Development and Internal Validation of a Risk Score to Detect Asymptomatic Carotid Stenosis.
Ontology highlight
ABSTRACT: Objective
Asymptomatic carotid stenosis (ACS) is associated with an increased risk of ischaemic stroke and myocardial infarction. Risk scores have been developed to detect individuals at high risk of ACS, thereby enabling targeted screening, but previous external validation showed scope for refinement of prediction by adding additional predictors. The aim of this study was to develop a novel risk score in a large contemporary screened population.Methods
A prediction model was developed for moderate (≥50%) and severe (≥70%) ACS using data from 596 469 individuals who attended screening clinics. Variables that predicted the presence of ≥50% and ≥70% ACS independently were determined using multivariable logistic regression. Internal validation was performed using bootstrapping techniques. Discrimination was assessed using area under the receiver operating characteristic curves (AUROCs) and agreement between predicted and observed cases using calibration plots.Results
Predictors of ≥50% and ≥70% ACS were age, sex, current smoking, diabetes mellitus, prior stroke/transient ischaemic attack, coronary artery disease, peripheral arterial disease, blood pressure, and blood lipids. Models discriminated between participants with and without ACS reliably, with an AUROC of 0.78 (95% confidence interval [CI] 0.77-0.78) for ≥ 50% ACS and 0.82 (95% CI 0.81-0.82) for ≥ 70% ACS. The number needed to screen in the highest decile of predicted risk to detect one case with ≥50% ACS was 13 and that of ≥70% ACS was 58. Targeted screening of the highest decile identified 41% of cases with ≥50% ACS and 51% with ≥70% ACS.Conclusion
The novel risk model predicted the prevalence of ACS reliably and performed better than previous models. Targeted screening among the highest decile of predicted risk identified around 40% of all cases with ≥50% ACS. Initiation or intensification of cardiovascular risk management in detected cases might help to reduce both carotid related ischaemic strokes and myocardial infarctions.
SUBMITTER: Poorthuis MHF
PROVIDER: S-EPMC7994015 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Background Significant asymptomatic carotid stenosis (ACS) is associated with higher risk of strokes. While the prevalence of moderate and severe ACS is low in the general population, prediction models may allow identification of individuals at increased risk, thereby enabling targeted screening. We identified established prediction models for ACS and externally validated them in a large screening population. Methods and Results Prediction models for prevalent cases with ≥50% ACS were identified in a systematic review (975 studies reviewed and 6 prediction models identified [3 for moderate and 3 for severe ACS]) and then validated using data from 596 469 individuals who attended commercial vascular screening clinics in the United States and United Kingdom. We assessed discrimination and calibration. In the validation cohort, 11 178 (1.87%) participants had ≥50% ACS and 2033 (0.34%) had ≥70% ACS. The best model included age, sex, smoking, hypertension, hypercholesterolemia, diabetes mellitus, vascular and cerebrovascular disease, measured blood pressure, and blood lipids. The area under the receiver operating characteristic curve for this model was 0.75 (95% CI, 0.74-0.75) for ≥50% ACS and 0.78 (95% CI, 0.77-0.79) for ≥70% ACS. The prevalence of ≥50% ACS in the highest decile of risk was 6.51%, and 1.42% for ≥70% ACS. Targeted screening of the 10% highest risk identified 35% of cases with ≥50% ACS and 42% of cases with ≥70% ACS. Conclusions Individuals at high risk of significant ACS can be selected reliably using a prediction model. The best-performing prediction models identified over one third of all cases by targeted screening of individuals in the highest decile of risk only.
| S-EPMC7428515 | biostudies-literature
Project description:Two positive randomized trials established carotid endarterectomy (CEA) as a superior treatment to medical management alone for the treatment of asymptomatic carotid artery stenosis. However, advances in medical therapy have led to an active and spirited debate about the best treatment for asymptomatic carotid stenosis. The Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis (CREST 2) trial aims to better define the best treatment for the average patient with severe asymptomatic carotid stenosis. Enrollment in the trial may be hampered by strong opinions on either side of the debate. It is important to realize that equipoise exists and that neither the old data on CEA nor the new data on optimal medical therapy provide a rigorous answer. The assumption that medical therapy has already been proven superior to revascularization procedures may hinder both enrollment in the trial and technical advancements in revascularization procedures.
