Effect of prior statin use on outcome after severe traumatic brain injury in a South-East Asian population

The protective effects of statins in traumatic brain injury

Traumatic brain injury (TBI), often referred to as the "silent epidemic", is the most common cause of mortality and morbidity worldwide among all trauma-related injuries. It is associated with considerable personal, medical, and economic consequences. Although remarkable advances in therapeutic approaches have been made, current treatments and clinical management for TBI recovery still remain to be improved. One of the factors that may contribute to this gap is that existing therapies target only a single event or pathology. However, brain injury after TBI involves various pathological mechanisms, including inflammation, oxidative stress, blood-brain barrier (BBB) disruption, ionic disturbance, excitotoxicity, mitochondrial dysfunction, neuronal necrosis, and apoptosis. Statins have several beneficial pleiotropic effects (anti-excitotoxicity, anti-inflammatory, anti-oxidant, anti-thrombotic, immunomodulatory activity, endothelial and vasoactive properties) in addition to promoting angiogenesis, neurogenesis, and synaptogenesis in TBI. Supposedly, using agents such as statins that target numerous and diverse pathological mechanisms, may be more effective than a single-target approach in TBI management. The current review was undertaken to investigate and summarize the protective mechanisms of statins against TBI. The limitations of conducted studies and directions for future research on this potential therapeutic application of statins are also discussed.

HMG-CoA Reductase Inhibitors for Traumatic Brain Injury

Traumatic brain injuries (TBIs) are associated with high morbidity and mortality due to both the original insult as well as the destructive biological response that follows. Medical management aims to slow or even halt secondary neurological injury while simultaneously laying the groundwork for recovery. Statins are one class of medications that is showing increased promise in the management of TBI. Used extensively in cardiovascular disease, these drugs were originally developed as competitive inhibitors within the cholesterol production pipeline. They are now used in diverse disease states due to their pleiotropic effects on other biological processes such as inflammation and angiogenesis. Preclinical studies, retrospective reviews, and randomized clinical trials have shown a variety of benefits in the management of TBI, but to date, no large-scale randomized clinical trial has been performed. Despite this limitation, statins' early promise and well-tolerated side effect profile make them a promising new tool in the management of TBIs. More bench and clinical studies are needed to delineate proper treatment regimens as well as understand their true potential.

Pharmacotherapy for mild traumatic brain injury: an overview of the current treatment options

INTRODUCTION

Accounting for 90% of all traumatic brain injuries (TBIs), mild traumatic brain injury (mTBI) is currently the most frequently seen type of TBI. Although most patients can recover from mTBI, some may suffer from prolonged symptoms for months to years after injury. Growing evidence indicates that mTBI is associated with neurodegenerative diseases including dementias and Parkinson's disease (PD). Pharmacological interventions are necessary to address the symptoms and avoid the adverse consequences of mTBI.

AREAS COVERED

To provide an overview of the current treatment options, the authors herein review the potential drugs to reduce the secondary damage and symptom-targeted therapy as well as the ongoing clinical trials about pharmacotherapy for mTBI.

EXPERT OPINION

There has been no consensus on the pharmacotherapy for mTBI. Several candidates including n-3 PUFAs, melatonin, NAC and statins show potential benefits in lessening the secondary injury and improving neurological deficits in pre-clinic studies, which, however, still need further investigation in clinical trials. The current pharmacotherapy for mTBI is empirical in nature and mainly targets to mitigate the symptoms. Well-designed clinical trials are now warranted to provide high level evidence.

Evaluation of the Effect of Atorvastatin Administration on the Outcomes of Patients with Traumatic Brain Injury: A Double-blinded Randomized Clinical Trial

Background

Traumatic brain injury (TBI) is one of the common causes of long-term disabilities and mortality. This study aimed to evaluate the effect of atorvastatin administration on the Glasgow Coma Scale (GCS), Glasgow Outcome Scale (GOS), and Disability Rating Scale (DRS) in patients with TBI.

Methods

This double-blinded randomized clinical trial included 60 patients with TBI in Golestan Hospital of Ahvaz, Iran. After obtaining an informed consent from all patients, the patients were randomly assigned into two groups. For the intervention group, atorvastatin with a daily dose of 20 mg was used. The control group was administered the same amount of placebo for 10 days. Changes in the level of consciousness were measured using the GCS, and functional recovery rate in patients was measured by GOS and DRS in the third follow-up month.

