Pulmonary vascular volume heterogeneity in association with emphysema: a multicenter study based on non-contrast...

To investigate the associations between emphysema and pulmonary vessels in patients with chronic obstructive pulmonary disease (COPD) and controls.

This multicenter retrospective study recruited COPD patients and controls. Participants underwent pulmonary function tests and noncontrast chest CT. Emphysema was identified and visually graded based on the Fleischner Society guidelines, with pulmonary vascular volume parameters (BV1, BV5, BV5-10, BV10-15) performed using artificial intelligence.

We enrolled 690 subjects (576 males; mean age, 66 ± 9 years [SD]), consisting of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 0 group (n = 117), the preserved ratio impaired spirometry (PRISm) group (n = 58), and GOLD 1-4 groups (n = 515). Of these participants, the number of emphysema-positive subjects was 319 (46.2%). Compared to the non-emphysema group, the emphysema group exhibited lower volumes of distal small pulmonary vessels (BV1, BV5) (p < 0.05 for both), but higher volumes of proximal vessels (BV5-10, BV10-15) (p < 0.05 for both). Notably, a similar pattern was observed in the control group. Centrilobular emphysema (CLE) severity grading revealed reduced BV1 and BV5 in both Confluent CLE and Advanced destructive CLE (p < 0.05 for both). General linear model analysis showed that BV1 and BV5 did not differ significantly across GOLD stages after adjusting for confounders, whereas all other intrapulmonary vascular volume indices did (all p < 0.05).

Emphysema acts as an "accomplice" in accelerating the remodeling and pruning of small pulmonary vessels, with this phenomenon persisting even in populations with preserved pulmonary function.

Question Emphysema elevates the risk of cardiovascular disease-related mortality, yet its underlying association with intrapulmonary vessels remains unclear. Findings The presence of emphysema further exacerbates pulmonary vascular remodeling and pruning, a phenomenon that also occurs in individuals with normal lung function. Clinical relevance From a noninvasive perspective, this study aims to investigate the association between emphysema and intrapulmonary vessels, clarify the underlying pathological mechanisms, and thereby optimize early monitoring and intervention strategies to prevent associated cardiovascular diseases.