| S-EPMC5440242 | biostudies-literature
Project description:Even clinically "asymptomatic" carotid stenosis is associated with multidomain cognitive impairment, gray matter (GM) atrophy, and silent lesion. However, the links between them remain unclear. Using structural MRI data, we examined GM asymmetry index (AI) and white matter hyperintensity (WMH) in 24 patients with severe asymptomatic carotid stenosis (SACS), 24 comorbidity-matched controls, and independent samples of 84 elderly controls and 22 young adults. As compared to controls, SACS patients showed worse verbal memories, higher WMH burden, and right-lateralized GM in posterior middle temporal and mouth-somatomotor regions. These clusters extended to pars triangularis, lateral temporal, and cerebellar regions, when compared with young adults. Further, a full-path of WMH burden (X), GM volume (atrophy, M1), AI (asymmetry, M2), and neuropsychological variables (Y) through a serial mediation model was analyzed. This analysis identified that left-dominated GM atrophy and right-lateralized asymmetry in the posterior middle temporal cortex mediated the relationship between WMH burden and recall memory in SACS patients. These results suggest that the unbalanced hemispheric atrophy in the posterior middle temporal cortex is crucial to mediating relationship between WMH burden and verbal recall memories, which may underlie accelerated aging and cognitive deterioration in patients with SACS and other vascular cognitive impairment.
| S-EPMC8559457 | biostudies-literature
Project description:ImportanceRandomized clinical trials have demonstrated that patients with asymptomatic carotid stenosis are eligible for carotid endarterectomy (CEA) if the 30-day surgical complication rate is less than 3% and the patient's life expectancy is at least 5 years.ObjectiveTo develop a risk prediction tool to improve patient selection for CEA among patients with asymptomatic carotid stenosis.Design, setting, and participantsIn this cohort study, veterans 65 years and older who received both carotid imaging and CEA in the Veterans Administration between January 1, 2005, and December 31, 2009 (n = 2325) were followed up for 5 years. Data were analyzed from January 2005 to December 2015. A risk prediction tool (the Carotid Mortality Index [CMI]) based on 23 candidate variables identified in the literature was developed using Veterans Administration and Medicare data. A simpler model based on the number of 4 key comorbidities that were prevalent and strongly associated with 5-year mortality was also developed (any cancer in the past 5 years, chronic obstructive pulmonary disease, congestive heart failure, and chronic kidney disease [the 4C model]). Model performance was assessed using measures of discrimination (eg, area under the curve [AUC]) and calibration. Internal validation was performed by correcting for optimism using 500 bootstrapped samples.Main outcome and measureFive-year mortality.ResultsAmong 2325 veterans, the mean (SD) age was 73.74 (5.92) years. The cohort was predominantly male (98.8%) and of white race/ethnicity (94.4%). Overall, 29.5% (n = 687) of patients died within 5 years of CEA. On the basis of a backward selection algorithm, 9 patient characteristics were selected (age, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, any cancer diagnosis in the past 5 years, congestive heart failure, atrial fibrillation, remote stroke or transient ischemic attack, and body mass index) for the final logistic model, which yielded an optimism-corrected AUC of 0.687 for the CMI. The 4C model had slightly worse discrimination (AUC, 0.657) compared with the CMI model; however, the calibration curve was similar to the full model in most of the range of predicted probabilities.Conclusions and relevanceAccording to results of this study, use of the CMI or the simpler 4C model may improve patient selection for CEA among patients with asymptomatic carotid stenosis.
