Asymptomatic carotid stenosis and risk stratification

Carotid endarterectomy in patients with asymptomatic carotid stenosis (ACS) is controversial. Researchers focus on identification of the vulnerable carotid plaque to improve patients’ selection for surgery. However, there is no consensus on a specific algorithm. Also, most studies analyse static plaque measurements, despite carotid plaques being dynamic structures. The aims of this thesis were to determine the association of clinical parameters and ultrasonic plaque characteristics with stroke and mortality risk; also, stroke risk in terms of time. The final endpoint was to provide new methods of stroke and mortality stratification and assess new features of plaque instability, in patients with ACS. In a natural history study of 1121 patients with ACS, a high-risk subgroup with annual stroke risk of 7.2%, based on clinical parameters, was identified. Independent stroke predictors were creatinine, severity of stenosis, history of contralateral neurological events and progression of stenosis. A model based on six computer-extracted plaque texture features, predicting cerebrovascular events in the first two years, was developed. Finally, a subgroup of patients with 100% 5-year cardiovascular mortality was identified. Independent predictors of cardiovascular mortality were male gender, age, diabetes, stenosis >80%, not taking aspirin, cardiac failure and left ventricular hypertrophy. In the final part of the thesis, quantification of discordant plaque motion and its relationship to symptoms was evaluated. In a cross-sectional study, involving 116 patients (58 symptomatic and 58 asymptomatic), discordant motion was associated with a high prevalence of symptomatic carotid plaques. A method of objective computerised measurements for identification and quantification of discordant plaque motion was developed. The optimal predictor and a cut-off point for discordant motion were found. Plaque motion analysis is a potential tool in stroke risk stratification. It should be tested, in combination with other plaque features, in prospective studies of patients with ACS

Long-term mortality in patients with asymptomatic carotid stenosis:Implications for statin therapy

ObjectiveRecent studies with asymptomatic carotid patients on best medical management have shown that the annual risk of stroke has decreased to approximately 1%. There is no evidence that a similar decrease in mortality has occurred. In addition, the intensity of statin therapy for these patients has not yet been determined. The aims of this review were to determine (a) the reported long-term all-cause and cardiac-related mortality in patients with asymptomatic carotid stenosis (ACS) > 50%, (b) whether there has been a decrease in mortality in recent years, (c) the available methods of mortality risk stratification, and (d) whether the latest ACC/AHA guidelines on the treatment of serum lipids can be applied to this group of patients.MethodsSystematic review of PubMed, EuroPubMed, and Cochrane Library and meta-analysis using random effects for pooled proportions were performed regarding long-term all-cause and cardiac-related mortality and the associated risk factors in ACS patients. The last day for literature search was October 30, 2014.ResultsSeventeen studies were retrieved reporting 5-year all-cause mortality in 11,391 patients with ACS >50%. The 5-year cumulative all-cause mortality across all 17 studies was 23.6% (95% CI 20.50–26.80). Twelve additional studies, reporting both all-cause and cardiac mortality with a minimum of 2 year follow-up and involving 4,072 patients were identified. Of the 930 deaths reported, 589 (62.9%; 95% CI 58.81–66.89) were cardiac-related. This translates into an average cardiac-related mortality of 2.9% per year.ConclusionsAll-cause and cardiac mortality in ACS patients are very high. Although risk stratification is possible, most patients are classified as high risk. In view of this high risk, aggressive statin therapy is indicated if the new ACC/AHA guidelines on serum lipids are to be adhered to

