Clinical Retrospective Analysis Of Pulmonary Hypertension In Patients With Idiopathic Pulmonary Fibrosis

Background Pulmonary hypertension is a kind of pathophysiological status caused by a variety of known or unknown reasons which change pulmonary vascular bed structure and(or)function,increase pulmonary vascular resistance and pulmonary artery pressure.The hemodynamic diagnostic criteria: at sea level,the mean pulmonary arterial pressure(m PAP)≥25 mm Hg measured at rest by right heart catheterization(RHC).Refer to the 2015 ESC/ERS Pulmonary Hypertension Guideline,pulmonary hypertension due to lung disease belongs to the third classification,which includes chronic obstructive pulmonary disease,interstitial lung disease,sleep apnea,pulmonary dysplasia and so on.Pulmonary hypertension is a common complication in IPF patients,It is also thought to be the primary risk factor of the death of these patients.Because the clinical manifestations of pulmonary hypertension and IPF are very similar(shortness of breath,dyspnea),so pulmonary hypertension is not easy to be found in IPF patients.The study subjects abroad were mostly gained during the end-stage of IPF patients recommended for lung transplantation,which were relatively limited.At present,there are few studies on pulmonary hypertension in IPF patients in China.Objective An retrospective analysis was performed through the clinical data to learn the rate of pulmonary hypertension in patients with IPF,and evaluate the correlation between s PAP and lung function,chest high resolution computed tomography(HRCT),blood gas,N-terminal fragment of pro-BNP(NT-pro BNP).To observe whether the level of s PAP in IPF patients is related to the above indexes,so as to improve the clinician’s knowledge of pulmonary hypertension in IPF patients.Methods 177 hospitalized patients with IPF,who evaluated for s PAP by Doppler echocardiography were selected from the Department of Respiratory Medicine,the First Affiliated Hospital of Zhengzhou University,China,from October 2013 to July 2016.Pulmonary hypertension was defined as an estimated s PAP>50mm Hg by Doppler echocardiography based on 2009 ESC/ERS Pulmonary Hypertension Guideline,and divided into three grades:(1)pulmonary hypertension unlikely: TRV ≦2.8m/s,s PAP ≦36mm Hg(2)pulmonary hypertension possible: TRV 2.9-3.4m/s,s PAP 37-50 mm Hg(3)pulmonary hypertension likely: TRV>3.4m/s,s PAP>50mm Hg.The differences of general information,clinical manifestation,pulmonary function,chest HRCT,blood gas,plasma NT-pro BNP were compared by ANOVA or nonparametric test or chi square test among the three categories.Pearson product moment correlation or Spearman rank correlation were used to evaluate the correlations between the above indexes and s PAP.Statistical analysis were performed by SPSS 17.0.Results 1.177 IPF patients were evaluated for s PAP by echocardiography and were dignosed as pulmonary hypertension unlikely(n=105,59.3%),pulmonary hypertension possible(n=32,18.1%),pulmonary hypertension likely(n=40,22.6%)respectively.The rate of pulmonary hypertension in IPF was 40.3%(72/177)when likely pulmonary hypertension and possible pulmonary hypertension were taken together,22.6%(40/177)when likely pulmonary hypertension was regarded as pulmonary hypertension.2.The differences were not statistically significant in age,gender,smoking habits,clinical manifestations such as symptoms(dyspnea / cough / expectoration)and signs(digital clubbing / lower lung crackles or Velcro rale)among groups of s PAP of IPF patients.The differences were statistically significant in DLco%pred、MPAD、MPAD /MAD、Pa O2、Sa O2 、NT-pro BNP among the three groups of s PAP.3.DLco%pred was negatively correlated with s PAP(r=-0.404,P<0.001).Pa O2 was negatively correlated with s PAP,(r=-0.434,P<0.001).MPAD and NT-pro BNP were positively correlated with s PAP(r=0.524,P<0.001 and r=0.384,P=0.011).Conclusions 1.The rate of pulmonary hypertension in 177 IPF patients was 22.6%,Pulmonary hypertension is a common complication in patients with IPF.2.Pulmonary hypertension may decrease pulmonary diffusion capacity,cause hypoxia,increase pulmonary artery diameter,and reduce right ventricular function.