Carotid Artery Stenosis and Ischemic Stroke in Patients With Head and Neck Cancer Treated With Radiation Therapy: A Critical Review.

The purpose of this review is to summarize the literature on carotid artery stenosis (CAS) and ischemic stroke (IS) in patients with head and neck cancer (HNC) treated with radiation therapy (RT) to guide assessment, screening, and management strategies. Patients treated with RT for HNC are at an elevated risk of developing CAS, with published meta-analyses demonstrating that CAS >50% occurs in approximately 25% of patients. Previous research suggests a 10-year cumulative incidence of stroke between 5.7% and 12.5%. Cardiovascular disease (CVD) risk prediction tools such as Qstroke, QRISK-2, and Framingham risk score perform poorly for predicting IS for patients with HNC who received RT. Duplex ultrasound is the most common imaging modality to assess CAS, but controversy remains as to the utility of screening asymptomatic individuals. Only 3 of the 5 major HNC survivorship guidelines acknowledge RT as a risk factor for CAS or IS, while only 1 makes a specific recommendation on screening for CAS (American Head and Neck Society). Within the general population, only 1 CVD guideline discusses RT as a risk factor for CAS (Society for Vascular Surgery). Clinicians involved in the care of patients with HNC treated with RT should be aware of the increased risk of CAS and IS and the challenges in risk prediction. Although there is a lack of evidence to make firm recommendations, HNC survivorship recommendations should ensure HNC survivors and primary care providers are informed of these risks and the importance of assessment and management of CVD risk factors. Future studies are required to refine risk prediction models in patients with HNC and to determine those most likely to benefit from targeted screening and initiation of early preventative strategies.

A Systematic Review and Meta-Analysis of the Incidence and Risk Factors for Major Adverse Cardiovascular Events in Patients with Unrepaired Abdominal Aortic Aneurysms.

Major adverse cardiovascular events (MACE), including myocardial infarction (MI), stroke and cardiovascular death, cause substantial morbidity and mortality. This review assessed the incidence rate of MACE and the association with modifiable risk factors (diabetes, hypertension) and medication use (aspirin, statins) in patients with unrepaired abdominal aortic aneurysm (AAA). Electronic databases were searched systematically for observational studies reporting the incidence of MI, stroke or cardiovascular death in patients with unrepaired AAAs. The primary outcome was cardiovascular death reported as an incidence rate (events per 100 person-years (PY)). Fourteen studies, including 69,579 participants with a mean follow-up time of 5.4 years, were included. Meta-analysis revealed the overall incidence of cardiovascular death, MI and stroke of 2.31 per 100 PY (95% CI, 1.63-3.26; I2 = 98%), 1.65 per 100 PY (95% CI, 1.01-2.69, I2 = 88%) and 0.89 per 100 PY (95% CI, 0.53-1.48, I2 = 87.0%), respectively. The mean rates of statin and aspirin prescriptions were 58.1% and 53.5%, respectively. In conclusion, there is a substantial incidence of MACE in patients with unrepaired AAA, but the prescription of preventative medication is suboptimal. Greater emphasis should be placed on secondary prevention in this population.

A systematic review on nutcracker syndrome and proposed diagnostic algorithm.

OBJECTIVE: Nutcracker syndrome (NCS) is an increasingly recognized venous compressive disease. Although people with NCS can experience debilitating symptoms, making an accurate diagnosis can often be challenging owing to the broad spectrum of clinical presentations and radiologic findings. In the present systematic review, we assessed the most frequent clinical and radiologic criteria used in establishing a diagnosis of NCS and have proposed a comprehensive framework for clinical decision-making. METHODS: We performed a systematic review to identify all observational studies or case series conducted within the previous 10 years that had studied patients with a clinical and radiologic diagnosis of NCS. The extracted data included details related to the study design, participant demographics, presenting clinical features, and radiologic criteria. These details were compared between studies and synthesized to establish a comprehensive diagnostic framework that would be applicable to clinical practice. RESULTS: In the present review, we included 14 studies with a total of 384 patients with NCS. The most common clinical features of NCS were hematuria (69.5%), left flank or abdominal pain (48.4%), pelvic pain (23.1%), and varicocele (15.8%). Computed tomography and ultrasound were the most commonly used imaging modalities, with a threshold for left renal vein stenosis of >80% the most frequently used diagnostic parameter. Eight studies had used venography, with the renocaval pressure gradient the most commonly measured parameter. Two studies had reported using intravascular ultrasound. The findings from our review have shown that a thorough clinical workup of NCS should include critical evaluation of the presenting clinical features and exclusion of alternative diagnoses. All patients should undergo duplex ultrasound with or without the addition of computed tomography or magnetic resonance imaging. Any patient considered for therapeutic intervention should also undergo diagnostic venography with measurement of the renocaval pressure gradient and, if available, intravascular ultrasound with measurement of the left renal vein diameters. CONCLUSIONS: NCS is a challenging condition in terms of the diagnosis and management both. We have proposed a comprehensive diagnostic framework based on the currently available literature to aid in clinical decision-making.

