Further work is required before the technique is recommended as part of universal patient care.
There is still much to be done before vascular ultrasound is used in the diagnosis and management of polymyalgia rheumatica, say the authors of a recent commentary in The Lancet Rheumatology.
The co-occurrence of polymyalgia rheumatica and giant cell arteritis is common. Despite the two conditions having different pathophysiological mechanisms, it has been suggested that vascular ultrasound – which has been shown to be cost effective and more sensitive than a temporal artery biopsy in diagnosing GCA in high-risk patients – could be used in the diagnosis of PMR, where no recommendations or guidelines for vascular screening exist.
But a recent viewpoint article outlines numerous key considerations that need to be addressed before vascular ultrasound in PMR becomes routine practice.
The first consideration is whether vascular ultrasounds are necessary and offer any meaningful benefit to patients.
“An alternative consideration in interpreting population data is that people with PMR who later develop anterior ischaemic optic neuropathy in the absence of clinical symptoms of GCA could be reclassified as having GCA,” wrote Dr Max Yates, Dr Charlotte Davies, and Professor Alexander MacGregor, from the University of East Anglia in the UK.
“We have found no evidence to support this [proposition].”
How accurately a vascular ultrasound can detect PMR is another point of contention.
“Ultrasound diagnosis of GCA depends on vascular morphology including arterial wall echogenicity, intima-media thickness and compressibility and established cutoff values for developing an outcome assessment tool for clinical trials,” the trio wrote.
Although EULAR recommendations include proposed diagnostic thresholds for large vessel vasculitis, Yates et al. highlight that the recommendations themselves acknowledge that the thresholds require further validation, “particularly in older patients and patients with severe arteriosclerosis, which is common in PMR”.
“Without validated thresholds, there is a risk of misdiagnosis or overdiagnosis of large vessel vasculitis in PMR, potentially increasing anxiety for patients, particularly in cases of ambiguous findings,” the viewpoint authors noted.
Related
Finally, evidence for the cost-effectiveness of routine ultrasound screening in subclinical GCA in patients with PMR is lacking, according to Professor Yates and his colleagues.
“Screening for diseases with low prevalence typically increases cost per patient and diverts resources from other areas within the healthcare system,” they note.
“Expanding diagnostic capacity to accommodate routine screening would require substantial investment, including additional workforce training, expansion of diagnostic facilities and a potential increase in wait times for other services.
“These costs would also extend to secondary care consultant appointments and any necessary follow-up care, which are currently not part of clinical practice.”
