Statins Reduce Abdominal Aortic Aneurysm Growth, Rupture, and Perioperative Mortality: A Systematic Review and Meta-Analysis

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Epidemiology and management of aortic disease: aortic aneurysms and acute aortic syndromes

The aorta is the 'greatest artery', through which oxygenated blood is delivered from the left ventricle to end organs with each cardiac cycle (200 million litres of blood transported in an average lifetime). The aorta can be affected by a wide spectrum of acute factors (such as cocaine use, weight lifting and trauma) and chronic acquired and/or genetic conditions (such as systemic arterial hypertension and phaeochromocytoma), which variously lead to increased aortic wall stress. The medial layer of the aorta can also be subject to abnormalities (such as Marfan syndrome, bicuspid aortic valve, inflammatory vasculitis, atherosclerosis and infections). Despite important advances in diagnostic and therapeutic interventions, data derived from registries and population-based studies highlight that the burden of aortic diseases remains high. Therefore, specific resources need to be allocated to design and implement preventive strategies (healthy lifestyles, modifications to cardiovascular risk factors, and educational and screening programmes) at individual and community levels. In this Review, we discuss the epidemiology, management and outcomes of the most common aortic diseases, namely, aortic aneurysms and acute aortic syndromes.

Gender-Based Differences in Abdominal Aortic Aneurysm Rupture: A Retrospective Study

Background

Annually, 5% of sudden deaths are due to abdominal aortic aneurysm (AAA) rupture. There is evidence suggesting that AAA ruptures have worse outcomes in females than males and the aneurysms rupture at a smaller size in females than in males. The United States Preventive Services Task Force (USPSTF) recommends a one-time ultrasound screening for males aged 65 - 75 years who ever smoked. There is insufficient evidence to screen females aged 65 - 75 years who ever smoked though there is evidence suggesting that AAAs rupture at a smaller size and have worse outcomes in females. The objective of this study is to compare the characteristics, mortality and morbidity of ruptured AAAs in females and males.

Methods

This is a retrospective review of 117 patients from two teaching institutions over a period of 6 years. A total of 39 parameters were compared between males and females including demographic variables, comorbidities like hypertension, dyslipidemia, cardiovascular diseases; previous history of AAA; medications, characteristics of aneurysm, type of surgery and its outcome; postoperative complications and long-term survival.

Results

The overall incidence of AAA rupture was higher in males (68%) than in females (32%). Females die from AAA rupture at a later age. There was a significant difference in the size of AAA rupture between females (mean = 7.4 cm, standard deviation (SD) = 2.0) and males (mean = 8.2 cm, SD = 1.8; P = 0.04). The probability to undergo surgery for ruptured AAA was significantly lower for females as compared to males (P = 0.03). Females had higher overall mortality (P = 0.001), postoperative mortality (P = 0.02), higher length of intensive care unit (ICU) stay, incidence of postoperative complications, use of vasopressors and use of ventilator.

Conclusions

Using a similar threshold of size of AAA for elective surgery for both males and females might not be appropriate. Further population-based studies are needed to warrant AAA screening for high-risk females owing to the higher morbidity and mortality.

Therapeutic Potential of Heme Oxygenase-1 in Aneurysmal Diseases

Abdominal aortic aneurysm (AAA) and intracranial aneurysm (IA) are serious arterial diseases in the aorta and brain, respectively. AAA and IA are associated with old age in males and females, respectively, and if rupture occurs, they carry high morbidity and mortality. Aneurysmal subarachnoid hemorrhage (SAH) due to IA rupture has a high rate of complication and fatality. Despite these severe clinical outcomes, preventing or treating these devastating diseases remains an unmet medical need. Inflammation and oxidative stress are shared pathologies of these vascular diseases. Therefore, therapeutic strategies have focused on reducing inflammation and reactive oxygen species levels. Interestingly, in response to cellular stress, the inducible heme oxygenase-1 (HO-1) is highly upregulated and protects against tissue injury. HO-1 degrades the prooxidant heme and generates molecules with antioxidative and anti-inflammatory properties, resulting in decreased oxidative stress and inflammation. Therefore, increasing HO-1 activity is an attractive option for therapy. Several HO-1 inducers have been identified and tested in animal models for preventing or alleviating AAA, IA, and SAH. However, clinical trials have shown conflicting results. Further research and the development of highly selective HO-1 regulators may be needed to prevent the initiation and progression of AAA, IA, or SAH.

