Noninvasive Evaluation System For Chronic Obstructive Pulmonary Disease Associated Pulmonary Hypertension

Part 1 microRNA in the pathogenesis of chronic obstructive pulmonary disease associated pulmonary hypertensionmicroRNAs(miRNA)play an important role in various aspects of pulmonary inflammation and vascular remodeling in chronic obstructive pulmonary disease(COPD)and pulmonary hypertension(PH).Studies only focused on miRNAs in COPD or PH,there was no research to investigate the expression and mechanism of miRNAs in patients of COPD associated PH(COPD-PH),except some experiments of hypoxic animal models.The research of miRNAs in COPD-PH would be helpful to clarify the pathogenesis of how PH develop on the basis of COPD,providing a new way for early diagnosis,treatment and prognosis of COPD-PH.miRNAs were sequenced from the serum of normal controls,patients with COPD and COPD-PH by high-throughput sequencing technologies,and analyzed by systemic comparison to look for differentially expressed or specific miRNAs in COPD and COPD-PH.The identification and functional analysis of target genes in differentially expressed and specific miRNAs were performed,to elucidate the development of the disease.On the basis of this,the selected miRNAs were validated in another large sample in order to make a biomarker,which could be used for the evaluation of diagnosis and prognosis.In 48 included samples,the database of 43 including 16 patients with COPD,15 patients with COPD-PH,and 12 healthy controls were successfully established.COPD was diagnosed according to global initiative for chronic obstructive lung disease(GOLD)2013,while PH was diagnosed by pulmonary artery systolic pressure(sPAP)measured by echocardiography and the ratio of main pulmonary artery diameter/descending aortic diameter(MPA/DAo)and the diameter of MPA measured on chest CT.Controls were subjects on medical examination that lung or cardiovascular diseases were excluded.After RNA extracted from the serum,miRNAs library established,and sequenced,it was found that,compared with controls,miR-140-3p,miR-181a-5p,miR-106b-3p,miR-151a-3p,miR-23-3p,miR-186-5p,miR-148a-3p and miR-451a in patients with COPD downregulated significantly.Similarly,miR-140-3p,miR-181a-5p,miR-106b-3p,miR-151a-3p,miR-23-3p,miR-93-5p,miR-181a-2-3p and miR-223-3p in patients with COPH-PH were also obviously decreased compared with controls.However,interestingly,six miRNAs(miR-140-3p,miR-182-5p,miR-101-3p,miR-143-3p,miR-148a-3p and miR-100-5p)were unregulated after the occurrence of PH on the basis of COPD,although the level was still lower than those in controls.According to miRNA database,these miRNAs had not yet been reported in PH or COPD.Quantitative PCR(qPCR)validated the significant differential expression of miR-140-3p and miR-182-5p in the sequenced samples.Thereafter,serum miRNAs from another 79 samples(including 10 controls,30 patients with COPD,39 patients with COPD-PH)measured by qPCR confirmed the differential expression of these two miRNAs.GO(Gene Ontology)target gene prediction and KEGG(Kyoto Encyclopedia of Genes and Genomes)pathway analysis indicated that,miR-182-5p acted on phosphoinositide 3-kinase(PI3K),hypoxia inducible factor-1?(HIF-1?),nuclear factor-?B(NF-?B)and so on,while miR-140-3p acted on mitogen-activated protein kinase 8(MAPK8),cysteinyl aspartate specific proteinase 10(CASP10)and so on.Nevertheless,both might regulate apoptosis,angiogenesis,and cell cycle to act on the signal pathway of HIF-1?,which involed in the development of COPD-PH.This study firstly detected differentially expression of miR-140-3p and miR-182-5p in patients with COPD-PH,the results would be helpful to elucidate the pathogenesis of COPD-PH.The detection of circulation difference miRNAs could be applied to PH screening,diagnosis,and assessment for disease severity and response to therapy.Part 2 Noninvasive imaging assessment for COPD-PH1.Computed tomography measurement of pulmonary artery for diagnosis of COPD and its comorbidity pulmonary hypertensionComputed tomography(CT)is widely used for evaluation of lung diseases.To evaluate the value of CT measurement of pulmonary artery for diagnosis of chronic obstructive pulmonary disease(COPD)and its comorbidity pulmonary hypertension(PH),we retrospectively reviewed the CT of 221 patients with COPD and 115 control patients without cardiovascular or lung diseases.Patients with COPD were divided into PH(COPD-PH)and non-PH according to pulmonary artery systolic pressure(sPAP).Main pulmonary artery(MPA),right and left branches,and ascending aorta(AAo)and descending aorta diameters(DAo)were measured.Meanwhile,the ratios of MPA/AAo and MPA/DAo were calculated.MPA,right and left branches diameters were significantly larger in COPD than those in the controls,and this augment was more obvious in COPD-PH.AAo and DAo diameters did not vary obviously between groups,while MPA/AAo and MAP/DAo increased significantly in COPD and PH.MPA could be helpful for COPD diagnosis(MPA diameter>27.5 mm,sensitivity 54%,and specificity 80%),and right pulmonary artery(RPA)could be applied to COPD-PH diagnosis(RPA diameter ? 