Preadmission statin use and one-year mortality among patients in intensive care - a cohort study

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.

Prior statin therapy and 30-day mortality in South Korean patients with acute respiratory distress syndrome

BACKGROUND

The effect of prior statin therapy on mortality in patients with acute respiratory distress syndrome (ARDS) remains controversial. This study aimed to investigate whether prior statin therapy was associated with lower 30-day mortality compared to non-statin use.

METHODS

This population-based cohort study used nationwide data procured from the National Health Insurance service in South Korea, and included all the adult patients admitted to a hospital for ARDS treatment between January 1, 2013 and December 31, 2017.

RESULTS

In total, 14,600 patients with ARDS were included: 4,319 were statin users and 10,281 were non-statin users. After propensity score matching, 6,046 patients with ARDS (3,023 patients in each group) were included in the analysis. The 30-day mortality of statin users was 44.4% (1,331 of 3,023), while that of non-statin users was 45.2% (1,331 of 3,023). On Cox regression analysis in the propensity score matched cohort, 30-day mortality was not significantly associated with statin use compared to non-statin use (hazard ratio: 0.95, 95% confidence interval: 0.88 to 1.02; P = .165). On Kaplan-Meier estimation, the median survival time in statin users was 45 days (95% CI: 39 to 50), while that in non-statin users was 42 days (95% CI: 37 to 47) after propensity score matching, and there was no statistical difference with the log-rank test (P = .215).

CONCLUSION

This population-based cohort study in South Korea showed that prior statin therapy was not significantly associated with 30-day mortality in patients with ARDS. Our findings should be confirmed in future prospective studies.

Prior statin therapy and mortality among critically ill patients: a systemic review and meta-analysis of cohort studies

The effect of prior statin exposure in critically ill patients remains controversial and has not been established in previous cohort studies. We performed a systematic review of previous cohort studies to evaluate the association of prior statin therapy with mortality in critically ill patients and conducted a meta-analysis. The MEDLINE, EMBASE, and Cochrane CENTRAL databases, from their inception to January 7, 2020, were used for this study. Statin users were defined as patients prescribed statin regularly before intensive care unit admission or diagnosis of a specific disease, such as sepsis. The Cochran chi-square test and I statistics were used to determine heterogeneity between studies. In total, 199,985 critically ill patients from nine studies (44,582 statin users and 155,403 non-statin users) were included in the meta-analysis. According to the random effect model, the 30-day mortality of statin users was 31% lower than that of non-statin users (hazard ratio: 0.69, 95% confidence interval: 0.56 to 0.85). This association was similar in atorvastatin users and simvastatin users. However, hospital mortality in statin users was not significantly associated with that in non-statin users [odds ratios (ORs): 0.71, 95% CI: 0.42 to 1.21]. This study showed that there was a beneficial association of prior statin therapy with 30-day mortality in critically ill patients. However, there was no significant association with hospital mortality. Additional prospective cohort studies with a large sample size should be performed to confirm these findings.

Preadmission Statin Use and 90-day Mortality in the Critically Ill

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

This study aimed to examine the association between preadmission statin use and 90-day mortality in critically ill patients and to investigate whether this association differed according to statin type and dose. We hypothesized that preadmission statin use was associated with lower 90-day mortality.

Methods

This retrospective cohort study analyzed the medical records of all adult patients admitted to the intensive care unit in a single tertiary academic hospital between January 2012 and December 2017. Data including preadmission statin use, statin subtype, and daily dosage were collected, and the associations between these variables and 90-day mortality after intensive care unit admission were examined. The primary endpoint was 90-day mortality.

Results

A total of 24,928 patients (7,396 statin users and 17,532 non–statin users) were included. After propensity score matching, 5,354 statin users and 7,758 non–statin users were finally included. The 90-day mortality rate was significantly higher in non–statin users (918 of 7,758; 11.8%) than in statin users (455 of 5,354; 8.5%; P &lt; 0.001). In Cox regression analysis, the 90-day mortality rate was lower among statin users than among non–statin users (hazard ratio: 0.70, 95% CI: 0.63 to 0.79; P &lt; 0.001). Rosuvastatin use was associated with 42% lower 90-day mortality (hazard ratio: 0.58, 95% CI: 0.47 to 0.72; P &lt; 0.001). There were no specific significant differences in the association between daily statin dose and 90-day mortality. In competing risk analysis, the risk of noncardiovascular 90-day mortality in statin users was 32% lower than that in non–statin users (hazard ratio: 0.68, 95% CI: 0.60 to 0.78; P &lt; 0.001). Meanwhile, cardiovascular 90-day mortality was not significantly associated with statin use.

