Inhaled nitric oxide testing in predicting prognosis in pulmonary hypertension due to left-sided heart diseases.

AIMS: The pathophysiology of pulmonary hypertension (PH) due to left-sided heart disease (Group 2 PH) is distinct from that of other groups of PH, yet there are still no approved therapies that selectively target pulmonary circulation. The increase in pulmonary capillary pressure due to left-sided heart disease is a trigger event for physical and biological alterations of the pulmonary circulation, including the nitric oxide (NO)-soluble guanylate cyclase-cyclic guanosine monophosphate axis. This study investigated inhaled NO vasoreactivity tests for patients with Group 2 PH and hypothesized that these changes may have a prognostic impact. METHODS AND RESULTS: This was a single-centre, retrospective study with a median follow-up of 365 days. From January 2011 to December 2015, we studied 69 patients with Group 2 PH [age, 61.5 ± 13.0 (standard deviation) years; male:female, 49:20; left ventricular ejection fraction, 50.1 ± 20.4%; mean pulmonary arterial pressure, ≥25 mmHg; and pulmonary arterial wedge pressure (PAWP), >15 mmHg]. No adverse events were observed after NO inhalation. Thirty-four patients with Group 2 PH showed increased PAWP (ΔPAWP: 3.26 ± 2.22 mmHg), while the remaining 35 patients did not (ΔPAWP: -2.11 ± 2.29 mmHg). Multivariate analysis revealed that increased PAWP was the only significant predictor of all-cause death or hospitalization for heart failure (HF) after 1 year (hazard ratio 4.35; 95% confidence interval, 1.27-14.83; P = 0.019). The acute response of PAWP to NO differed between HF with preserved and reduced ejection fractions. CONCLUSIONS: Patients with Group 2 PH were tolerant of the inhaled NO test. NO-induced PAWP is a novel prognostic indicator.

Clinical and Sociodemographic Factors Associated With Health-Related Quality of Life in Patients With Adult Congenital Heart Disease　- A Nationwide Cross-Sectional Multicenter Study.

BACKGROUND: Little is known about clinical or sociodemographic factors that influence health-related quality of life (HRQoL) in patients with adult congenital heart disease (ACHD).Methods and Results: We conducted a nationwide prospective cross-sectional multicenter study at 4 large ACHD centers in Japan. From November 2016 to June 2018, we enrolled 1,223 ACHD patients; 1,025 patients had an HRQoL score. Patients completed a questionnaire survey, including sociodemographic characteristics, and the 36-Item Short-Form Health Survey (SF-36). To determine factors associated with HRQoL, correlations between 2 SF-36 summary scores (i.e., physical component score [PCS] and mental component score [MCS]) and other clinical or sociodemographic variables were examined using linear regression analysis. In multivariable analysis, poorer PCS was significantly associated with 11 variables, including older age, higher New York Heart Association class, previous cerebral infarction, being unemployed, and limited participation in physical education classes and sports clubs. Poorer MCS was associated with congenital heart disease of great complexity, being part of a non-sports club, current smoking, and social drinking. Student status and a higher number of family members were positively correlated with MCS. CONCLUSIONS: This study demonstrates that HRQoL in ACHD patients is associated with various clinical and sociodemographic factors. Further studies are needed to clarify whether some of these factors could be targets for future intervention programs to improve HRQoL outcomes.

Beneficial Effects of Low-Intensity Pulsed Ultrasound Therapy on Right Ventricular Dysfunction in Animal Models.

Right ventricular failure (RVF) is a leading cause of death in patients with pulmonary hypertension; however, effective treatment remains to be developed. We have developed low-intensity pulsed ultrasound therapy for cardiovascular diseases. In this study, we demonstrated that the expression of endothelial nitric oxide synthase (eNOS) in RVF patients was downregulated and that eNOS expression and its downstream pathway were ameliorated through eNOS activation in 2 animal models of RVF. These results indicate that eNOS is an important therapeutic target of RVF, for which low-intensity pulsed ultrasound therapy is a promising therapy for patients with RVF.

