Vaccination against coronavirus disease 2019 in patients with pulmonary hypertension: A national prospective cohort study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has potential risks for both clinically worsening pulmonary hypertension (PH) and increasing mortality. However, the data regarding the protective role of vaccination in this population are still lacking. This study aimed to assess the safety of approved vaccination for patients with PH. METHODS: In this national prospective cohort study, patients diagnosed with PH (World Health Organization [WHO] groups 1 and 4) were enrolled from October 2021 to April 2022. The primary outcome was the composite of PH-related major adverse events. We used an inverse probability weighting (IPW) approach to control for possible confounding factors in the baseline characteristics of patients. RESULTS: In total, 706 patients with PH participated in this study (mean age, 40.3 years; mean duration after diagnosis of PH, 8.2 years). All patients received standardized treatment for PH in accordance with guidelines for the diagnosis and treatment of PH in China. Among them, 278 patients did not receive vaccination, whereas 428 patients completed the vaccination series. None of the participants were infected with COVID-19 during our study period. Overall, 398 patients received inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, whereas 30 received recombinant protein subunit vaccine. After adjusting for baseline covariates using the IPW approach, the odds of any adverse events due to PH in the vaccinated group did not statistically significantly increase (27/428 [6.3%] vs. 24/278 [8.6%], odds ratio = 0.72, P = 0.302). Approximately half of the vaccinated patients reported at least one post-vaccination side effects, most of which were mild, including pain at the injection site (159/428, 37.1%), fever (11/428, 2.6%), and fatigue (26/428, 6.1%). CONCLUSIONS: COVID-19 vaccination did not significantly augment the PH-related major adverse events for patients with WHO groups 1 and 4 PH, although there were some tolerable side effects. A large-scale randomized controlled trial is warranted to confirm this finding. The final approval of the COVID-19 vaccination for patients with PH as a public health strategy is promising.

Clonal Hematopoiesis of Indeterminate Potential in Chronic Thromboembolic Pulmonary Hypertension: A Multicenter Study.

BACKGROUND: The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is multifactorial and growing evidence has indicated that hematological disorders are involved. Clonal hematopoiesis of indeterminate potential (CHIP) has recently been associated with an increased risk of both hematological malignancies and cardiovascular diseases. However, the prevalence and clinical relevance of CHIP in patients with CTEPH remains unclear. METHODS: Using stepwise calling on next-generation sequencing data from 499 patients with CTEPH referred to 3 centers between October 2006 and December 2021, CHIP mutations were identified. We associated CHIP with all-cause mortality in patients with CTEPH. To provide insights into potential mechanisms, the associations between CHIP and inflammatory markers were also determined. RESULTS: In total, 47 (9.4%) patients with CTEPH carried at least 1 CHIP mutation at a variant allele frequency of ≥2%. The most common mutations were in DNMT3A, TET2, RUNX1, and ASXL1. During follow-up (mean, 55 months), deaths occurred in 22 (46.8%) and 104 (23.0%) patients in the CHIP and non-CHIP groups, respectively (P<0.001, log-rank test). The association of CHIP with mortality remained robust in the fully adjusted model (hazard ratio, 2.190 [95% CI, 1.257-3.816]; P=0.006). Moreover, patients with CHIP mutations showed higher circulating interleukin-1ß and interleukin-6 and lower interleukin-4 and IgG galactosylation levels. CONCLUSIONS: This is the first study to show that CHIP mutations occurred in 9.4% of patients with CTEPH are associated with a severe inflammatory state and confer a poorer prognosis in long-term follow-up.

Congenital thrombophilia in East-Asian venous thromboembolism population: a systematic review and meta-analysis.

