Pharmacological interventions for asymptomatic carotid stenosis

BACKGROUND

Carotid artery stenosis is narrowing of the carotid arteries. Asymptomatic carotid stenosis is when this narrowing occurs in people without a history or symptoms of this disease. It is caused by atherosclerosis; that is, the build-up of fats, cholesterol, and other substances in and on the artery walls. Atherosclerosis is more likely to occur in people with several risk factors, such as diabetes, hypertension, hyperlipidaemia, and smoking. As this damage can develop without symptoms, the first symptom can be a fatal or disabling stroke, known as ischaemic stroke. Carotid stenosis leading to ischaemic stroke is most common in men older than 70 years. Ischaemic stroke is a worldwide public health problem.

OBJECTIVES

To assess the effects of pharmacological interventions for the treatment of asymptomatic carotid stenosis in preventing neurological impairment, ipsilateral major or disabling stroke, death, major bleeding, and other outcomes.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register, CENTRAL, MEDLINE, Embase, two other databases, and three trials registers from their inception to 9 August 2022. We also checked the reference lists of any relevant systematic reviews identified and contacted specialists in the field for additional references to trials.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs), irrespective of publication status and language, comparing a pharmacological intervention to placebo, no treatment, or another pharmacological intervention for asymptomatic carotid stenosis.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Two review authors independently extracted the data and assessed the risk of bias of the trials. A third author resolved disagreements when necessary. We assessed the evidence certainty for key outcomes using GRADE.

MAIN RESULTS

We included 34 RCTs with 11,571 participants. Data for meta-analysis were available from only 22 studies with 6887 participants. The mean follow-up period was 2.5 years. None of the 34 included studies assessed neurological impairment and quality of life. Antiplatelet agent (acetylsalicylic acid) versus placebo Acetylsalicylic acid (1 study, 372 participants) may result in little to no difference in ipsilateral major or disabling stroke (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.47 to 2.47), stroke-related mortality (RR 1.40, 95% CI 0.54 to 3.59), progression of carotid stenosis (RR 1.16, 95% CI 0.79 to 1.71), and adverse events (RR 0.81, 95% CI 0.41 to 1.59), compared to placebo (all low-certainty evidence). The effect of acetylsalicylic acid on major bleeding is very uncertain (RR 0.98, 95% CI 0.06 to 15.53; very low-certainty evidence). The study did not measure neurological impairment or quality of life. Antihypertensive agents (metoprolol and chlorthalidone) versus placebo The antihypertensive agent, metoprolol, may result in no difference in ipsilateral major or disabling stroke (RR 0.14, 95% CI 0.02 to1.16; 1 study, 793 participants) and stroke-related mortality (RR 0.57, 95% CI 0.17 to 1.94; 1 study, 793 participants) compared to placebo (both low-certainty evidence). However, chlorthalidone may slow the progression of carotid stenosis (RR 0.45, 95% CI 0.23 to 0.91; 1 study, 129 participants; low-certainty evidence) compared to placebo. Neither study measured neurological impairment, major bleeding, adverse events, or quality of life. Anticoagulant agent (warfarin) versus placebo The evidence is very uncertain about the effects of warfarin (1 study, 919 participants) on major bleeding (RR 1.19, 95% CI 0.97 to 1.46; very low-certainty evidence), but it may reduce adverse events (RR 0.89, 95% CI 0.81 to 0.99; low-certainty evidence) compared to placebo. The study did not measure neurological impairment, ipsilateral major or disabling stroke, stroke-related mortality, progression of carotid stenosis, or quality of life. Lipid-lowering agents (atorvastatin, fluvastatin, lovastatin, pravastatin, probucol, and rosuvastatin) versus placebo or no treatment Lipid-lowering agents may result in little to no difference in ipsilateral major or disabling stroke (atorvastatin, lovastatin, pravastatin, and rosuvastatin; RR 0.36, 95% CI 0.09 to 1.53; 5 studies, 2235 participants) stroke-related mortality (lovastatin and pravastatin; RR 0.25, 95% CI 0.03 to 2.29; 2 studies, 1366 participants), and adverse events (fluvastatin, lovastatin, pravastatin, probucol, and rosuvastatin; RR 0.76, 95% CI 0.53 to1.10; 7 studies, 3726 participants) compared to placebo or no treatment (all low-certainty evidence). The studies did not measure neurological impairment, major bleeding, progression of carotid stenosis, or quality of life.