Drug discovery focused on novel pathogenic proteins for pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a fatal disease in which the wall thickening and narrowing of pulmonary microvessels progress due to complicated interactions among processes such as endothelial dysfunction, the proliferation of pulmonary artery smooth muscle cells (PASMCs) and adventitial fibrocytes, and inflammatory cell infiltration. Early diagnosis of patients with PAH is difficult and lung transplantation is the only last choice to save severely ill patients. However, the number of donors is limited. Many patients with PAH show rapid progression and a high degree of pulmonary arterial remodeling characterized by the abnormal proliferation of PASMCs, which makes treatment difficult even with multidrug therapy comprising pulmonary vasodilators. Thus, it is important to develop novel therapy targeting factors other than vasodilation, such as PASMC proliferation. In the development of PAH, inflammation and oxidative stress are deeply involved in its pathogenesis. Excessive proliferation and apoptosis resistance in PASMCs are key mechanisms underlying PAH. Based on those characteristics, we recently screened novel pathogenic proteins and have performed drug discovery targeting those proteins. To confirm the clinical significance of this, we used patient-derived blood samples to evaluate biomarker potential for diagnosis and prognosis. Moreover, we conducted high throughput screening and found several inhibitors of the pathogenic proteins. In this review, we introduce the recent progress on basic and clinical PAH research, focusing on the screening of pathogenic proteins and drug discovery.

Identification of Celastrol as a Novel Therapeutic Agent for Pulmonary Arterial Hypertension and Right Ventricular Failure Through Suppression of Bsg (Basigin)/CyPA (Cyclophilin A).

OBJECTIVE: Pulmonary arterial hypertension is characterized by abnormal proliferation of pulmonary artery smooth muscle cells and vascular remodeling, which leads to right ventricular (RV) failure. Bsg (Basigin) is a transmembrane glycoprotein that promotes myofibroblast differentiation, cell proliferation, and matrix metalloproteinase activation. CyPA (cyclophilin A) binds to its receptor Bsg and promotes pulmonary artery smooth muscle cell proliferation and inflammatory cell recruitment. We previously reported that Bsg promotes cardiac fibrosis and failure in the left ventricle in response to pressure-overload in mice. However, the roles of Bsg and CyPA in RV failure remain to be elucidated. Approach and Results: First, we found that protein levels of Bsg and CyPA were upregulated in the heart of hypoxia-induced pulmonary hypertension (PH) in mice and monocrotaline-induced PH in rats. Furthermore, cardiomyocyte-specific Bsg-overexpressing mice showed exacerbated RV hypertrophy, fibrosis, and dysfunction compared with their littermates under chronic hypoxia and pulmonary artery banding. Treatment with celastrol, which we identified as a suppressor of Bsg and CyPA by drug screening, decreased proliferation, reactive oxygen species, and inflammatory cytokines in pulmonary artery smooth muscle cells. Furthermore, celastrol treatment ameliorated RV systolic pressure, hypertrophy, fibrosis, and dysfunction in hypoxia-induced PH in mice and SU5416/hypoxia-induced PH in rats with reduced Bsg, CyPA, and inflammatory cytokines in the hearts and lungs. CONCLUSIONS: These results indicate that elevated Bsg in pressure-overloaded RV exacerbates RV dysfunction and that celastrol ameliorates RV dysfunction in PH model animals by suppressing Bsg and its ligand CyPA. Thus, celastrol can be a novel drug for PH and RV failure that targets Bsg and CyPA. Graphic Abstract: A graphic abstract is available for this article.

Identification of the Novel Variants in Patients With Chronic Thromboembolic Pulmonary Hypertension.