Conclusions

Preadmission statin use was associated with a lower 90-day mortality. This association was more evident in the rosuvastatin group and with noncardiovascular 90-day mortality; no differences were seen according to daily dosage intensity.

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.

The Danish Intensive Care Database

AIM OF DATABASE

The aim of this database is to improve the quality of care in Danish intensive care units (ICUs) by monitoring key domains of intensive care and to compare these with predefined standards.

STUDY POPULATION

The Danish Intensive Care Database (DID) was established in 2007 and includes virtually all ICU admissions in Denmark since 2005. The DID obtains data from the Danish National Registry of Patients, with complete follow-up through the Danish Civil Registration System.

MAIN VARIABLES

For each ICU admission, the DID includes data on the date and time of ICU admission, type of admission, organ supportive treatments, date and time of discharge, status at discharge, and mortality up to 90 days after admission. Descriptive variables include age, sex, Charlson comorbidity index score, and, since 2010, the Simplified Acute Physiology Score (SAPS) II. The variables are recorded with 90%-100% completeness in the recent years, except for SAPS II score, which is 73%-76% complete. The DID currently includes five quality indicators. Process indicators include out-of-hour discharge and transfer to other ICUs for capacity reasons. Outcome indicators include ICU readmission within 48 hours and standardized mortality ratios for death within 30 days after admission using case-mix adjustment (initially using age, sex, and comorbidity level, and, since 2013, using SAPS II) for all patients and for patients with septic shock.

DESCRIPTIVE DATA

The DID currently includes 335,564 ICU admissions during 2005-2015 (average 31,958 ICU admissions per year).

CONCLUSION

The DID provides a valuable data source for quality monitoring and improvement, as well as for research.

The association between prior statin use and long-term outcomes after critical care admission

BACKGROUND

Statins may have immunomodulatory effects that benefit critically ill patients. Therefore, we retrospectively examined the association between survival and the prescription of statins prior to admission to an intensive care unit (ICU), or high dependency unit (HDU), as a result of major elective surgery or as an emergency with a presumed diagnosis of sepsis.

METHODS

We retrospectively studied critical care patients (ICU or HDU) from a tertiary referral UK teaching hospital. Nottingham University Hospitals have more than 2200 beds, of which 39 are critical care beds. Over a 5-year period (2000-2005), 414 patients were identified with a presumed diagnosis of sepsis, and 672 patients were identified who had planned ICU/HDU admissions following elective major surgery. Patients prescribed statins prior to hospital admission were compared with those who were not. Demographics, medical history, drug history, and Acute Physiology and Chronic Health Evaluation II scores were examined. Univariate and multivariate analyses were applied using the primary end point of survival at 5 years after admission.

RESULTS

Patients prescribed statins prior to critical care admission were, on average, older and had higher initial Acute Physiology and Chronic Health Evaluation II scores and more preexisting comorbidities. Statins were almost invariably stopped following admission to critical care. Statin use was not associated with significantly altered survival during hospital admission, or at 5 years, for either patients with sepsis (9% vs 15%, P=.121; 73% vs 84%, P=.503, respectively) or postoperative patients (55% vs 58%, P=.762; 57% vs 63%, P=.390).

CONCLUSIONS

Prior statin use was not associated with improved outcomes in patients admitted to critical care after elective surgical cases or with a presumed diagnosis of sepsis.

Simvastatin's effects on survival and outcome in traumatic braininjury patients: a comparative study

BACKGROUND/AIM

Mortality and morbidity still remain high in patients with traumatic brain injuries. Understanding the role of new treatments in these patients is critical. The aim of this study was to determine the effect of simvastatin on survival and outcome in traumatic brain injury patients.

MATERIALS AND METHODS

Forty-four patients were assigned to receive either simvastatin or a placebo. The serum interleukin-6 and C-reactive protein levels were measured at the first 24 h and 48 h after trauma. All data, including the Glasgow Coma Scale score, survival at discharge, length of intensive care unit stay, and duration of mechanical ventilation, were collected. The effect of simvastatin on the collected data was then investigated.

RESULTS

The Glasgow Coma Scale level at discharge was significantly higher in the simvastatin group. The overall mortality rate, duration of mechanical ventilation, and length of intensive care unit stay were similar between the 2 groups. The C-reactive protein concentration 48 h after trauma was significantly lower in the simvastatin group, but there was no significant difference according to the interleukin-6 level 48 h after trauma between the 2 groups.

CONCLUSION

Simvastatin could be suggested as an adjunctive therapy in traumatic brain injury patients.