Dynamic carotid plaque imaging using ultrasonography

Objective Dynamic image analysis of carotid plaques has demonstrated that during systole and early diastole, all plaque components will move in the same direction (concordant motion) in some plaques. However, in others, different parts of the plaque will move in different directions (discordant motion). The aim of our study was (1) to determine the prevalence of discordant motion in symptomatic and asymptomatic plaques, (2) to develop a measurement of the severity of discordant motion, and (3) to determine the correlation between the severity of discordant motion and symptom prevalence. Methods A total of 200 patients with 204 plaques resulting in 50% to 99% stenosis (112 asymptomatic and 92 symptomatic plaques) had video recordings available of the plaque motion during 10 cardiac cycles. Video tracking was performed using Farneback's method, which relies on frame comparisons. In our study, these were performed at 0.1-second intervals. The maximum angular spread (MAS) of the motion vectors at 10-pixel intervals in the plaque area was measured in degrees. Plaques were classified as concordant (MAS, 120°). Results Motion was discordant in 89.1% of the symptomatic plaques but only in 17.9% of asymptomatic plaques (P 120°, the hazard ratio for the presence of symptoms was 47.7 (95% confidence interval, 18.1-125.6) compared with the rest of the plaques after adjustment for the degree of stenosis and mean pixel motion. The area under the receiver operating characteristic curve for the prediction of the presence of symptoms using the MAS was 0.876 (95% confidence interval, 0.823-0.929). The use of the median MAS (120°) as a cutoff point classified 86% of the plaques correctly (sensitivity, 81.4%; specificity, 91.2%; positive predictive value, 90.2%; and negative predictive value, 83.0%). Conclusions The use of the MAS value to identify asymptomatic plaques at increased risk of developing symptoms and, in particular, stroke should be tested in prospective studies

Direct oral anticoagulant-vs vitamin k antagonist-related nontraumatic intracerebral hemorrhage

Objective: To compare the neuroimaging profile and clinical outcomes among patients with intracerebral hemorrhage (ICH) related to use of vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF). Methods: We evaluated consecutive patients with NVAF with nontraumatic, anticoagulant-related ICH admitted at 13 tertiary stroke care centers over a 12-month period. We also performed a systematic review and meta-analysis of eligible observational studies reporting baseline characteristics and outcomes among patients with VKA- or DOAC-related ICH. Results: We prospectively evaluated 161 patients with anticoagulation-related ICH (mean age 75.6 ± 9.8 years, 57.8% men, median admission NIH Stroke Scale [NIHSSadm] score 13 points, interquartile range 6–21). DOAC-related (n = 47) and VKA-related (n = 114) ICH did not differ in demographics, vascular risk factors, HAS-BLED and CHA2DS2-VASc scores, and antiplatelet pretreatment except for a higher prevalence of chronic kidney disease in VKA-related ICH. Patients with DOAC-related ICH had lower median NIHSSadm scores (8 [3–14] vs 15 [7–25] points, p = 0.003), median baseline hematoma volume (12.8 [4–40] vs 24.3 [11–58.8] cm3, p = 0.007), and median ICH score (1 [0–2] vs 2 [1–3] points, p = 0.049). Severe ICH (>2 points) was less prevalent in DOAC-related ICH (17.0% vs 36.8%, p = 0.013). In multivariable analyses, DOAC-related ICH was independently associated with lower baseline hematoma volume (p = 0.006), lower NIHSSadm scores (p = 0.022), and lower likelihood of severe ICH (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.13–0.87, p = 0.025). In meta-analysis of eligible studies, DOAC-related ICH was associated with lower baseline hematoma volumes on admission CT (standardized mean difference = −0.57, 95% CI −1.02 to −0.12, p = 0.010) and lower in-hospital mortality rates (OR = 0.44, 95% CI 0.21–0.91, p = 0.030). Conclusions: DOAC-related ICH is associated with smaller baseline hematoma volume and lesser neurologic deficit at hospital admission compared to VKA-related ICH

Direct oral anticoagulant- vs vitamin K antagonist-related nontraumatic intracerebral hemorrhage