Results

According to the obtained results, compared with the control group, the atorvastatin administration significantly increased the level of GCS and DRS within 2 - 3 months post-intervention and improved GOS since the tenth day after the study (P < 0.05).

Conclusions

The results revealed the positive effect of atorvastatin on the improvement of outcomes measurements such as GCS, DRS, and GOS in patients after moderate and severe TBI.

The Effect of Oral Simvastatin on the Clinical Outcome of Patients with Severe Traumatic Brain Injury: A Randomized Clinical Trial

Background

Despite recent promising pharmacological and technological advances in neurosurgical intensive care, the overall TBI-related mortality and morbidity remain high and still pose a major clinical problem. The aim of this study was to evaluate the effect of oral simvastatin on the clinical outcome of patients with severe TBI.

Methods

In a double-blind placebo-controlled randomized clinical trial a total of 98 patients with severe TBI in Imam Khomeini Hospital in Sari, Iran, were evaluated. Patients who meet the inclusion criteria were randomly allocated into two groups (n=49). In addition to supportive therapies, the intervention group received oral simvastatin (40 mg, daily) for 10 days, and the control group received the placebo (10 days). Patients' Glasgow coma scale (GCS) score, in hospital mortality, duration of mechanical ventilation and length of ICU and neurosurgery ward stay were evaluated during three-time intervals (T1: admission, T2: discharge and T3: one month after discharge).

Results

The percentage of conscious patients was 18.9% (7 cases) in the simvastatin group and 3.1% (1 case) in controls (P=0.06) at T2. One month after discharge (T3) the proportion of conscious patients significantly increased in the simvastatin group compared to control group (64.9 % versus 28.1 %; P=0.002). There was no significant difference for the mean of GCS score between the simvastatin group and control group at T1 (6.41 ± 1.30 versus 6.41 ± 1.28, respectively; P = 0.98). However, the mean score of GCS in patients who received simvastatin was significantly greater than controls at T2 and T3 (p<0.05). There was no significant differences between two group in-terms of length of mechanical ventilation, ICU and neurosurgery ward stay.

Conclusion

According to the results of this study it seems that using simvastatin may be an effective and promising therapeutic modality for improving GCS score during TBI recovery.

Inflammation in Traumatic Brain Injury

There is an increasing evidence that inflammation contributes to clinical and functional outcomes in traumatic brain injury (TBI). Many successful target-engaging, lesion-reducing, symptom-alleviating, and function-improving interventions in animal models of TBI have failed to show efficacy in clinical trials. Timing and immunological context are paramount for the direction, quality, and intensity of immune responses to TBI and the resulting neuroanatomical, clinical, and functional course. We present components of the immune system implicated in TBI, potential immune targets, and target-engaging interventions. The main objective of our article is to point toward modifiable molecular and cellular mechanisms that may modify the outcomes in TBI, and contribute to increasing the translational value of interventions that have been identified in animal models of TBI.

Neuropharmacology in traumatic brain injury: from preclinical to clinical neuroprotection?

Traumatic brain injury (TBI) constitutes a major health problem worldwide and is a leading cause of death and disability in individuals, contributing to devastating socioeconomic consequences. Despite numerous promising pharmacological strategies reported as neuroprotective in preclinical studies, the translation to clinical trials always failed, albeit the great diversity of therapeutic targets evaluated. In this review, first, we described epidemiologic features, causes, and primary and secondary injuries of TBI. Second, we outlined the current literature on animal models of TBI, and we described their goals, their advantages and disadvantages according to the species used, the type of injury induced, and their clinical relevance. Third, we defined the concept of neuroprotection and discussed its evolution. We also identified the reasons that might explain the failure of clinical translation. Then, we reviewed post‐TBI neuroprotective treatments with a focus on the following pleiotropic drugs, considered “low hanging fruit” with high probability of success: glitazones, glibenclamide, statins, erythropoietin, and progesterone, that were largely tested and demonstrated efficient in preclinical models of TBI. Finally, our review stresses the need to establish a close cooperation between basic researchers and clinicians to ensure the best clinical translation for neuroprotective strategies for TBI.

Association Between Statin Use and Risk of Dementia After a Concussion

Importance

Concussions are an acute injury that may lead to chronic disability, while statin use might improve neurologic recovery.

Objective

To test whether statin use is associated with an increased or decreased risk of subsequent dementia after a concussion.

