A longitudinal study of ankle brachial pressure indices in a cohort of patients with systemic sclerosis.

Objectives: Digital ischaemia, often progressing beyond RP to digital ulceration and sometimes even gangrene, is the most common vascular manifestation of SSc. Both microvascular and macrovascular disease can contribute and coexistence of microvascular and macrovascular (proximal vessel) disease in patients with SSc is potentially limb threatening. The aims of this study were to examine the change over time in the ankle brachial pressure index (ABPI) in a cohort of patients with SSc and to examine whether age, gender, smoking status, disease duration, disease subtype and ACA are associated with ABPI.

Methods: The clinical and laboratory data of 217 patients attending the SSc clinic at a tertiary referral centre and who had their ABPIs checked between 1996 and 2011 were reviewed retrospectively. Data were analysed to see how the ABPI changed with time and linear mixed effects modelling was used to determine which factors were associated with ABPI.

Results: In most patients with SSc, the ABPI remained constant over time [median rate of change 0 units/year, interquartile range (IQR) -0.01-0.01]. There was a significant association between lower ABPI and increasing age (P = 0.04), the limited cutaneous subtype of SSc (P = 0.01) and ACA positivity (P = 0.03). Additionally there was an association between ABPI and smoking status of borderline statistical significance (P = 0.08).

Conclusion: This study provides further evidence for associations between the severity of vascular disease in patients with SSc and increasing age, smoking, limited cutaneous disease and positive ACA. Reassuringly, in most patients ABPI remains stable over time.