Pulmonary-vein-to-pulmonary-artery ratio can be utilized to evaluate myxomatous mitral valve disease progression in dogs.

OBJECTIVE: To evaluate the diagnostic value of pulmonary-vein-to-pulmonary-artery ratio (PV:PA) in dogs with myxomatous mitral valve degeneration (MMVD), classified according to the American College of Veterinary Internal Medicine (ACVIM) consensus guidelines. ANIMALS: 80 client-owned dogs with either MMVD (n = 65) or no cardiovascular disease (control group; n = 15) between August 5, 2020, and July 19, 2023. METHODS: This is a retrospective study. Dogs with MMVD were classified according to ACVIM consensus guidelines. Echocardiograms, thoracic radiographs, and other measurements needed in this study were reviewed in all dogs. Spearman correlation was used to determine the correlation between the PV:PA and the following variables: vertebral heart size, vertebral left atrial size, left-atrium-to-aorta ratio, normalized left ventricular internal diameter, and peak transmitral early diastolic velocity. Receiver operating characteristic (ROC) curve analysis was used to evaluate the value of PV:PA in distinguishing between stages B1 and B2 and stages B2 and C. RESULTS: All conventional indices showed correlations with PV:PA. The area under the ROC curve (AUC) for stages B1 and B2 was 0.83, and the cutoff value for differentiating stage B2 was 1.52. The AUC for stages B2 and C was 0.81, and the cutoff value for differentiating stage C was 2.09. CLINICAL RELEVANCE: PV:PA was significantly different between control and the stage B1 group, stage B1 and B2 group, and stage B2 and C group. PV:PA can be an index that can be used in evaluating MMVD dogs.

Derivation of Stroke Volume from Pulmonary Artery Pressures.

INTRODUCTION: Intermittent cardiac output (CO) studies using thermodilution are considered the gold standard. We have developed a stroke volume (SV) calculator from pulmonary pulse pressure (PP) to allow continuous monitoring of SV and CO from PP. METHODS: Hemodynamic data on 169 patients following orthotopic heart transplantation were used to compare our calculator-derived SV (and SV index, or SVi) against thermodilution-derived SV on admission into intensive care unit immediately following heart transplantation (T0) and 6 h after admission (T6). RESULTS: The calculated SV correlated with thermodilution-derived SV T0 (r = 0.920, p < 0.001, coefficient of 0.539 and the constant of 2.06). The median calculator SV, adjusted for coefficient and constant, was 48.4 ml (37.7, 60.7), comparable to the median thermodilution-derived SV 47.9 ml (37.5, 61.0), p = 0.737 with acceptable agreement on Bland-Altman plots. The thermodilution-derived SVi was 28.1 ml (19.7, 38.7) and adjusted calculator-derived SVi 28.9 ml (19.7, 39.9), p = 0.781. At T6, median thermodilution-derived SVi was 27.7 ml (19.5, 35.9) compared to the calculator-derived SVi median of 26.1 ml (17.7, 37.7), p = 0.203. CONCLUSIONS: Changes in PP can be used to track changes in SV using this calculator. Changes in PP may be used to assess response to treatment in the early post-operative period.

Neutrophil extracellular traps promote proliferation of pulmonary smooth muscle cells mediated by CCDC25 in pulmonary arterial hypertension.

BACKGROUND: Previous studies have indicated that neutrophil extracellular traps (NETs) play a pivotal role in pathogenesis of pulmonary arterial hypertension (PAH). However, the specific mechanism underlying the impact of NETs on pulmonary artery smooth muscle cells (PASMCs) has not been determined. The objective of this study was to elucidate underlying mechanisms through which NETs contribute to progression of PAH. METHODS: Bioinformatics analysis was employed in this study to screen for potential molecules and mechanisms associated with occurrence and development of PAH. These findings were subsequently validated in human samples, coiled-coil domain containing 25 (CCDC25) knockdown PASMCs, as well as monocrotaline-induced PAH rat model. RESULTS: NETs promoted proliferation of PASMCs, thereby facilitating pathogenesis of PAH. This phenomenon was mediated by the activation of transmembrane receptor CCDC25 on PASMCs, which subsequently activated ILK/ß-parvin/RAC1 pathway. Consequently, cytoskeletal remodeling and phenotypic transformation occur in PASMCs. Furthermore, the level of NETs could serve as an indicator of PAH severity and as potential therapeutic target for alleviating PAH. CONCLUSION: This study elucidated the involvement of NETs in pathogenesis of PAH through their influence on the function of PASMCs, thereby highlighting their potential as promising targets for the evaluation and treatment of PAH.

Pulmonary artery pseudoaneurysm after thoracic radiation therapy: A case report and review of the literature.

Pulmonary artery pseudoaneurysm (PAP) is a rare cause of hemoptysis. Potential causes include trauma, infection, or medical interventions. There is a risk of rupture, which is associated with a high mortality rate. We describe a 72-year-old patient, with a past medical history of a lung carcinoma for which she was treated with chemoradiotherapy 6 years prior, who presented with hemoptysis. She was hemodynamically stable and there were no other complaints. CT angiography of the thorax showed a PAP originating from a branch of the right pulmonary artery in the previously irradiated area. The patient was successfully treated by an embolization with plugs. Treatment of lung carcinoma with chemoradiotherapy can result in the development of a PAP. Clinicians should be aware of this complication, even years after the therapy. In literature, only a few cases of PAP in patients treated with (chemo)radiotherapy for lung cancer are described, with a maximum interval up to 7 years.