Pre-existing atrial fibrillation and risk of arterial thromboembolism and death in intensive care unit patients: a population-based cohort study

INTRODUCTION

Pre-existing atrial fibrillation (AF) may worsen prognosis in patients admitted to the intensive care unit (ICU).

METHODS

In a cohort study (2005-2011) including all patients with first-time ICU admissions in Denmark (n=57,110), we compared patients with and without pre-existing AF and estimated absolute risks and relative risks (RRs) of arterial thromboembolism and death within 30 days and 365 days following admission, using Kaplan-Meier methods and multivariate regression analyses. We analysed the prognostic impact of AF within strata of patient age, sex, coexisting cardiac diseases, and ICU therapies.

RESULTS

Among ICU patients, 5065 (9%) had pre-existing AF. Compared with patients without AF, those with AF were older (median age 75 vs. 62 years) and had more comorbidity. The risk of arterial thromboembolism was 2.8% in patients with AF and 2.0% in non-AF patients at 30 days, and 4.3% and 2.9%, respectively, at 365 days. Corresponding RRs were 1.41 crude and 1.14 (95% confidence interval [CI] 0.93-1.40) adjusted at 30 days, and 1.50 crude and 1.20 (95% CI 1.02-1.41) adjusted at 365 days. Thirty-day mortality was 27% in patients with pre-existing AF and 16% in non-AF patients (crude RR 1.67, adjusted RR 1.04, 95% CI 0.99-1.10). Corresponding mortality estimates at 365 days were 40.9% and 25.4%, respectively (crude RR 1.61, adjusted RR 1.03, 95% CI 1.00-1.07). In stratified analyses, pre-existing AF increased mortality in ICU patients aged <55 years (adjusted RR at 30 days 1.73, 95% CI 1.29-2.32; adjusted RR at 365 days 1.34, 95% CI 1.06-1.69) and in ICU patients treated with mechanical ventilation (adjusted RR at 30 days 1.12, 95% CI 1.05-1.20, adjusted RR at 365 days 1.09, 95% CI: 1.04-1.15). Analyses stratified by sex and coexisting cardiac diseases yielded adjusted RRs close to 1.

CONCLUSIONS

In ICU patients, pre-existing AF was associated with modestly increased risk of arterial thromboembolism when adjusted for the substantially higher age and comorbidity levels in patients with AF, whereas there was no overall association with mortality. In ICU patients aged <55 years and in those treated with mechanical ventilation, AF predicted increased mortality.

Preadmission use of ACE inhibitors or angiotensin receptor blockers and short-term mortality after stroke

BACKGROUND AND AIM

The prognostic impact of ACE inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) on stroke mortality remains unclear. We aimed to examine whether prestroke use of ACE-Is or ARBs was associated with improved short-term mortality following ischaemic stroke, intracerebral haemorrhage (ICH) and subarachnoid haemorrhage (SAH).

METHODS

We conducted a nationwide population-based cohort study using medical registries in Denmark. We identified all first-time stroke patients during 2004-2012 and their comorbidities. We defined ACE-I/ARB use as current use (last prescription redemption <90 days before admission for stroke), former use and non-use. Current use was further classified as new or long-term use. We used Cox regression modelling to compute 30-day mortality rate ratios (MRRs) with 95% CIs, controlling for potential confounders.

RESULTS

We identified 100 043 patients with a first-time stroke. Of these, 83 736 patients had ischaemic stroke, 11 779 had ICH, and 4528 had SAH. For ischaemic stroke, the adjusted 30-day MRR was reduced in current users compared with non-users (0.85, 95% CI 0.81 to 0.89). There was no reduction in the adjusted 30-day MRR for ICH (0.95, 95% CI 0.87 to 1.03) or SAH (1.01, 95% CI 0.84 to 1.21), comparing current users with non-users. No association with mortality was found among former users compared with non-users. No notable modification of the association was observed within sex or age strata.

CONCLUSIONS

Current use of ACE-Is/ARBs was associated with reduced 30-day mortality among patients with ischaemic stroke. We found no association among patients with ICH or SAH.

Are there any benefits from statin treatment for the septic patient?

Statins have become the most widely used drugs for lowering cholesterol levels worldwide. At least 20% of patients requiring admission to hospital are on established statin therapy, and this proportion is growing each year. Evidence from observational studies and basic science research suggests that statins might be associated with a reduced mortality in sepsis. Randomized trials are producing equivocal results but have not shown the marked improvement in outcome suggested by the observational studies. Continued use in current statin users appears a more fruitful area for future research than statin use de novo as an adjuvant therapy in sepsis. Statin use in patients with pneumonia, acute lung injury or early sepsis warrants further study. International practice of statin use in critically ill patients is variable, and potential toxicity mandates careful monitoring. Further studies are required to address fundamental issues such as efficacy, potential target patient populations, dose, class equivalence and safety.

