Mortality and prognostic factors in connective tissue disease-associated pulmonary arterial hypertension patients complicated with right heart failure

Objective: To identify predictive factors associated with mortality in connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) patients who were complicated with right heart failure (RHF).Methods: In this single-center retrospective study, baseline demographics, clinical features, laboratory results, and hemodynamic assessments were collected. Kaplan-Meier analysis was applied to analyze all-cause mortality. Univariate and forward stepwise multivariate Cox proportional regression analyses were performed to identify independent predictors of mortality.Results: A total of 51 right heart catheterization-confirmed CTD-PAH patients complicated with RHF were consecutively enrolled in this study from 2012 to 2022. Forty-eight (94%) enrolled patients were female and the mean age was 36.0 +/- 11.8 years. Thirty-two (61.5%) were systemic lupus erythematosus-PAH and 33%/67% showed World Health Organization functional class III/IV, respectively. Twenty-five (49%) of those patients died and Kaplan-Meier analysis showed the overall 1-, 3-, and 5-week survival rates from the time of hospitalization as 86.28%, 60.78%, and 56.86%, respectively. RHF in CTD-PAH patients mainly resulted from progression of PAH (n = 19) and infection (n = 5), which also contributed to the leading causes of death. Statistical analysis between survivors and non-survivors showed that death from RHF was associated with higher levels of urea (9.66 vs 6.34 mmol/L, P = 0.002), lactate (cLac: 2.65 vs 1.9 mmol/L, P = 0.006), total bilirubin (23.1 vs 16.9 mu mol/L, P = 0.018) and direct bilirubin (10.5 vs 6.5 mu mol/L, P = 0.004), but with lower levels of hematocrit (33.7 vs 39, P = 0.004), cNa+ (131 vs 136 mmol/L, P = 0.003). Univariate and forward stepwise multivariate Cox proportional regression analyses indicated that the level of cLac (hazards ratio:1.297; 95% CI: 1.076-1.564; P = 0.006) was an independent risk factor for mortality.Conclusion: The short-term prognosis of CTD-PAH complicated with RHF was very poor, and hyperlactic acidemia (cLac > 2.85 mmoL/L) was an independent predicting factor for mortality of CTD-PAH patients complicated with RHF.