Background Although chronic thromboembolic pulmonary hypertension (CTEPH) and acute pulmonary embolism (APE) share some clinical manifestations, a limited proportion of patients with CTEPH have a history of APE. Moreover, in histopathologic studies, it has been revealed that pulmonary vasculature lesions similar to pulmonary arterial hypertension existed in patients with CTEPH. Thus, it remains unknown whether these 3 disorders also share genetic backgrounds. Methods and Results Whole exome screening was performed with DNA isolated from 51 unrelated patients with CTEPH of Japanese ancestry. The frequency of genetic variants associated with pulmonary arterial hypertension or APE in patients with CTEPH was compared with those in the integrative Japanese Genome Variation Database 3.5KJPN. Whole exome screening analysis showed 17 049 nonsynonymous variants in patients with CTEPH. Although we found 6 nonsynonymous variants that are associated with APE in patients with CTEPH, there was no nonsynonymous variant associated with pulmonary arterial hypertension. Patients with CTEPH with a history of APE had nonsynonymous variants of F5, which encodes factor V. In contrast, patients with CTEPH without a history of APE had a nonsynonymous variant of THBD, which encodes thrombomodulin. Moreover, thrombin-activatable fibrinolysis inhibitor, which is one of the pathogenic proteins in CTEPH, was significantly more activated in those who had the variants of THBD compared with those without it. Conclusions These results provide the first evidence that patients with CTEPH have some variants associated with APE, regardless of the presence or absence of a history of APE. Furthermore, the variants might be different between patients with CTEPH with and without a history of APE.

Beneficial effects of riociguat on hemodynamic responses to exercise in CTEPH patients after balloon pulmonary angioplasty - A randomized controlled study.

BACKGROUND: Although balloon pulmonary angioplasty (BPA) improves symptoms and pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH), the effects of riociguat on hemodynamics and exercise capacity in patients after BPA remain to be elucidated. METHODS AND RESULTS: This study was a single-center, prospective, randomized, open-label trial. From November 2015 to November 2018, we prospectively examined 21 patients with CTEPH (65 ± 9 years old, M/F 2/19) who showed hemodynamic improvement with mean pulmonary arterial pressure (mPAP) < 30 mmHg after BPA without any vasodilators. We performed hemodynamic evaluation and expired gas analysis both at rest and during exercise in supine position using cycle ergometer. After right heart catheterization during exercise, they were randomly assigned to 2 groups with minimized method, using age, sex, and resting mPAP; riociguat (N = 10) and control (N = 11) groups. After 6 months, exercise capacity evaluated by 6-min walk distance and cardiopulmonary exercise testing, and resting hemodynamic parameters were comparable in both groups. However, cardiac output (CO) (6.0 ± 1.7-7.4 ± 1.6, P < 0.01) and pulmonary vascular resistance (4.8 ± 1.8-3.2 ± 0.7 Wood units, P = 0.02) at peak workload were significantly improved in the riociguat group as compared with the control group. The slope of linearized mPAP-CO relationship was significantly decreased in the riociguat group [14.5 (7.8, 14.7) to 6.41 (5.1, 11.4), P < 0.01] but not in the control group. CONCLUSIONS: These results indicate that riociguat exerts beneficial effects on hemodynamic response to exercise in CTEPH patients even after hemodynamic improvement by BPA.

Non-invasive screening using ventilatory gas analysis to distinguish between chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension.

BACKGROUND AND OBJECTIVE: Clinical presentations associated with chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH) at rest are highly similar. Differentiating between CTEPH and PAH using non-invasive techniques remains challenging. Thus, we examined whether analysis of ventilatory gas in response to postural changes can be useful as a non-invasive screening method for pulmonary hypertension (PH), and help differentiate CTEPH from PAH. METHODS: We prospectively enrolled 90 patients with suspected PH and performed right heart catheterization, ventilation/perfusion scan and ventilatory gas analysis. Various pulmonary function parameters were examined in the supine and sitting postures, and postural changes were calculated (Δ(supine - sitting)). RESULTS: In total, 25 patients with newly diagnosed PAH, 40 patients with newly diagnosed CTEPH and 25 non-PH patients were included. ΔEnd-tidal CO2 pressure (PET CO2 ) was significantly lower in patients with CTEPH and PAH than in non-PH patients (both P < 0.001). ΔPET CO2 < 0 mm Hg could effectively differentiate PH from non-PH (area under the curve (AUC) = 0.969, sensitivity = 89%, specificity = 100%). Postural change from sitting to supine significantly increased the ratio of ventilation to CO2 production (VE/VCO2 ) in the CTEPH group (P < 0.001). By contrast, VE/VCO2 significantly decreased in the PAH group (P = 0.001). Notably, CTEPH presented with higher ΔVE/VCO2 than PAH, although no differences were observed in haemodynamic and echocardiographic parameters between the two groups (P < 0.001). Furthermore, ΔVE/VCO2 > 0.8 could effectively differentiate CTEPH from PAH (AUC = 0.849, sensitivity = 78%, specificity = 88%). CONCLUSION: Postural changes in ventilatory gas analysis are useful as a non-invasive bedside evaluation to screen for the presence of PH and distinguish between CTEPH and PAH.