Comparing the anti-inflammatory effects of Simvastatin and Rosuvastatin by measuring IL-1β, IL-6 and TNF-α levels using a murinic caecal ligation and puncture induced sepsis model / Compararea efectelor anti-inflamatoare ale Simvastatinei și Rosuvastatinei măsurând nivelele serice ale IL-1β, IL-6 si TNF-α folosind un model de sepsis la șobolan indus prin ligatură și puncție cecală

Background: Sepsis is a systemic host response to an infection which may evolve into severe sepsis and septic shock. It raises many health care related concerns around the world, carrying almost 30% mortality rates and a high financial burden. The disease is characterized by the triggering of some inflammatory pathways that are ultimately proven deleterious to the host organism. Although antibiotics, fluid administration, vasopressor therapy and infectious source control remain the recommended management strategies, emerging scientific data proposes statins as a new line of treatment. These drugs were first introduced in clinical practice for their cholesterol-lowering effect but the inhibition of HMG-CoA reductase and cholesterol biosynthetic pathway exhibits some less studied effects generally referred to as pleiotropic: anti-inflammatory, antithrombotic, immunomodulatory and antioxidant properties. Objective: To asses and compare the anti-inflammatory effect of two statins - Simvastatin and Rosuvastatin - measuring blood levels of IL-1β, IL-6 and TNFα using a previously described murinic model of sepsis. Methods: We compiled four groups (C, n=7; SEP, SV, RV, n=8). Statins were administered in two doses 18 and 3 hours before surgical intervention. Sepsis was induced using the caecal ligation and puncture technique. Blood samples were obtained by venepuncture from each subject in day 1, 4, 7 and 14 (the last samples were obtained by cardiac puncture). Complete blood count, Procalcitonin, IL-1β, IL-6 and TNF-α levels were assessed. Results: White blood cell counts differed across the groups showing a higher count for the septic but untreated group. Procalcitonin reacted in all septic groups but both statin treated groups had lower levels when compared to untreated group. IL-1β levels were higher in the Rosuvastatin treated group. IL-6 levels were more heterogeneously dispersed but higher levels were noticed in the untreated septic group. The Simvastatin treated group had higher levels compared to the Rosuvastatin treated one. TNFα levels were higher in the septic untreated group and in the Rosuvastatin treated one. For the Simvastatin treated subjects, the level of TNFα was similar with the control group. Conclusion: We concluded that both drugs showed anti-inflammatory effects on the murinic CLP-induced sepsis model. Between the two, Simvastatin had greater impact by lowering blood levels of established pro-inflammatory markers.

Preadmission metformin use and mortality among intensive care patients with diabetes: a cohort study

Introduction

Metformin has anti-inflammatory and anti-thrombotic effects that may improve the outcome of critical illness, but clinical data are limited. We examined the impact of preadmission metformin use on mortality among intensive care unit (ICU) patients with type 2 diabetes.

Methods

We conducted this population-based cohort study among all persons admitted to the 17 ICUs in Northern Denmark (population approximately 1.8 million). We focused on all patients with type 2 diabetes who were admitted to the ICUs between January 2005 and December 2011. Through individual-level linkage of population-based medical databases, type 2 diabetes was identified using a previously validated algorithm including hospital diagnoses, filled prescriptions for anti-diabetic drugs, and elevated HbA1c levels. Metformin use was identified by filled prescriptions within 90 days before admission. Covariates included surgery, preadmission morbidity, diabetes duration, and concurrent drug use. We computed 30-day mortality and hazard ratios (HRs) of death using Cox regression adjusted for covariates, both overall and after propensity score matching.

Results

We included 7,404 adult type 2 diabetes patients, representing 14.0% of 52,964 adult patients admitted to the ICUs. Among type 2 diabetes patients, 1,073 (14.5%) filled a prescription for metformin as monotherapy within 90 days before admission and 1,335 (18.0%) received metformin in combination with other anti-diabetic drugs. Thirty-day mortality was 17.6% among metformin monotherapy users, 17.9% among metformin combination therapy users, and 25.0% among metformin non-users. The adjusted HRs were 0.80 (95% confidence interval (CI): 0.69, 0.94) for metformin monotherapy users and 0.83 (95% CI: 0.71, 0.95) for metformin combination therapy users, compared to non-users. Propensity-score-matched analyses yielded the same results. The association was evident across most subgroups of medical and surgical ICU patients, but most pronounced in elderly patients and in patients with well-controlled diabetes. Former metformin use was not associated with decreased mortality.

