Systemic sclerosis (SSc) is a multisystem connective tissue disease characterized by vasculopathy and fibrosis. Pulmonary arterial hypertension (PAH) is one of the most severe organ complications and a leading cause of death in SSc. Estimations are that patients with SSc that have associated PAH have a 3-year survival of just 50%. Since early identification has been found to improve the outcome, researchers have been working on pinpointing the optimal care management for patients with SSc.
The most-used pulmonary hypertension screening guidelines are from the European Society of Cardiology / Respiratory Society (ESC/ERS), and are based on symptoms and transthoracic echocardiography (TTE). However, recent evidence shows that there are some limitations on the current guidelines, as well as questions concerning the cost-effectiveness of TTE-based screening. Current limitations of screening algorithms emphasize the need for alternative approaches to improve the selection of patients for referral for right heart catheterization (RHC), the ‘gold standard’ test for the diagnosis of PAH. In response to this, new screening algorithms include pulmonary function tests (PFT) and biomarkers such as N-terminal pro-B type natriuretic peptide (NT-proBNP).
In 2012, the Australian Scleroderma Interest Group (ASIG) developed a screening algorithm (DETECT) for SSc-PAH utilizing serum NT-proBNP level and PFT that was found to have similar sensitivity and higher specificity, positive (PPV) and negative predictive value (NPV) compared to the ESC/ERS guidelines. DETECT reached a sensitivity of screening for SSc-PAH from 71% to 96%, compared to the ESC/ERS guidelines.
Mandana Nikpour from the Department of Rheumatology, St Vincent’s Hospital Melbourne in Australia and colleagues, compared the predictive accuracy of the screening algorithms (DETECT and ASIG) for SSc-associated PAH (SSc-PAH) with the commonly used European Society of Cardiology/Respiratory Society (ESC/ERS) guidelines. The researchers applied the three screening methods in 73 patients with a SSc diagnosis with suspected PAH that were undergoing right heart catheterization (RHC). The analysis included determinators of sensitivity, specificity, positive (PPV) and negative predictive values (NPV) for PAH. A subsequent analysis was performed with PAH prevalence set at 10%.
After assessment with RHC, 36.9% of SSc patients were found to have PAH. The DETECT and ASIG algorithms had an equal performance, achieving a sensitivity and NPV of 100%, while the ESC/ERS guidelines had sensitivity of 96.3% and NPV of only 91%. In terms of specificity, the results revealed that the ASIG achieve that best results of 54.5%.
Based on these results, the researchers concluded that DETECT and ASIG algorithms outperform the ESC/ERS guidelines, indicating that the ESC/ERS guidelines have limitations in the absence of a TR jet. However, as the researchers point out, clinicians should consider guidelines for SSc-PAH screening algorithms based on the cost-effectiveness of the approach.
The study, entitled “A comparison of the predictive accuracy of three screening models for pulmonary arterial hypertension in systemic sclerosis” was recently published in the journal Arthritis Research & Therapy.