| S-EPMC6484803 | biostudies-literature
Project description:Background: Specific microRNAs (miRs) have been implicated in the pathophysiology of atherosclerosis and may represent interesting diagnostic and therapeutic targets in carotid stenosis. We hypothesized that the levels of specific circulating miRs are altered in patients with symptomatic carotid stenosis (sCS) in comparison to those in patients with asymptomatic carotid stenosis (aCS) planned to undergo carotid endarterectomy (CEA). We also studied whether miR levels are associated with plaque vulnerability and stability over time after CEA. Methods: Circulating levels of vascular-enriched miR-92a, miR-126, miR-143, miR-145, miR-155, miR-210, miR-221, miR-222, and miR-342-3p were determined in 21 patients with sCS and 23 patients with aCS before CEA and at a 90-day follow-up. Transcranial Doppler ultrasound for detection of microembolic signals (MES) in the ipsilateral middle cerebral artery was performed prior to CEA. Carotid plaques were histologically analyzed. Results: Mean levels of miRs were not considerably different between groups and were only marginally higher in sCS than aCS concerning miR-92a, miR-210, miR-145, and miR-143 with the best evidence concerning miR-92a. After adjustment for vascular risk factors and statin pre-treatment, the effect sizes remained essentially unchanged. At follow-up, however, these modest differences remained uncorroborated. There were no relevant associations between miR-levels and MES or histological plaque vulnerability features. Conclusions: This study does not provide evidence for strong associations between specific circulating miRs and symptomatic state in a collective of comprehensively characterized patients with carotid stenosis. Further work is needed to elucidate the role of circulating miRs as targets in advanced carotid atherosclerosis.
| S-EPMC8651616 | biostudies-literature
Project description:Background and purposeHigh-grade carotid artery stenosis may alter hemodynamics in the ipsilateral hemisphere, but consequences of this effect are poorly understood. Cortical thinning is associated with cognitive impairment in dementia, head trauma, demyelination, and stroke. We hypothesized that hemodynamic impairment, as represented by a relative time-to-peak (TTP) delay on MRI in the hemisphere ipsilateral to the stenosis, would be associated with relative cortical thinning in that hemisphere.MethodsWe used baseline MRI data from the NINDS-funded Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis-Hemodynamics (CREST-H) study. Dynamic contrast susceptibility MR perfusion-weighted images were post-processed with quantitative perfusion maps using deconvolution of tissue and arterial signals. The protocol derived a hemispheric TTP delay, calculated by subtraction of voxel values in the hemisphere ipsilateral minus those contralateral to the stenosis.ResultsAmong 110 consecutive patients enrolled in CREST-H to date, 45 (41%) had TTP delay of at least 0.5 seconds and 9 (8.3%) subjects had TTP delay of at least 2.0 seconds, the maximum delay measured. For every 0.25-second increase in TTP delay above 0.5 seconds, there was a 0.006-mm (6 micron) increase in cortical thickness asymmetry. Across the range of hemodynamic impairment, TTP delay independently predicted relative cortical thinning on the side of stenosis, adjusting for age, sex, hypertension, hemisphere, smoking history, low-density lipoprotein cholesterol, and preexisting infarction (P=0.032).ConclusionsOur findings suggest that hemodynamic impairment from high-grade asymptomatic carotid stenosis may structurally alter the cortex supplied by the stenotic carotid artery.