Conclusions

Preadmission metformin use was associated with reduced 30-day mortality among medical and surgical intensive care patients with type 2 diabetes.

Type 2 diabetes and 1-year mortality in intensive care unit patients

BACKGROUND

Data on the prognostic impact of diabetes and diabetic complications in intensive care unit (ICU) patients are limited and inconsistent. We, therefore, examined mortality in ICU patients with type 2 diabetes with and without pre-existing heart and kidney diseases compared with nondiabetic patients.

DESIGN

We conducted this population-based cohort study in Northern Denmark during 2005-2011. We included all ICU patients aged 40 years or older from the 17 ICUs in the area and identified type 2 diabetes by either a filled prescription for an antidiabetic drug, a previous diagnosis of diabetes, or an elevated glycosylated haemoglobin level. Diabetic patients were disaggregated according to pre-existing diagnoses of heart disease (myocardial infarction or heart failure) and kidney disease. We estimated 1-year mortality by the Kaplan-Meier method and hazard ratios of death (HRs) during follow-up using Cox regression, controlling for confounding factors and stratified by relevant subgroups.

RESULTS

Among 45 018 ICU patients, 7219 (16·0%) had type 2 diabetes. Overall, 1-year mortality was 36·0% in ICU patients with type 2 diabetes, rising to 54·6% in patients with pre-existing heart and kidney diseases, compared with 29·1% in nondiabetic patients. Comparing diabetic with nondiabetic patients, the adjusted 0- to 30-day HR was 1·20 (95% confidence interval (CI): 1·13-1·26) and 1·19 (95% CI: 1·10-1·28) during the 31- to 365-day follow-up period. Pre-existing kidney disease further increased the impact of diabetes, while heart disease alone had no such effect.

CONCLUSIONS

ICU patients with type 2 diabetes had higher 1-year mortality compared with nondiabetic ICU patients, particularly those with pre-existing kidney disease.

The immune response: targets for the treatment of severe sepsis

The clinical process of severe sepsis is characterized by extreme inflammation interlinked with potent stimulation of the coagulation cascade often followed by a state of relative immune paralysis. In this paper, we will review many of the potential therapies directed at various steps along the inflammatory cascade from modulation of inflammatory mediators eliciting the immune response, alteration of the host's immune response in both a stimulatory and depressive manner, and taming the overexuberant coagulation response triggered by the fierce coagulation-inflammation cycle. Finally, we will discuss further opportunities for research to improve our ability to design effective therapies.

Effects of low-dose acetylsalicylic acid and atherosclerotic vascular diseases on the outcome in patients with severe sepsis or septic shock

Sepsis and its sequelae of multiple organ failure is one of the leading causes of death in the industrial countries. Several studies have shown that patients who are treated with low-dose acetyl salicylic acid (ASA) for secondary prevention of atherothrombosis may have a lower risk to develop organ failure in the case of critical illness. The benefit of ASA is probably due to an inhibition of platelet activation as well as an increase in the formation of anti-inflammatory lipoxin A4. On the other hand, the effect of ASA could be - at least partially - an indirect one, caused by atherosclerotic vascular diseases as the cause of ASA treatment. Atherosclerosis is considered as a moderate systemic inflammation and we hypothesise that this chronic condition could have an impact on the outcome in sepsis. To get more information on the benefit of ASA in critically ill patients and on possible interference with atherosclerotic vascular diseases, we analysed the medical records of 886 septic patients who were admitted to the surgical intensive care unit (ICU) of a university hospital. Logistic regression analysis indicated that patients who were treated during the ICU stay with ASA (100 mg/d) had a significantly lower mortality. Odds ratios (ORs; with 95% confidential intervals) of 0.56 (0.37-0.84) and 0.57 (0.39-0.83) were calculated for ICU and hospital mortality, respectively. In contrast, statin treatment did not have significant effect on mortality. Diagnosis of atherosclerotic vascular diseases according to ICD classification did not influence ICU mortality but lowered hospital mortality (OR = 0.71 (0.52-0.99)). Subgroup analysis provided preliminary evidence that clopidogrel when given as only anti-platelet drug may have a similar benefit as ASA, but the combination of ASA and clopidogrel failed to improve the outcome. The time course of plasma fibrinogen and procalcitonin levels indicate that ASA seems to reduce the activation of haemostasis and increase the resolution of inflammation. It is concluded that prospective interventional studies should be done to test the use of ASA as novel therapeutic approach in critically ill patients.

Do aspirin and statins prevent severe sepsis?

