Clinical Characteristics Of Interstitial Lung Disease Complicated With Pulmonary Hypertension

Objective:By studying the clinical characteristics of patients with idiopathic pulmonary fibrosis complicated with pulmonary hypertension（IPF-PH）and interstitial pulmonary disease associated with connective tissue disease complicated with pulmonary hypertension（CTD-ILD-PH）,comparing the similarities and differences of clinical characteristics of ILD-PH patients with different degrees of pulmonary hypertension,and analyzing the correlation between pulmonary artery systolic blood pressure（PASP）and clinical indicators.To better distinguish IPF-PH and CTD-ILD-PH,and provide guidance for early diagnosis,treatment and prognosis improvement of ILD-PH.Methods:The basic data,clinical manifestations,lung function,laboratory results,high-resolution CT（HRCT）and other auxiliary examination results of patients diagnosed with IPF-PH and CTD-ILD-PH in the Second Hospital of Hebei Medical University from October 2016 to October 2022 were collected to analyze the similarities and differences between the two groups.This group was divided into two groups according to the pulmonary artery systolic blood pressure（PASP）in echocardiography:（1）Mild to moderate PH group（35mm Hg<PASP<70mm Hg）;（2）In the severe PH group（PASP≥70mm Hg）,the imaging,lung function and laboratory examination of the two groups were analyzed and compared,and the correlation between some indicators and PASP was analyzed.Results:1.General data analysis of IPF-PH group and CTD-ILD-PH group:There were 98 patients in IPF-PH group,including 67 males and 31 females.The ratio of male to female was 2.16:1,the age of onset was 37-98 years old,the average age was 70.51±9.66 years old,and the number of smokers accounted for 55%.The median smoking index and interquart interval were 280.00（0.00,600.00）*years.The median length of hospital stay and interquartile distance were 10.90（8.59,14.65）days.There were 146 CTD-ILD-PH patients,including 49 males and 97 females,with an incidence ratio of 1:1.98.The age of onset ranged from 23 to 91 years with an average age of 63.21±12.91 years.The number of smokers accounted for about 3.4%.The median and interquartile length of hospital stay were 14.91（10.81,19.00）days.There were significant differences in gender,age,length of hospital stay and smoking index between IPF-PH group and CTD-ILD-PH group（P<0.05）.2.Clinical manifestations of IPF-PH group and CTD-ILD-PH group:Among the 244 patients included,the clinical manifestations were chest tightness（200 cases）,cough（178 cases）,Velcro rale（152 cases）,lower limb edema（63 cases）,chest pain（10 cases）,palpitation（9 cases）,Syncope（4cases）,and jugular vein rage（2 cases）.The analysis and comparison between IPF-PH and CTD-ILD-PH groups showed:Chest tightness,shortness of breath,cough and Velcro rales were more common in the IPF-PH group（P<0.05）,but there was no difference in other clinical manifestations between the two groups.3.HRCT examination of IPF-PH group and CTD-ILD-PH group:Among the 244 patients included,76 patients were combined with emphysema,including 42 cases in the IPF-PH group,accounting for 42.9%of the IPF-PH group,and 34 cases in the CTD-ILD-PH group,accounting for 23.3%of the CTD-ILD-PH group,the difference between the two groups was statistically significant（P<0.05）;There were 120 cases（49.2%）with mediastinal lymph node enlargement,including 54 cases（55.1%）in IPF-PH group and 66 cases（45.2%）in CTD-ILD-PH group;There were 52 cases（21.3%）with pleural effusion,including 24 cases（24.5%）in IPF-PH group and 28 cases（19.2%）in CTD-ILD-PH group.There was no significant difference in lymph node enlargement and pleural effusion between the two groups（P>0.05）.4.Lung function and laboratory examination in IPF-PH group and CTD-ILD-PH group:Among the 244 patients included,47 patients underwent pulmonary function examination,most of which showed restricted ventilation dysfunction and diffusion dysfunction.There was no statistical significance in FVC%pred,DLCO%pred and FVC/DLCO between IPF-PH and CTD-ILD-PH groups（P>0.05）.There were 205 cases with blood gas analysis results,including 116 cases with type I respiratory failure and 7 cases with type II respiratory failure.PCO₂ in IPF-PH group was higher than that in CTD-ILD-PH group,and the difference was statistically significant（P<0.05）.5.Imaging,lung function and laboratory examination of different degrees of pulmonary hypertension were as follows:180 cases were in mild to moderate group,including 67 cases in IPF-PH group,accounting for 68.3%of IPF-PH,113 cases in CTD-ILD group,accounting for 77.4%in CTD-ILD-PH group,64 cases in severe group,including 31 cases in IPF-PH group,accounting for 48.4%.The pulmonary artery systolic blood pressure in IPF-PH group was higher than that in CTD-ILD-PH group,and the difference between the two groups was statistically significant（Z=-2.202,P=0.028）.Imaging:The pulmonary artery/ascending aorta（PA/A）diameter ratio（r PA）measured by chest HRCT was>0.9 in 97 cases,of which 49 cases were in the mild to moderate group,accounting for 27.2%,and 48 cases were in the severe group,accounting for 75%.There were statistically significant differences in pulmonary artery diameter（d PA）and r PA between the mild to moderate group and the severe group（P<0.05）;The comparison of lung function between the two groups showed that DLCO%pred of the mild to moderate group was higher than that of the severe group（P<0.05）,and the FVC/DLCO value was lower than that of the severe group（P<0.05）.There was no statistical significance in FVC%pred and FEV1%pred between the two groups;The comparison of the results of blood gas analysis and NT-pro BNP between the two groups showed that PO₂ in the mild to moderate group was higher than that in the severe group（P<0.05）,NT-pro BNP was lower than that in the severe group（P<0.05）,and there was no statistical significance in PCO₂ between the two groups（P>0.05）.6.Correlation analysis between PASP and each index:DLCO%pred was negatively correlated with PASP（r_s=-0.483,P=0.001）;PO2 was negatively correlated with PASP（r_s=-0.268,P<0.001）;FVC/DLCO was positively correlated with PASP（r_s=0.476,P=0.001）;NT-pro BNP was positively correlated with PASP（r_s=0.431,P<0.001）;d PA was positively correlated with PASP（r=0.647,P<0.001）;r PA was positively correlated with PASP（r=0.534,P<0.001）.Conclusions:1.IPF-PH patients with emphysema are more common than CTD-ILD-PH patients.2.ILD-PH is more common in mild to moderate pulmonary hypertension.3.The pulmonary artery systolic blood pressure in IPF-PH group was higher than that in CTD-ILD-PH group.4.FVC/DLCO,NT-proBNP,dPA,rPA were positively correlated with PASP,indicating that the higher the level of the above indicators,the greater the pulmonary artery pressure;DLCO%pred and PO2 were negatively correlated with PASP,suggesting that the lower the above indexes,the greater the pulmonary artery pressure.