| S-EPMC9911846 | biostudies-literature
Project description:National guidelines on carotid endarterectomy (CEA) for asymptomatic patients state that the procedure should be performed with a ? 3% risk of perioperative death or stroke. We developed and validated a multivariate model of risk of death or stroke within 30 days of CEA for asymptomatic disease and a related clinical prediction rule.We analyzed asymptomatic cases in a population-based cohort of CEAs performed in Medicare beneficiaries in New York State. Medical records were abstracted for sociodemographics, neurologic history, disease severity, diagnostic imaging data, comorbidities, and deaths and strokes within 30 days of surgery. We used multivariate logistic regression to identify independent predictors of perioperative death or stroke. The CEA-8 clinical risk score was derived from the final model.Among the 6553 patients, the mean age was 74 years, 55% were male, 62% had coronary artery disease, and 22% had a history of distant stroke or transient ischemic attack. The perioperative rate of death or stroke was 3.0%. Multivariable predictors of perioperative events were female sex (odds ratio [OR] = 1.5; 95% CI, 1.1 to 1.9), nonwhite race (OR = 1.8; 95% CI, 1.1 to 2.9), severe disability (OR = 3.7; 95% CI, 1.8 to 7.7), congestive heart failure (OR = 1.6; 95% CI, 1.1 to 2.4), coronary artery disease (OR = 1.6; 95% CI, 1.2 to 2.2), valvular heart disease (OR = 1.5; 95% CI, 1.1 to 2.3), a distant history of stroke or transient ischemic attack (OR = 1.5; 95% CI, 1.1 to 2.0), and a nonoperated stenosis ? 50% (OR = 1.8; 95% CI, 1.3 to 2.3). The CEA-8 risk score stratified patients with a predicted probability of death or stroke rate from 0.6% to 9.6%.Several sociodemographic, neurologic severity, and comorbidity factors predicted the risk of perioperative death or stroke in asymptomatic patients. The CEA-8 risk score can help clinicians calculate a predicted probability of complications for an individual patient to help inform the decision about revascularization.
| S-EPMC3017529 | biostudies-literature
Project description:To evaluate the cost-effectiveness of a decision-making rule based on the magnetic resonance (MR) imaging assessment of intraplaque hemorrhage (IPH) in patients with asymptomatic carotid artery stenosis.Two competing stroke prevention strategies were compared: (a) an intensive medical therapy-based management strategy versus (b) an imaging-based strategy in which the subset of patients with asymptomatic carotid artery stenosis with IPH on MR images would undergo immediate carotid endarterectomy in addition to ongoing intensive medical therapy. Patients in the medical therapy-only group could undergo carotid endarterectomy only with substantial carotid artery stenosis disease progression. Lifetime quality-adjusted life years (QALYs) and costs were modeled for patients with asymptomatic carotid artery stenosis with 70%-89% and 50%-69% carotid artery stenosis at presentation. Risks of stroke and complications from carotid endarterectomy, costs, and quality of life values were estimated from published sources.The medical therapy-based strategy had a lower life expectancy (12.65 years vs 12.95 years), lower lifetime QALYs (9.96 years vs 10.05 years), and lower lifetime costs ($13 699 vs $15 297) when compared with the MR imaging IPH-based strategy. The incremental cost-effectiveness ratio (ICER) for the MR imaging IPH strategy compared with the medical therapy-based strategy was $16 000 per QALY by using a base-case 70-year-old patient. When using starting patient ages of 60 and 80 years, the ICERs for the MR imaging IPH strategy were $3100 per QALY and $73 000 per QALY, respectively. The ICERs for the MR imaging IPH strategy were slightly higher at all ages for 50%-69% stenosis but remained below a willingness-to-pay threshold of $100 000 per QALY for starting ages of 60 and 70 years.MR imaging IPH can be used as a cost-effective tool to identify patients with asymptomatic carotid artery stenosis most likely to benefit from carotid endarterectomy.