The Potential Benefits and Costs of an Intensified Approach to Low Density Lipoprotein Cholesterol Lowering in People with Abdominal Aortic Aneurysm.

OBJECTIVE: The aims of this study were to assess the incidence of major vascular events (MVE) and peripheral vascular events (PVE) in people with a small asymptomatic abdominal aortic aneurysm (AAA) and model the theoretical benefits and costs of an intensified low density lipoprotein cholesterol (LDL-C) lowering programme. METHODS: A total of 583 participants with AAAs measuring 30 - 54 mm were included in this study. The control of LDL-C and prescription of lipid lowering drugs were assessed by dividing participants into approximately equal tertiles depending on their year of recruitment into the study. The occurrence of MVE (myocardial infarction, stroke, cardiovascular death, and coronary or non-coronary revascularisation) and PVE (non-coronary revascularisation, AAA repair, and major amputation) were recorded prospectively, and the incidence of these events was calculated using Kaplan-Meier analysis. The relative risk reduction reported for these events in a previous randomised control trial (RCT) was then applied to these figures to model the absolute risk reduction and numbers needed to treat (NTT) that could theoretically be achieved with a mean LDL-C lowering of 1 mmol/L. The maximum allowable expense for a cost effective intensive LDL-C lowering programme was estimated using a cost utility analysis. RESULTS: At entry, only 28.5% of participants had an LDL-C of < 1.8 mmol/L and only 18.5% were prescribed a high potency statin (atorvastatin 80 mg or rosuvastatin 40 mg). The five year incidences of MVE and PVE were 38.1% and 44.7%, respectively. It was estimated that if the mean LDL-C of the cohort had been reduced by 1 mmol/L, this could have reduced the absolute risk of MVE and PVE by 6.5% (95% CI 4.4 - 8.7; NNT 15) and 5.3% (95% CI 1.4 - 7.5; NNT 19), respectively. It was estimated that the maximum allowable expense for a cost effective LDL-C lowering programme would be between $1 239 AUD (€768) and $1 582 AUD (€981) per person per annum over a five year period. CONCLUSION: People with a small asymptomatic AAA are at high risk of MVE and PVE. This study provides evidence of the possible benefits and allowable expense for a cost effective intensive LDL-C lowering programme in this population.

The cost-effectiveness of intensive low-density lipoprotein cholesterol lowering in people with peripheral artery disease.

BACKGROUND: People with peripheral artery disease are at a high risk of major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Randomized controlled trials suggest that intensive lowering of low-density lipoprotein cholesterol (LDL-C) with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors is an effective strategy to prevent these events. This study estimated the potential benefit and cost-effectiveness of administrating PCSK9 inhibitors to a cohort of participants with peripheral artery disease. METHODS: A total of 783 participants with intermittent claudication (IC; n = 582) or chronic limb-threatening ischemia (CLTI; n = 201) were prospectively recruited from three hospitals in Australia. Serum LDL-C was measured at recruitment, and the occurrence of MACE and MALE was recorded over a median (interquartile range) follow-up of 2.2 years (0.3-5.7 years). The potential benefit of administering a PCSK9 inhibitor was estimated by calculating the absolute risk reduction and numbers needed to treat (NNT) based on relative risk reductions reported in published randomized trials. The incremental cost-effectiveness ratio per quality-adjusted life year gained was estimated. RESULTS: Intensive LDL-C lowering was estimated to lead to an absolute risk reduction in MACE of 6.1% (95% confidence interval [CI], 2.0-9.3; NNT, 16) and MALE of 13.7% (95% CI, 4.3-21.5; NNT, 7) in people with CLTI compared with 3.2% (95% CI, 1.1-4.8; NNT, 32) and 5.3% (95% CI, 1.7-8.3; NNT, 19) in people with IC. The estimated incremental cost-effectiveness ratios over a 10-year period were $55,270 USD and $32,800 USD for participants with IC and CLTI, respectively. CONCLUSIONS: This analysis suggests that treatment with a PCSK9 inhibitor is likely to be cost-effective in people with CLTI.

The effect of angiopoietin-1 upregulation on the outcome of acute ischaemic stroke in rodent models: A meta-analysis.