Background: Various inherited traits contribute to the overall risk of venous thromboembolism (VTE). In addition, the epidemiology of thrombophilia in the East-Asian VTE population remains unclear; thus, we aimed to assess the proportion of hereditary thrombophilia via a meta-analysis. Methods: Publications from PubMed, EMBASE, web of science, and Cochrane before December 30, 2022, were searched. Studies from Japan, Korea, China, Hong Kong, Taiwan, Singapore, Thailand, Vietnam, Myanmar, and Cambodia were included. Congenital thrombophilia was described as diseases including protein C (PC) deficiency, protein S (PS) deficiency, antithrombin (AT) deficiency, factor (F)V Leiden (FVL), and prothrombin G20210A mutations. Studies were selected by 2 reviewers for methodological quality analysis. A random-effects model was used for the meta-analysis, assuming that estimated effects in the different studies are not identical. Results: Forty-four studies involving 6453 patients from 7 counties/regions were included in the meta-analysis. The prevalence of PC, PS, and AT deficiencies were 7.1%, 8.3%, and 3.8%, respectively. Among 2924 patients from 22 studies, 5 patients were carriers of FVL mutation. Among 2196 patients from 10 studies, 2 patients were carriers of prothrombin G20210A mutation in a Thailand study. Conclusion: The prevalence of PC, PS, and AT deficiencies was relatively high, while a much lower prevalence of FVL and prothrombin G20210A mutations were identified in East-Asian patients with VTE. Our data stress the relative higher prevalence of PC, PS, and AT deficiencies for thrombophilia in the East-Asian VTE population.

Human Plasma IgG N-Glycome Profiles Reveal a Proinflammatory Phenotype in Chronic Thromboembolic Pulmonary Hypertension.

BACKGROUND: The pathological mechanism of chronic thromboembolic pulmonary hypertension (CTEPH) is not fully understood, and inflammation has been reported to be one of its etiological factors. IgG regulates systemic inflammatory homeostasis, primarily through its N-glycans. Little is known about IgG N-glycosylation in CTEPH. We aimed to map the IgG N-glycome of CTEPH to provide new insights into its pathogenesis and discover novel markers and therapies. METHODS: We characterized the plasma IgG N-glycome of patients with CTEPH in a discovery cohort and validated our results in an independent validation cohort using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Thereafter, we correlated IgG N-glycans with clinical parameters and circulating inflammatory cytokines in patients with CTEPH. Furthermore, we determined IgG N-glycan quantitative trait loci in CTEPH to reveal partial mechanisms underlying glycan changes. RESULTS: Decreased IgG galactosylation representing a proinflammatory phenotype was found in CTEPH. The distribution of IgG galactosylation showed a strong association with NT-proBNP (N-terminal pro-B-type natriuretic peptide) in CTEPH. In line with the glycomic findings, IgG pro-/anti-inflammatory N-glycans correlated well with a series of inflammatory markers and gene loci that have been reported to be involved in the regulation of these glycans or inflammatory immune responses. CONCLUSIONS: This is the first study to reveal the full signature of the IgG N-glycome of a proinflammatory phenotype and the genes involved in its regulation in CTEPH. Plasma IgG galactosylation may be useful for evaluating the inflammatory state in patients with CTEPH; however, this requires further validation. This study improves our understanding of the mechanisms underlying CTEPH inflammation from the perspective of glycomics.

Percutaneous transluminal pulmonary angioplasty for Takayasu arteritis-associated pulmonary hypertension: A single-arm meta-analysis.

BACKGROUND: The efficacy and safety of percutaneous transluminal pulmonary angioplasty (PTPA) for Takayasu arteritis-associated pulmonary hypertension (TA-PH) remain unclear. OBJECTIVES: To examine the efficacy and safety of PTPA in TA-PH. METHODS: PubMed, Embase, and the Cochrane Central Register of Controlled Trials Library were searched from inception to August 18, 2022, for articles investigating the efficacy and safety of PTPA for TA-PH. The primary efficacy outcomes were pulmonary vascular resistance (PVR) changes from baseline to re-evaluation and 6-minute walking distance (6MWD). The safety outcome was procedure-related complications. RESULTS: Five articles comprising 104 patients with TA-PH who underwent PTPA were included. The scores of article quality, as assessed using the methodological index for nonrandomized studies tool, were high, ranging from 13 to 15 points. The pooled treatment effects of PVR (weighted mean difference [WMD]: -4.8 WU; 95% confidence interval [CI]: -6.0 to -3.5 WU; I2 = 0.0%), 6MWD (WMD: 101.9 m; 95% CI: 60.3-143.6 m; I2 = 70.4%) significantly improved. Procedure-related complications, which predominantly present as pulmonary artery injury and pulmonary injury, occurred in 32.0% of the included patients. Periprocedural death occurred in one patient (1.0%, 1/100). CONCLUSIONS: Patients with TA-PH could benefit from PTPA in terms of hemodynamics and exercise tolerance, at the expense of procedure-related complications. PTPA should be encouraged to enhance the treatment response in TA-PH. These findings need to be confirmed by further studies, ideally, randomized controlled trials. REGISTRATION: PROSPERO CRD42022354087.

