Influencing factors and prognostic value of pulmonary arterial hypertension in chronic kidney disease patients

Objective To explore the influencing factors of pulmonary arterial hypertension(PAH) in CKD stage 3-5 non-dialysis patients and observe the prognostic influence of PAH. Methods From January 1, 2014 to January 1, 2017, a total of 283 patients with CKD stage 3-5 were admitted and followed up. They were divided into two groups of PAH and non-PAH. Follow-up endpoints included all-cause mortality and progression to renal replacement therapy(RRT). Kaplan-Meier survival curve was utilized for comparing the differences in overall and renal survivals in each group. Cox proportional risk regression model was employed for analyzing the risk factors affecting poor prognosis. Results There were 166 males(58. 66%) and 117 females(41. 34%) with an average age of(46. 06±14. 18) years. Compared with non-PAH group, age, blood pressure and C-reactive protein(CRP) level were all higher in PAH group(all P<0. 05). The levels of hemoglobin(Hb), hematocrit(HCT), estimate glomerular filtration rate(eGFR), bicarbonate and cholesterol were all lower than those in PAH group(all P<0. 05). Multivariate binary Logistic regression analysis indicated that systolic blood pressure(SBP) (OR=1. 032, 95%CI 1. 007-1. 056, P=0. 007), hemocrit(HCT) (OR=0. 812, 95%CI 0. 739-0. 892, P<0. 001) and bicarbonate(OR=0. 856, 95%CI 0. 781-0. 938, P<0. 001) were influential factors for PAH in non-dialysis CKD patients. Kaplan-Meier survival analysis revealed that survival rate was significantly lower in PAH group than that in non-PAH group(Log-rank, χ²=13. 184, P<0. 001). And renal survival rate was also significantly lower than that of non-PAH group(Log-rank, χ²=21. 948, P<0. 001). Multivariate Cox regression model analysis showed that the risk of all-cause mortality was 2. 228 folds higher in PAH group than that in PAH group(HR=2. 228, 95%CI 1. 088-4. 564, P=0. 029). And the risk of progression to RRT was 1. 692 folds higher than that in PAH group(HR=1. 692, 95%CI 1. 064-2. 728, P=0. 031). Conclusion Hypertension, low HCT and low bicarbonate level are risk factors for PAH development in CKD stage3-5. And PAH is a risk factor for all-cause mortality and progression to RRT in non-dialysis CKD patients.