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Purpose: Diagnosing carotid near-occlusion (CNO) with colour duplex ultrasound (CDU) is challenging. We hypothesised that CNO is associated with a reduced distal internal carotid artery (ICA) velocity and aimed to assess if distal velocity is able to diagnose CNO accurately. If not, we aimed to develop CDU rule-out and rule-in criteria to diagnose CNO.

Methods: This is a prospective cross-sectional study in consecutive participants with suspected ≥ 50% carotid stenosis on CT angiography (CTA). CDU velocities in the common carotid artery, the stenosis and distal to the stenosis were examined. CTAs were assessed for CNO, serving as a reference test. If no CDU parameter was both sensitive and specific for CNO, rule-out (98% sensitive) and rule-in (99% specific) criteria were created.

Results: Of the 315 included participants with ≥ 50% stenosis, 190 (60%) were conventional ≥ 50% stenosis and 125 (40%) CNO. No CDU parameter was both sensitive and specific for CNO. The best exclusion criteria were stenosis end diastolic velocity (EDV) ≤ 63 cm/s and/or distal peak systolic velocity (PSV) > 23 cm/s, seen in 115 (38%) participants. The best rule-in criteria were stenosis EDV ≥ 280 cm/s and/or distal PSV ≤ 23 cm/s, seen in 35 (12%) participants. Of the remaining participants, 143 (47%) were uncertain (74 CNOs) and 9 (3%) were misdiagnosed as carotid occlusion (all CNOs).

Conclusions: CDU alone cannot diagnose CNO but can rule in or rule out CNO in half of participants with ≥ 50% stenosis. These criteria are intended for inclusion in an algorithm, sorting cases needing further exams, such as CTA and/or phase-contrast magnetic resonance angiography.

Objectives: Reduced progression of atherosclerosis can decrease the risk of cardiovascular disease (CVD). This study aimed at evaluating the effect of a pictorial intervention showing atherosclerotic severity on the progression of carotid atherosclerosis.

Methods: A prospective randomised open-label blinded end-point trial with participants aged 40–60 years enroled from a routine CVD prevention programme. The intervention group (n: 1575) and their treating physicians received an image based presentation of subclinical atherosclerotic severity measured by carotid ultrasound. The control group (n: 1579) did not receive any information about ultrasound results. Carotid ultrasound at baseline and at 3-year follow-up contained plaque detection and measurements of carotid intima media thickness (cIMT). The left, right and bilateral-mean-cIMT, plaque prevalence and total plaque area (TPA) at 3-year follow-up were compared between groups. Significance level was set to p = 0.01 to adjust for multiple comparisons.

Results: The intervention group revealed reduced cIMT progression in the left-mean-cIMT of −0.011 mm (p = 0.001) compared with the control group. The intervention effect on cIMT progression was most prominent in individuals with increased cIMT and plaque prevalence at baseline (−0.021 mm, p = 0.005). There were no differences in progression between groups for the right-and bilateral-mean-cIMT (−0.005 mm, p = 0.223 and −0.005 mm, p = 0.036, respectively), nor any differences between groups for plaque prevalence or TPA (odds ratio 0.88, p = 0.09 and 0.89, p = 0.21, respectively).

Conclusion: Pictorial presentation of subclinical atherosclerotic severity sent to both the individual and their treating physician resulted in significantly reduced left cIMT progression. Pictorial presentation has the potential to increase adherence in CVD prevention.

Background: Assessment of pulmonary vascular resistance (PVR) is critical for accurate diagnosis and optimal pharmacotherapy in pulmonary hypertension. We aimed to test the diagnostic performance of a novel, Doppler-based method to evaluate PVR based on Ohm’s law (PVR_echo) using pragmatic estimates of pulmonary capillary wedge pressure (PCWP).