Efficient Suppression of Abdominal Aortic Aneurysm Expansion in Rats through Systemic Administration of Statin-Loaded Nanomedicine

Abdominal aortic aneurysm (AAA) is a life-threatening disease. However, no systemically injectable drug has been approved for AAA treatment due to low bioavailability. Polymeric micelles are nanomedicines that have the potential to improve therapeutic efficacy by selectively delivering drugs into disease sites, and research has mainly focused on cancer treatments. Here, we developed a statin-loaded polymeric micelle to treat AAAs in rat models. The micelle showed medicinal efficacy by preventing aortic aneurysm expansion in a dose-dependent manner. Furthermore, the micelle-injected group showed decreased macrophage infiltration and decreased matrix metalloproteinase-9 activity in cases of AAA.

Involvement of Myeloid Cells and Noncoding RNA in Abdominal Aortic Aneurysm Disease

Significance: Abdominal aortic aneurysm (AAA) is a potentially fatal condition, featuring the possibility of high-mortality rupture. To date, prophylactic surgery by means of open surgical repair or endovascular aortic repair at specific thresholds is considered standard therapy. Both surgical options hold different risk profiles of short- and long-term morbidity and mortality. Targeting early stages of AAA development to decelerate disease progression is desirable. Recent Advances: Understanding the pathomechanisms that initiate formation, maintain growth, and promote rupture of AAA is crucial to developing new medical therapeutic options. Inflammatory cells, in particular macrophages, have been investigated for their contribution to AAA disease for decades, whereas evidence on lymphocytes, mast cells, and neutrophils is sparse. Recently, there has been increasing interest in noncoding RNAs (ncRNAs) and their involvement in disease development, including AAA. Critical Issues: The current evidence on myeloid cells and ncRNAs in AAA largely originates from small animal models, making clinical extrapolation difficult. Although it is feasible to collect surgical human AAA samples, these tissues reflect end-stage disease, preventing examination of critical mechanisms behind early AAA formation. Future Directions: Gaining more insight into how myeloid cells and ncRNAs contribute to AAA disease, particularly in early stages, might suggest nonsurgical AAA treatment options. The utilization of large animal models might be helpful in this context to help bridge translational results to humans.

Aortic Aneurysm Natural Progression is Not Influenced by Concomitant Malignancy and Chemotherapy

BACKGROUND

Aortic aneurysms occur concomitantly with malignancy in approximately 1.0-17.0% of patients. There is little published information regarding the effects of subsequent oncological therapies on aortic aneurysm growth. The aim of this study was to determine the effects of chemoradiation therapies on the natural progression of small abdominal aortic aneurysm (AAA), thoracic aortic aneurysm, and thoracoabdominal aortic aneurysm.

METHODS

Patients with aortic aneurysms with and without malignancy between 2005 and 2017 were identified within institutional databases using Current Procedural Terminology and International Classification of Disease codes. Inclusion criteria included complete chemotherapy documentation, a minimum of 3 multiplanar axial/coronal imaging or ultrasonography before, during, and after receiving therapy or 2 studies for patients without malignancy. Propensity matching, Cox and linear regression, and Kaplan-Meier survival analyses were performed.

RESULTS

A total of 159 (172 aneurysms) patients with malignancy and 127 (149 aneurysms) patients without malignancy were included. Average patient demographics were 74.4 ± 9.8-years-old, Caucasian (66.8%), male (70.3%), with hypertension (71.1%), current smoking (24.5%), coronary atherosclerotic disease (26.2%), and AAA (71.0%). The most common malignancy was lung cancer (48.4%) with most chemotherapy regimens including a platinum-based alkylating agent and concurrent antimetabolite (56.0%). The overall median follow-up time was 28.2 (range 3.1-174.4) months. Aortic aneurysms in patients without malignancy grew to larger sizes (4.43 ± 0.96 vs. 4.14 ± 1.00, P = 0.008) with similar median growth rates (0.12 vs. 0.12 cm/year, P = 0.090), had more atypical morphologic features (14.1% vs. 0.6%, P < 0.001), more frequently underwent repair (22.1% vs. 8.7%, P = 0.001), and more frequently required emergency repair for rupture (5.4% vs. 0.0%, P = 0.087). Cox regression identified initial aortic size ≥4.0 cm (hazard ratio [HR] 3.028), AAA (HR 2.146), chronic aortic findings (3.589), and the use of topoisomerase inhibitors (HR 2.694). Linear regression demonstrated increased growth rates predicted by antimetabolite chemotherapy (β 0.170), initial aortic size (β 0.086), and abdominal aortic location (β 0.139, all P < 0.002).

