Chronic thromboembolic pulmonary hypertension (CTEPH), a severe long-term complication of acute pulmonary thromboembolism, is characterized by high mortality and disability rates.The Guidelines for the Diagnosis and Treatment of Chronic Thromboembolic Pulmonary Hypertension(2024 edition) represents the first comprehensive systematic evaluation of evidence-based medical evidence on CTEPH published domestically and internationally in recent years, formulating recommendations tailored to clinical practice in China to standardize the clinical diagnosis and management of CTEPH. This article provides an interpretative analysis focusing on early recognition of CTEPH, the diagnostic value of various imaging modalities, and the selection of therapeutic strategies, with the aim of providing clinical guidance and support.

Objective To assess the incidence of contrast-induced nephropathy(CIN)in patients with chronic thromboembolic pulmonary hypertension(CTEPH)after receiving balloon pulmonary angioplasty(BPA),and to evaluate the effect of the contrast agents on renal function.Methods A total of 143 CTEPH patients,who received BPA at the China-Japan Friendship Hospital of China from December 2018 to May 2022,were enrolled in this study.The clinical data,hemodynamic indicators,and serum creatinine(SC)concentrations within one week before and 48-72 h after BPA were collected.The estimated glomerular filtration rate(eGFR)was calculated according to the Modification of Diet in Renal Disease(MDRD)formula.The SC concentration and eGFR changes before and after each BPA procedure were compared.The incidence of CIN and its risk factors were evaluated,and the changes in hemodynamics,SC and eGFR after the initial and last time of BPA treatment were analyzed.Results A total of 192 BPA procedures were performed in 115 CTEPH patients,including 88 BPA procedures in males and 103 BPA procedures in females.The mean amount of contrast agent used for each BPA was(145.58±47.26)mL.After BPA,12 patients developed 13 times of CIN,with an incidence of 6.8％.There was no significant differences(P＞0.05)in the baseline characteristics and SC concentration before BPA between CIN patients and non-CIN patients.In terms of the hemodynamic indexes,the mixed venous oxygen saturation(SvO2)in CIN patients was significantly lower than that in non-CIN patients(58.58％±10.38％vs.66.15％±8.02％,P=0.002),and no statistically significant differences(P＞0.05)in the other hemodynamic indexes existed between CIN group and non-CIN group.No statistically significant differences in SC concentration and eGFR existed before and after each BPA procedure.In patients who had received several BPA procedures,significant improvements in the SC[(78.09±18.760)μmol/L vs.(82.26±21.37)μmol/L,P＜0.001]and eGFR[(86.08±21.22)mL/(min·1.73 m2)vs.(82.07±22.05)mL/(min·1.73 m2),P=0.007]was achieved when compared with their baseline values.Conclusion CTEPH patients may develop CIN after receiving BPA treatment.After receiving several BPA treatments the patient's clinical symptoms and hemodynamics can be improved,and the patient's renal function is also significantly improved.

Objective:To investigate the values of two-dimensional and three-dimensional echocardiographic parameters in predicting pulmonary vascular resistance (PVR) in chronic pulmonary thromboembolic pulmonary hypertension (CTEPH).Methods:A total of 141 patients diagnosed with CTEPH in China-Japan Friendship Hospital from November 2015 to December 2022 were included. Two-dimensional echocardiographic indicators reflecting PVR were constructed according to the calculation formula of PVR: echocardiographic estimated systolic pulmonary artery pressure (sPAP Echo)/left ventricular end-diastolic diameter (LVIDd), echocardiographic estimated mean pulmonary artery pressure (mPAP Echo)/LVIDd. sPAP Echo/left ventricular end-diastolic volume (LVEDV), sPAP Echo/left ventricular cardiac output (LVCO) were measured by three-dimensional echocardiography. The correlations between two-dimensional and three-dimensional echocardiographic ratios and invasive PVR were then analyzed using the Spearman correlation method. Using receiver operating characteristic curve analysis, cut-off values for the ratios were generated to identify patients with PVR>1 000 dyn·s -1·cm -5. Pre- and postoperative hemodynamics and echocardiographic data were analyzed, as well as the correlation between the reduction rate of the echocardiographic index and PVR in 54 patients who underwent pulmonary endarterectomy (PEA). Results:sPAP Echo/LVIDd, sPAP Echo/LVEDV and sPAP Echo/LVCO were moderately correlated with PVR( rs=0.62, 0.52, 0.63, both P<0.001). The ratio of sPAP Echo to LVEDV, when greater than or equal to 1.41, had a sensitivity of 0.800 and a specificity of 0.930 for determining PVR >1 000 dyn·s -1·cm -5 (AUC=0.860, P<0.001). Similarly, the ratio of sPAP Echo to LVIDd, when greater than or equal to 2.14, had a sensitivity of 0.647 and a specificity of 0.861 for determining PVR >1000 dyn·s -1·cm -5 (AUC=0.830, P<0.001). The sPAP Echo/LVIDd and mPAP Echo/LVIDd significantly decreased after PEA (both P<0.001). The sPAP Echo/LVIDd and mPAP Echo/LVIDd reduction rate (ΔsPAP Echo/LVIDd and ΔmPAP Echo/LVIDd) were significantly correlated with PVR reduction rate (ΔPVR), respectively ( rs=0.61, 0.63, both P<0.05). Conclusions:Two-dimensional ratio sPAP Echo/LVIDd and three-dimensional ratio sPAP Echo/LVEDV can be used to noninvasively estimate PVR in CTEPH patients. The conventional ratio sPAP Echo/LVIDd is convenient and reproducibly suitable for monitoring the improvement of PVR before and after treatment, and its ratio of 2.14 can predict the significant increase of PVR in CTEPH patients (>1 000 dyn·s -1·cm -5).

