Background/Purpose: We investigated predictors of outcome, including mortality and cardiopulmonary hospitalizations in the Òat riskÓ group for pulmonary hypertension in PHAROS, a prospective longitudinal cohort study to understand the natural history of pulmonary hypertension (PH) in systemic sclerosis (SSc). 

Methods: The Òat riskÓ population for PH was defined by the following entry criteria: echocardiogram (echo) systolic pulmonary arterial pressure (sPAP) >40mmHg, or diffusion lung capacity of carbon monoxide (DLco) <55% predicted or ratio of % forced vital capacity (FVC) /%DLco >1.6 measured by pulmonary function testing (PFT) (1), were followed annually between 2005 and 2015. The population was stratified into 2 groups: those who developed PH, confirmed by right heart catheterization (RHC), and those who remained Òat riskÓ.  Associations of baseline predictors with all-cause mortality and cardio-pulmonary hospitalizations were assessed using Kaplan Meier plots and Cox proportional hazards models adjusted for age, gender, race and disease duration.

Results: In total, 266 Òat riskÓ SSc patients were followed for a median of 4 years (range 0.4-8.5 years). The median overall survival was 84.6% at 5 years and nearly 80% at 8.5 years.  Thirty four patients Òat riskÓ developed PH and 232 remained Òat riskÓ.  Though median survival was similar in both groups, 45% deaths in the Òat riskÓ group were due to cardio-pulmonary complications versus 70% in the PH group.  In the Òat riskÓ group (Table 1), lower risk of mortality was significantly associated with female sex, higher %DLCO, and no exercise oxygen desaturation, whereas higher mortality risk was significantly associated with anemia, higher UCSD scores, and presence of pericardial effusion. Moreover, higher UCSD scores and presence of pericardial effusion were associated with elevated risk of cardiopulmonary hospitalizations. Stratified analysis showed that PH patients with DLCO<50% had higher risk of cardiopulmonary hospitalizations as compared to other groups (figure 1). No other significant differences were observed in the associations of predictors with cardiopulmonary hospitalization risk comparing PH and Òat-riskÓ groups.Ó .

Conclusion:  This is one of the largest prospective study of SSc patients Òat riskÓ for PH. Though survival was better than those with incident PH (2, 3), male sex, low %DLCO, exercise oxygen desaturation and pericardial effusion, were similarly associated with worse outcomes.

Table 1: Predictors of overall mortality and cardiopulmonary hospitalizations in the Òat-riskÓ group,       N=232

* Adjusted for age, gender, race (white versus non-white) and disease duration from Raynaud and non-Raynaud symptoms.  **  HRs per 10% increase *** HRs per 40% increase Figure 1: