Pulmonary artery diameter did not differ significantly between patients with a Pulmonary Artery Pulsatility Index <2.3 (34.25 mm) and ≥2.3 (34.34 mm; p=0.970).
Observational (n=78)
No
Does pulmonary artery diameter correlate with Pulmonary Artery Pulsatility Index (PAPi) decline in adults undergoing right heart catheterization?
In this interim analysis, pulmonary artery diameter measured by CT did not significantly differ between patients with PAPi < 2.3 and ≥ 2.3, suggesting PA size alone may not reflect early right ventricular hemodynamic decline.
Absolute Event Rate: 34.25% vs 34.34%
p-value: p=0.970
Abstract Rationale The Pulmonary Artery Pulsatility Index (PAPi) is an established hemodynamic marker of right ventricular (RV) performance and is associated with outcomes in advanced heart failure and critical illness. However, PAPi measurement requires invasive right heart catheterization. Identifying imaging-based markers that parallel PAPi decline could allow for earlier, noninvasive identification of patients at risk for RV failure and mortality. Pulmonary artery (PA) enlargement has been linked to elevated pulmonary pressures, yet its correlation with PAPi and its potential threshold for hemodynamic compromise remain unclear. This study aims to determine whether increasing PA diameter correlates with a decline in PAPi and whether a specific anatomic cutoff can stratify risk for adverse outcomes. Methods In this single-center retrospective study, 292 adults who underwent both chest CT and right heart catheterization between 2015 and 2025 were identified. Of these, 78 patients have been analyzed to date. The main PA diameter (PAdiam, mm) was measured at the level of bifurcation. PAPi was calculated as (PA systolic - PA diastolic) ÷ right atrial pressure and categorized as 2.3 or ≥ 2.3, a threshold previously associated with RV failure. Between-group comparisons were performed using independent t-tests, and percentile distributions were evaluated for potential inflection points. Ongoing analyses will assess lower PAPi cutoffs (1.7-2.0) reported in the literature to identify potential anatomical correlates of worsening RV hemodynamics. Results Among the 78 analyzed patients (n = 8 with PAPi 2.3, n = 70 with PAPi ≥2.3; 2 missing), mean PA diameter was 34.25 ± 7.63 mm in the low-PAPi group and 34.34 ± 6.49 mm in the higher-PAPi group (p = 0.970). Median diameters (31.5 mm vs. 34 mm) and interquartile ranges (30-37 mm) were similar. No statistically significant difference in PA diameter was observed across the 2.3 threshold. However, exploratory modeling suggests that lower PAPi thresholds may demonstrate increased separation, supporting continued analysis to identify potential PA diameter inflection points linked to clinical outcomes. Conclusions In this interim analysis, pulmonary artery diameter did not differ significantly between patients above and below a PAPi of 2.3, indicating that PA size alone may not reflect early hemodynamic decline. Ongoing work will expand the cohort and incorporate lower PAPi thresholds to evaluate whether larger PA diameters predict reduced RV performance and, ultimately, mortality. If validated, PA diameter could serve as a simple, widely available imaging biomarker to identify high-risk patients before invasive testing is pursued—bridging the gap between anatomic imaging and physiologic risk assessment. This abstract is funded by: None
Srivastava et al. (Fri,) conducted a observational in Patients undergoing chest CT and right heart catheterization (n=78). Pulmonary artery diameter measurement vs. PAPi < 2.3 vs ≥ 2.3 was evaluated on Mean pulmonary artery diameter (p=0.970). Pulmonary artery diameter did not differ significantly between patients with a Pulmonary Artery Pulsatility Index <2.3 (34.25 mm) and ≥2.3 (34.34 mm; p=0.970).