Non-Ischemic, Non-Hypoxic Myocardial Injury, and Long-Term Mortality in Patients with Coronavirus Disease 2019: A Retrospective Cohort Study.

Objective: Cardiac damage is commonly reported in patients with coronavirus disease 2019 (COVID-19) but its prevalence and impact on the long-term survival of patients remain uncertain. This study aimed to explore the prevalence of myocardial injury and assess its prognostic value in patients with COVID-19. Methods: A single-center, retrospective cohort study was performed at the Affiliated Hospital of Jianghan University. Data from 766 patients with confirmed COVID-19 who were hospitalized from December 27, 2019 to April 25, 2020 were collected. Demographic, clinical, laboratory, electrocardiogram, treatment data and all-cause mortality during follow-up were collected and analyzed. Results: Of the 766 patients with moderate to critically ill COVID-19, 86 (11.2%) died after a mean follow-up of 72.8 days. Myocardial injury occurred in 94 (12.3%) patients. The mortality rate was 64.9% (61/94) and 3.7% (25/672) in patients with and without myocardial injury, respectively. Cox regression showed that myocardial injury was an independent risk factor for mortality (hazard ratio: 8.76, 95% confidence interval: 4.76-16.11, P < 0.001). Of the 90 patients with myocardial injury with electrocardiogram results, sinus tachycardia was present in 29, bundle branch block in 26, low voltage in 10, and abnormal T-wave in 53. Conclusions: COVID-19 not only involves pneumonia but also cardiac damage. Myocardial injury is a common complication and an independent risk factor for mortality in COVID-19 patients.

Time-Velocity Integral of Left Ventricular Outflow Tract Predicts Worse Long-Term Survival in Pulmonary Arterial Hypertension.

Background: The time-velocity integral of the left ventricular outflow tract (TVILVOT) has been demonstrated to correlate with heart failure hospitalization and mortality, but the association of TVILVOT with the severity and prognosis of pulmonary arterial hypertension (PAH) has not been evaluated. Objectives: The aim of this study was to investigate the predictive value of baseline TVILVOT in PAH. Methods: A total of 225 consecutive patients with a diagnosis of incident PAH were prospectively studied and echocardiology-derived TVILVOT was measured at enrollment followed by right heart catheterization examination within 48 hours. Cox proportional hazards analysis was performed to assess the association between baseline variables and mortality. Results: During a median follow-up period of 33.8 months, 44 patients died of cardiovascular events. Baseline TVILVOT was significantly lower in the nonsurvivors compared with the survivors (P < 0.001). Baseline TVILVOT was positively correlated with stroke volume obtained by right heart catheterization (r = 0.709; P < 0.001), and inversely correlated with N-terminal pro-B-type natriuretic peptide (r = -0.533; P < 0.001), pulmonary vascular resistance (r = -0.423; P < 0.001). Multivariate analysis showed that baseline TVILVOT (hazard ratio: 0.856; 95% CI: 0.780-0.941; P = 0.001) was an independent predictor of cardiovascular mortality in PAH. Patients with a baseline TVILVOT <17.1 cm (median value) had a significantly worse survival than those with a baseline TVILVOT ≥17.1 cm (P < 0.001). Conclusions: The findings of this study suggest that noninvasive TVILVOT provides a practical method to assess the severity and predict long-term outcome of PAH.