Clinical studies report that low circulating angiopoietin-1 concentration at presentation predicts worse outcomes after ischaemic stroke. Upregulating angiopoietin-1 may therefore have therapeutic benefit for ischaemic stroke. This systematic review assessed whether upregulating angiopoietin-1 improved outcomes in rodent models of ischaemic stroke. Random-effects models quantified the effect of angiopoietin-1 upregulation on stroke severity in terms of the size of cerebral infarction and the extent of blood-brain barrier permeability. Eleven studies utilising rat and mouse models of ischaemic stroke fulfilled the inclusion criteria. Meta-analyses demonstrated that angiopoietin-1 upregulation significantly reduced cerebral infarction size (standardised mean difference: -3.02; 95% confidence intervals: -4.41, -1.63; p < 0.001; n = 171 animals) and improved blood-brain barrier integrity (standardized mean difference: -2.02; 95% confidence intervals: -3.27, -0.77; p = 0.002; n = 129 animals). Subgroup analyses demonstrated that angiopoietin-1 upregulation improved outcomes in models of transient, not permanent cerebral ischaemia. Six studies assessed the effect of angiopoietin-1 upregulation on neurological function; however, inter-study heterogeneity prevented meta-analysis. In conclusion, published rodent data suggest that angiopoietin-1 upregulation improves outcome following temporary cerebral ischaemia by reducing cerebral infarction size and improving blood-brain barrier integrity. Additional research is required to examine the effect of angiopoietin-1 upregulation on neurological function during stroke recovery and investigate the benefit and risks in patients.

The effects of continued smoking in head and neck cancer patients treated with radiotherapy: A systematic review and meta-analysis.

PURPOSE: To determine the effects of continued smoking in head and neck cancer (HNC) patients undergoing radiotherapy on overall survival (OS), locoregional control (LRC), quality of life (QoL) and acute and late toxicities. METHODS: Articles from January 1990 to August 14, 2018 were searched in PubMed, MEDLINE (Ovid), Embase, Scopus, The Cochrane Library, CINAHL and AUSThealth. Articles were included if majority of patients were treated with radiotherapy and smokers were defined as those who continued to smoke during or after radiotherapy. Data extraction and risk of bias assessment was performed by three independent co-authors using summary data of original studies. A meta-analysis using a random effects model was conducted for OS and LRC. In addition, a qualitative synthesis was performed for toxicities and quality of life as only a limited number of articles were available. RESULTS: The initial search identified 2217 studies, with 24 articles comprising 6332 patients eligible for inclusion. Analysis demonstrated that continued smoking was associated with approximately two times the risk of mortality (RR = 1.85, 95% CI 1.55-2.21, p < 0.0001, I2 = 43%) in HNC patients. Similarly, the risk of locoregional failure was more than two times greater in HNC patients who continued smoking (RR = 2.24, CI 1.42-3.52, p = 0.0005, I2 = 64%). The qualitative synthesis indicates that continued smoking may contribute to an elevated incidence of late but not acute toxicities. CONCLUSIONS: This review provides evidence that continued smoking is associated with a lower OS and LRC and a higher incidence of late toxicities. Therefore, clinicians should strongly encourage smoking cessation amongst all head and neck cancer patients.

Prescription of Pharmacotherapy and the Incidence of Stroke in Patients With Symptoms of Peripheral Artery Disease.

Background and Purpose- Current guidelines recommend prescription of a number of medications to prevent cardiovascular events in patients with peripheral artery disease (PAD). The impact that these medications have on the incidence of stroke in PAD patients has not been thoroughly investigated. This study aimed to investigate the association of prescription of antihypertensive drugs, antiplatelet medications, and statins, as well as cardiovascular disease risk factors, with stroke incidence in patients with symptoms of PAD. Methods- A database search was completed to identify studies reporting the incidence of stroke and prescription of antihypertensive drugs, antiplatelet medications, and statins in patients with PAD symptoms. A random-effects model was used to meta-analyze the incidence of stroke in patients with symptoms of PAD and in subgroups with intermittent claudication and critical limb ischemia. Metaregression was performed to explore the association between the incidence of stroke and the prescription of medications and the presence of cardiovascular disease risk factors. Results- Twelve studies including 67 915 patients with symptoms of PAD were included. A meta-analysis of data from 7 studies demonstrated an incidence of stroke of 1.31 per 100 patient-years. Patients with critical limb ischemia experienced stroke 2.3× more frequently than those with intermittent claudication (95% CI, 1.58-3.36; P<0.01). The reported prescription of antihypertensive agents varied between 10% and 71%, antiplatelet drugs between 49% and 90%, and statins between 11% and 79% in different studies. Metaregression suggested an association between a lower incidence of stroke and the prescription of antiplatelet drugs ( R2=0.81, P<0.01), and statins ( R2=0.85, P<0.01), but not antihypertensives medications. A prior history of cerebrovascular events was associated with a higher incidence of stroke ( R2=0.58, P<0.05). Conclusions- This review supports previous research which suggests the need for more effective means of ensuring more widespread prescription of preventative medications in patients with PAD.