AUTHORS' CONCLUSIONS

Although there is no high-certainty evidence to support pharmacological intervention, this does not mean that pharmacological treatments are ineffective in preventing ischaemic cerebral events, morbidity, and mortality. High-quality RCTs are needed to better inform the best medical treatment that may reduce the burden of carotid stenosis. In the interim, clinicians will have to use other sources of information.

Assessment of Therapeutic Response to Statin Therapy in Patients With Intracranial or Extracranial Carotid Atherosclerosis by Vessel Wall MRI: A Systematic Review and Updated Meta-Analysis

Background and Aims: Statin therapy is an essential component of cardiovascular preventive care. In recent years, various vessel wall MRI (VW-MRI) techniques have been used to monitor atherosclerosis progression or regression in patients with extracranial or intracranial large-artery atherosclerosis. We aimed to perform a systematic review and meta-analysis on the effects of statin therapy on plaque evolution as assessed by VW-MRI.

Materials and Methods: Prospective studies investigating carotid and intracranial atherosclerotic plaques in patients on statin therapy monitored by serial VW-MRI were systematically identified in the literature. The plaque burden and lipid-rich necrotic core (LRNC) volume of carotid plaque and the imaging features of intracranial plaques were extracted and summarized. For studies investigating carotid artery wall volume and LRNC volume, combined estimates were derived by meta-analysis.

Results: The study identified 21 studies of carotid plaque and two studies of intracranial plaque. While 16 studies investigating carotid plaques that included 780 patients by High-resolution VW-MRI were included in the meta-analysis. There was no significant change in carotid wall volume from baseline to 12 months. A significant change in LRNC volume was observed at > 12 months compared with baseline (Effect = −10.69, 95% CI = −19.11, −2.28, P < 0.01), while no significant change in LRNC volume at 3–6 months or 7–12 months after statin therapy initiation in 6 studies. Increases in fibrous tissue and calcium and reduction in neovascularization density of the plaque were seen in 2/3 studies (including 48/59 patients), 1/3 studies (including 17/54 patients), and 2/2 studies (including 71 patients) after statin therapy, respectively. Two studies with 257 patients in intracranial atherosclerosis showed that statins could effectively decrease wall volume and plaque enhancement volume.

Conclusions: Collective data indicated that statins could potentially stabilize carotid plaques by significantly reducing LRNC with 1 year of therapy as shown on serial carotid VW-MRI. There was no significant decrease in wall volume, which nonetheless indicated that plaque composition changes might be more sensitive to response monitoring than wall volume. It is likely that more sensitive, clinically relevant, and preferably quantitative indicators of therapeutic effects on intracranial vessel plaque morphology will be developed in the future.

The relationship between coronary artery distensibility and fractional flow reserve

Discordance between angiography-based anatomical assessment of coronary stenosis severity and fractional flow reserve (FFR) has been attributed to several factors including lesion length and irregularity, and the myocardial territory supplied by the target vessel. We sought to examine if coronary arterial distensibility is an independent contributor to this discordance. There were two parts to this study. The first consisted of “in silico” models of 26 human coronary arteries. Computational fluid dynamics-derived FFR was calculated for fully rigid, partially distensible and fully distensible models of the 26 arteries. The second part of the study consisted of 104 patients who underwent coronary angiography and FFR measurement. Distensibility at the lesion site (Distensibility_MLA) and for the reference vessel (Distensibility_Ref) was determined by analysing three-dimensional angiography images during end-systole and end-diastole. Computational fluid dynamics-derived FFR was 0.67±0.19, 0.70±0.18 and 0.75±0.17 (P<0.001) in the fully rigid, partially distensible and fully distensible models respectively. FFR correlated with both Distensibility_MLA (r = 0.36, P<0.001) and Distensibility_Ref (r = 0.44, P<0.001). Two-way ANCOVA analysis revealed that Distensibility_MLA (F (1, 100) = 4.17, p = 0.031) and percentage diameter stenosis (F (1, 100) = 60.30, p < 0.01) were both independent predictors of FFR. Coronary arterial distensibility is a novel, independent determinant of FFR, and an important factor contributing to the discordance between anatomical and functional assessment of stenosis severity.