CONCLUSIONS

Small aortic aneurysms with concomitant malignancies are discovered at smaller initial sizes, grow at similar rates, require fewer interventions, and have fewer ruptures and acute dissections than patients without malignancy. Antimetabolite therapies modestly accelerate aneurysmal growth, and patients receiving topoisomerase inhibitors may require earlier repair. Patients with concomitant disease can be confidently treated according to standard institutional aneurysm surveillance protocols. Overall, we recommend treatment of the malignancy before small aortic aneurysm repair as these aneurysms behave similarly to those in patients without malignancy.

Hyperlipidemia does not affect development of elastase-induced abdominal aortic aneurysm in mice

BACKGROUND AND AIMS

Hyperlipidemia is a suggested risk factor for abdominal aortic aneurysm (AAA). However, whether hyperlipidemia is causally involved in AAA progression remains elusive. Here, we tested the hypothesis that hyperlipidemia aggravates AAA formation in the widely used porcine pancreatic elastase (PPE) model of AAA in mice with varying levels of plasma lipids.

METHODS

Prior to PPE-surgery, 8-week-old male C57BL/6J mice (n = 32) received 1·10¹¹ viral genomes of rAAV8-D377Y-mPcsk9 or control rAAV8 via the tail vein. Mice were fed either western type diet or regular chow. At baseline and during the 28 days following PPE-surgery, mice underwent weekly ultrasonic assessment of AAA progression. Experiments were repeated using Apolipoprotein E knockout (ApoE^-/-) mice (n = 7) and wildtype C57BL/6J mice (n = 5).

RESULTS

At sacrifice, maximal intergroup plasma cholesterol and non-HDL/HDL ratio differences were >5-fold and >20-fold, respectively. AAA diameters expanded to 150% of baseline, but no intergroup differences were detected. This was verified in an independent experiment comparing 8-week-old male ApoE^-/- mice with wildtype mice. Histological evaluation of experimental AAA lesions revealed accumulated lipid in neointimal and medial layers, and analysis of human AAA lesions (n = 5) obtained from open repair showed medial lipid deposition.

CONCLUSIONS

In summary, we find that lipid deposition in the aortic wall is a feature of PPE-induced AAA in mice as well as human AAA lesions. Despite, our data do not support the hypothesis that hyperlipidemia contributes to AAA progression.

Influence of preoperative statins and aspirin administration on biological and magnetic resonance imaging properties in patients with abdominal aortic aneurysm

Background: Main objective of this study was to evaluate the influence of statins and/or acetylsalicylic acid on biochemical characteristics of abdominal aortic aneurysm (AAA) wall and intraluminal thrombus (ILT). Patients and methods: Fifty patients with asymptomatic infrarenal AAA were analyzed using magnetic resonance imaging on T1w sequence. Relative ILT signal intensity (SI) was determined as a ratio between ILT and psoas muscle SI. Samples containing the full ILT thickness and aneurysm wall were harvested from the anterior surface at the level of the maximal diameter. The concentration of enzymes such as matrix metalloproteinase (MMP) 9, MMP2 and neutrophil elastase (NE/ELA) were analyzed in ILT and AAA wall; while collagen type III, elastin and proteoglycan 4 were analyzed in harvested AAA wall. Oxidative stress in the AAA wall was assessed by catalase and malondialdehyde activity in tissue samples. Results: Relative ILT signal intensity (1.09 ± 0.41 vs 0.89 ± 0.21, p = 0.013) were higher in non-statin than in statin group. Patients who were taking aspirin had lower relative ILT area (0.89 ± 0.19 vs 1.13. ± 0.44, p = 0.016), and lower relative ILT signal intensity (0.85 [0.73-1.07] vs 1.01 [0.84-1.19], p = 0.021) compared to non-aspirin group. There were higher concentrations of elastin in AAA wall among patients taking both of aspirin and statins (1.21 [0.77-3.02] vs 0.78 (0.49-1.05) ng/ml, p = 0.044) than in patients who did not take both of these drugs. Conclusions: Relative ILT SI was lower in patients taking statin and aspirin. Combination of antiplatelet therapy and statins was associated with higher elastin concentrations in AAA wall.

