Reevaluating risk assessment in connective tissue disease-associated pulmonary arterial hypertension: The prognostic superiority of stroke volume index.

Objective: To evaluate the prognostic value of stroke volume index (SVI) compared to cardiac index (CI) in risk stratification and outcome prediction in connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH).

Methods: We performed a retrospective analysis of patients diagnosed with CTD-PAH through right heart catheterization (RHC) from two Chinese medical centers. This retrospective study analyzed 206 CTD-PAH patients, with risk stratification performed using the 2018 World Symposia on Pulmonary Hypertension (WSPH) framework. Restricted cubic splines (RCS) and log-rank tests were utilized to identify the optimal SVI cutof values for categorizing patients into low-, intermediate-, and high-risk groups. Kaplan-Meier (KM) curves were used to analyze survival rates and event-free survival. Receiver operating characteristic (ROC) analysis was used to assess the predictive accuracy of diferent models for prognostic outcomes.

Results: SVI was categorized into low-risk (SVI ≥ 33.35 mL/m²), intermediate-risk (24.66 mL/m²≤ SVI < 33.35 mL/m²), and high-risk (SVI < 24.66 mL/m²) groups. Among the 206 CTD-PAH patients, 55 exhibited discrepancies in risk stratification between CI and SVI. SVI-based stratification provided more accurate risk categorization and demonstrated superior predictive value compared to CI, showing significant diferences in both survival and event-free survival rates across the groups.

Conclusion: SVI enhances risk stratification and prognosis prediction in CTD-PAH by efectively distinguishing patients at higher risk for adverse outcomes.