D28-09 Invasive Hemodynamic Phenotyping Reveals Diagnostic Discordance of Pulmonary Hypertension in Takayasu Arteritis

Background

Takayasu arteritis (TA) is a rare large-vessel vasculitis that can involve pulmonary arteries, potentially leading to pulmonary hypertension (PH). Noninvasive evaluation by echocardiography is often used, but its reliability in confirming and characterizing PH in TA is unclear. We investigated the role of invasive hemodynamic testing in TA patients with suspected PH.

Methods

We retrospectively identified 10 patients with TA meeting 2022 ACR criteria and suspected PH based on symptoms and/or echocardiography; all underwent echocardiography followed by right heart catheterization (RHC).PH was defined as mean pulmonary artery pressure (mPAP) >20 mmHg. PH was classified as pre-capillary (pulmonary artery wedge pressure [PAWP] ≤15 mmHg), post-capillary (PAWP >15 mmHg), or combined (PAWP >15 mmHg with elevated pulmonary vascular resistance). Echocardiographic parameters were collected where available, along with invasive hemodynamics, cardiac biomarkers (BNP/NT-proBNP), inflammatory markers (ESR, CRP), NYHA functional class, and outcomes.

Results

Median age was 44 years (range 18-58), and 90% were female. Based on invasive hemodynamics, pre-capillary PH was present in 5 patients, combined pre-/post-capillary PH in 3, and isolated post-capillary PH in 2. Median mPAP was 38 mmHg (IQR 30-55), median pulmonary vascular resistance 3.5 Wood units (IQR 2.3-8.7), and median PAWP 15 mmHg (IQR 8-24). Echocardiography frequently underestimated disease severity. Several patients with absent or low tricuspid regurgitation velocity (≤1.0 m/s), where measurable, demonstrated severe pre-capillary PH on RHC, including pulmonary vascular resistance >6 Wood units. Among patients with available data, NT-proBNP levels ranged from 59 to 51,968 pg/mL, and inflammatory markers varied widely (CRP <0.3 to 107.9 mg/L). Among patients with available NYHA data, most were class II-III.

Conclusions

In this TA cohort, RHC was essential to confirm and phenotype PH, which was present in the majority of those with suspected PH. Echocardiography alone often underestimated or misclassified PH in TA - in one case missing severe pre-capillary PH due to an absent TR signal, and in another failing to discern elevated left-heart filling pressure. Invasive assessment prevented missed diagnoses and misclassification, ensuring appropriate management of TA-associated PH

This abstract is funded by: None