Cyclophilin A as a biomarker for the therapeutic effect of balloon angioplasty in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Although cardiac troponin and natriuretic peptide have been shown to decrease after balloon pulmonary angioplasty (BPA) with improved right ventricular afterload in chronic thromboembolic pulmonary hypertension (CTEPH), biomarkers to evaluate the effects of BPA independently of heart failure status remain to be developed. METHODS: In 39 consecutive CTEPH patients including 31 who underwent BPA, we measured plasma levels of cyclophilin A (CyPA), which we demonstrated is secreted from pulmonary vascular smooth muscle cells in response to mechanical stretch and hypoxia. RESULTS: CyPA levels were elevated in CTEPH patients (12.7, IQR: 7.6-16.0) compared with 8 thromboembolic controls with a history of venous thromboembolism (4.9, IQR: 2.4-11.2) or 18 healthy controls (4.1, IQR: 2.4-6.8) (both p< 0.05) and were linearly correlated with mean pulmonary arterial pressure (r=0.50, p = 0.0003) and pulmonary vascular resistance (r=0.32, p= 0.026). BPA reduced CyPA levels and tended to lower brain-type natriuretic peptide (BNP) levels (p< 0.01 and p = 0.07). When comparing the changes in CyPA before and after BPA in the two subgroups with higher (≥35pg/mL) and normal (<35pg/mL) BNP at baseline, CyPA decreased both in patients with higher BNP and those with normal BNP (both p< 0.05). In contrast, BNP decreased only in patients with higher BNP (p< 0.05). Also, CyPA decreased both in patients with lower (<25 kg/m2) and higher (≥25kg/m2) body mass index (BMI) at baseline (both p<0.05), whereas BPA tended to reduce BNP in patients with lower BMI (p = 0.12) but not in those with higher BMI (p = 0.55). CONCLUSIONS: CyPA could be a useful biomarker to evaluate the effects of BPA even in patients with normal BNP or high BMI.

Prognostic value of the model for end-stage liver disease excluding INR score (MELD-XI) in patients with adult congenital heart disease.

Patients with adult congenital heart disease (ACHD) are at increased risk of developing late cardiovascular complication. However, little is known about the predictive factors for long-term outcome. The Model for End-Stage Liver Disease eXcluding INR (MELD-XI) score was originally developed to assess cirrhotic patients and has the prognostic value for heart failure (HF) patients. In the present study, we examined whether the score also has the prognostic value in this population. We retrospectively examined 637 ACHD patients (mean age 31.0 years) who visited our Tohoku University hospital from 1995 to 2015. MELD-XI score was calculated as follows; 11.76 x ln(serum creatinine) + 5.11 x ln(serum total bilirubin) + 9.44. We compared the long-term outcomes between the high (≥10.4) and the low (<10.4) score groups. The cutoff value of MELD-XI score was determined based on the survival classification and regression tree (CART) analysis. The major adverse cardiac event (MACE) was defined as a composite of cardiac death, HF hospitalization, and lethal ventricular arrhythmias. During a mean follow-up period of 8.6 years (interquartile range 4.4-11.4 years), MACE was noted in 51 patients, including HF hospitalization in 37, cardiac death in 8, and lethal ventricular arrhythmias in 6. In Kaplan-Meier analysis, the high score group had significantly worse MACE-free survival compared with the low score group (log-rank, P<0.001). Multivariable Cox regression analysis showed that the MELD-XI score remained a significant predictor of MACE (hazard ratio 1.36, confidence interval 1.17-1.58, P<0.001) even after adjusting for patient characteristics, such as sex, functional status, estimated glomerular filtration rate, and cardiac function. Furthermore, CART analysis revealed that the MELD-XI score was the most important variable for predicting MACE. These results demonstrate that the MELD-XI score can effectively predict MACE in ACHD patients, indicating that ACHD patients with high MELD-XI score need to be closely followed.