23.4 mm,sensitivity 67%,and specificity 76%).There was a marked correlation between MPA/DAo and sPAP(r =0.594,P<0.001),indicating that MPA/DAo could better reflect the changes of pulmonary artery pressure.Therefore,diameter measurement of MPA and RPA,and calculating ratio of MPA/DAo on chest CT could be a simple and effective modality for diagnostic evaluation of COPD and its comorbidity PH.2.Cross sectional area of small pulmonary vessels in assessment of the severity of COPD and the prediction of acute exacerbationChronic obstructive pulmonary disease(COPD)is characterized by persistent airflow limitation that is not fully reversible,and pulmonary vascular alteration is one of the important characteristics.It was reported that cross sectional area(CSA)of small pulmonary vessels could be used to assess pulmonary vascular alterations in patients with COPD.To analysis whether CSA could be applied to assess the severity of COPD and to predict the occurrence of acute exacerbation of COPD(AECOPD),we retrospectively reviewed 154 patients with COPD and another 154 patients without lung or cardio-cerebrovascular diseases as control.General information and lung function were collected.CSA was measured on chest CT and the percentage of total CSA less than 5 mm2 and 5-10 mm2 to the whole area of the lung(%CSA<5 and%CSA5-10)were calculated respectively.The correlations of%CSA with forced expiratory volume in one second/forced vital capacity(FEV1/FVC)and FEV1%predicted were analyzed.According to the history of AECOPD in last year,receiver operating characteristic(ROC)curve was performed to analyze whether%CSA could predict the occurrence of AECOPD and what the cutoff value was.It was indicated that,following with the aggravation of the severity,%CSA<5 of COPD also decreased.There was a positive correlation between%CSA<5 and FEV1%predicted or FEV1/FVC(r = 0.579 and 0.686,respectively,P<0.001)in patients with COPD.In addition,%CSA<5 could be used for the prediction of AECOPD,the cutoff value was 0.56%(sensitivity 86.3%,specificity 73.1%).Therefore,%CSA<5 of small pulmonary vessels was significantly correlated lung function of patients with COPD.%CSA<5 could be used for the assessment of the severity of airflow limitation in COPD,more important,it could be used to predict AECOPD.3.Cardiovascular magnetic resonance in evaluation of right ventricular function of rats with hypoxic pulmonary hypertensionChronic hypoxia plays an important role in the pathophysiology of respiratory diseases.Sustained hypoxia caused small vessels injury,which led to pulmonary vascular endothelial dysfunction,resulted in pulmonary vascular remodeling and increased vascular resistance,and gradually developed into pulmonary hypertension(PH).Right ventricular(RV)adaptive and maladaptive to overload was usually an important indicator for the severity of PH.Doppler echocardiography could assess cardiac structure,function and hemodynamics,but vulnerable to be influenced by various factors.Multidetector CT could provide anatomical information of lung and heart,but could not provide cardiac function and hemodynamic information.Previous studies have shown that cardiovascular magnetic resonance(CMR)imaging could be a comprehensive and accurate modality to assess the anatomic and morphological alterations and cardiac function.The objective of this study was to observe the feature of hypoxia PH during its development in rats,and to evaluate right ventricular function by CMR.Male SD rats were randomly divided into control and hypoxia groups.Controls were fed in normal environment,while hypoxia rats were fed in a hypoxic chamber(oxygen concentration(10±0.5)%).Rats were anesthetized with 10%hydral via intraperitoneal injection,and then gradient echo sequences,MR imaging,PC and LGE sequences were scanned by 3.0 T or 7.0 T CMR in 0,1st,2nd,3rd,and 4th week respectively.After that,right heart catheterization was performed to measure right ventricular systolic pressure(RVSP),mean pulmonary artery pressure(mPAP).The heart was dissected and right ventricular hypertrophy index was calculated(RV mass/left ventricular mass + interventricular septum mass,RV/LV+S).Pathological changes of pulmonary vascular walls were observed on hematoxylin and eosin(HE)staining slices,and the percentage of medial thickness to outer(MT%)in remodeling vessels was measured.It was indicated that,RVSP and mPAP increased,pulmonary artery intimal thickened,and right ventricular hypertrophy