The effect of calcium channel blockers on digital ulcers in systemic sclerosis: data from a prospective cohort study

Digital ulcers (DU) are a common, severe vascular manifestation of systemic sclerosis (SSc) with few effective treatment options. Using data from the Australian Scleroderma Cohort Study (ASCS), we sought to evaluate the effect of calcium channel blockers (CCB) on the treatment and prevention of DU. Using data from 1953 participants, with a median of 4.34 years of follow-up, we used generalised estimating equations to evaluate the clinical characteristics associated with CCB use and ascertain the risk factors for the presence of DU at subsequent study visits. A time-dependent Cox-proportional hazard model was applied to evaluate the risk of future occurrence of DU with CCB use. Sixty-six percent of participants received CCB and patients with a history of DU were more likely to be prescribed a CCB (76.76% vs 53.70%, p < 0.01). CCB use was more frequent in patients with severe complications of DU including chronic DU (OR 1.47, p = 0.02), need for hospitalisation for iloprost (OR 1.30, p = 0.01) or antibiotics (OR 1.36, p = 0.04) and digital amputation (OR 1.48, p < 0.01). Use of CCB was more likely in patients who experienced DU at subsequent study visits (OR 1.32, p < 0.01) and was not associated with a decreased risk of the development of a first DU (HR 0.94, p = 0.65). CCB are frequently used in the management of SSc in the ASCS and their use is associated with severe peripheral vascular manifestations of SSc. However, our results suggest that CCB may not be effective in the healing or prevention of DU.