Prevalence, Genetic Background, and Clinical Phenotype of Congenital Thrombophilia in Chronic Thromboembolic Pulmonary Hypertension.

Background: The role of congenital thrombophilia in chronic thromboembolic pulmonary hypertension (CTEPH) remains unresolved. Objectives: The purpose of this study was to investigate the prevalence, genetic background, and clinical phenotype of congenital thrombophilia in CTEPH. Methods: In total, 367 patients with CTEPH from May 2013 to December 2020 were consecutively enrolled in this cross-sectional study in FuWai Hospital and Peking Union Medical College Hospital in China. The primary outcome was the occurrence of congenital thrombophilia diagnosed through tests for congenital anticoagulants activity (including protein C, protein S, and antithrombin III), factor V Leiden and prothrombin G20210A sequence variants. Next-generation sequencing was conducted for patients with congenital thrombophilia. Clinical phenotype was compared between patients with and without thrombophilia. Results: A total of 36 (9.8%; 95% CI: 6.8%-12.9%) patients were diagnosed as congenital thrombophilia, including 13 protein C deficiency (3.5%; 95% CI: 1.6%-5.4%), 19 protein S deficiency (5.2%; 95% CI: 2.9%-7.5%), and 4 antithrombin III deficiency (1.1%; 95% CI: 0%-2.2%). No factor V Leiden or prothrombin G20210A sequence variants were identified. Genotype for patients with thrombophilia revealed that 10 (76.9%) protein C deficiency patients were PROC sequence variant carriers, 4 (21.1%) protein S deficiency were PROS1 sequence variant carriers, and 2 (50.0%) antithrombin III deficiency were SERPINC1 sequence variant carriers. In the logistic regression model, male sex (OR: 3.24; 95% CI: 1.43-7.31) and proximal lesion in pulmonary arteries (OR: 4.10; 95% CI: 1.91-8.85) had significant differences between the congenital thrombophilia and nonthrombophilia group in CTEPH patients. Conclusions: Congenital thrombophilia was not rare. Male sex and proximal lesion in pulmonary arteries might be the specific clinical phenotype for CTEPH patients with congenital thrombophilia.

Case report: Recurrent syncope as initial symptom in a patient with neck lymphoma.

Syncope may have many different causes, requiring careful identification. Recurrent syncope is uncommon as an initial symptom of neck lymphoma. Head and neck tumors involving the carotid artery cause syncope associate with carotid sinus syndrome. We report the case of a 72-year-old man who suffered from recurrent syncope due to compression of the right carotid sinus by diffuse large B-cell lymphoma and was successfully treated with immunochemotherapy. Syncope may be an early or sole sign of a neck or head tumor. We should be aware of the possibility of an underlying malignancy in patients with unexplained syncope after initial evaluation.

Percutaneous Pulmonary Angioplasty for Patients With Takayasu Arteritis and Pulmonary Hypertension.

BACKGROUND: Percutaneous transluminal pulmonary angioplasty (PTPA) is a treatment modality for chronic thromboembolic pulmonary hypertension, but whether it can be applied to Takayasu arteritis-associated pulmonary hypertension (TA-PH), another chronic obstructive pulmonary vascular disease, remains unclear. OBJECTIVES: This study sought to investigate the efficacy and safety of PTPA for TA-PH. METHODS: Between January 1, 2016, and December 31, 2019, a total of 50 patients with TA-PH who completed the PTPA procedure (the PTPA group) and 21 patients who refused the PTPA procedure (the non-PTPA group) were prospectively enrolled in this cohort study. The primary outcome was all-cause mortality. The safety outcomes included PTPA procedure-related complications. RESULTS: Baseline characteristics and medical therapies were similar between the PTPA group and the non-PTPA group. During a mean follow-up time of 37 ± 14 months, deaths occurred in 3 patients (6.0%) in the PTPA group and 6 patients (28.6%) in the non-PTPA group, contributing to the 3-year survival rate of 93.7% in the PTPA group and 76.2% in the non-PTPA group (P = 0.0096 for log-rank test). The Cox regression model showed that PTPA was associated with a significantly reduced hazard of all-cause mortality in TA-PH patients (HR: 0.18; 95% CI: 0.05-0.73; P = 0.017). No periprocedural death occurred. Severe complications requiring noninvasive positive pressure ventilation occurred in only 1 of 150 total sessions (0.7%). CONCLUSIONS: PTPA tended to be associated with a reduced risk of all-cause mortality with acceptable safety profiles and seemed to be a promising therapeutic option for TA-PH patients.

