Life line screening versus Dr McCartney: who is right?

Life line report that Dr. McCartney mentions that she believes that carotid artery screening is only worthwhile once the person has already had a stroke. The current evidence certainly backs up this position: we have known for many years that carotid screening is not recommended.

For example: ‘In the December 18 issue of the Annals of Internal Medicine, the US Preventive Services Task Force (USPSTF) released updated guidelines on the advisability of screening for stenosis (blockage) in the carotid arteries (the main arteries, located in the neck, that supply blood to the brain). In patients who have risk factors but no symptoms suggestive of carotid artery disease, the USPSTF concludes that screening for carotid artery stenosis is not recommended.’

The reference pointed to by life line is for a study of outcomes after elective repair of infra-renal abdominal aortic aneurysm.  I fail to understand how that result can be then associated with carotid artery screening. The last time I checked, the carotid is in the neck, whilst the aorta is in the abdomen.

In terms of the current evidence-base a recent systematic review, published in the European Journal of Endovascular Surgery, reports there is Limited economic evidence of carotid artery stenosis diagnosis and treatment.

Of note, the highest quality evidence, an individual patient data analysis published in the Lancet this year concludes: ‘The association between carotid intimedia (cIMT) thickness progression assessed from two ultrasound scans and cardiovascular risk in the general population remains unproven. No conclusion can be derived for the use of cIMT.

Finally, evidence from a recent meta-analysis reports intervention with carotid endarterectomy is helpful for recently symptomatic patients with carotid artery stenosis ≥50% (NASCET technique) but adds no benefit in terms of stroke/death for asymptomatic patients.

Therefore the overwhelming body of evidence tells us this intervention is not beneficial in asymptomatic patients.

Questions that life line screening should answer include how many patients are harmed by such  screening and what would you expect a GP to do when you refer such a patient onto primary care. I, like Dr McCartney am a GP, and would inform the patient that this type of screening is not helpful and often creates unwanted anxiety.

At some point the additional NHS costs will be passed back to those undertaking the tests in the first place.

If you want the answer and want to know who is right, its simple, stick to the evidence.


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