OBJECTIVE: To compare the neuroimaging profile and clinical outcomes among patients with intracerebral hemorrhage (ICH) related to use of vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF). METHODS: We evaluated consecutive patients with NVAF with nontraumatic, anticoagulant-related ICH admitted at 13 tertiary stroke care centers over a 12-month period. We also performed a systematic review and meta-analysis of eligible observational studies reporting baseline characteristics and outcomes among patients with VKA- or DOAC-related ICH. RESULTS: We prospectively evaluated 161 patients with anticoagulation-related ICH (mean age 75.6 ± 9.8 years, 57.8% men, median admission NIH Stroke Scale [NIHSSadm] score 13 points, interquartile range 6-21). DOAC-related (n = 47) and VKA-related (n = 114) ICH did not differ in demographics, vascular risk factors, HAS-BLED and CHA2DS2-VASc scores, and antiplatelet pretreatment except for a higher prevalence of chronic kidney disease in VKA-related ICH. Patients with DOAC-related ICH had lower median NIHSSadm scores (8 [3-14] vs 15 [7-25] points, p = 0.003), median baseline hematoma volume (12.8 [4-40] vs 24.3 [11-58.8] cm3, p = 0.007), and median ICH score (1 [0-2] vs 2 [1-3] points, p = 0.049). Severe ICH (\u3e2 points) was less prevalent in DOAC-related ICH (17.0% vs 36.8%, p = 0.013). In multivariable analyses, DOAC-related ICH was independently associated with lower baseline hematoma volume (p = 0.006), lower NIHSSadm scores (p = 0.022), and lower likelihood of severe ICH (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.13-0.87, p = 0.025). In meta-analysis of eligible studies, DOAC-related ICH was associated with lower baseline hematoma volumes on admission CT (standardized mean difference = -0.57, 95% CI -1.02 to -0.12, p = 0.010) and lower in-hospital mortality rates (OR = 0.44, 95% CI 0.21-0.91, p = 0.030). CONCLUSIONS: DOAC-related ICH is associated with smaller baseline hematoma volume and lesser neurologic deficit at hospital admission compared to VKA-related ICH

Predictors and clinical significance of progression or regression of asymptomatic carotid stenosis

OBJECTIVE: To determine baseline clinical and ultrasonographic plaque factors predictive of progression or regression of asymptomatic carotid stenosis and the predictive value of changes in stenosis severity on risk of first ipsilateral cerebral or retinal ischemic events (including stroke). METHODS: A total of 1121 patients with asymptomatic carotid stenosis of 50% to 99% in relation to the bulb diameter (European Carotid Surgery Trial [ECST] method) underwent six monthly clinical assessments and carotid duplexes for up to 8 years (mean follow-up, 4 years). Progression or regression was considered present if there was a change of at least one grade higher or lower, respectively, persisting for at least two consecutive examinations. RESULTS: Regression occurred in 43 (3.8%), no change in 856 (76.4%), and progression in 222 (19.8%) patients. Younger age, high grades of stenosis, absence of discrete white areas in the plaque, and taking lipid lowering therapy were independent baseline predictors of increased incidence of regression. High serum creatinine, male gender, not taking lipid lowering therapy, low grades of stenosis, and increased plaque area were independent baseline predictors of progression. One hundred and thirty first ipsilateral cerebral or retinal ischemic events, including 59 strokes, occurred. Forty (67.8%) of the strokes occurred in patients whose stenosis was unchanged, 19 (32.2%) in those with progression, and zero in those with regression. For the entire cohort, the 8-year cumulative ipsilateral cerebral ischemic stroke rate was zero in patients with regression, 9% if the stenosis was unchanged, and 16% if there was progression (average annual stroke rates of 0%, 1.1%, and 2.0%, respectively; log-rank, P = .05; relative risk in patients with progression, 1.92; 95% confidence interval, 1.14-3.25). For patients with baseline stenosis 70% to 99% in relation to the distal internal carotid (North American Symptomatic Carotid Endarterectomy Trial [NASCET] method), in the absence of progression (n = 349), the 8-year cumulative ipsilateral cerebral ischemic stroke rate was 12%. In the presence of progression (n = 77), it was 21% (average annual stroke rates of 1.5% and 2.6%, respectively; log-rank, P = .34). Only nine (30%) of the 30 strokes occurred in the progression group. CONCLUSIONS: Progressive asymptomatic carotid stenosis identified a subgroup with about twice the risk of ipsilateral stroke compared with those without progression. However, the clinical value of screening for progression simply for selecting patients for carotid procedures is limited because of the low frequency of progression and its relatively low associated stroke rate. The cost effectiveness of screening for change in stenosis severity to better direct current optimal medical treatment needs testing