sinus rhythm at the time of cardiac surgery. The endocardial expression of CD40, the release of CD40L, and adhesion of platelets to endocardium. Additionally, the thickness of platelet aggregates and the platelet distribution on the endocardium were also evaluated.

RESULTS

Atrial fibrillation was associated with a significant increase of endocardial CD40 expression (293.1+/-55.1 pg/ml vs. 230.9+/-53.3 pg/ml, p<0.01), and platelet-endocardial adhesion compared with sinus rhythm atria (10.8+/-2.2 vs. 5.2+/-1.3 platelet CD41 AU p<0.01). At immunofluorescence about 62% of fibrillating endocardium was covered by platelets, compared with 12% of not sinus rhythm atria. Addition of simvastatin significantly reduced CD40 expression as well as platelet adhesion to fibrillating atria; its efficacy was not reversed by the addition of mevalonic acid.

CONCLUSIONS

Chronic atrial fibrillation acutely upregulates CD40 expression as well as platelet adhesion to the endocardium. Simvastatin is effective in modulating this expression, thus it may potentially contribute to reduce the risk of intra-atrial thrombus formation.

Statins and sepsis

Severe sepsis and septic shock is common and frequently fatal. Over the last few years, the primary treatments demonstrated to improve outcome from several major clinical trials have finally emerged. However, translating these recent therapeutic advances to routine clinical practice has proven controversial, and new approaches of additional strategies are continued to be developed. Given their pleiotropic effects related to many pathophysiological determinants of sepsis, statin therapy could be the next step in the search for adjuvant therapy. A future challenge may be to test both the efficacy and the safety by large randomized controlled clinical trials ascertaining the effects of statins administered at the onset of sepsis and in patients with severe sepsis or septic shock admitted into intensive care units.

Preoperative statin therapy is not associated with a decrease in the incidence of postoperative atrial fibrillation in patients undergoing cardiac surgery

BACKGROUND

Atrial fibrillation (AF) after cardiac surgery is associated with significant morbidity. We investigated whether preoperative statin therapy was associated with decreased incidence of postoperative AF in patients undergoing cardiac surgery, including isolated valve surgery and patients with low ejection fraction (EF).

METHODS

A retrospective study of consecutive patients without history of AF (n = 4044) who underwent cardiac surgeries at St. Luke's Episcopal Hospital (Houston, TX), from January 1, 2003, through April 30, 2006, was conducted. Postoperative AF was assessed by continuous telemetry monitoring during hospitalization for cardiac surgery.

RESULTS

A total of 2096 patients (52%) received preoperative statins. Atrial fibrillation occurred in 1270 patients (31.4% in both the statin and nonstatin groups). In multivariate regression analysis, age >65 years, history of valvular heart disease, rheumatic disease, pulmonary disease, and New York Heart Association class III/IV were independent predictors of increased risk, whereas female sex was associated with decreased risk. Preoperative statin therapy was not associated with decreased risk in the entire cohort (odds ratio [OR] 1.13, 95% confidence interval [CI] 0.98-1.31) or in subgroups undergoing isolated coronary artery bypass grafting (OR 1.16, 95% CI 0.97-1.43), isolated valve surgery (OR 1.09, 95% CI 0.81-1.46), or both (OR 1.09, 95% CI 0.72-1.65), or the subgroup with EF <35% (OR 1.23, 95% CI 0.84-1.82). After propensity score analysis (n = 867 patients in each group), preoperative statin therapy was not associated with decreased AF incidence (OR 1.14, 95% CI 0.92-1.41).

CONCLUSIONS

Preoperative statin therapy was not associated with decreased incidence of postoperative AF in patients undergoing cardiac surgery, including patients with low EF.

Prevention of atrial fibrillation following cardiac surgery: basis for a novel therapeutic strategy based on non-hypoxic myocardial preconditioning

Atrial fibrillation is the most common complication of cardiac surgical procedures performed with cardiopulmonary bypass. It contributes to increased hospital length of stay and treatment costs. At present, preventive strategies offer only suboptimal benefits, despite improvements in anesthesia, surgical technique, and medical therapy. The pathogenesis of postoperative atrial fibrillation is considered to be multifactorial. However oxidative stress is a major contributory factor representing the unavoidable consequences of ischemia/reperfusion cycle occurring in this setting. Considerable evidence suggests the involvement of reactive oxygen species (ROS) in the pathogenic mechanism of this arrhythmia. Interestingly, the deleterious consequences of high ROS exposure, such as inflammation, cell death (apoptosis/necrosis) or fibrosis, may be abrogated by a myocardial preconditioning process caused by previous exposure to moderate ROS concentration known to trigger survival response mechanisms. The latter condition may be created by n-3 PUFA supplementation that could give rise to an adaptive response characterized by increased expression of myocardial antioxidant enzymes and/or anti-apoptotic pathways. In addition, a further reinforcement of myocardial antioxidant defenses could be obtained through vitamins C and E supplementation, an intervention also known to diminish enzymatic ROS production. Based on this paradigm, this review presents clinical and experimental evidence supporting the pathophysiological and molecular basis for a novel therapeutic approach aimed to diminish the incidence of postoperative atrial fibrillation through a non-hypoxic preconditioning plus a reinforcement of the antioxidant defense system in the myocardial tissue.

Potential Use of Statins to Prevent Atrial Fibrillation After Coronary Artery Bypass Surgery

Objective:

To review the published literature evaluating the effectiveness of statin therapy for preventing postoperative atrial fibrillation (POAF) after coronary artery bypass graft (CABG) surgery,

Data Sources:

A MEDLINE search was performed (1950–October 2007) using the search terms statins, HMG-CoA reductase inhibitors, coronary artery bypass graft, cardiac surgery, and atrial fibrillation,

Study Selection and Data Extraction:

All articles published in English describing or evaluating the use of statins in humans to prevent atrial fibrillation (AF) were included. Additional pertinent articles were identified from reference lists.

Data Synthesis:

POAF is a common complication following CABG surgery that is associated with significant morbidity. Current preventive strategies include the use of β-blockers and antiarrhythmic drugs such as amiodarono and Sotalol. Accumulating evidence suggests that statins may also reduce the risk of POAF. Numerous studies in nonsurgical cardiovascular patients have found reduced rates of AF with statins. In patients who have undergone CABG, several observational studies have also documented benefit. One randomized controlled trial reported a significant reduction in the risk of POAF and reduced length of hospital stay in patients given preoperative atorvastatin beginning 7 days before surgery. Ongoing research suggests that statins may reduce the risk of AF through pleiotropic effects independent of cholesterol lowering such as reductions in inflammation, oxidative damage, neurohormonal activation, and thrombosis.

Conclusions:

While the current evidence evaluating the use of statins to prevent POAF is encouraging, definitive conclusions cannot be drawn. However, because statins are widely used in cardiac patients for other indications and are not associated with the risks inherent to antiarrhythmic drugs, their value as an adjunct to current preventive strategies (or POAF deserves further study. Additional research is needed to examine the effectiveness of statins in risk-stratified patients undergoing CABG surgery and the impact on patient outcomes and attributed costs.