Risk Factors And Risk Prediction Model Of Pulmonary Hypertension Associated With Chronic Obstructive Pulmonary Disease

Part One A meta-analysis of the prevalence and risk factors of Pulmo-nary hypertension(PH)associated with chronic obstructivepulmonary diseaseObjective: Pulmonary hypertension(PH)associated with chronic obstructive pulmonary disease(COPD)is one of the most common complications of COPD,which usually leads to worse prognosis.Although the estimated prevalence and risk factors of PH associated with COPD(COPD-PH)have been widely reported,these results have not been well integrated.The purpose of this study was to review the prevalence and risk factors of COPDPH.Methods: The Pub Med,Embase and other databases were systematically searched for all qualified documents on the prevalence and risk factors of PH associated with COPD published before April 2022.The qualification screening,quality evaluation and data extraction of the search study were independently conducted by two reviewers.A meta-analysis was conducted to determine the prevalence of PH in the COPD population.The combined prevalence of PH was calculated by random effect model,and subgroup analysis was conducted to investigate the source of heterogeneity.Finally,sensitivity analysis and publication bias were conducted.In addition,the risk factors for PH caused by COPD were further summarized.Results: Forty studies were selected,involving 18486 patients with chronic obstructive pulmonary disease,and the prevalence of COPD-PH was39.6%(95% CI: 35.3%-44.1%,I2=96%,p<0.01),while the total prevalence of severe PH was 6.3%(95% CI: 4.3%-9.4%,I2=96%,p<0.01).Further subgroup analysis based on heterogeneity revealed a higher prevalence of PH in the group with pulmonary dysfunction(13.5% vs 5.1%).There was no significant statistical difference in the prevalence of PH between the ECHO group and the RHC group.In the study of 32 clinical features,we observed that patients with PH were older,with lower FEV1%,lower Pa O2,higher PLT,higher MPV,higher BNP,and higher Pa CO2 compared to COPD without PH.Summary: PH is very common in patients with chronic obstructive pulmonary disease,but there are large differences in the estimated prevalence.This may be due to the differences in PH definitions and different inclusion criteria in different studies.Understanding the potential risk factors for PH can help clinicians identify patients with COPD who are at increased risk for PH,take timely diagnostic and therapeutic measures,and further reduce the prevalence of PH.Prospective research is also needed to convert these risk factors into a risk prediction model.Part Two Development and validation of nomogram for pulmonaryhypertension associated with chronic obstructive pulmo-nary diseaseObjective: Pulmonary hypertension(PH)is a life-threatening complication of chronic obstructive pulmonary disease(COPD).Timely diagnosis of PH in COPD patients is vital to achieve proper treatment;however,there is no algorithm to identify those at high risk.We aimed to develop a predictive model for PH in patients with COPD that provides individualized risk estimates.Methods: A total of 527 patients with COPD who were admitted to our hospital between May 2019 and December 2020 were retrospectively enrolled in this study.Using echocardiographic results as a standard,patients were stratiffed into a moderate or high PH probability group and a low-PH probability group.These patients were randomly divided into a training set(n=368)and a validation set(n=159)in a ratio of 7:3.The potential predictive variables of the training set were screened by LASSO regression,and the selected variables were incorporated into the multivariable logistic regression.The independent predictive factors of PH associated with COPD were determined by the stepwise backward regression minimum AIC value method,and the prediction model of the line graph was constructed.The predictive performance of the model was evaluated using receiver operating characteristic curve,calibration curve and clinical decision curve analysis(DCA)in the training set and validation set,respectively.Results: Global Initiative for Chronic Obstructive Lung Disease(GOLD)stage,emphysema,Pa CO2,NT-pro-BNP,red blood cell(RBC)distribution width-standard deviation(RDW-SD),and neutrophil/ lymphocyte ratio(NLR)were independent predictors of COPD associated PH.The area under the receiver operating characteristic curve(AUC)of the prediction model based on these predictors was 0.770(95%CI: 0.719-0.820)in the training set and0.741(95%CI: 0.659-0.823)in the validation set.It is suggested that the prediction model shows good discrimination in both the training set and the validation set.The predictive model was well calibrated,and the DCA showed that the proposed nomogram had strong clinical applicability.Summary: This study showed that a simple nomogram could be used to calculate the risk of PH in patients associated with COPD.Clinicians can develop personalized screening and intervention measures based on this model,which is crucial for the personalized clinical management of patients with chronic obstructive pulmonary disease who may develop PH.Conclusion:1.GOLD grade and the levels of Pa CO2,NT pro BNP,RDW-SD and NLR,as well as the presence of emphysema are independent predictors of COPD-PH.The nomogram constructed based on this can be used to predict the risk of PH in COPD patients,which has good predictive ability and clinical applicability.2.Multiple risk factors can increase the risk of PH in patients with COPD.PH is common and has a high prevalence in COPD patients.