Patients with acute PE had significantly lower small venous volume normalized by lung volume compared to patients with CTEPH (6.6 vs 8.9, p=0.003).
Observational (n=238)
No
Are there differential changes in intraparenchymal vascular volume on CT pulmonary angiography between patients with acute PE and CTEPH?
Acute PE is associated with lower small and medium-sized venous volumes on CT pulmonary angiography compared to CTEPH, suggesting these volumes may serve as a marker of disease chronicity.
Absolute Event Rate: 6.6% vs 8.9%
p-value: p=0.003
Abstract Introduction Computed Tomography (CT) pulmonary angiography is an integral part of both the diagnosis and treatment of patients with thromboembolic disease. Changes in intraparenchymal vascular volume which can be computed using automated quantitative methods has been previously described in both acute pulmonary embolus (PE) and chronic thromboembolic pulmonary hypertension (CTEPH). However, larger systematic studies spanning the arterial and venous system comparing PE and CTEPH are lacking. In this work we sought to examine the differential findings of vascular volume between those with acute PE and CTEPH. Methods Patients with CT imaging with adequate resolution were enrolled from consecutive patients undergoing PTE at Northwestern University Medical Center for the diagnosis of CTEPH. From a larger cohort of patients with CT Pulmonary angiography patients with a positive diagnosis of PE were selected based on age, sex and BMI matching. Vascular reconstruction was performed using the Chest Imaging Platform. This included sizing of the vessels and separation of arteries and veins. Vessel volumes were pooled based on cross-sectional area of the vessels (5mm2, BV5, 10mm2, BV10, = 5mm2 BVg5, total arterial or venous volume TBV) and normalized either by TBV or by lung volume. Comparisons were made using the Wilcoxon Rank-Sum Test, performed using R version 4.1. Results 87 CTEPH patients and 151 PE patients were included in the analysis. 151 subjects formed the PE comparator group. There was no significant difference in lung volume between the two groups (3.01L vs 2.97L p = 0.31). The most notable difference between the two cohorts was a significantly lower small venous volume BV5 normalized by either lung volume (6.6 vs 8.9 p = 0.003) or total venous volume (0.31 vs 0.41, p = 0.006) in the PE cohort. Similarly venous BV10 normalized by lung volume (15.2 vs 17.0 p = 0.02) and total venous volume (0.31 vs 0.41 p = 0.006) were lower in the acute PE cohort. There was no difference in total arterial (35.0 vs 35.1 p = 0.90) and total venous (22.7 vs 22.3 p = 0.61). Discussion In this comparison of patients with established CTEPH undergoing PTE and those with diagnosis of acute PE, we found lower small and medium sized venous volumes in acute PE as compared to CTEPH. This may represent the acute loss of flow into the venous system which may be partially compensated in CTEPH by establishment of collaterals. Venous small vessel volumes may serve as a marker of disease chronicity in thromboembolic disease. This abstract is funded by: R01ActfHL164717Projectf
Rahaghi et al. (Fri,) conducted a observational in Acute pulmonary embolus (PE) and chronic thromboembolic pulmonary hypertension (CTEPH) (n=238). Acute PE vs. CTEPH was evaluated on Small venous volume (BV5) normalized by lung volume (p=0.003). Patients with acute PE had significantly lower small venous volume normalized by lung volume compared to patients with CTEPH (6.6 vs 8.9, p=0.003).