Objective:To investigate the safety and efficacy of balloon pulmonary angioplasty (BPA) for residual pulmonary hypertension (PH) of chronic thromboembolic pulmonary hypertension(CTEPH) after pulmonary endarterectomy (PEA).Methods:Patients diagnosed as PH after PEA in China-Japan Friendship Hospital from Oct 2016 to Jun 2022 were included. The indication for BPA was decided on the basis of a consensus of the multi-disciplinary team for all patients with CTEPH. Before treatment, the patient′s exercise tolerance and pulmonary artery flow parameters were evaluated. A comparative analysis of various parameters before BPA treatment and at the last BPA was conducted. 6-min walk distance (6MWD) was analyzed using the paired Wilcoxon test; N-terminal pro-brain natriuretic peptide (NT-proBNP), mixed venous oxygen saturation, mean pulmonary arterial pressure (mPAP), cardiac index (CI) and pulmonary vascular resistance (PVR) were compared using the paired-samples t-test. WHO functional class was compared using McNemar′s test. Results:Twenty patients with a total of 130 vessels underwent 46 sessions of BPA treatment. The postoperative 6-minute walk distance (6MWD) [447 (415, 485) m] showed a significant improvement compared to the preoperative baseline [389 (335, 470) m] ( Z=6.52, P<0.05), Postoperative mixed venous oxygen saturation (72.0%±1.9%) showed a significant improvement compared to the preoperative levels (64.0%±2.7%) ( t=2.14, P<0.05).Postoperatively, plasma NT-proBNP [(351.9±129.9) pg/ml], mPAP [(24.2±1.9) mmHg], and PVR [(3.0±1.4) WU] significantly decreased compared to preoperative levels [(982.5±426.2) pg/ml, (33±2.1) mmHg, (8.0±1.6) WU)] ( t=3.38, 1.22, 2.10, P<0.05 for all). Postoperatively, there was a significant improvement in WHO functional class (Ⅰ，Ⅱ，Ⅲ，Ⅳ: 14, 4, 2, 0 cases) compared to preoperative status (Ⅰ，Ⅱ，Ⅲ，Ⅳ: 0, 13, 5, 2 cases) ( χ2=20.17, P<0.05). Four cases of pulmonary artery dissection and one episode of hemoptysis occurred postoperatively, with no other complications reported. Conclusions:BPA can significantly improve exercise tolerance and hemodynamic parameters for residual PH after PEA. BPA is a relatively safe and effective treatment for residual PH after PEA.

