Introduction Diagnosing connective tissue-related pulmonary hypertension (PH) poses challenges for clinicians due to overlapping PH phenotypes, which complicate treatment. We present a case of mixed pre- and post-capillary pulmonary hypertension in a patient with systemic sclerosis (Ssc).

Case Presentation 49-year-old woman, initially diagnosed with mixed connective tissue disease 15 years ago, was treated with methotrexate, prednisolone, and hydroxychloroquine. Despite treatment, her symptoms, including cough and shortness of breath, progressively worsened. Earlier this year, her diagnosis was revised to systemic sclerosis, as her clinical features aligned more with this condition. She was started on mycophenolate mofetil (MMF) and prednisolone. A high-resolution CT confirmed interstitial lung disease (ILD), and she was commenced on nintedanib. Despite treatment, her symptoms persisted, leading to a cardiology referral for suspected pulmonary hypertension (PH). ECG showed p-pulmonale and right heart strain pattern, and echocardiography revealed dilated right heart and pressure overload with TR Vmax of 3.87ms. Right heart catheterization confirmed mixed pre- and post-capillary pulmonary hypertension, with mPAP of 53 mmHg, PVR 9.33WU and PCWP of 25 mmHg. She was started on bosentan and tadalafil, with gradual dose titration. At follow-up, she showed marked improvement in her 6-minute walk test and overall symptoms.

Discussion Systemic sclerosis is difficult to diagnose due to its varied manifestations which explains the delayed diagnosis in our patient. Pulmonary hypertension is a common and serious complication of systemic sclerosis, presenting in various phenotypes due to the disease's heterogeneity. Our patient exhibited mixed pre- and post-capillary PH, with myocardial fibrosis likely contributing to the post-capillary component. Studies show that SSc patients with PH due to left-ventricular diastolic dysfunction (Group 2) have double the risk of death compared to those with SSc-PAH (Group 1). This elevated risk is partly because current PH treatments mainly target PAH rather than other PH forms. Given the mixed phenotype in our patient, she was treated with an endothelin receptor antagonist and a phosphodiesterase-5 inhibitor, leading to significant improvement.

Conclusion Early diagnosis of the primary disease and precise phenotyping of pulmonary hypertension are critical in managing connective tissue disease-related PH, ensuring the most effective therapeutic strategy is adopted.