Top 10 candidate aortic disease trials

Aortic pathologies such as aneurysm, dissection and trauma are relatively common and potentially fatal diseases. Over the past two decades, we have experienced unprecedented technical and medical developments in the field. Despite this, there is a great need, and great opportunities, to further explore the area. In this review, we have identified important areas that need to be further studied and selected priority aortic disease trials. There is a pressing need to update the AAA natural history and the role for endovascular AAA repair as well as to define biomarkers and genetic risk factors as well as influence of gender for development and progression of aortic disease. A key limitation of contemporary treatment strategies of AAA is the lack of therapy directed at small AAA, to prevent AAA expansion and need for surgical repair, as well as to reduce the risk for aortic rupture. Currently, the most promising potential drug candidate to slow AAA growth is metformin, and RCTs to verify or reject this hypothesis are warranted. In addition, the role of endovascular treatment for ascending pathologies and for uncomplicated type B aortic dissection needs to be clarified.

Lack of an effective drug therapy for abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) rupture is a common cause of death in adults. Current AAA treatment is by open surgical or endovascular aneurysm repair. Rodent model and human epidemiology, and genetic and observational studies over the last few decades have highlighted the potential of a number of drug therapies, including medications that lower blood pressure, correct dyslipidaemia, or inhibit thrombosis, inflammation or matrix remodelling, as approaches to managing small AAA. This review summarizes prior AAA pathogenesis data from animal and human studies aimed at identifying targets for the development of drug therapies. The review also systematically assesses past randomized placebo-controlled drug trials in patients with small AAAs. Eleven previously published randomized-controlled clinical trials testing different drug therapies aimed at slowing AAA progression were identified. Five of the trials tested antibiotics and three trials assessed medications that lower blood pressure. Meta-analyses of these trials suggested that neither of these approaches limit AAA growth. Allocation to blood pressure-lowering medication was associated with a small reduction in AAA rupture or repair, compared to placebo (relative risk 0.94, 95% confidence intervals 0.89, 1.00, P = 0.047). Three further trials assessed the effect of a mast cell inhibitor, fibrate or platelet aggregation inhibition and reported no effect on AAA growth or clinical events. Past trials were noted to have a number of design issues, particularly small sample sizes and limited follow-up. Much larger trials are needed to properly test potential therapeutic approaches if a convincingly effective medical therapy for AAA is to be identified.

Early Detection of Undiagnosed Abdominal Aortic Aneurysm and Sub-Aneurysmal Aortic Dilatations in Patients with High-Risk Coronary Artery Disease: The Value of Targetted Screening Programme

INTRODUCTION

Abdominal aortic aneurysm (AAA) and coronary artery disease (CAD) share common risk factors. The objective of this study was to determine the prevalence of undiagnosed AAA in patients with angiographically diagnosed significant CAD.

PATIENTS AND METHODS

Male patients aged 50 years and above (including indigenous people) with angiographically diagnosed significant CAD in the recent one year were screened for AAA. Standard definition of abdominal aortic aneurysm and CAD was used. All new patients were followed up for six months for AAA events (ruptured AAA and AAA-related mortality).

RESULTS

A total of 277 male patients were recruited into this study. The total prevalence of undiagnosed AAA in this study population was 1.1% (95% CI 0.2-3.1). In patients with high-risk CAD, the prevalence of undiagnosed AAA was 1.7% (95% CI 0.3-4.8). The detected aneurysms ranged in size from 35.0mm to 63.8mm. Obesity was a common factor in these patients. There were no AAA-related mortality or morbidity during the follow-up. Although the total prevalence of undiagnosed AAA is low in the studied population, the prevalence of sub-aneurysmal aortic dilatation in patients with significant CAD was high at 6.6% (95% CI 3.9-10.2), in which majority were within the younger age group than 65 years old.

CONCLUSION

This was the first study on the prevalence of undiagnosed AAA in a significant CAD population involving indigenous people in the island of Borneo. Targeted screening of patients with high-risk CAD even though they are younger than 65 years old effectively discover potentially harmful asymptomatic AAA and sub-aneurysmal aortic dilatations.

