AB0652 Prevalence of Interstitial lung disease and pulmonary arterial hypertension in systemic sclerosis patients cohort at a rheumatology referral centre in the United Arab Emirates

Abstract

Background: Scleroderma, also known as Systemic Sclerosis (SSc), is a connective tissue disease that affects multiple organ systems, including the cardiovascular and respiratory systems, namely, pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) as the leading causes of death in this patient population. Objectives: The purpose of this study is to determine the prevalence of PAH and ILD in a cohort of patients diagnosed with SSc. Methods: We performed a retrospective chart review of clinical characteristics of all patients diagnosed with SSc Cleveland Clinic Abu Dhabi between April 2015 and April 2020. PAH was estimated by echocardiographic fndings and diagnosed based on right heart catheterization (RHC) using 2019 World Symposium on Pulmonary Hypertension. The CT scan of the chest was read by a board-certifed radiologist in chest radiology. Results: Fifty individuals were diagnosed with SSc, with 46% having diffuse cutaneous systemic sclerosis and 54% having limited cutaneous systemic sclerosis. The majority of the patients (88%) were female, with a mean age of 41 ±13 years. The average period from presentation to diagnosis was 5 ±5.4 years. The majority of the cohort (86%) were from the United Arab Emirates. The average BMI was 26.0 kg/m2. Patients' most prevalent symptoms are fatigue (80%), gastrointestinal symptoms (72%) followed by shortness of breath (58%) and cough (50%). Twenty-six out of fifty patients (52%) underwent a CT chest scan, with 19 (38%) having ILD. Eight patients had more than 30% fibrotic alterations, four patients had 10-30% fibrotic changes, and seven patients had less than 10% fibrotic abnormalities. Patients with more than 10% fibrotic changes were more likely to have usual interstitial pneumonia, whereas those with less than 10% fibrotic changes were more likely to have none specific fibrosis. The majority of patients (92%) had echocardiogram. All except one patient had a normal ejection fraction, and five had grade 1 left ventricular diastolic dysfunction. Five patients were described as having mild, 1 moderate and 2 severe PAH. Only 4 patients underwent RHC. One patient had group II PAH based on elevated wedge pressure. One had group 1 PAH with systemic sclerosis as the only cause for her PAH and two patients had group III PAH due to having more than 30 % pulmonary fibrosis and severe restrictive defect on spirometry. Therefore, the precapillary PA H prevalence was 6% (3/50). Conclusion: While the prevalence of pulmonary fbrosis in our SSc patients refects what has been reported in the literature, the prevalence of PAH is sig-nifcantly lower than the reported 15-20%.1 This is likely due to underdiagno-sis of PAH considering the number of years of systemic sclerosis diagnosis on presentation to our clinic. A systematic approach is needed to assess for the presence and severity of PAH using tools as in Detect algorithm which has been validated and commonly used in Europe and North America to screen for PAH.2 Validation of such algorithm is likely needed in middle eastern population before it is universally adopted.