LAUSR

As sleep disordered breathing(SDB)-related pathophysiology of intermittent hypoxia, autonomic dysfunction and intrathoracic pressure alterations, etc. likely exerts differential influences across World Symposium on Pulmonary Hypertension(WSPH) groups that have yet to be characterized , we postulate differing SDB-pulmonary hemodynamics relationships across these groups. Pulmonary Vascular Disease Phenomics(PVDOMICS-NCT02980887), a multicenter cohort study, included patients with mean pulmonary artery pressure(mPAP) on right heart catheterization(RHC) ≥ 25mmHg and home sleep apnea testing(HSAT) within 6 weeks of RHC. SDB measures included apnea-hypopnea index(AHI, 3% desaturation hypopnea definition used) and % recording time< 90% SpO2(TRT< 90%). Pulmonary hemodynamic indices included:mPAP, mean pulmonary capillary wedge pressure(PCWP), right atrial mean pressure(RAP). Linear regression models(beta coefficients±standard error) were constructed to assess sleep indices and RHC measurements with adjustment for age, sex, race, body-mass index(BMI), PH medication and supplemental oxygen use; PH group interaction was analyzed. We included 424 participants with available data in the final analytic sample. Groups 2 and 3 were older(65.6±11.9, 64.2±10.8 years, respectively) and Group 5 had the highest % males(71.4%). Group 2 had highest BMI: 34.3±9.2kg/m2 and Group 5 lowest: 28.7±6.4k g/m2. SDB(AHI≥5), was most prevalent in Group 2(71.4%) and least in Group 4(42.9%). TRT< 90% was highest in Group 1(37.0%, [P25=2.2, P75=87.3]) followed by Group 4(35.7% [5.3,82.9]) and lowest in Group 2(6.4% [0.61,41.8]). AHI and RAP association differed across groups, p=0.027 and was strongest in Group 2; per 5-unit increase in AHI, RAP increased by 0.75mmHg (estimate=0.75, standard error[0.15,1.36],p=0.015). TRT< 90% and mPAP had significant cross-group differences, p=0.004. TRT< 90% was associated with mPAP in Groups 1 and 4:per 5-unit increase in TRT< 90%, mPAP increased by 2mmHg(2.10,[1.52,2.68],p< 0.001) and 1.4mmHg(1.40,[0.07,2.73],p=0.039) respectively. Other associations were not significant. SDB prevalence differs across WSPH groups and was highest in Group 2 PH. Findings suggest that AHI and TRT< 90%SaO2 differentially contribute to the pathogenesis in PH groups; with AHI associating with RAP, especially in Group 2 PH, and TRT< 90%SaO2 with mPAP in Groups 1 and 4 PH, perhaps via hypoxia-induced pulmonary vasoconstriction and remodeling. Funding: U01 HL125218, U01 HL125205, U01 HL125212, U01 HL125208, U01 HL125175, U01 HL125215, and U01 HL125177 and the Pulmonary Hypertension Association.