A Personalized Pulmonary Circulation Model to Non-Invasively Calculate Fractional Flow Reserve for Artery Stenosis Detection.

OBJECTIVE: Fractional Flow Reserve (FFR) is regarded as a fundamental index to assess pulmonary artery stenosis. The application of FFR can increase the accuracy of detection of pulmonary artery stenosis. However, the invasive examination may carry a number of physiological risks for patients. Therefore, we propose a personalized pulmonary circulation model to non-invasively calculate FFR of pulmonary artery stenosis. METHODOLOGY: We have employed a personalized pulmonary circulation model to non-invasively calculate FFR. This model combines boundary condition estimation and 3D pulmonary artery morphology reconstruction for CFD simulation. Firstly, we obtain patient-specific boundary conditions by matching cardiac output and main pulmonary artery pressure. Secondly, the 3D pulmonary artery morphology is reconstructed by semi-automatic segmentation. The CFD simulation is performed to obtain the pressure distribution in the entire pulmonary artery. Finally, the FFR in pulmonary artery stenosis is calculated as the ratio of distal pressure and proximal pressure. RESULTS: To validate our model, we compare the simulated FFR with the measured FFR by pressure guide wires examination of 20 patients. The FFR simulated by our model shows a good agreement with the measured FFR by pressure guide wires examination ( r= 0.989, 0.001). CONCLUSION: Our proposed personalized pulmonary circulation model is shown to be capable of non-invasively calculating FFR with sufficient accuracy. SIGNIFICANCE: The FFR calculated by our personalized circulation model may effectively contribute to non-invasive detection of pulmonary artery stenosis and to a comprehensive evaluation of the entire pulmonary artery vascular tree.

Plasma metabolomics in the perioperative period of defect repair in patients with pulmonary arterial hypertension associated with congenital heart disease.

The quality of life and survival rates of patients with pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH) have been greatly improved by defect-repair surgery and personalized treatments. However, those who survive surgery may remain at risk of persistent PAH, the prognosis may be considerably worse than those unoperated. Dynamic monitoring of clinical measures during the perioperative period of shunt correction is therefore indispensable and of great value. In this study, we explored the plasma-metabolite profiling in 13 patients with CHD-PAH during the perioperative period of defect repair. Plasma was harvested at four time points: prior to cardiopulmonary bypass (CPB) after anesthesia (Pre), immediately after CPB (T0), 24 h (T24), and 48 h (T48) after defect repair. Untargeted metabolomics strategy based on UPLC Q-TOF MS was used to detect the metabolites. A total of 193 distinguishing metabolites were determined at different time points, enriched in pathways such as oxidation of branched-chain fatty acids. We found that 17 metabolite alterations were significantly correlated with the reduction in mean pulmonary arterial pressure (MPAP) at T48 versus Pre. Gradients in diastolic pulmonary arterial pressure (DPAP), bicarbonate in radial artery (aHCO3), bicarbonate in superior vena cava (svcHCO3), and the partial pressure of dissolved CO2 gas in radial artery (aPCO2) were positively correlated with MPAP gradient. Notably, these clinical-measure gradients were correlated with alterations in shunt-correction-associated metabolites. In total, 12 out of 17 identified metabolites in response to defect repair were increased at both T24 and T48 (all P < 0.05, except propionylcarnitine with P < 0.05 at T24). In contrast, galactinol dihydrate, guanosine monophosphate, and hydroxyphenylacetylglycine tended to decline at T24 and T48 (only galactinol dihydrate with P < 0.05 at T48). In conclusion, 17 metabolites that respond to shunt correction could be used as suitable noninvasive markers, and clinical measures, including DPAP, aHCO3, svcHCO3, and aPCO2, would be of great value in disease monitoring and evaluating future therapeutic interventions.

