Clinical characteristics and outcomes of Group 3 and Group 4 Pulmonary Hypertension

Introduction: Pulmonary hypertension (PH) is associated with increased mortality, and lung diseases are the second most common cause of PH. Transthoracic echocardiogram (TTE) is often employed for PH diagnosis in low-to-middle income countries. Methods: A retrospective chart review of adult patients hospitalized from June 2012 to May 2021. Patients with pulmonary artery systolic pressure (PASP) ≥ 35 mmHg on TTE were included in the study. Patients with group 1 PH, group 2, or group 5 PH were excluded. Results: 128 patients were included, with females being 69.5%. Group 3 PH consisted of 79.7% and Group 4 PH consisted of 20.3%. Obesity hypoventilation syndrome / obstructive sleep apnea (OHS/OSA) consisted of 31.3% of the population and was the most common etiology of PH. The overall 1-year mortality after diagnosis of PH was 20.3%, with bronchiectasis having the highest group-specific 1-year mortality of 45.5%. 1-year hospital readmission was seen in 46.9% of patients. The difference in mortality rates between the groups was statistically significant ( x 2 = 18.1, P=0.004). The mean PASP was 59.2 ± 16.5 mmHg. On multivariate analysis, patients who did not have 1-year hospital readmission or were treated with diuretics, had decreased odds of 1-year mortality. Conclusion: Clinical outcomes of patients with group 3 PH vary based on causative etiology. Patients with bronchiectasis had the highest 1-year mortality and 1-year readmission rate. Currently, TTE based diagnosis for PH is a reality in LMIC.