Background::Acute pulmonary embolism (APE) is a fatal cardiovascular disease, yet missed diagnosis and misdiagnosis often occur due to non-specific symptoms and signs. A simple, objective technique will help clinicians make a quick and precise diagnosis. In population studies, machine learning (ML) plays a critical role in characterizing cardiovascular risks, predicting outcomes, and identifying biomarkers. This work sought to develop an ML model for helping APE diagnosis and compare it against current clinical probability assessment models.Methods::This is a single-center retrospective study. Patients with suspected APE were continuously enrolled and randomly divided into two groups including training and testing sets. A total of 8 ML models, including random forest (RF), Na?ve Bayes, decision tree, K-nearest neighbors, logistic regression, multi-layer perceptron, support vector machine, and gradient boosting decision tree were developed based on the training set to diagnose APE. Thereafter, the model with the best diagnostic performance was selected and evaluated against the current clinical assessment strategies, including the Wells score, revised Geneva score, and Years algorithm. Eventually, the ML model was internally validated to assess the diagnostic performance using receiver operating characteristic (ROC) analysis.Results::The ML models were constructed using eight clinical features, including D-dimer, cardiac troponin T (cTNT), arterial oxygen saturation, heart rate, chest pain, lower limb pain, hemoptysis, and chronic heart failure. Among eight ML models, the RF model achieved the best performance with the highest area under the curve (AUC) (AUC = 0.774). Compared to the current clinical assessment strategies, the RF model outperformed the Wells score ( P = 0.030) and was not inferior to any other clinical probability assessment strategy. The AUC of the RF model for diagnosing APE onset in internal validation set was 0.726. Conclusions::Based on RF algorithm, a novel prediction model was finally constructed for APE diagnosis. When compared to the current clinical assessment strategies, the RF model achieved better diagnostic efficacy and accuracy. Therefore, the ML algorithm can be a useful tool in assisting with the diagnosis of APE.

Objective To assess the predictive value of computed tomography pulmonary angiography(CTPA)cardiovascular parame-ters for chronic thromboembolic pulmonary hypertension(CTEPH)under the 2022 European Society of Cardiology/European Respiratory Society(ESC/ERS)guidelines,and to compare with the 2021 Chinese guidelines.Methods A total of 201 suspected CTEPH patients were retrospectively selected.All patients underwent right heart catheterization(RHC)and CTPA evaluation.According to the Euro-pean guidelines,they were divided into three groups:mean pulmonary artery pressure(mPAP)≤20 mmHg control group(63 cases)(1 mmHg=0.133 kPa),mPAP＞20 mmHg CTEPH group(138 cases),and mPAP≥25 mmHg CTEPH group(123 cases).Inter-group comparison of CTPA cardiovascular parameters was performed,and receiver operating characteristic(ROC)curve analysis was performed for each parameter.Results Under the 2022 European guidelines,the diagnostic efficacy of the diameter of the main pulmonary artery trunk(MPAd)was the highest[area under the curne(AUC)was 0.933].The binary logistic regression analysis revealed that the MP Ad,right ventricular free wall thickness(RVWT),and interventricular septal angle(IVSA)were inde-pendent risk factors for the diagnosis of CTEPH(P＜0.05).Under both the Chinese and European guidelines,the MPAd,the transverse diameter and area of the right atrium,the transverse diameter and area of the bi-ventricle,the RVWT,and the IVSA showed significant statistical differences in CTEPH and control groups(P＜0.05).Conclusion Under both the Chinese and European guidelines,the MP Ad measured by CTPA has the highest diagnostic efficacy for CTEPH,while the IVSA has the strongest correlation with clinical prognostic indicators.The right atrium structure also has evaluation value.

Objective:To assess the configuration and systolic function of the left ventricle in patients with chronic thromboembolic pulmonary hypertension (CTEPH) by routine ultrasound, two-dimensional speckle tracking imaging and three-dimensional echocardiography, and to observe the recovery after pulmonary endarterectomy (PEA).Methods:The patients who were diagnosed with CTEPH, underwent PEA and had no left heart disease were enrolled as the CTEPH group ( n=30) in the China-Japan Friendship Hospital from November 2016 and June 2021. The right heart catheterization data before and after surgery were recorded. In the meantime, gender- and age-matched healthy individuals who sought for physical examination during the same period were included as the control group ( n=23). Echocardiography findings before and after PEA were comparatively analyzed and compared between the two groups, including left ventricular end-diastolic diameter (LVEDd), right and left ventricular cross-section ratio (RVd/LVd), left ventricular global longitudinal strain (LVGLS), left ventricular end-diastolic/systolic volume index (LVEDVi/LVESVi), left ventricular ejection fraction (LVEF) and left ventricular stroke volume (LVSV). Associations between the mean pulmonary arterial pressure (mPAP)/pulmonary vascular resistance (PVR) and left ventricular function were discussed. Results:When compared with the control group, the LVEDd, LVEDVi, LVESVi, LVSV, LVGLS and the mitral early to late diastolic flow velocity ratio (E/A) in the CTEPH group were lower (all P<0.05). There were no significant differences between the two groups regarding LVEF, cardiac output (CO), and cardiac index (CI) (all P>0.05). There were no statistical differences of the left ventricular volume and LVSV between PEA group and the control group (both P>0.05), while the LVGLS and E/A remained lower (both P<0.05). Correlation analysis showed negative associations between mPAP and LVSV as well as E/A ( r=-0.490, -0.455; both P<0.05). Conclusions:There are changes in left ventricular configuration with abnormal filling pattern and potential systolic dysfunction in CTEPH patients. The PEA surgery could lead to recovery of the left ventricular configuration and volume, but the filling pattern and LVGLS at follow-up can not recover completely.

