A28-20 High-Output Heart Failure in Systemic Sclerosis: Clinical Characteristics and Hemodynamic Outcomes

Rationale Systemic sclerosis (SSc) is a multisystem autoimmune disease commonly complicated by cardiopulmonary disease. While cardiomyopathy related to pulmonary hypertension (PH) occurs frequently, high output (HO) physiology can also occur but is less well-described. We sought to identify SSc patients with HO states to better characterize the clinical features and outcomes of these patients. Methods We conducted a retrospective study of SSc patients at the Johns Hopkins Scleroderma Center who underwent right heart catheterization (RHC) between 2003-2025. PH and hemodynamic classification followed guideline recommendations. HO state was defined as cardiac index ≥3.9 L/min/m². Clinical and hemodynamic data were extracted. Survival was assessed from the index RHC. RHC was repeated in a subset of patients (n = 18) Results Out of 722 SSc patients who underwent RHC, we identified 44 (6%) SSc patients with HO states. The majority of these patients were middle aged (age 57.2±14.6 years), white (68.2%), female (72.7%), and had limited SSc (54.5%) with borderline BMI (25.3±6.4 kg/m²) . Laboratory studies showed mean TSH (3.1±3.5 mIU/L) and hemoglobin (11.5±1.6 g/dL). Most had WHO class 2 (31.8%) or 3 (34.1%) symptoms, reduced exercise capacity (mean 6MWD 266 ±191m), mild restrictive lung disease and moderate diffusion impairment (mean % predicted FVC 76.2 ± 19.2%, % predicted DLCO 59.3 ± 26.7%,). RHC demonstrated 8 patients (18.2%) without PH, 21 (47.7%) with precapillary PH, 1 (2.3%) with combined pre-post capillary PH, and 2 (4.5%) with isolated post-capillary PH, and 12 (27.3%) with unclassifiable hemodynamics. (Table 1) The majority of patients (33, 75.0%) had no identifiable predisposing conditions for HO physiology. Over an average follow-up of 5.2 years, 29 (65.9%) died, most commonly patients with precapillary PH (58.6% of deaths). Repeat RHC in a subset of patients revealed substantial changes in hemodynamics, with the majority of patients progressing from non-PH or borderline/unclassified states to precapillary PH accompanied by declining cardiac index. Conclusions A small but significant proportion of SSc patients have HO physiology. These patients have significant symptoms, reduced functional capacity, and abnormal lung function. Most have precapillary pulmonary hypertension and do not have an identifiable risk factor for HO states. Overall survival was poor. Serial RHC demonstrated rapid progression to precapillary pulmonary hypertension physiology in a subset of patients. These observations suggest HO states in SSc may be associated with poor outcomes despite less severe hemodynamic perturbations. Further characterization, including identification of predisposing factors and pathophysiologic mechanisms, is needed to inform appropriate treatment. This abstract is funded by: None