| S-EPMC4672599 | biostudies-literature
Project description:This study aimed to test the hypothesis that the risk of major adverse cardiovascular events (MACE) is similar for subjects with asymptomatic mild and moderate carotid artery stenosis (CAS). We enrolled a total of 453 subjects with asymptomatic CAS (30-69%) detected on baseline screening Doppler ultrasound (DUS) examination between January 2008 and December 2010. The follow-up DUS findings and MACE occurrence (fatal or nonfatal myocardial infarction or stroke and all-cause mortality) were compared between subjects with mild (30-49%) and moderate (50-69%) CAS during the 8-year follow-up period. There was no significant difference in the occurrence of MACE between subjects with mild (n = 289) and moderate (n = 164) CAS (13.8% vs. 15.9%, respectively; p = 0.56), although there was a nonsignificant trend toward an increased risk of major ipsilateral stroke in subjects with moderate CAS (1.4% vs. 4.3%; p = 0.06). Multivariate regression analysis indicated that worsening CAS was independently associated with MACE occurrence (hazard ratio [HR], 4.40; 95% confidence interval [CI], 2.65-7.27; p < 0.01), whereas an increased serum high-density lipoprotein cholesterol level was correlated with a decreased risk of MACE (HR, 0.42; 95% CI, 0.23-0.75; p < 0.01). The cumulative risk of MACE in subjects with asymptomatic mild CAS is similar to that in subjects with asymptomatic moderate CAS.
| S-EPMC5856768 | biostudies-literature
Project description:ObjectiveWe have shown that almost 50% of patients with asymptomatic carotid stenosis (ACS) will demonstrate cognitive impairment. Recent evidence has suggested that cerebral hypoperfusion is an important cause of cognitive impairment. Carotid stenosis can restrict blood flow to the brain, with consequent cerebral hypoperfusion. In contrast, cross-hemispheric collateral compensation through the Circle of Willis, and cerebrovascular vasodilation can also mitigate the effects of flow restriction. It is, therefore, critical to develop a clinically relevant measure of net brain perfusion in patients with ACS that could help in risk stratification and in determining the appropriate treatment. To determine whether ACS results in cerebral hypoperfusion, we developed a novel approach to quantify interhemispheric cerebral perfusion differences, measured as the time to peak (TTP) and mean transit time (MTT) delays using perfusion-weighted magnetic resonance imaging (PWI) of the whole brain. To evaluate the utility of using clinical duplex ultrasonography (DUS) to infer brain perfusion, we also assessed the relationship between the PWI findings and ultrasound-based peak systolic velocity (PSV).MethodsStructural and PWI of the brain and magnetic resonance angiography of the carotid arteries were performed in 20 patients with ≥70% ACS. DUS provided the PSV, and magnetic resonance angiography provided plaque geometric measures at the stenosis. Volumetric perfusion maps of the entire brain from PWI were analyzed to obtain the mean interhemispheric differences for the TTP and MTT delays. In addition, the proportion of brain volume that demonstrated a delay in TTP and MTT was also measured. These proportions were measured for increasing severity of perfusion delays (0.5, 1.0, and 2.0 seconds). Finally, perfusion asymmetries on PWI were correlated with the PSV and stenosis features on DUS using Pearson's correlation coefficients.ResultsOf the 20 patients, 18 had unilateral stenosis (8 right and 10 left) and 2 had bilateral stenoses. The interhemispheric (left-right) TTP delays measured for the whole brain volume identified impaired perfusion in the hemisphere ipsilateral to the stenosis in 16 of the 18 patients. More than 45% of the patients had had ischemia in at least one half of their brain volume, with a TTP delay >0.5 second. The TTP and MTT delays showed strong correlations with PSV. In contrast, the correlations with the percentage of stenosis were weaker. The correlations for the PSV were strongest with the perfusion deficits (TTP and MTT delays) measured for the whole brain using our proposed algorithm (r = 0.80 and r = 0.74, respectively) rather than when measured on a single magnetic resonance angiography slice as performed in current clinical protocols (r = 0.31 and r = 0.58, respectively).ConclusionsInterhemispheric TTP and MTT delay measured for the whole brain using PWI has provided a new tool for assessing cerebral perfusion deficits in patients with ACS. Carotid stenosis was associated with a detectable reduction in ipsilateral brain perfusion compared with the opposite hemisphere in >80% of patients. The PSV measured at the carotid stenosis using ultrasonography correlated with TTP and MTT delays and might serve as a clinically useful surrogate to brain hypoperfusion in these patients.
| S-EPMC8209736 | biostudies-literature