Background Pulmonary arterial hypertension (PAH) may occur in 20% of patients with systemic sclerosis (SS) which has a poor prognosis with survival approaching 50% at 2 years following diagnosis (1). Early diagnosis of PAH may enable prompt pharmacological intervention, retard disease progression and improve long term outcomes(2). It is recognised that proactive screening for SS-PAH with lung function testing and echocardiography (ECHO) is superior to investigations after PAH symptoms are established. In the UK, screening is based on the ESC/ESR guidelines, which includes annual ECHO and lung function testing. Although not widely utilised, screening with the DETECT protocol(3), an evidence based 2 step algorithm which includes serum urate, N-terminal pro-brain natriuretic peptide (BNP) and lung function testing may assist with earlier identification of patients with SS-PAH.
Objectives To evaluate the utility of the DETECT protocol in identifying SS associated PAH in a secondary care connective tissue disease service.
Methods A retrospective review of 74 patients with Systemic Sclerosis (Limited, Diffuse and Mixed CTD) attending a secondary care connective tissue disease clinic in Northwest London. All patients were analysed for general demographics, autoantibody profiles and parameters required for a DETECT 1 and DETECT 2 score within a 12 month period. Each score was correlated with diagnosis of PAH made at the regional PAH centre.
Results 90% (68) of patients were female, mean age 56 years (range 27–85). Limited Systemic Sclerosis (LSSc) accounted for 53% of patients (Diffuse 24%, Mixed CTD 23%) and 43% (32) of all patients were anti-centromere positive (RNP- 24%, Scl-70 20%, PM-Scl 9%). DETECT 1&2 parameters were available for 26–100% of variables (Table 1). A full set of parameters to calculate DETECT 1 was achievable in 32/74 (43%) patients. 21/32 patients had a detect score >300 recommending ECHO with LSSc accounting for a majority of this group (LSSc 14, Diffuse 4, Mixed CTD 3). DETECT 2 parameters were complete in 15/21 patients. 7 of these patients had a score >35 recommending right heart catheterisation (RHC). 1 patient had RHC and a diagnosis of PAH was made in 3 patients (3/32) consistent with respective DETECT scores. Conversely, 7 patients with a DETECT 1 score<300 had echocardiography, against protocol recommendations.
Conclusions This small study indicates that the DETECT screening protocol for SS-PAH may be effective in secondary care connective tissue disease services enabling earlier diagnosis and a more prudent approach to using ECHO and rationalising tertiary service referrals. Limitations of this screening tool include the timely collection of clinical parameters required for calculation of DETECT scores, as was evident in our attrition rate.
Hemodynamics and survival in patients with pulmonary artery hypertension related to systemic sclerosis. Kawut SM, et al. Chest (2003) 123:344–350.
Screening for pulmonary arterial hypertension in patients with systemic sclerosis: Clinical characteristics at diagnosis and long-term survival. Humbert M, et al. Arthritis & Rheumatism (2011)63:3522–3530
Evidence-based detection of pulmonary arterial hypertension in systemic sclerosis: the DETECT study. Coghlan JG et al. Ann Rheum Dis (2014)73:1340–1349
Disclosure of Interest None declared