Identification of Adipsin as a Novel Prognostic Biomarker in Patients With Coronary Artery Disease.

Background Circulating proteins are exposed to vascular endothelial layer and influence their functions. Among them, adipsin is a member of the trypsin family of peptidases and is mainly secreted from adipocytes, monocytes, and macrophages, catalyzing the rate-limiting step of the alternative complement pathway. However, its pathophysiological role in cardiovascular disease remains to be elucidated. Here, we examined whether serum adipsin levels have a prognostic impact in patients with coronary artery disease. Methods and Results In 370 consecutive patients undergoing diagnostic coronary angiography, we performed a cytokine array analysis for screening serum levels of 50 cytokines/chemokines and growth factors. Among them, classification and regression analysis identified adipsin as the best biomarker for prediction of their long-term prognosis (median 71 months; interquartile range, 55-81 months). Kaplan-Meier curve showed that higher adipsin levels (≥400 ng/mL) were significantly associated with all-cause death (hazard ratio [HR], 4.2; 95% CI, 1.7-10.6 [P<0.001]) and rehospitalization (HR, 2.4; 95% CI, 1.7-3.5 [P<0.001]). Interestingly, higher high-sensitivity C-reactive protein levels (≥1 mg/L) were significantly correlated with all-cause death (HR, 3.2; 95% CI, 1.7-5.9 [P<0.001]) and rehospitalization (HR, 1.5, 95% CI, 1.1-1.9 [P<0.01]). Importantly, the combination of adipsin (≥400 ng/mL) and high-sensitivity C-reactive protein (≥1 mg/L) was more significantly associated with all-cause death (HR, 21.0; 95% CI, 2.9-154.1 [P<0.001]). Finally, the receiver operating characteristic curve demonstrated that serum adipsin levels predict the death caused by acute myocardial infarction in patients with coronary artery disease (C-statistic, 0.847). Conclusions These results indicate that adipsin is a novel biomarker that predicts all-cause death and rehospitalization in patients with coronary artery disease, demonstrating the novel aspects of the alternative complementary system in the pathogenesis of coronary artery disease.

Diagnostic and Prognostic Significance of Serum Levels of SeP (Selenoprotein P) in Patients With Pulmonary Hypertension.

OBJECTIVE: Despite the recent progress in upfront combination therapy for pulmonary arterial hypertension (PAH), useful biomarkers for the disorder still remain to be developed. SeP (Selenoprotein P) is a glycoprotein secreted from various kinds of cells including pulmonary artery smooth muscle cells to maintain cellular metabolism. We have recently demonstrated that SeP production from pulmonary artery smooth muscle cells is upregulated and plays crucial roles in the pathogenesis of PAH. However, it remains to be elucidated whether serum SeP levels could be a useful biomarker for PAH. Approach and Results: We measured serum SeP levels and evaluated their prognostic impacts in 65 consecutive patients with PAH and 20 controls during follow-up (mean, 1520 days; interquartile range, 1393-1804 days). Serum SeP levels were measured using a newly developed sol particle homogeneous immunoassay. The patients with PAH showed significantly higher serum SeP levels compared with controls. Higher SeP levels (cutoff point, 3.47 mg/L) were associated with the outcome (composite end point of all-cause death and lung transplantation) in patients with PAH (hazard ratio, 4.85 [1.42-16.6]; P<0.01). Importantly, we found that the absolute change in SeP of patients with PAH (ΔSeP) in response to the initiation of PAH-specific therapy significantly correlated with the absolute change in mean pulmonary artery pressure, pulmonary vascular resistance (ΔPVR), and cardiac index (ΔCI; R=0.78, 0.76, and -0.71 respectively, all P<0.0001). Moreover, increase in ΔSeP during the follow-up predicted poor outcome of PAH. CONCLUSIONS: Serum SeP is a novel biomarker for diagnosis and assessment of treatment efficacy and long-term prognosis in patients with PAH.

