Systematic screening of pulmonary hypertension in individuals with connective tissue disease

Abstract

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder mainly presented with extensive inflammation and tissue damage throughout the involved organs. Patients with SLE have the possibility of developing pulmonary hypertension (PH), and further progress to right ventricular hypertrophy and cardiac dysfunction. The European Respiratory Society (ERS) was not recommended screening PH in individuals with SLE each year due to relatively few cases of SLE-associated PH being involved. However, SLE is more prevalent in China and other Asia countries than in western countries. Due to the limited studies coming from Asian SLE cohorts, the generalizability of disease characteristics in patients with SLE in Asia still needs further investigation. The objectives of this study were to screen for PH in individuals with SLE in Hong Kong and to establish a risk stratifying strategy to discern the patients who are at the greatest hazard of PH.

In chapter 3, I explored the major disease characteristics and cardiopulmonary performance in 1054 patients with SLE. Chronic kidney disease (54.8%) is the most common comorbidity in our study. 264 (25.0%) patients had leukopenia, and 124 patients (11.8 %) had thrombocytopenia. In addition, 342 (32.4%) patients have positive anti-RNP antibodies. ST-T changes (15.0%) were the greatest prevalent abnormalities of electrocardiogram (ECG) in individuals with SLE. Obstructive lung disorder indicated by pulmonary lung function was more prevalent than restrictive patterns in SLE patients.

In chapter 4, I screened PH based on the possibility of PH by echocardiography derived from the European Society of Cardiology (ESC) /ERS guidelines. 147 patients with the intermediate- or high possibility of PH demonstrated a notable dissimilarity in clinical characteristics, laboratory data, ECG features, and pulmonary function compared to patients with a low possibility of PH.

In chapter 5, a simplified risk assessment strategy that depended on ESC/ERS guidelines was established to distinguish who has the greatest hazard of evolving PH and to ascertain the potential independent predictors for PH in individuals with SLE. 26 out of 49 patients who had an intermediate- or high risk of PH were received right heart catheterization. 11 patients were identified with mean pulmonary artery pressure (mPAP) >25 mmHg, and 6 patients with mPAP ranging at 21~24 mmHg. Multivariate analysis was performed in four kinds of modes, indicating anti-RNP (OR=10.5, CI: 1.9, 56.5) and right axis deviation (RAD, OR=21.9, CI: 5.2, 92.2) in mode 1, right ventricular hypertrophy (RVH, OR=10.4, CI: 1.9, 56.3) in mode 2, RAD (OR=10.3, CI: 2.0, 50.7) and forced expiratory flow at 50% of forced vital capacity (FEF50%, OR=1.0, CI: 0.90, 0.97) in mode 3, and RVH (OR=56.8, CI: 6.9, 467.5) and FEF50% (OR=1.0, CI: 0.90, 0.97) in mode 4 were verified as the independent predictors of PH for patients with SLE.

In chapter 6, I compared the difference in clinical features, and the cardiopulmonary performance among patients with SLE who are at the specific ages of onset (childhood-onset, young adulthood onset, and adulthood onset). Lastly, I explored the clinical and demographic findings and cardiopulmonary function in patients with scleroderma.