Subendocardial Involvement as an Underrecognized Cardiac MRI Phenotype in Myocarditis.

Background Subendocardial late gadolinium enhancement (LGE) detected with cardiac MRI in myocarditis represents a diagnostic dilemma, since it may resemble myocardial ischemia. Purpose To explore and compare the histopathologic characteristics and clinical features and outcomes in patients with myocarditis with and without subendocardial involvement at cardiac MRI. Materials and Methods This retrospective study evaluated 39 patients with myocarditis pathologically proven by means of either endomyocardial biopsy or explant pathologic findings between 2015 and 2020. Patients were divided into two groups according to cardiac MRI phenotype: 18 with subendocardial involvement (mean age ± standard deviation, 40 years ± 17; 10 women) and 21 with no subendocardial involvement (mean age, 35 years ± 11; six women). The median follow-up period was 784 days (interquartile range [IQR], 90-1123 days). The Student t test, Mann-Whitney U test, and univariable Cox regression were used for statistical analyses. Results In the 18 patients with subendocardial involvement, 12 (67%) had lymphocytic myocarditis and six (33%) had giant cell myocarditis. Patients with subendocardial involvement compared with those without subendocardial involvement had lower left ventricular ejection fraction (mean ± standard deviation, 27% ± 11 vs 41% ± 19; P = .004), larger LGE extent (median, 13% [IQR, 10%-22%] vs 5% [IQR, 2%-17%]; P < .001), higher rates of cardiac death or transplant (eight of 18 patients [44%] vs one of 21 patients [4.8%]; P = .006), higher probability of giant cell myocarditis (six of 18 [33%] vs one of 21 [4.8%]; P = .02), and more major adverse cardiovascular events (MACE) (15 of 18 [83%] vs seven of 21 [33%]; P = .002). In a subgroup of patients with comparable LGE extent (median, 15% vs 16%; P = .40) and left ventricular ejection fraction (median, 27% vs 31%; P = .26), the prognostic difference in terms of MACE remained (15 of 17 patients [88%] vs five of 10 [50%]; P = .02). Conclusion Subendocardial involvement detected with cardiac MRI in myocarditis indicated more severe clinical features, including a higher frequency of severe lymphocytic myocarditis or giant cell myocarditis and worse prognosis. © RSNA, 2021 See also the editorial by de Roos in this issue.

Clinical features and survival in Takayasu's arteritis-associated pulmonary hypertension: a nationwide study.

AIMS: This study aimed to assess the clinical characteristics and long-term survival outcome in patients with Takayasu's arteritis-associated pulmonary hypertension (TA-PH). METHODS AND RESULTS: We conducted a nationally representative cohort study of TA-PH using data from the National Rare Diseases Registry System of China. Patients with pulmonary artery involvement who fulfilled the diagnostic criteria of Takayasu's arteritis and pulmonary hypertension were included. The primary outcome was the time from diagnosis of TA-PH to the occurrence of all-cause death. Between January 2007 and January 2019, a total of 140 patients were included, with a mean age of 41.4 years at diagnosis, and a female predominance (81%). Patients with TA-PH had severely haemodynamic and functional impairments at diagnosis. Significant improvements have been found in N-terminal pro-B-type natriuretic peptide (NT-proBNP) and haemodynamic profiles in patients with TA-PH receiving drugs approved for pulmonary arterial hypertension. The overall 1-, 3-, and 5-year survival rates in TA-PH were 94.0%, 83.2%, and 77.2%, respectively. Predictors associated with an increased risk of all-cause death were syncope [adjusted hazard ratio (HR) 5.38 (95% confidence interval 1.77-16.34), P = 0.003], NT-proBNP level [adjusted HR 1.04 (1.03-1.06), P < 0.001], and mean right atrial pressure [adjusted HR 1.07 (1.01-1.13), P = 0.015]. CONCLUSION: Patients with TA-PH were predominantly female and had severely compromised haemodynamics. More than 80% of patients in our cohort survived for at least 3 years. Medical treatment was based on investigators' personal opinions, and no clear risk-to-benefit ratio can be derived from the presented data.