Objective: To compare the value of right ventricular (RV) free wall longitudinal strain (FWLS) by speckle tracking echocardiography (STE) and conventional parameters in evaluation of RV dysfunction in chronic thromboembolic pulmonary hypertension (CTEPH). Methods: Sixty CTEPH patients were enrolled as group A and 45 pulmonary embolism (PE) patients with normal pulmonary pressure were enrolled as group B in this study. CTEPH patients were divided into 2 subgroups using the World Health Organization (WHO) function classification: patients with WHO Ⅰ-Ⅱ were designated as group A1 and those with WHO Ⅲ-Ⅳ were designated as group A2. Conventional RV functional parameters including tricuspid annular plane systolic excursion (TAPSE), tissue Doppler-derived tricuspid annular systolic velocity (S′), fractional area change (FAC), RV index of myocardial performance (RVIMP), and STE-derived RV FWLS were measured and compared. Clinical right heart failure (RHF) was defined as the presence of symptoms of heart failure and signs of systemic circulation congestion during hospitalization. Results: Compared to group B, group A patients had significant enlarged right heart dimension and impaired RV systolic function parameters (all P<0.001). The TAPSE, S′, FAC, and RV FWLS showed significant differences between CTEPH patients with mild (group A1) and severe symptoms (group A2) (all P<0.01), while RVIMP showed no significant difference (P=0.188). On receiver operating characteristic analysis, FWLS had the largest AUC to identify RHF (AUC=0.864, P<0.001), when the cutoff value was 15.05%, the sensitivity was 85.71%, and the specificity was 64.29%, respectively. On binary logistic regression analysis, only right atria area (OR=1.212, 95%CI=1.004-1.48, P=0.046) and RV FWLS (OR=0.662, 95%CI=0.470-0.933, P=0.018) were identified as independent predictor of RHF. Conclusions Compared with conventional parameters, RV FWLS showed advantages in identifying abnormal RV function in CTEPH patients.

Objective To evaluate the efficacy and safety of long-term anticoagulation therapy with warfarin in elderly patients with pulmonary thromboembolism (PTE) and the maintenance dosage of warfarin,and provide evidence for anticoagulation therapy. Methods Twenty elderly patients ( ≥65 years old) with PTE whose anticoagulation therapy duration exceeded 12 months were included into this study. The hemorrhage event, recurrence event and the maintenance dosage of warfarin in each patient were determined by the follow-up record. Results Six male patients and 14 female patients [(73.55 ± 5.76) years old] were diagnosed as PTE by CT pulmonary arteriography(CTPA). The average duration of follow-up was (22.60 ± 11.45 ) months. No fatal hemorrhage event such as cerebral hemorrhage was found during the course of long term anticoagulation therapy, and mild hemorrhage was found in 5 patients, including 1 patient with gingiva hemorrhage, 1 patient with epistaxis, 1 patient with hemoptysis, 1 patient with ecchymosis in the left leg and 1 patient with conjunctiva hemorrhage. PTE recurrence emerged in 1 patient and the recurrence rate was 5%.No change was found in the maintenance dosage of warfarin during the course of long-term anticoagulation therapy and the average dosage of warfarin was about 3.5 mg with sufficient anticoagulation therapy.Conclusions Long-term anticoagulation therapy with warfarin in elderly patients with PTE is safe and efficacious. The maintenance dosage of warfarin is about 3.5 mg, and detecting the international normalized ratio regularly is necessary.