Koichiro, S; Yosihiro, F; Oikawa, M; Satoh, K; Nakano, M; Miura, Y; Shimokawa, H
Background: Pulmonary veno-oclusive disease (PVOD) is known to have poor prognosis, and PVOD patients require urgent lung transplantation due to the unresponsiveness to current medical therapy. Since PVOD is a disorder difficult to diagnose because lung biopsy is usually needed to accurately diagnose PVOD, it is necessary to develop new diagnostic tools for this disorder. In this study, we aimed to identify new diagnostic tools for PVOD.
Methods: Our subjects were 69 patients with pulmonary arterial hypertension who were diagnosed by standard diagnostic criteria in our department, including idiopathic pulmonary arterial hypertension (IPAH, n=52), collagen PAH (n=9), porto-PAH (n=4), and PVOD (n=4). In those patients, mean pulmonary arterial pressure (mPAP) was 53±15 mmHg, right atrial pressure (RAP) 7±5 mmHg, and cardic index (CI) 2.60±0.68 L/min/m^2. We performed multivariable Logistic regression analysis in 69 patients to examine the independent effect of each variable on diagnosis of PVOD. The variables tested included mPAP, RAP, CI, pulmonary vascular resistance (PVR), acute vasodilator response to inhaled NO, and serum level of BNP.
Results: The extent of PVR reduction in response to NO inhalation was greater in patients with PVOD than in those with PAH (-29±8% vs. -10±15%, P=0.015). There were no significant differences in other hemodynamic variables or BNP level between the patients with PVOD and those with PAH. Multivariable logistic regression analysis revealed that only PVR reduction in response to inhaled NO is a significant predictor of PVOD (RR 1.13, 95% CI, 1.004 to 1.273, P=0.043). Furthermore, on lung CT examination, the PVOD patients also showed characteristic nodular ground-glass opacities and septal lines compared with the PAH patients. During the follow–up period, among the 4 PVOD patients, despite the intense medical treatment, 3 died and 1 underwent lung transplantation.
Conclusion: These results suggest that pulmonary vascular response to inhaled NO and charactestitic findings on CT are useful to diagnose PVOD.