ADAMTS8 Promotes the Development of Pulmonary Arterial Hypertension and Right Ventricular Failure: A Possible Novel Therapeutic Target.

RATIONALE: Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with aberrant pulmonary artery smooth muscle cells (PASMCs) proliferation, endothelial dysfunction, and extracellular matrix remodeling. OBJECTIVE: Right ventricular (RV) failure is an important prognostic factor in PAH. Thus, we need to elucidate a novel therapeutic target in both PAH and RV failure. METHODS AND RESULTS: We performed microarray analysis in PASMCs from patients with PAH (PAH-PASMCs) and controls. We found a ADAMTS8 (disintegrin and metalloproteinase with thrombospondin motifs 8), a secreted protein specifically expressed in the lung and the heart, was upregulated in PAH-PASMCs and the lung in hypoxia-induced pulmonary hypertension (PH) in mice. To elucidate the role of ADAMTS8 in PH, we used vascular smooth muscle cell-specific ADAMTS8-knockout mice (ADAMTSΔSM22). Hypoxia-induced PH was attenuated in ADAMTSΔSM22 mice compared with controls. ADAMTS8 overexpression increased PASMC proliferation with downregulation of AMPK (AMP-activated protein kinase). In contrast, deletion of ADAMTS8 reduced PASMC proliferation with AMPK upregulation. Moreover, deletion of ADAMTS8 reduced mitochondrial fragmentation under hypoxia in vivo and in vitro. Indeed, PASMCs harvested from ADAMTSΔSM22 mice demonstrated that phosphorylated DRP-1 (dynamin-related protein 1) at Ser637 was significantly upregulated with higher expression of profusion genes (Mfn1 and Mfn2) and improved mitochondrial function. Moreover, recombinant ADAMTS8 induced endothelial dysfunction and matrix metalloproteinase activation in an autocrine/paracrine manner. Next, to elucidate the role of ADAMTS8 in RV function, we developed a cardiomyocyte-specific ADAMTS8 knockout mice (ADAMTS8ΔαMHC). ADAMTS8ΔαMHC mice showed ameliorated RV failure in response to chronic hypoxia. In addition, ADAMTS8ΔαMHC mice showed enhanced angiogenesis and reduced RV ischemia and fibrosis. Finally, high-throughput screening revealed that mebendazole, which is used for treatment of parasite infections, reduced ADAMTS8 expression and cell proliferation in PAH-PASMCs and ameliorated PH and RV failure in PH rodent models. CONCLUSIONS: These results indicate that ADAMTS8 is a novel therapeutic target in PAH.

Identification of Emetine as a Therapeutic Agent for Pulmonary Arterial Hypertension: Novel Effects of an Old Drug.