PURPOSE OF REVIEW

Sepsis is an inflammatory condition associated with significant morbidity and mortality. Given the lack of specific therapies for the condition, prevention has garnered significant interest and increased importance. The article reviews the current literature regarding the use of aspirin and statins for the prevention of sepsis.

RECENT FINDINGS

Aspirin and statins have been integral in the prevention of atherosclerotic disease. Additionally, statins have proven beneficial in the prevention of nonatherosclerotic conditions secondary to their pleiotropic effects. In animal models, this pleiotropism modulates many inflammatory pathways of sepsis. The platelet also plays an integral role in this inflammatory cascade of sepsis. Scientific data indicates that antiplatelet therapy, including aspirin, may attenuate these undesirable effects of platelets. Finally, observational studies have shown that patients taking statins have a decreased incidence of sepsis and septic shock, and aspirin may potentiate these benefits.

SUMMARY

Sepsis is a deadly and costly condition with no available, specific treatment options. The statins and aspirin are well tolerated and widely used for prevention of cardiovascular disease. Because of their effects on the immune system and inflammatory pathways, they may present viable medical options for the prevention of sepsis.

Statins in the critically ill

The use or misuse of statins in critically ill patients recently attracted the attention of intensive care clinicians. Indeed, statins are probably the most common chronic treatment before critical illness and some recent experimental and clinical data demonstrated their beneficial effects during sepsis, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), or after aneurismal subarachnoidal hemorrhage (aSAH). Due to the heterogeneity of current studies and the lack of well-designed prospective studies, definitive conclusions for systematic and large-scale utilization in intensive care units cannot be drawn from the published evidence. Furthermore, the extent of statins side effects in critically ill patients is still unknown. For the intensive care clinician, it is a matter of individually identifying the patient who can benefit from this therapy according to the current literature. The purpose of this review is to describe the mechanisms of actions of statins and to synthesize the clinical data that underline the relevant effects of statins in the particular setting of critical care, in an attempt to guide the clinician through his daily practice.

In the critically ill patient, diabetes predicts mortality independent of statin therapy but is not associated with acute lung injury: a cohort study

OBJECTIVES

Patients with diabetes mellitus form 23%-30% of published cohorts of critically ill patients. Conflicting published evidence links diabetes mellitus to both higher and lower mortality. Other cohort studies suggest that diabetes mellitus protects against acute lung injury. We hypothesized that diabetes mellitus is an independent risk factor for mortality. We further hypothesized that diabetes mellitus is a risk factor for cardiac overload and not for acute lung injury.

DESIGN

Retrospective cohort study.

SETTING

The intensive care unit of a tertiary referral hospital.

PATIENTS

From November 1, 2004, to October 1, 2007, a cohort of patients admitted ≥48 hrs to the intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 2,013 patients, 317 had diabetes mellitus. Ninety-day mortality was higher in the diabetes mellitus patients compared to patients without diabetes mellitus (hazard ratio 1.53, 95% confidence interval 1.29-1.80). This association strengthened after adjusting for confounders and for medication (hazard ratio 1.53, 95% confidence interval 1.07-2.17).We found no association between diabetes mellitus and acute lung injury (relative risk ratio 1.01, 95% confidence interval 0.78-1.32; adjusted relative risk ratio 0.99, 95% confidence interval 0.75-1.31), but diabetes mellitus was a risk factor for cardiac overload (relative risk ratio 1.91, 95% confidence interval 1.30-2.81; adjusted relative risk ratio 1.45, 95% confidence interval 0.97-2.18). Statins were associated with both a reduced risk of mortality (hazard ratio 0.74, 95% confidence interval 0.63-0.87; adjusted hazard ratio 0.53, 95% confidence interval 0.44-0.64) and a decreased risk of developing acute lung injury (relative risk ratio 0.71, 95% confidence interval 0.56-0.89; adjusted relative risk ratio 0.61, 95% confidence interval 0.47-0.79).

CONCLUSIONS

Diabetes mellitus is an independent risk factor for mortality in critically ill patients and failure to adjust for statins underestimates the size of this association. Diabetes mellitus is not associated with acute lung injury but is associated with cardiac overload. A diagnosis of cardiac overload excludes a diagnosis of acute lung injury. Investigators who do not account for cardiac overload as a competing alternative outcome may therefore falsely conclude that diabetes mellitus protects from acute lung injury.

