Background Atherosclerosis and a higher risk of developing premature cardiovascular disease are well known in chronic inflammatory rheumatic diseases. Ultrasound (US) measurement of the carotid intima-media thickness (cIMT) is a non-invasive outcome measure of premature sub-clinical atherosclerosis with a predictive value in terms of vascular events. Recently, an automated method based on radiofrequency (RF-QIMT)to assess cIMThas been developed.
Objectives To determine the prevalence of increased cIMT, as sign of pre-clinical atherosclerosis, in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA) using an automated RF-QIMT. The secondary aim was to determine the intra and inter-observer reliability of the new software in the assessment of cIMT.
Methods One hundred and eight patients (68 with RA and 40 with PsA) were enrolled by the different centers involved in the study. Before the US cIMT assessment, all patients underwent a clinical examination aimed to record disease duration, HAQ, DAS28, DAPSA/DAREA, smoking, use of coffee, ischemic cardiopathy or peripheral arteriopathy, previous myocardial infarction or cerebrovascular events and familiar history for them, comorbidities, waist circumference, and systemic blood pressure, current therapy. Moreover, ESR, CRP, total cholesterol, HDL, triglycerides, serum glucose, creatinine, uricemia, RF and cyclic citrullinated peptide were recorded.
US examinations of the cIMT were performed bilaterally by 4 independent rheumatologist in 4 European centres, using a My Lab 70 XVG (Esaote SpA – Genoa- Italy) equipped by a linear probe (frequency, 4-13 MHz) and an automatic RF-QIMT. This provides in real-time a measure which is the average of six mean values obtained during six consecutive cardiac cycles. All the investigators tested their inter- and intra-observer reproducibility in the assessment of the cIMT using the RF-QIM in 7 patients with RA. Moreover, the agreement between the automatic RF-QIM and conventional method (performed by a cardiologist expert in vascular US) was previously investigated. For the IMT, the definition of Mannheim cIMT Consensus was adopted.
Results A total of 216 common carotids were assessed. In 45 (66%) out of the 68 patients with RA and 26 (67%) out of the 39 patients with PsA, US detected an increased cIMT. The multiple regression analysis found a significant correlation between increased cIMTand both disease duration (p=0.0127) and age (p=0.0001). No significant correlation was found with the other clinical and laboratory parameters. Moreover no difference was found between RA and PsA.
Inter-observer ICC values for the RF-QIM were in a range from 0.77 (95% CI: 0.55-0.91) to 0.85 (95% CI: 0.69-0.94)whereas for the intra-observer was 0.61 (95% CI 0.46-0.71). The ICC agreement between both methods was above 0.6 for all the participants.
Conclusions The automated RF-QIMT technique of measurement of cIMT demonstrated to be a reliable and useful alternative to conventional method to assess the cardiovascular risk. Our results show that patients with RA and PsA without clinically evident cardiovascular disease have a high prevalence of increased cIMT.
Disclosure of Interest None Declared