Methods and results: Simultaneous right heart catheterization (RHC) and echocardiography was performed in a derivation cohort of 111 patients in sinus rhythm referred for PH evaluation and PVR_echo independently validated in 238 patients. PVR_echo was calculated using pulmonary artery mean pressure estimates (PAMP_echo) obtained from peak tricuspid gradient employing a fixed right atrial pressure estimate, PCWP_echo was estimated as 10 or 20 mmHg using age-related mitral E/A cut-offs and cardiac output from left ventricular outflow. In the derivation cohort, both PAMP_echo and PCWP_echo estimates demonstrated excellent agreement with catheterization measurements. PVR_echo was highly feasible, demonstrated negligible bias and excellent agreement with PVR_RHC (Bias = −0.58, SD 2.2 mmHg) and outperformed the Abbas method to identify PVR_RHC > 3WU (AUC = 0.85 vs. 0.70; p = 0.02). In the validation cohort, PVR_echo preserved good invasive agreement with negligible bias, displayed strong diagnostic performance (AUC = 0.84) and significant ability to distinguish isolated post-capillary from combined post- and pre-capillary pulmonary hypertension (PH) subgroups (AUC = 0.77).

Conclusion: PVR_echo based on Ohm’s law employing pragmatic estimates of PCWP_echo demonstrates excellent agreement with invasive reference standard measurements and strong diagnostic ability to identify elevated PVR_RHC. This novel approach may be useful during therapy selection to distinguish PH hemodynamic subgroups.

Purpose: To assess the sensitivity and specificity of common carotid ultrasound method for carotid near-occlusion diagnosis.

Methods: Five hundred forty-eight patients examined with both ultrasound and CTA within 30 days of each other were analyzed. CTA graded by near-occlusion experts was used as reference standard. Low flow velocity, unusual findings, and commonly used flow velocity parameters were analyzed.

Results: One hundred three near-occlusions, 272 conventional ≥50% stenosis, 162 <50% stenosis, and 11 occlusions were included. Carotid ultrasound was 22% (95%CI 14–30%; 23/103) sensitive and 99% (95%CI 99–100%; 442/445) specific for near-occlusion diagnosis. Near-occlusions overlooked on ultrasound were found misdiagnosed as occlusions (n = 13, 13%), conventional ≥50% stenosis (n = 65, 63%) and < 50% stenosis (n = 2, 2%). No velocity parameter or combination of parameters could identify the 65 near-occlusions mistaken for conventional ≥50% stenoses with >75% sensitivity and specificity.

Conclusion: Near-occlusion is difficult to diagnose with commonly used carotid ultrasound methods. Improved carotid ultrasound methods are needed if ultrasound is to retain its position as sole preoperative modality.

Aims: Health literacy, the degree to which individuals understand and act upon health information, may have a pivotal role in the prevention of cardiovascular disease (CVD), with low health literacy potentially explaining poorer adherence to prevention guidelines. We investigated the associations between health literacy, ultrasound-detected carotid atherosclerosis and cardiovascular risk factors.

Methods: Baseline data (cross-sectional analysis) from a randomized controlled trial, integrated within the Västerbotten Intervention Program, Northern Sweden, was used. We included 3459 individuals, aged 40 or 50 years with ≥1 conventional risk factor or aged 60 years old. The participants underwent clinical examination, blood sampling, carotid ultrasound assessment of intima-media wall thickness (CIMT) and plaque formation, and answered a questionnaire on health literacy – the Brief Health Literacy Screen. The European Systematic Coronary Risk Evaluation and Framingham Risk Score were calculated.

Results: About 20% of the participants had low health literacy. Low health literacy was independently associated with the presence of ultrasound-detected carotid artery plaques after adjustment for age and education, odds ratio (95% confidence interval) 1.54 (1.28–1.85), demonstrating a similar level of risk as for smoking. Health literacy was associated with CIMT in men. Low health literacy was associated with higher CVD risk scores. Sensitivity analyses with low health literacy set to 9% or 30% of the study sample, respectively, yielded essentially the same results.

Conclusions: Low health literacy was independently associated with carotid artery plaques and a high level of CVD risk scores. Presenting health information in a fashion that is understood by all patients may improve preventive efforts.

Aims: To determine the inter-sonographer reproducibility of carotid ultrasound plaque detection using Mannheim consensus in a subclinical population and evaluate associations related to the reproducibility.