Bias in observational studies of prevalent users: lessons for comparative effectiveness research from a meta-analysis of statins

Randomized clinical trials (RCTs) are usually the preferred strategy with which to generate evidence of comparative effectiveness, but conducting an RCT is not always feasible. Though observational studies and RCTs often provide comparable estimates, the questioning of observational analyses has recently intensified because of randomized-observational discrepancies regarding the effect of postmenopausal hormone replacement therapy on coronary heart disease. Reanalyses of observational data that excluded prevalent users of hormone replacement therapy led to attenuated discrepancies, which begs the question of whether exclusion of prevalent users should be generally recommended. In the current study, the authors evaluated the effect of excluding prevalent users of statins in a meta-analysis of observational studies of persons with cardiovascular disease. The pooled, multivariate-adjusted mortality hazard ratio for statin use was 0.77 (95% confidence interval (CI): 0.65, 0.91) in 4 studies that compared incident users with nonusers, 0.70 (95% CI: 0.64, 0.78) in 13 studies that compared a combination of prevalent and incident users with nonusers, and 0.54 (95% CI: 0.45, 0.66) in 13 studies that compared prevalent users with nonusers. The corresponding hazard ratio from 18 RCTs was 0.84 (95% CI: 0.77, 0.91). It appears that the greater the proportion of prevalent statin users in observational studies, the larger the discrepancy between observational and randomized estimates.

Do aspirin and other antiplatelet drugs reduce the mortality in critically ill patients?

Platelet activation has been implicated in microvascular thrombosis and organ failure in critically ill patients. In the first part the present paper summarises important data on the role of platelets in systemic inflammation and sepsis as well as on the beneficial effects of antiplatelet drugs in animal models of sepsis. In the second part the data of retrospective and prospective observational clinical studies on the effect of aspirin and other antiplatelet drugs in critically ill patients are reviewed. All of these studies have shown that aspirin and other antiplatelet drugs may reduce organ failure and mortality in these patients, even in case of high bleeding risk. From the data reviewed here interventional prospective trials are needed to test whether aspirin and other antiplatelet drugs might offer a novel therapeutic option to prevent organ failure in critically ill patients.

Prehospital statin and aspirin use and the prevalence of severe sepsis and acute lung injury/acute respiratory distress syndrome

OBJECTIVES

To determine whether prehospital statin use is associated with a lower risk of sepsis, acute lung injury/acute respiratory distress syndrome, and mortality in critically ill patients. We also investigated the effect of combined prehospital use of both statins and aspirin.

DESIGN

Cross-sectional analysis of a prospective cohort.

PATIENTS

A total of 575 critically ill patients admitted to the medical or surgical intensive care unit of an academic tertiary-care hospital.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 575 patients, 149 (26%) were on statin therapy before hospitalization. A multivariable analysis including age, gender, current tobacco use, prehospital aspirin use, race, and Acute Physiology and Chronic Health Evaluation II score revealed that patients on statin therapy before hospitalization were less likely to have or develop severe sepsis (odds ratio 0.62, 95% confidence interval 0.40-0.96) or acute lung injury/acute respiratory distress syndrome (odds ratio 0.60, 95% confidence interval 0.36-0.99) during the first four intensive care unit days. In-hospital mortalities for patients with and without prehospital statin use (odds ratio 1.06, 95% confidence interval 0.62-1.83) were similar. Patients who had prehospital use of both statins and aspirin had the lowest rates of severe sepsis, acute lung injury/acute respiratory distress syndrome, and mortality.

CONCLUSIONS

Prehospital use of statins may be protective against sepsis and acute lung injury. This effect may be potentiated by prehospital aspirin use.

Association between statin therapy and outcomes in critically ill patients: a nested cohort study

Background

The effect of statin therapy on mortality in critically ill patients is controversial, with some studies suggesting a benefit and others suggesting no benefit or even potential harm. The objective of this study was to evaluate the association between statin therapy during intensive care unit (ICU) admission and all-cause mortality in critically ill patients.

Methods

This was a nested cohort study within two randomised controlled trials conducted in a tertiary care ICU. All 763 patients who participated in the two trials were included in this study. Of these, 107 patients (14%) received statins during their ICU stay. The primary endpoint was all-cause ICU and hospital mortality. Secondary endpoints included the development of sepsis and severe sepsis during the ICU stay, the ICU length of stay, the hospital length of stay, and the duration of mechanical ventilation. Multivariate logistic regression was used to adjust for clinically and statistically relevant variables.