OBJECTIVE: Excessive proliferation and apoptosis resistance are special characteristics of pulmonary artery smooth muscle cells (PASMCs) in pulmonary arterial hypertension (PAH). However, the drugs in clinical use for PAH target vascular dilatation, which do not exert adequate effects in patients with advanced PAH. Here, we report a novel therapeutic effect of emetine, a principal alkaloid extracted from the root of ipecac clinically used as an emetic and antiprotozoal drug. Approach and Results: We performed stepwise screenings for 5562 compounds from original library. First, we performed high-throughput screening with PASMCs from patients with PAH (PAH-PASMCs) and found 80 compounds that effectively inhibited proliferation. Second, we performed the repeatability and counter assay. Finally, we performed a concentration-dependent assay and found that emetine inhibits PAH-PASMC proliferation. Interestingly, emetine significantly reduced protein levels of HIFs (hypoxia-inducible factors; HIF-1α and HIF-2α) and downstream PDK1 (pyruvate dehydrogenase kinase 1). Moreover, emetine significantly reduced the protein levels of RhoA (Ras homolog gene family, member A), Rho-kinases (ROCK1 and ROCK2 [rho-associated coiled-coil containing protein kinases 1 and 2]), and their downstream CyPA (cyclophilin A), and Bsg (basigin) in PAH-PASMCs. Consistently, emetine treatment significantly reduced the secretion of cytokines/chemokines and growth factors from PAH-PASMCs. Interestingly, emetine reduced protein levels of BRD4 (bromodomain-containing protein 4) and downstream survivin, both of which are involved in many cellular functions, such as cell cycle, apoptosis, and inflammation. Finally, emetine treatment ameliorated pulmonary hypertension in 2 experimental rat models, accompanied by reduced inflammatory changes in the lungs and recovered right ventricular functions. CONCLUSIONS: Emetine is an old but novel drug for PAH that reduces excessive proliferation of PAH-PASMCs and improves right ventricular functions.

Usefulness of ventilatory gas analysis for the non-invasive evaluation of the severity of chronic thromboembolic pulmonary hypertension.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by organic thrombotic obstructions in the pulmonary arteries with reduced pulmonary vascular reserve. This study aimed to examine whether postural changes in ventilatory gas analysis parameters are useful for assessing pulmonary hemodynamics in patients with CTEPH. METHODS: A total of 44 patients with newly diagnosed CTEPH (CTEPH group), 33 patients with improved CTEPH (mean pulmonary arterial pressure [mPAP] <25 mm Hg), and 25 controls were enrolled. Patients with improved CTEPH referred to patients without residual PH who were previously diagnosed with CTEPH and already received optimal therapies. Various pulmonary function parameters were examined in supine and sitting positions, and postural changes were calculated (Δ[supine - sitting]). In 32 patients with CTEPH, we examined hemodynamic and ventilatory gas analysis parameters before the first balloon pulmonary angioplasty (BPA) and during follow-up. RESULTS: Patients with CTEPH had significantly lower supine end-tidal carbon dioxide pressure (PETCO2) and ΔPETCO2 than controls (both P < 0.001), and these parameters were significantly correlated with mPAP (R2 = 0.507, P < 0.0001 and R2 = 0.470, P < 0.001, respectively). Supine PETCO2 and ΔPETCO2 were significantly lower in patients with improved CTEPH than in controls (both P < 0.001). Hemodynamic and echocardiographic parameters were comparable in both groups. Furthermore, significant correlation between the change in mPAP and change in supine PETCO2 by BPA was noted (R2 = 0.478, P < 0.001). CONCLUSION: These results indicate that postural changes in ventilatory gas analysis parameters are useful and non-invasive method for the evaluation of mPAP, which is one of the hemodynamic parameters of CTEPH severity.

Successful Management of Acute Congestive Heart Failure by Emergent Caesarean Section Followed by Adrenalectomy in a Pregnant Woman with Cushing's Syndrome-induced Cardiomyopathy.

Congestive heart failure (CHF) is rare during pregnancy. We herein report a 35-year-old woman who developed CHF with severe left ventricular dysfunction at 35 weeks' gestation. She underwent emergency Caesarean section followed by intensive-care treatment for CHF. The diagnosis of Cushing's syndrome (CS) caused by adrenal adenoma was confirmed by endocrinological examinations and histology after adrenalectomy. She was discharged on heart failure medications and glucocorticoid replacement therapy. Both the symptoms and cardiac function had recovered after 12 months of follow-up. This case highlights the importance of considering CS-induced cardiomyopathy as a cause of CHF in pregnant women.