in hypoxic rats following hypoxia time prolonged.However,it was not a linear growth,these indications were significant from the 2nd week,and the transmutation was relative alleviated after 3rd week(no significant difference between 3rd week and 4th week).There were similar trends for right ventricular function assessed by CMR.Right-ventricular end diastolic volume and systolic function did not change obviously before 3rd week,and after that,right ventricular end diastolic volume significantly increased,meanwhile systolic function decreased.Mean velocity of main pulmonary artery was gradually decreased with hypoxia time,and the difference was statistically significant.Therefore,CMR could evaluate the anatomy and function of pulmonary artery and right ventricle,reflect the hemodynamic changes in hypoxia PH.Part 3 The treatment of pulmonary hypertension1.Therapy in stable chronic obstructive pulmonary disease patients with pulmonary hypertension:a systematic review and meta-analysisCurrently,specific pulmonary vasodilators(targeted drugs)are mainly used for pulmonary arterial hypertension(PAH),especially for idiopathic PAH(IPAH),while for chronic obstructive pulmonary disease associated pulmonary hypertension(COPD-PH),there was no effective drug.To evaluate whether PAH specific therapies were effective for stable COPD patients,we conducted a systematic review and meta-analysis.Data were extracted from PubMed,Cochrane Central Register of Controlled Trials and China Knowledge Resource Integrated Database(CNKI).Randomized controlled trials(RCTs)with PAH specific therapy treated more than 4 weeks in COPD were selected.The main outcome was exercise capacity(6 minutes walking distance,6MWD);meanwhile pulmonary arterial pressure(PAP),hypoxemia and health related life quality were also measured.Nine trials involving 365 subjects were included,among which two were treated with bosentan and seven with sildenafil.The study time varied from 4 weeks to 18 months and mostly was 12 weeks.In a pooled analysis of nine trials,exercise capacity of COPD patients was improved by PAH-specific therapy[mean difference(MD)66.39 m,95%confidence intervals(CI):59.44-73.34 m].Exercise capacity was improved significantly(MD 67.24 m,95%CI:60.26-74.23 m)in COPD patients with severe PH(mean PAP>35 mmHg by right heart catheterization or systolic PAP>50mmHg by echocardiography),but not for COPD patients without PH at rest(MD-9.24 m,95%CI:-75.08 to 56.31).Meanwhile PAP was notably decreased(MD-9.02 mmHg,95%CI:-10.71 to-7.34 mmHg).Although hypoxemia and life quality were not improved,the dyspnea was alleviated or at least not aggravated(Borg dyspnea index,MD-0.86,95%CI:-1.86 to 0.14).In conclusion,PAH specific drugs(especially sildenafil)could be applied in COPD patients with severe PH,accordingly improve exercise capacity and decrease PAP.2.The clinical prognosis of pulmonary arterial hypertension patients treated with bosentan and combinationTo observe and assess the long-term efficacy and safety of bosentan for pulmonary arterial hypertension(PAH),23 patients,of whom 21 were PAH,2 were chronic thromboembolism pulmonary hypertension,were followed up in outpatient every 2 months in the first affiliated hospital of Nanjing Medical University from September 2013 to October 2015.The patients were firstly treated with bosentan 62.5 mg bid,and 125 mg bid after 4 weeks,then combined with phosphodiesterase-5 inhibitor(PDE-5i)or prostacyclin analogue according to the condition during the follow up when it was necessary.Liver function and N-terminal-pro brain natriuretic peptide(NT-proBNP)were monitored,WHO function classification and 6 min walking distance(6MWD)were evaluated,and pulmonary arterial systolic pressure(sPAP),tricuspid regurgitation velocity and ventricle size were measured by echocardiography.To the end of follow up,the mean duration of treatment with bosentan was(21 ±4)months,and the time from bosentan monotherapy to be replaced by another drug or combined therapy was(17±4)months.The condition was effectively improved with high survival rate.Only one died because of right heart failure,as that the overall survival was 95.67%.Compared with pretherapy,WHO function classification,6MWD and sPAP were significantly improved.There was a decrease tend for NT-proBNP without statistically difference.The side effect of bosentan was low.ALT/AST increased mildly in 2 patients at the beginning,then retrieved 3 months later without intervention.One increased because of right heart failure,and recovered after actively treated with cardiotonic,diuretics and combined with sildenafil.Thus,unselective endothelin receptor antagonist bosentan could be long-term used for PAH,which could improve heart function,exercise capacity and sPAP.The prognosis of patients was well with great safety.