Results

Statin therapy was associated with a reduction in hospital mortality (adjusted odds ratio [aOR] = 0.60, 95% confidence interval [CI] 0.36-0.99). Statin therapy was associated with lower hospital mortality in the following groups: patients >58 years of age (aOR = 0.58, 95% CI 0.35-0.97), those with an acute physiology and chronic health evaluation (APACHE II) score >22 (aOR = 0.54, 95% CI 0.31-0.96), diabetic patients (aOR = 0.52, 95% CI 0.30-0.90), patients on vasopressor therapy (aOR = 0.53, 95% CI 0.29-0.97), those admitted with severe sepsis (aOR = 0.22, 95% CI 0.07-0.66), patients with creatinine ≤100 μmol/L (aOR = 0.14, 95% CI 0.04-0.51), and patients with GCS ≤9 (aOR = 0.34, 95% CI 0.17-0.71). When stratified by statin dose, the mortality reduction was mainly observed with statin equipotent doses ≥40 mg of simvastatin (aOR = 0.53, 95% CI 0.28-1.00). Mortality reduction was observed with simvastatin (aOR = 0.37, 95% CI 0.17-0.81) but not with atorvastatin (aOR = 0.80, 95% CI 0.84-1.46). Statin therapy was not associated with a difference in any of the secondary outcomes.

Conclusion

Statin therapy during ICU stay was associated with a reduction in all-cause hospital mortality. This association was especially noted in high-risk subgroups. This potential benefit needs to be validated in a randomised, controlled trial.

Propensity scores in intensive care and anaesthesiology literature: a systematic review

INTRODUCTION

Propensity score methods have been increasingly used in the last 10 years. However, the practical use of the propensity score (PS) has been reported as heterogeneous in several papers reviewing the use of propensity scores and giving some advice. No precedent work has focused on the specific application of PS in intensive care and anaesthesiology literature.

OBJECTIVES

After a brief development of the theory of propensity score, to assess the use and the quality of reporting of PS studies in intensive care and anaesthesiology, and to evaluate how past reviews have influenced the quality of the reporting.

STUDY DESIGN AND SETTING

Forty-seven articles published between 2006 and 2009 in the intensive care and anaesthesiology literature were evaluated. We extracted the characteristics of the report, the type of analysis, the details of matching procedures, the number of patients in treated and control groups, and the number of covariates included in the PS models.

RESULTS

Of the 47 articles reviewed, 26 used matching on PS, 12 used stratification on PS and 9 used adjustment on PS. The method used was reported in 81% of the articles, and the choice to conduct a paired analysis or not was reported in only 15%. The comparison with the previously published reviews showed little improvement in reporting in the last few years.

CONCLUSION

The quality of reporting propensity scores in intensive care and anaesthesiology literature should be improved. We provide some recommendations to the investigators in order to improve the reporting of PS analyses.

Statins in candidemia: clinical outcomes from a matched cohort study

Background

HMG CoA reductase inhibitors (statins) in patients with bacteremic sepsis have shown significant survival benefits in several studies. There is no data on the effect of statins in candidemic patients, however in-vitro models suggest that statins interfere with ergesterol formation in the wall of yeasts.

Methods

This retrospective matched- cohort study from 1/2003 to 12/2006 evaluated the effects of statins on patients with candidemia within intensive care units. Statin-users had candidemia as a cause of their systemic inflammatory response and were on statins throughout their antifungal therapy, while non-statin users were matched based on age +/- 5 years and co-morbid factors. Primary analysis was 30-day survival or discharge using bivariable comparisons. Multivariable comparisons were completed using conditional logistic regression. All variables with a p-value less than 0.10 in the bivariable comparisons were considered for inclusion in the conditional logistic model.

Results

There were 15 statin-users and 30 non-statin users that met inclusion criteria, all with similar demographics and co-morbid conditions except the statin group had more coronary artery disease (P < 0.01) and peripheral vascular disease (P = 0.03) and lower median APCAHE II scores (14.6 vs 17, p = 0.03). There were no differences in duration of candidemia, antifungal therapy or Candida species between the groups. Statins were associated with lower mortality on bivariable (OR 0.09, 95% CI 0.11-0.75, p = 0.03) and multivariable (OR 0.22, 95% CI 0.02-2.4, p = 0.21) analyses compared to controls; although, in the latter the protective effect lacked statistical signficance.

Conclusion

In our small, single-center matched-cohort study, statins may provide a survival benefit in candidemia, however further studies are warranted to validate and further explore this association.

Statins for acutely hospitalized patients: randomized controlled trials are long overdue

From the earliest studies of statins for control of plasma cholesterol, observations have been made that the reductions in mortality observed occurred in a manner seemingly independent from what could be anticipated from cholesterol lowering alone. Over the last decade, the pleiotropic effects of statins have been increasingly elucidated. Perhaps most intriguing are the effects statins appear to have on the immune system, especially the modulation of diffuse or systemic inflammation. There is a growing body of observational literature suggesting that statins can actually reduce hospital mortality through mechanisms far beyond those that can be explained by reductions in cardiovascular events.