Design, Setting, and Participants

Large extended population-based double cohort study in Ontario, Canada, from April 1, 1993, to April 1, 2013 (enrollment), and continued until March 31, 2016 (follow-up). Dates of analysis were April 28, 2014, through March 21, 2019. Participants were older adults diagnosed as having a concussion, excluding severe cases resulting in hospitalization, individuals with a prior diagnosis of dementia or delirium, and those who died within 90 days.

Exposure

Statin prescription within 90 days after a concussion.

Main Outcome and Measure

Long-term incidence of dementia.

Results

This study identified 28 815 patients diagnosed as having a concussion (median age, 76 years; 61.3% female), of whom 7058 (24.5%) received a statin, and 21 757 (75.5%) did not receive a statin. A total of 4727 patients subsequently developed dementia over a mean follow-up of 3.9 years, equal to an incidence of 1 case per 6 patients. Patients who received a statin had a 13% reduced risk of dementia compared with patients who did not receive a statin (relative risk, 0.87; 95% CI, 0.81-0.93; P < .001). The decreased risk of dementia associated with statin use applied to diverse patient groups, remained independent of other cardiovascular medication use, intensified over time, was distinct from the risk of subsequent depression, and was not observed in patients after an ankle sprain.

Conclusions and Relevance

In this study, older adults had a substantial long-term risk of dementia after a concussion, which was associated with a modest reduction among patients receiving a statin.

In-Hospital Mortality Following Traumatic Brain Injury Among Older Medicare Beneficiaries, Comparing Statin Users With Nonusers

Background

Traumatic brain injury (TBI) is a significant public health concern for older adults. Small-scale human studies have suggested pre-TBI statin use is associated with decreased in-hospital mortality following TBI, highlighting the need for large-scale translational research.

Objective

To investigate the relationship between pre-TBI statin use and in-hospital mortality following TBI.

Methods

A retrospective study of Medicare beneficiaries 65 and older hospitalized with a TBI during 2006 to 2010 was conducted to assess the impact of pre-TBI statin use on in-hospital mortality following TBI. Exposure of interest included atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin, and simvastatin. Beneficiaries were classified as current, recent, past, and nonusers of statins prior to TBI. The outcome of interest was in-hospital mortality. Logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs) comparing current, recent, and prior statin use to nonuse.

Results

Most statin users were classified as current users (90%). Current atorvastatin (OR = 0.88; 95% = CI 0.82, 0.96), simvastatin (OR = 0.84; 95% CI = 0.79, 0.91), and rosuvastatin (OR = 0.79; 95% CI = 0.67, 0.94) use were associated with a significant decrease in the risk of in-hospital mortality following TBI.

Conclusions

In addition to being the most used statins, current use of atorvastatin, rosuvastatin, and simvastatin was associated with a significant decrease in in-hospital mortality following TBI among older adults. Future research must include clinical trials to help exclude the possibility of a healthy user effect in order to better understand the impact of statin use on in-hospital mortality following TBI.

Patterns of Statin Use in Older Medicare Beneficiaries With Traumatic Brain Injury

BACKGROUND

In addition to lowering lipids, statins also may be beneficial for older adults sustaining a traumatic brain injury (TBI), as statin use prior to and following trauma may decrease mortality following injury. However, despite statins' potential to reduce mortality, there is limited research regarding statin use among older adults.

OBJECTIVE

To characterize and investigate factors associated with statin use among older adults with TBI.

METHODS

A retrospective drug utilization study was used to characterize statin use among Medicare beneficiaries 65 and older hospitalized with a TBI during 2006 to 2010 and with continuous Medicare Parts A, B, and D coverage 6 months prior and 12 months following TBI. Logistic regression was used to investigate the factors associated with statin use. The exposure of interest was statin use prior to and following TBI.

RESULTS

Of the 75 698 beneficiaries included in the study, 37 874 (~50%) of beneficiaries used a statin at least once during the study period. The most common statin used was simvastatin, while fluvastatin was the least used statin. Statin users were more likely to have cardiovascular diseases when compared to nonusers. Hyperlipidemia was a major factor associated with statin use and had the greatest impact on statin use compared to nonuse (odds ratio = 9.54; 95% confidence interval = 9.07, 10.03).

CONCLUSIONS

This national sample of older adults with TBI suggests that statins are commonly used. Future studies must next examine the impact of statin use on mortality and secondary injury in order to shape pharmacological therapy guidelines following TBI.