Clinical, Functional, and Hemodynamic Profile of Schistosomiasis-Associated Pulmonary Arterial Hypertension Patients in Brazil: Systematic Review and Meta-Analysis.

Background: Schistosoma-associated pulmonary arterial hypertension (Sch-PAH), a complication of hepatosplenic schistosomiasis, is still underdiagnosed and undertreated. Sch-PAH is the third-most common cause of pulmonary arterial hypertension (PAH) in Brazil, and it is estimated that there are around 60,000 afflicted individuals. However, there is a lack of data on these patients, especially in endemic areas. Therefore, this study aimed to describe baseline demographic data, hemodynamic severity of disease, and functional impairment of Sch-PAH patients at diagnosis.

Methods: For this systematic review, five databases (Embase, PubMed, SciELO, LILACS, and Cochrane) were searched to identify candidate publications reporting clinical, hemodynamic, and functional data at diagnosis of Sch-PAH patients referred to a PAH reference center in Brazil. Studies were excluded if they enrolled patients under the age of 18, the diagnosis was not confirmed by right heart catheterization (RHC), consisted of case reports, or did not report original data. Risk of bias was assessed using the Newcastle-Ottawa Scale and an adapted version for cross-sectional studies. Single-arm meta-analysis with a random-effect model was performed for each variable.

Results: From 459 studies identified through systematic database searching, five studies were selected for this meta-analysis. The majority of the included patients were women (67%), New York Heart Association (NYHA) functional class III/IV (57%), mean age 49 years (95% confidence interval [95% CI], 46-52), 6 min walk distance 392 m (95% CI, 291-493), mean pulmonary arterial pressure (mPAP) 59 mmHg (95% CI, 56-61), pulmonary vascular resistance (PVR) 12 WU (95% CI, 11-13) and cardiac index (CI) 2.57 L/min/m² (95% CI, 2.25-2.88).

Conclusions: In summary, Sch-PAH has clinical characteristics similar to other forms of PAH, including connective tissue disease and idiopathic PAH. Additional studies or a unified registry would be essential for a better understanding of this relevant disease in Brazil.