Morbidity and Mortality Associated With Pulmonary Arterial Hypertension in a Schistosomiasis‐Endemic Region of Brazil

Data about pulmonary arterial hypertension (PAH) patients living in low‐ and middle‐income countries remain scarce. This study assessed prognostic factors associated with time to clinical worsening (CW) or death of a cohort of PAH patients in Minas Gerais, Brazil. This retrospective cohort study describes baseline clinical variables by PAH etiology and estimates time from diagnosis to CW [all‐cause death, any‐cause hospitalization, or disease progression (decrease of ≥ 15% in 6MWD and need for additional PAH therapy or worsening of functional class (FC)] and time to death. 79 out of 102 participants developed CW and 38 died while under follow‐up. The most prevalent etiologies were PAH associated with schistosomiasis (PAH‐Sch), idiopathic (IPAH), with congenital heart disease (PAH‐CHD), and with connective tissue disease (PAH‐CTD). The overall median event‐free time to CW was 3.3 (95% CI, 2.3–4.6) years, which was similar across etiologies (log‐rank test: p = 0.12). WHO FC III‐IV, DLCO < 70%, heart rate recovery in 1 min after the 6‐min walk test (HRR1) < 18 beats/minute, and baseline mPAP ≥ 50 mmHg were predictive of CW‐free time. The median time to all‐cause mortality was 10.2 (95% CI, 6.8 – > 10) years and varied among etiologies (log‐rank test: p < 0.001). Time to CW was statistically independent of PAH etiology but depended on baseline WHO FC, DLCO, HRR, and mPAP. After CW events, PAH‐Sch and PAH‐CTD survived less on average than IPAH and PAH‐CHD participants.