Depletion of CD11c+ dendritic cells in apolipoprotein E-deficient mice limits angiotensin II-induced abdominal aortic aneurysm formation and growth

OBJECTIVE

The role of chronic inflammation in abdominal aortic aneurysm (AAA) is controversial. CD11c+ antigen-presenting cells (APCs) (dendritic cells (DCs)) have been reported in human AAA samples but their role is unclear. The effect of conditional depletion of CD11c+ cells on experimental AAA was investigated in the angiotensin II (AngII)-infused apolipoprotein E-deficient (ApoE-/-) mouse model.

APPROACH

CD11c-diphtheria toxin (DT or D.tox) receptor (DTR), ovalbumin (OVA) fragment aa 140-386, and enhanced green fluorescent protein (eGFP)-ApoE-/- (CD11c.DOG.ApoE-/-) mice were generated and CD11c+ cell depletion achieved with D.tox injections (8 ng/g body weight, i.p., every-other-day). AAA formation and growth were assessed by measurement of supra-renal aortic (SRA) diameter in vivo by serial ultrasound and by morphometry assessment of harvested aortas at the end of the study.

RESULTS

Depletion of CD11c+ cells by administration of D.tox on alternative days was shown to reduce the maximum diameter of AAAs induced by 28 days AngII infusion compared with controls (D.tox, 1.58 ± 0.03 mm vs Vehicle control, 1.81 ± 0.06 mm, P<0.001). CD11c+ depletion commencing after AAA establishment by 14 days of AngII infusion, was also shown to lead to smaller AAAs than controls after a further 14 days (D.tox, 1.54 ± 0.04 mm vs Vehicle control, 1.80 ± 0.03 mm, P<0.001). Flow cytometry revealed significantly lower numbers of circulating CD44hi CD62Llo effector CD4 T cells, CD44hi CD62Llo effector CD8 T cells and B220+ B cells in CD11c+ cell-depleted mice versus controls. CD11c+ depletion attenuated SRA matrix degradation indicated by decreased neutrophil elastase activity (P=0.014), lower elastin degradation score (P=0.012) and higher collagen content (P=0.002).

CONCLUSION

CD11c+ cell-depletion inhibited experimental AAA development and growth associated with down-regulation of circulating effector T cells and attenuated matrix degradation. The findings suggest involvement of autoreactive immune cells in AAA pathogenesis.

Different Drugs Effect on Mesenchymal Stem Cells Isolated From Abdominal Aortic Aneurysm

BACKGROUND

Abdominal aortic aneurysm (AAA) is a progressive dilation of the aortic wall, determined by the unbalanced activity of matrix metalloproteinase (MMPs). In vitro and in vivo studies support the pivotal role of MMP-9 to AAA pathogenesis. In our experience, we elucidated the expression of MMP-9 in an ex vivo model of human mesenchymal stem cells isolated from AAA specimen (AAA-MSCs). Thus, MMP-9 inhibition could be an attractive therapeutic strategy for inhibiting AAA degeneration and rupture. Our study was aimed at testing the effect of 3 different drugs (pioglitazone, doxycycline, simvastatin) on MMP-9 and peroxisome proliferator-activated receptor (PPAR)-γ expression in AAA-MSCs.

METHODS

Aneurysmal aortic wall segments were taken from AAA patients after the open surgical treatment. MSCs were isolated from AAA (n = 20) tissues through enzymatic digestion. AAA-MSCs were exposed to different doses of pioglitazone (5-10-25 μM), doxycycline (10-25 μM), and simvastatin (10 μM) for 24 h. The effect of each drug was evaluated in terms of cell survival, by crystal violet stain. MMP-9 and PPAR-γ mRNA were analyzed using real-time PCR.

RESULTS

AAA-MSCs were not affected by the exposure to the selected drugs, as shown by the analysis of cell viability. Interestingly, MMP-9 mRNA resulted significantly decreased after each treatment, recording a downregulation of 50% in presence of pioglitazone, 90% with doxycycline, and 40% with exposed to simvastatin, in comparison to untreated cells. We further analyzed the expression of PPAR-γ, target of pioglitazone, observing an upregulation in exposed AAA-MSCs to controls.

