Cost-efficiency of imaging strategies for detecting subclinical atherosclerosis in psoriatic arthritis.

backgroundPatients with psoriatic arthritis (PsA) face increased cardiovascular (CV) risk, but conventional calculators such as SCORE tend to underestimate it. Imaging of subclinical atherosclerosis may help refine risk stratification. However, the relative cost-efficiency of available modalities has not been systematically compared.

objectivesTo evaluate the diagnostic yield and cost-efficiency of femoral ultrasound, carotid ultrasound, and abdominal X-ray in detecting subclinical atherosclerosis among PsA patients.

methodsA cross-sectional PsA cohort (N = 146) fulfilling CASPAR criteria was studied. Ultrasound of femoral and carotid arteries and abdominal X-ray imaging were performed. Unit costs were estimated from typical European healthcare tariffs: ultrasound €50-150; abdominal X-ray €20-50. Cost per detected case was calculated as = unit cost × NNS (number needed to screen to detect a case). A threshold condition was derived to establish when X-ray becomes more cost-efficient than vascular ultrasound: Cost (Rx) < 0.4985 × Cost (US).

resultsFemoral ultrasound yielded the best diagnostic performance (NNS 1.62; cost per case €81-243). Carotid ultrasound was less efficient (NNS 2.98; €149-447). Abdominal X-ray, despite lower plaque prevalence (30.8%), was the most cost-efficient option (€65-162.5 per case), as long as its price remained < 50% of the ultrasound cost.

conclusionsFemoral artery ultrasound provides the highest diagnostic yield for subclinical atherosclerosis in PsA, while abdominal X-ray may represent a pragmatic, low-cost alternative for detecting calcified lesions. Carotid ultrasound appears less efficient. These findings highlight the need to balance diagnostic yield, cost, and clinical objectives in CV risk management for PsA. Key points • Femoral ultrasound provided the highest diagnostic yield for detecting subclinical atherosclerosis in PsA patients. • Carotid ultrasound was less efficient, identifying plaques with higher cost and lower sensitivity than femoral scans. • Abdominal X-ray was the most cost-efficient option when priced below half the ultrasound cost. • Imaging strategy in PsA should balance diagnostic yield, economic factors, and healthcare resource availability.