Radiofrequency Catheter Ablation of Supraventricular Tachycardia in Patients With Pulmonary Hypertension: Feasibility and Long-Term Outcome.

BACKGROUND: Supraventricular tachycardia (SVT) occurs commonly and is strongly correlated with clinical deterioration in patients with pulmonary hypertension (PH). This study aimed to investigate the feasibility and long-term outcome of radiofrequency catheter ablation (RFCA) in PH patients with SVT. MATERIALS AND METHODS: Consecutive PH patients with SVT who were scheduled to undergo electrophysiological study and RFCA between September 2010 and July 2019 were included. The acute results and long-term success of RFCA were assessed after the procedure. RESULTS: In total, 71 PH patients with 76 episodes of SVT were analyzed. Cavotricuspid isthmus-dependent atrial flutter (n = 33, 43.5%) was the most common SVT type, followed by atrioventricular nodal reentrant tachycardia (n = 16, 21.1%). Of the 71 patients, 60 (84.5%) underwent successful electrophysiological study and were subsequently treated by RFCA. Among them, acute sinus rhythm was restored in 54 (90.0%) patients, and procedure-related complications were observed in 4 (6.7%) patients. Univariate logistic regression analysis showed that cavotricuspid isthmus-independent atrial flutter [odds ratio (OR) 25.00, 95% confidence interval (CI) 3.45-180.98, p = 0.001] and wider pulmonary artery diameter (OR 1.19, 95% CI 1.03-1.38; p = 0.016) were associated with RFCA failure. During a median follow-up of 36 (range, 3-108) months, 7 patients with atrial flutter experienced recurrence, yielding a 78.3% 3-year success rate for RFCA treatment. CONCLUSION: The findings suggest that RFCA of SVT in PH patients is feasible and has a good long-term success rate. Cavotricuspid isthmus-independent atrial flutter and a wider PAD could increase the risk for ablation failure.

Association Between Anticoagulation Outcomes and Venous Thromboembolism History in Chronic Thromboembolic Pulmonary Hypertension.

Background: The association between anticoagulation outcomes and prior history of venous thromboembolism (VTE) in chronic thromboembolic pulmonary hypertension (CTEPH) has not been established. This study aimed to compare the efficacy and safety of anticoagulation treatment in CTEPH patients with and without prior history of VTE. Methods: A total of 333 CTEPH patients prescribed anticoagulants were retrospectively included from May 2013 to April 2019. The clinical characteristics were collected at their first admission. Incidental recurrent VTE and clinically relevant bleeding were recorded during follow-up. The Cox proportional regression models were used to identify potential factors associated with recurrent VTE and clinically relevant bleeding. Results: Seventy patients (21%) without a prior history of VTE did not experience recurrent VTE during anticoagulation. Compared to CTEPH patients without a prior history of VTE, those with a prior history of VTE had an increased risk of recurrent VTE [2.27/100 person-year vs. 0/100 person-year; hazard ratio (HR), 8.92; 95% confidence interval (CI), 1.18-1142.00; P = 0.029] but a similar risk of clinically relevant bleeding (3.90/100 person-year vs. 4.59/100 person-year; HR, 0.83; 95% CI, 0.38-1.78; P = 0.623). Multivariate Cox analyses suggested that a prior history of VTE and interruption of anticoagulation treatments were significantly associated with an increased risk of recurrent VTE, while anemia and glucocorticoid use were significantly associated with a higher risk of clinically relevant bleeding. Conclusions: This study is the first to reveal that a prior history of VTE significantly increases the risk of recurrent VTE in CTEPH patients during anticoagulation treatment. This finding should be further evaluated in prospective studies.

Rare variants in MTHFR predispose to occurrence and recurrence of pulmonary embolism.