Methods and results: Bilateral ultrasound screening for carotid plaques defined by Mannheim consensus was performed on 106 subclinical participants. Two different sonographers scanned the same participant, and reproducibility of plaque detection was measured by Cohens kappa. Associations with reproducibility were evaluated by comparing wall, and plaque characteristics between subjects with plaques identified in one and both scans. In general, the inter-sonographer reproducibility of plaque detection was substantial with a kappa value of 0 center dot 70 (95% CI 0 center dot 60-0 center dot 80). Plaques detected in only one scan had significantly lower plaque area and plaque thickness (6 center dot 82 mm(2) and 1 center dot 45 mm) as compared to plaques detected in both scans (11 center dot 65 mm(2) and 1 center dot 96 mm, P<0 center dot 001).

Conclusion: Minor carotid plaques contribute to decreased reproducibility as compared to large plaques when screening for subclinical atherosclerosis using Mannheim consensus. Using an alternative plaque definition based on plaque thickness >1.5 mm and plaque area >10 mm(2) could increase the reproducibility of plaque detection in subclinical atherosclerosis.

BACKGROUND: Primary prevention of cardiovascular disease often fails because of poor adherence among practitioners and individuals to prevention guidelines. We aimed to investigate whether ultrasound-based pictorial information about subclinical carotid atherosclerosis, targeting both primary care physicians and individuals, improves prevention.

METHODS: Visualization of asymptomatic atherosclerotic disease for optimum cardiovascular prevention (VIPVIZA) is a pragmatic, open-label, randomised controlled trial that was integrated within the Västerbotten Intervention Programme, an ongoing population-based cardiovascular disease prevention programme in northern Sweden. Individuals aged 40, 50, or 60 years with one or more conventional risk factors were eligible to participate. Participants underwent clinical examination, blood sampling, and ultrasound assessment of carotid intima media wall thickness and plaque formation. Participants were randomly assigned 1:1 with a computer-generated randomisation list to an intervention group (pictorial representation of carotid ultrasound plus a nurse phone call to confirm understanding) or a control group (not informed). The primary outcomes, Framingham risk score (FRS) and European systematic coronary risk evaluation (SCORE), were assessed after 1 year among participants who were followed up. This study is registered with ClinicalTrials.gov, number NCT01849575.

FINDINGS: 3532 individuals were enrolled between April 29, 2013, and June 7, 2016, of which 1783 were randomly assigned to the control group and 1749 were assigned to the intervention group. 3175 participants completed the 1-year follow-up. At the 1-year follow-up, FRS and SCORE differed significantly between groups (FRS 1·07 [95% CI 0·11 to 2·03, p=0·0017] and SCORE 0·16 [0·02 to 0·30, p=0·0010]). FRS decreased from baseline to the 1-year follow-up in the intervention group and increased in the control group (-0·58 [95% CI -0·86 to -0·30] vs 0·35 [0·08 to 0·63]). SCORE increased in both groups (0·13 [95% CI 0·09 to 0·18] vs 0·27 [0·23 to 0·30]).

INTERPRETATION: This study provides evidence of the contributory role of pictorial presentation of silent atherosclerosis for prevention of cardiovascular disease. It supports further development of methods to reduce the major problem of low adherence to medication and lifestyle modification.

Background: Atherosclerotic cardiovascular disease (CVD) is a common cause for mortality globally, and is expected to remain the single leading cause of death as the global population ages and as life expectancy increases.

Cardiovascular screening models have been developed, and continue to be developed, to identify individuals at high-risk of CVD.  This is necessary to establish prevention strategies to decrease the occurrence of an acute event or debilitating syndrome. These strategies largely take the form of lifestyle modification and pharmacological intervention. The Framingham risk score, NCEP/ATP II guidelines and SCORE risk assessment protocol are widely used screening models. Ultrasound based methods are non-invasive, affordable and have been suggested to improve assessment and definition of individual patients potential risk of CVD. Increased carotid artery intima-media thickness (cIMT) is a known and established sign of early atherosclerosis. The presence of plaque and the overall burden of atherosclerosis seems to have even greater value in predicting cerebrovascular and cardiovascular events. Ultrasound based texture characteristics of plaques such as entropy, grey scale median, discrete white area, coarseness and juxtaluminal hypoechoic black area have been proposed as useful possible predictors of plaque vulnerability. Moreover, ultrasound contrast agents have been developed to improve visualization and subsequent quantification of an atherosclerotic plaque. Considering the current available data and research, the importance of developing tools and techniques for detection and characterization of atherosclerotic changes, to indicate risk for CVD and the subsequent early intervention and prevention, appears clearly as an effort to improve public health. In this present collection of studies (4 papers) we aim to contribute to the development of clinically useful ultrasound methods and tools for the accurate assessment, understanding and management of atherosclerosis.