Beneficial effects of low-dose aspirin on aortic stiffness in hypertensive patients

While treatment with low-dose aspirin has been established as a therapeutic tool for secondary prevention, the role of aspirin on primary prevention remains controversial. Aortic stiffness and wave reflections are independent predictors of cardiovascular events. The aim of the present study was to investigate the effect of low-dose aspirin on aortic stiffness and wave reflections in hypertensive patients. We studied 30 patients with grade I hypertension. Fifteen patients were treated with 160 mg of aspirin and 15 patients with placebo. Aortic stiffness and wave reflections were assessed by measuring carotid–femoral pulse wave velocity (PWV) and heart rate-adjusted augmentation index (AIx75), respectively. All measurements were conducted at baseline and 2 weeks after treatment. In the aspirin group, there was a significant reduction in PWV compared to the placebo group (from 8.9±1.5 to 8.5±1.6 m/s for the aspirin group vs from 8.6±1.4 to 8.7±1.6 m/s for the placebo group, net change: –0.5 m/s; p=0.02). AIx75 showed a marginal decrease (from 28.0±5.4 to 26.2±5.0% for the aspirin group vs from 31.2±9.7 to 30.6±9.2% for the placebo group, net change: –1.2%; p=0.06). In conclusion, a 2-week course of aspirin administration has a favorable effect on aortic stiffness and, to a lesser extent, on wave reflections in hypertensive patients. Whether the reduction in arterial stiffness is translated to fewer cardiovascular events needs to be confirmed by future prospective studies.

International collaborative validation of intraneural invasion as a prognostic marker in adenoid cystic carcinoma of the head and neck

BACKGROUND

The purpose of this study was to characterize the incidence, pattern of spread, and prognostic correlation of nerve invasion in patients with adenoid cystic carcinoma (ACC).

METHODS

Using 3 different pathological categories of perineural invasion, intraneural invasion, and perineural inflammation, we investigated the prognostic value of nerve invasion in a total of 495 ACCs from 9 international patient cohorts with median follow-up 90 months (range, 12-288 months).

RESULTS

Of 239 patients (48%) with nerve invasion, 174 (73%) had perineural invasion, 65 (27%) intraneural invasion, and 37 (15%) perineural inflammation. Multivariate Cox regression analysis identified tumor site (p = .008; hazard ratio [HR] = 1.8; 95% confidence interval [CI] = 0.07-3.7) and intraneural invasion (p < .001; HR = 5.9; 95% CI = 0.8-12.3) as independent prognostic markers for both overall survival (OS) and disease-specific survival (DSS), but not of distant metastases.

CONCLUSION

Although perineural invasion has no impact on survival, intraneural invasion is an independent predictor of poor prognosis. Recognition of intraneural invasion may help optimize treatment of patients with head and neck ACC.

The association between low-density lipoprotein cholesterol goal attainment, physician and patient attitudes and perceptions, and healthcare policy

AIM

Withholding effective treatment is clinically prevalent. The CEntralized Pan-Asian survey on tHE Under-treatment of hypercholeSterolemia (CEPHEUS-PA) indicated suboptimal low-density lipoprotein cholesterol (LDL-C) goal attainment in Taiwan, which may be attributable to clinical inertia. We herein analyzed the Taiwanese cohort in the CEPHEUS-PA to identify key elements regarding clinical inertia and unsatisfactory LDL-C control.

METHODS

A questionnaire regarding the attitudes and perceptions for each physician and patient was included in the CEPHEUS-PA. Physicians completed the physician questionnaire before enrolling patients, who completed the patient questionnaire before the assessment.

RESULTS

The National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) guideline was used by 81.8% of physicians to establish the individual therapeutic targets; 50.2% of patients failed to take medications persistently. Regarding perceptions to hypercholesterolemia management, 75.9% of physicians were confident of having a sufficient number of patients at cholesterol targets; 80.2% and 65.9% of patients felt satisfied and motivated, respectively, but 46.0% had no strong feeling. The healthcare reimbursement policy used for treatment guidance was a significant determinant for LDL-C goal attainment (OR=0.32, 95% CI: 0.15-0.69, P=0.006) in addition to patient compliance. Low patient involvement indexed by having no strong feeling was associated with poor LDL-C control (OR=0.73, 95% CI: 0.56-0.95, P=0.020).

CONCLUSIONS

The referenced healthcare reimbursement policy, poor patient compliance, and low patient involvement with hypercholesterolemia management were associated with failure of LDL-C control. Our findings highlight the need to overcome those barriers to improve the under-treatment of hypercholesterolemia.