Prognostic role of comorbidities in patients with pulmonary arterial hypertension

Abstract

Abstract Background Epidemiology of pulmonary arterial hypertension (PAH) is changing and the age at diagnosis and the prevalence of comorbidities are increasing but their prognostic relevance is substantially undefined. Purpose To evaluate the prognostic value of comorbidities in patients with PAH and in the different clinical subgroups. Methods All patients with PAH referred to a single centre underwent baseline right heart catheterization, brain natriuretic peptide (BNP) plasma levels, 6-min walking distance (6MWD), WHO functional class and anamnestic comorbidities evaluation. Cox regression model was used for analysis (p-value <0.1 was considered for inclusion in multivariate analysis). Results 1311 patients were included [age 51 years; aetiology: 522 idiopathic/heritable/drug-induced (I/H/D)-PAH, 258 connective tissue disease (CTD)-associated PAH, 242 congenital heart disease (CHD)-associated PAH, 196 portal hypertension/HIV (PoHIV)-associated PAH and 93 pulmonary veno-occlusive disease (PVOD)]. 5% of patients have no comorbidities. At multivariate analysis comorbidities independently associated with prognosis are: systemic hypertension in I/H/D [HR 0.616, p=0.030], mean systemic blood pressure in CTD [HR 0.980, p=0.002] and PVOD [HR 0.962, p=0.006], dyslipidemia in CTD [HR 0.447, p=0.001] and PoHIV [HR 0.201, p=0.026], estimated glomerular filtration rate in PoHIV [HR 1.000, p<0.001] and body mass index (BMI) [HR 0.966, p=0.069] in CTD. In CHD comorbidities are not independent determinants of prognosis. Other variables independently predictive of a worse prognosis are: advanced age in all PAH subgroups except PVOD; male gender in I/H/D; reduced 6MWD in I/H/D, CTD and PVOD; high BNP in I/H/D, CHD and PVOD; low cardiac index in CTD, high right atrial pressure in I/H/D and low mixed venous oxygen saturation in CHD. Conclusion The age at PAH diagnosis and the prevalence of comorbidities are increasing but their prognostic role seems of poor relevance as we found a protective role of these variables: high systemic blood pressure (maybe indicative of a better haemodynamic stability) in I/H/D, CTD and PVOD; dyslipidemia and high BMI (maybe indicative of a better nutritional status and a less severe autoimmune disease) in CTD; dyslipidemia and a high glomerular filtration rate (both indicative of a less severe liver disease) in PoHIV. Funding Acknowledgement Type of funding source: None