BACKGROUND: Rare genetic variants play a critical role in unprovoked pulmonary embolism (PE). However, the known risk genes only account a small proportion of patients with PE. The objective of this study was to investigate the relationship between the rare variants of gene encoding methylenetetrahydrofolate reductase (MTHFR) and the initiation and long-term clinical outcomes of PE. METHODS: The rare variants of MTHFR were detected by whole exome sequencing of DNA from 258 unprovoked PE cases and 11,451 controls. Correlation of genotype and clinical phenotype and outcome were evaluated at baseline and after follow-up. RESULTS: MTHFR rare variants were found in 15 of 258 cases (5.81%) and 241 of 11,451 controls (2.10%), conferring 2.87-fold greater odds of the PE occurrence (OR = 2.87, 95% CI = 1.68-4.91, P = 5.6 × 10-5, chi-square test). The patients with MTHFR rare variants had higher plasma level of homocysteine than those without. During a follow-up of 3.0 years, a total of 84 events were identified. The recurrent PE (two or more events of PE) were significantly higher in patients carrying MTHFR rare variants (8/15, 53.3%) compared with those without (55/239, 23.0%) (P = 0.023). CONCLUSION: We speculate that MTHFR rare variants may increase the occurrence and recurrence of PE.

Alteration of Extracellular Superoxide Dismutase in Idiopathic Pulmonary Arterial Hypertension.

Background: Superoxide dismutases (SODs) are an important family of antioxidant enzymes that modulate reactive oxygen species levels. It is largely unknown which SOD isoform(s) change in vivo in idiopathic pulmonary arterial hypertension (IPAH) patients. Methods: A total of 133 consecutive adult IPAH patients who underwent bone morphogenetic protein receptor type 2 (BMPR2) genetic counseling were enrolled in this prospective study. The plasma activities of three subtypes of SOD [copper-zinc (Cu/Zn-SOD), manganese (Mn-SOD), and extracellular SOD (Ec-SOD)] were examined. Results: The activities of SODs were significantly lower in IPAH patients than in healthy subjects. However, only Ec-SOD activity in BMPR2 mutation patients was significantly decreased compared to those in patients without a mutation. The reduced Ec-SOD activity was markedly associated with mean pulmonary arterial pressure, pulmonary vascular resistance (PVR), and 6-min walking distance (6MWD). The reduction of Mn-SOD activity was only associated with 6MWD. There was no association between Cu/Zn-SOD and hemodynamics. Patients with a lower Ec-SOD level had a worse survival compared to those with a higher baseline. The reduced Ec-SOD activity and the raised PVR increased the mortality risk. Conclusions: Ec-SOD was correlated with BMPR2 mutation, hemodynamic dysfunction, and poor outcomes. Circulating Ec-SOD could be a potentially vital antioxidant enzyme in the pathogenesis of IPAH.

DNA methyltransferase 3B deficiency unveils a new pathological mechanism of pulmonary hypertension.

DNA methylation plays critical roles in vascular pathology of pulmonary hypertension (PH). The underlying mechanism, however, remains undetermined. Here, we demonstrate that global DNA methylation was elevated in the lungs of PH rat models after monocrotaline administration or hypobaric hypoxia exposure. We showed that DNA methyltransferase 3B (DNMT3B) was up-regulated in both PH patients and rodent models. Furthermore, Dnmt3b -/- rats exhibited more severe pulmonary vascular remodeling. Consistently, inhibition of DNMT3B promoted proliferation/migration of pulmonary artery smooth muscle cells (PASMCs) in response to platelet-derived growth factor-BB (PDGF-BB). In contrast, overexpressing DNMT3B in PASMCs attenuated PDGF-BB-induced proliferation/migration and ameliorated hypoxia-mediated PH and right ventricular hypertrophy in mice. We also showed that DNMT3B transcriptionally regulated inflammatory pathways. Our results reveal that DNMT3B is a previously undefined mediator in the pathogenesis of PH, which couples epigenetic regulations with vascular remodeling and represents a therapeutic target to tackle PH.