CONCLUSIONS

Our data support the potential therapeutic effect of pioglitazone, doxycycline, and simvastatin on AAA by reducing the MMP-9 expression in a patient-specific model (AAA-MSCs). In addition, pioglitazone drives the increase of PPAR-G, another promising target for AAA therapy. Further studies are necessary to elucidate the mechanism driving this inhibitory pathway, which can reduces the mortality risk associated with AAA rupture.

Lipid management in people with peripheral artery disease

PURPOSE OF REVIEW

To summarize recent data on the role of dyslipidaemia and the benefit from managing this in people with disease of the abdominal aorta and its peripheral branches (peripheral artery disease, PAD).

RECENT FINDINGS

Findings from the Further Cardiovascular Outcomes Research with Proprotein convertase subtilisin/kexin type 9 (PCSK9) Inhibition in Subjects with Elevated Risk (FOURIER) trial demonstrate the benefit of intensely lowering low-density lipoprotein-cholesterol (LDL-c) in people with PAD to substantially reduce the incidence of major cardiovascular events (MACE; myocardial infarction, stroke or cardiovascular death) and major adverse limb events (MALE). Despite the evidence of substantial benefits from lowering LDL-c, the uptake of drug therapies to lower LDL-c remains sub-optimal in people with PAD.

SUMMARY

Effective methods to educate physicians and patients on best medical management are needed. Further research is needed to examine the benefit of LDL-c lowering and other lipid therapies for PAD-specific problems like abdominal aortic aneurysm progression and walking impairment. Other novel lipid therapies, such as those that lower lipoprotein (a), maybe particularly beneficial to people with PAD given the evidence indicating high concentrations in this population and the high incidence of MACE in these individuals.

Statins Reduce Abdominal Aortic Aneurysm Growth, Rupture, and Perioperative Mortality: A Systematic Review and Meta-Analysis

Background

There are no recognized pharmacological treatments for abdominal aortic aneurysms (AAA), although statins are suggested to be beneficial. We sought to summarize the literature regarding the effects of statins on human AAA growth, rupture, and 30‐day mortality.

Methods and Results

We conducted a systematic review and meta‐analysis of randomized and observational studies using the Cochrane CENTRAL database, MEDLINE, and EMBASE up to June 15, 2018. Review, abstraction, and quality assessment were conducted by 2 independent reviewers, and a third author resolved discrepancies. Pooled mean differences and odds ratios with 95% confidence intervals were calculated using random effects models. Heterogeneity was quantified using the I² statistic, and publication bias was assessed using funnel plots. Our search yielded 911 articles. One case‐control and 21 cohort studies involving 80 428 patients were included. The risk of bias was low to moderate. Statin use was associated with a mean AAA growth rate reduction of 0.82 mm/y (95% confidence interval 0.33, 1.32, P=0.001, I²=86%). Statins were also associated with a lower rupture risk (odds ratio 0.63, 95% confidence interval 0.51, 0.78, P<0.0001, I²=27%), and preoperative statin use was associated with a lower 30‐day mortality following elective AAA repair (odds ratio 0.55, 95% confidence interval 0.36, 0.83, P=0.005, I²=57%).

Conclusions

Statin therapy may be associated with reduction in AAA progression, rupture, and lower rates of perioperative mortality following elective AAA repair. These data argue for widespread statin use in AAA patients.

Clinical Trial Registration

URL: http://www.crd.york.ac.uk. Unique identifier: CRD42017056480.

Meta-Analysis for Impact of Statin on Mortality After Transcatheter Aortic Valve Implantation

To determine whether statin (hydroxymethylglutaryl-CoA reductase inhibitor) therapy is associated with better midterm survival after transcatheter aortic valve implantation (TAVI), the first meta-analysis of currently available studies was performed. To identify all observational comparative studies and randomized controlled trials (RCTs) of statin versus control (no statin) therapy or cohort studies investigating statin treatment as one of covariates in patients undergoing TAVI, PubMed, Web of Science, and Google Scholar were searched through March 2019. Adjusted (if unavailable, unadjusted) hazard ratios (HRs) with their confidence interval (CIs) of midterm (≥1 year) all-cause mortality after TAVI for statin therapy were extracted from each study. Study-specific estimates were combined by means of inverse variance-weighted averages of logarithmic HRs in the random-effects model. Eight eligible studies with a total of 5,170 TAVI patients were identified and included in the present meta-analysis. The primary meta-analysis (including HRs for high intensity statin from 3 studies together with other HRs) demonstrated that statin treatment was associated with significantly lower midterm mortality (HR, 0.74; 95% CI, 0.60 to 0.91; p = 0.005). The secondary meta-analysis (including HRs for low/moderate intensity statin from 3 studies together with other HRs) also indicated an association of statin therapy with significantly lower midterm mortality (HR, 0.80; 95% CI, 0.69 to 0.93; p = 0.005). No funnel plot asymmetry for the primary meta-analysis (p = 0.64) was identified, which suggested probably no publication bias. In conclusion, statin therapy is associated with better midterm survival after TAVI.

