Hand-held and high-end vascular ultrasound devices show good agreement for carotid disease detection

25th February 2022

Hand-held carotid ultrasound has been demonstrated to have good agreement with conventional duplex ultrasound in ruling out carotid disease

A hand-held carotid ultrasound device shows an acceptable level of agreement with conventional duplex ultrasound for the examination of patients with suspected transitory ischaemic attack (TIA) or ischaemic stroke. This was the conclusion by a team of researchers from the Department of Internal Medicine, Levanger Hospital, Norway.

According to the World Stroke Organisation, 1 in 4 adults over the age of 25 will have a stroke in their lifetime and in 2019, there were 12·2 million incident cases of strokes, accounting for 11.6% of all global deaths.

Moreover, the presence of narrowing of the carotid artery or carotid stenosis, has been found to be associated with increased risk of ischaemic stroke. Carotid endarterectomy as a treatment, has been found to be of some benefit for patients with 50% to 69% symptomatic stenosis, in reducing the risk of stroke.

However, carotid stenosis cannot be adequately assessed through a physical examination and carotid ultrasonography has become a reproducible imaging method used to detect carotid atherosclerosis.

But could a hand-held carotid and hence much more portable, ultrasound device be just as reliable for the examination of patients with suspected TIA or an ischaemic stroke compared to a conventional high-end vascular ultrasound (HIGH)? This was the essential question addressed in the current study by the Norwegian team.

They included patients admitted to a community hospital with a suspected stroke or transient ischaemic attack. The patients were examined using a hand-held carotid ultrasound and the severity of carotid stenosis graded on a 7-point ordinal scale from 1 (normal) to 7 (occluded). Following this initial assessment, a HIGH was performed by a second cardiologist who remained unaware of the findings from the hand-held device and graded the degree of stenosis using the same scale.

The results of the two scans were then compared by weighted Cohen’s Kappa and which is designed to assess the level of agreement between the two techniques. Scores range from 0 to 1 with 0.41 – 0.60 rated as moderate agreement, 0.61 – 0.80 as substantial and over 0.81 as almost perfect agreement.

Hand-held carotid ultrasound agreement with HIGH

A total of 80 patients with a mean age of 71.5 years (47.5% women) were included in the study, 27.5% of whom, had a previous history of cardiovascular ischaemic events (i.e., ischaemic stroke, TIA, or myocardial infarction). From the total cohort, 11% were found to have a greater than 50% internal carotid stenosis (ICS) on examination. Overall, 77.5% of patients were discharged with a diagnosis of ischaemic stroke or TIA.

The overall agreement between the hand-held device and HIGH for the classification of the degree of internal carotid stenosis was 69%. In addition, the weighted Kappa agreement between the hand-held device and HIGH was 0.76 (95% CI 0.66 – 0.85). Nevertheless, there was evidence that the hand-held device overestimated ICS compared to HIGH when there was >50% occlusion (odds ratio for agreement = 0.15, 95% CI 0.06 – 0.42) using < 50% stenosis as the reference.

In discussing their results, the authors stated that there was a strong correlation between ICS grading between the hand-held carotid device and HIGH. They concluded that examining the level of carotid stenosis with a hand-held device was a reliable method for ruling out significant carotid artery disease.

But given the potential for overestimation when the carotid stenosis was greater than 50%, the authors suggested that the hand-device device should not be used for detailed classification of carotid disease.

Citation
Saxhaug LM et al. Reliability and agreement of point-of-care carotid artery examinations by experts using hand-held ultrasound devices in patients with ischaemic stroke or transitory ischaemic attack Open Heart 2022

Stroke risk after TIA higher in ED patients without follow-up compared with rapid-access TIA clinics

10th January 2022

The stroke risk after a TIA has been found to be higher among patients treated at an ED compared to those seen at a dedicated TIA clinic

The subsequent stroke risk among those who experience a transient ischaemic attack (TIA) is higher in patients seen at an emergency department compared to those seen at a rapid-access TIA clinic according to a meta-analysis by a team from the Neurology Department, Neuroscience Institute, Geisinger Health System, Pennsylvania, US.

After a TIA, the ischaemic stroke risk can range from 2.4% within 2 days to 4.7% within 90 days although the authors of this study hint that this risk may have reduced in the last two decades. Although patients with a suspected stroke might normally visit a hospital, the availability of 24-hour TIA clinics with immediate initiation of preventive treatment, have the potential to greatly reduce length of hospital stay.

Despite the presence of TIA clinics there is currently little is known about the outcomes for those experiencing a TIA who have been treated in different care settings. For the present study, the US team performed a meta-analysis to estimate and compare the risk of a subsequent ischaemic stroke in those with a TIA or minor ischaemic stroke (mIS) who received their care at either a rapid access TIA clinic, an inpatient unit, emergency departments (EDs) or other settings.

The researchers focused on the subsequent stroke risk after 4 defined time periods; 2, 7, 30 and 90 days. Their literature search covered medline, Embase, CINAHL and clinical trial databases for studies that provided information on the occurrence of an ischaemic stroke after a TIA or mIS and included both retrospective and prospective studies.

The primary outcome of the study was the proportion of early ischaemic strokes after the index TIA or mIS among patients receiving care in the four different settings and they focused their comparison on a TIA clinic vs inpatient facilities.

Findings

A total of 71 studies were included in the final analysis with 226,683 patients, 5636 from a TIA clinic, 130,136 inpatients, 3605 emergency department patient and 87,303 from a unspecified centre. The mean age of patients ranged from 65.7 to 78.3 years and proportion of male patients from 38.4% to 52.4%.

The stroke risk after a TIA or mIS at a TIA clinic was 0.3% within 2 days, 1% within 7 days, 1.3% after 30 days and 2.1% after 90 days. The highest risk was for patients treated at unspecified settings and which ranged from 2.2 % within 2 days to 6% within 90 days.

When comparing the stroke risk between a TIA clinic or inpatient facility, there was no significant difference in any of the 4 time intervals. However, the risks were significantly higher among those receiving emergency department care compared to a TIA clinic within 2, 7 and 90 days.

The authors concluded that the risk of subsequent stroke among patients who were evaluated in a TIA clinic was not higher than among those hospitalised adding that patients treated in an emergency department without further follow-up had a higher risk of subsequent stroke.

Citation

Shahjouei S et al. Risk of Subsequent Stroke Among Patients Receiving Outpatient vs Inpatient Care for Transient Ischemic Attack: A Systematic Review and Meta-analysis JAMA Netw Open 2022