Methods: To validate ultrasound-based methods for assessment of early signs of atherosclerosis, measured as cIMT, a total of 144 subjects underwent bilateral carotid ultrasound. In study I, the performance of an ultrasonography software capable of fully automated on-screen cIMT measurements was tested and compared with the traditional manual measurement approach. The coefficient of variation and the intraclass correlation coefficient for both methods were compared to verify the reliability and reproducibility of results generated by the new ultrasound software. To test the accessibility and possible clinical applications of this new technology tested in study I, the new software was used by novice’s scanners in study II, and the intraobserver variability of the cIMT measurements were assessed and compared with that of an expert operator. In study III, ultrasound texture characteristics of 327 plaques including entropy, grey scale median, discrete white area, coarseness and juxtaluminal hypoechoic black area were assessed as possible predictors of future cerebrovascular events in a cohort of 133 patients with symptomatic carotid stenosis waiting for carotid surgery. The reproducibility of measuring plaque area (expressed as intraclass correlation coefficient) using conventional ultrasound and contrast enhanced ultrasound was tested in study IV in an attempt to find a simple and reproducible parameter for monitoring changes in atherosclerotic burden.

Results: The technology tested in study I was found to have good inter- and intra-system reproducibility compared with conventional methods. Moreover, it was found to produce reproducible results when used by expert and novice operators after a short period of training (study II), confirming the possibility for the employment of this technology in a large screening public health programs. Although such technology may have immediate practical application, other and more sophisticated ultrasound based plaque characteristics (such as grey scale median, entropy, coarseness, juxtaluminal hypoechoic black area) were not shown to be beneficial in predicting plaque vulnerability (study III). Contrast enhanced ultrasound technic tested in study IV did not improve quantification of atherosclerotic plaque burden. 

Conclusion: Medical ultrasound technology by using a automatically measure of carotid intima media thickness can be used with high reproducibility and also possible to be transferred to primary care by a well designed training program.  Plaque characteristic using carotid ultrasound was not found to be useful in risk stratifying symptomatic patients with severe carotid stenosis. Furthermore, contrast enhanced ultrasound technique was found to have high reproducibility in plaque area assessment but not better than conventional b-mode based method in quantifying the atherosclerotic burden. Therefore, more sophisticated ultrasound based methods for assessment plaque characteristics was not found to be beneficial in predicting plaque vulnerability.

Objectives: Carotid plaque characteristic analysis are suggested to improve risk stratification. Plaque area and echolucent plaques have shown to correlate with increased risk for cardiovascular diseases. A limitation with B-mode imaging is the uncertainty that the whole plaque area is identified, primarily on echolucent plaques. Contrast-enhanced ultrasound (CEUS) is used to improve carotid imaging including better plaque area measurement. Aim: Evaluate if CEUS could improve accurate plaque area measurement compared with B-mode and Doppler color flow imaging. Methods: The study included 28 participants (50% females, mean age 58 years) with identified asymptomatic carotid plaques. We performed B-mode, Doppler color and CEUS ultrasound imaging whereas the plaque area was manually outdrawn by a single operator. Plaques were also subjectively classified as 1 echogenic, 2 echolucent, or 3 mixed plaques. Results: We did not find a significant difference in plaque area measurements between different ultrasound image modalities having all plaque types included. In the group of echolucent plaques (n= 11) we found a significant different between B-mode and CEUS (p=0.049) and also between B-mode and Doppler color imaging (p=0.039) (Illustrated in Fig 1). Conclusions: Echolucent plaque can be underestimated with B-mode imaging. Use of contrast-enhanced ultrasound should be considered in carotid plaque imaging on echolucent plaques when plaque outline is difficult to identify.