Nonsteroidal Anti-Inflammatory Drugs: A Potential Pharmacological Treatment for Intracranial Aneurysm

Background

Saccular intracranial aneurysms (IAs) are outpouchings of the vessel wall of intracranial arteries. Rupture of IAs results in subarachnoid hemorrhage which is associated with high morbidity and mortality. Surgical interventions, such as clipping and coiling, have associated risks. Currently, there are no proven pharmacological treatments to prevent the growth or rupture of IAs. Infiltration of proinflammatory cytokines in response to increased wall sheer stress is a hallmark of IA. Nonsteroidal anti-inflammatory drugs (NSAIDs) are being investigated as potential therapeutic agents for reduction in growth and/or prevention of IA through inhibition of inflammatory pathways.

Summary

This review will discuss the role of NSAIDs in attenuating the inflammation that drives IA progression and rupture. There are two main subtypes of NSAIDs, nonselective COX and selective COX-2 inhibitors, both of which have merit in treating IA. Evidence will be presented which shows that NSAIDs inhibit several key inflammatory mediators involved in IA progression including nuclear factor-κB, tumor necrosis factor-α, and matrix metalloproteinases. In addition, the role of NSAIDs in limiting inflammatory cell adhesion to endothelial cells and attenuating endothelial cell senescence will be discussed.

Key Messages

There is an abundance of basic science and preclinical data that support NSAIDs as a promising treatment for IA. Additionally, a combination treatment strategy of low-dose aspirin given concomitantly with a selective COX-2 inhibitor may result in a reduced side effect profile compared to aspirin or selective COX-2 inhibitor use alone. Several large clinical trials are currently planned to further investigate the efficacy of NSAIDs as an effective nonsurgical treatment for IAs.

APOA1 oxidation is associated to dysfunctional high-density lipoproteins in human abdominal aortic aneurysm

Background

High-density lipoproteins (HDL) are a complex mixture of lipids and proteins with vasculoprotective properties. However, HDL components could suffer post-translational modifications (PTMs) under pathological conditions, leading to dysfunctional HDL. We studied whether HDL are modified in abdominal aortic aneurysm (AAA) and the effect on HDL functionality.

Methods

HDL were isolated by ultracentrifugation from AAA tissue (HDL-T) and from plasma of healthy volunteers and then incubated with AAA tissue-conditioned medium (HDL-AAA CM). PTMs from these particles were characterized using Comet-PTM. The ability of HDL-AAA CM for promoting cholesterol efflux was determined ex vivo and in vivo by using J774A.1 [³H]cholesterol-labeled mouse macrophages and after injecting [³H]cholesterol-labeled mouse macrophages and HDL into the peritoneal cavity of wild-type C57BL/6 mice, respectively. Trp50 and Trp108 oxidized forms of APOA1 in HDL incubated with conditioned-medium of activated neutrophils and in plasma of AAA patients and controls were measured by targeted parallel reaction monitoring.

Findings

Oxidation was the most prevalent PTM in apolipoproteins, particularly in APOA1. Trp50 and Trp108 in APOA1 were the residues most clearly affected by oxidation in HDL-T and in HDL-AAA CM, when compared to their controls. In addition, cholesterol efflux was decreased in macrophages incubated with HDL-AAA CM in vitro and a decreased macrophage-to-serum reverse cholesterol transport was also observed in mice injected with HDL-AAA CM. Finally, both oxidized Trp50 and Trp108 forms of APOA1 were increased in HDL incubated with conditioned-medium of activated neutrophils and in plasma of AAA patients in relation to controls.

Interpretation

Oxidative modifications of HDL present in AAA tissue and plasma were closely associated with the loss of vasculoprotective properties of HDL in AAA.

Fund

MINECO, ISCiii-FEDER, CIBERDEM, CIBERCV and LA CAIXA.