Pulmonary artery involvement in Behçet's disease: A challenging case and comprehensive management approach.

A 26-year-old male with Behçet's disease (BD) presented with recurrent oral and genital ulcers, bilateral pneumonia, and a left lower pulmonary artery aneurysm. Endovascular coil embolization was initially performed, followed by treatment with prednisone, colchicine, and azathioprine. Despite treatment, disease progression occurred, requiring additional embolization, intravenous pulse methylprednisolone, and cyclophosphamide. Ultimately, a combination of medical and endovascular interventions resolved the pulmonary arterial aneurysms. This case highlights BD's systemic inflammatory nature and vascular complications like pulmonary artery aneurysms. It emphasizes the importance of early detection and individualized, multidisciplinary care for such complications.

Optimal Method for Assessing Right Ventricular to Pulmonary Arterial Coupling and Subclinical Right Ventricular Dysfunction in Older Aged Healthy Adults: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Right ventricular (RV) to pulmonary arterial (PA) coupling describes the ability of the RV to augment contractility in response to increased afterload. Several echocardiographic indexes of RV-PA coupling have been defined; however, the optimal numerator in the coupling ratio is unclear. We sought to establish which of these ratios is best for assessing RV-PA coupling based on their relationships with 6-minute walk distance (6MWD), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and the Kansas City Cardiomyopathy Questionnaire (KCCQ) in aging adults. METHODS: In this study of 1611 MESA participants who underwent echocardiography at Exam 6, we evaluated the association between different numerators, including tricuspid annular planar systolic excursion (TAPSE), fractional area change (FAC), RV free wall strain (RVFWS), and tissue Doppler imaging (TDI) S' velocity to pulmonary artery systolic pressure (PASP) with 6MWD, NT-proBNP, and KCCQ score, adjusted for socioeconomic and cardiovascular disease risk factors. RESULTS: Our cohort had a mean age of 73±8 years, 54% female, and 17% Chinese American, 22% African American, 22% Hispanic, and 39% White participants. The mean (± SD) TAPSE/PASP, FAC/PASP, TDI S' velocity/PASP, and RVFWS/PASP ratios were 0.7±0.2, 1.3±0.3, 0.5±0.1, and 0.8±0.2, respectively. All RV-PA coupling indices decreased with age (p<0.0001 for all). TAPSE/PASP ratio was lower in older (≥85 years) female (0.59 ± 0.14) vs. male (0.65 ± 0.17) participants (p=0.01), whereas FAC/PASP ratio was higher in the same female vs. male participants (p<0.01). TAPSE/PASP and FAC/PASP ratios were significantly and strongly associated with all NT-proBNP, 6MWD, and KCCQ scores in fully adjusted and receiver operating characteristic analysis. CONCLUSION: Among older community-dwelling adults free of heart failure and pulmonary hypertension, both FAC/PASP and TAPSE/PASP ratios are optimal for assessment of RV-PA coupling based on its association with 6MWD, NT-proBNP, and KCCQ score. FAC/PASP ratio has the additional benefit of reflecting age and sex-related geometric and functional changes.

Ductal stenting with bilateral pulmonary artery banding as a life-saving management for hypoplastic left heart syndrome with congenital esophageal atresia: A case series.

We present three cases of hypoplastic left heart syndrome (HLHS) complicated by congenital esophageal atresia and trachea-esophageal fistula (EA/TEF). The standard treatment for HLHS involves a staged surgical approach, eventually reaching Fontan completion. There is no report of patients with both HLHS and EA/TEF, and no established treatment strategy exists for such cases. Given the significant risk of simultaneously operating on HLHS and EA/TEF, we elected to pursue staged repair for each condition separately. Initially, soon after birth, we performed gastrostomy to secure the nutritional pathway for EA/TEF and stabilize breathing. Subsequently, we conducted bilateral pulmonary artery banding (bil-PAB) and ductal stenting for HLHS, as the Norwood operation carried an unacceptably high risk in these patients. Two of these patients were able to transition to home care, while the other patient died during hospitalization due to complications after EA repair. A combination of bil-PAB with ductal stenting for HLHS and staged repair for EA/TEF may provide effective management for patients with both conditions. Learning objective: Hypoplastic left heart syndrome (HLHS) and congenital esophageal atresia (EA) are both life-threatening conditions that require early intervention after birth. There are few reports of patients with both conditions, and no treatment strategy is established. Although the procedure carries a high risk, we successfully performed ductal stenting with bilateral pulmonary artery banding for HLHS, as well as staged repair procedures for EA. Our approach may be a viable strategy for these conditions.

Impact of Age-Related Change in Caval Flow Ratio on Hepatic Flow Distribution in the Fontan Circulation.

BACKGROUND: The Fontan operation is a palliative technique for patients born with single ventricle heart disease. The superior vena cava (SVC), inferior vena cava (IVC), and hepatic veins are connected to the pulmonary arteries in a total cavopulmonary connection by an extracardiac conduit or a lateral tunnel connection. A balanced hepatic flow distribution (HFD) to both lungs is essential to prevent pulmonary arteriovenous malformations and cyanosis. HFD is highly dependent on the local hemodynamics. The effect of age-related changes in caval inflows on HFD was evaluated using cardiac magnetic resonance data and patient-specific computational fluid dynamics modeling. METHODS: SVC and IVC flow from 414 patients with Fontan were collected to establish a relationship between SVC:IVC flow ratio and age. Computational fluid dynamics modeling was performed in 60 (30 extracardiac and 30 lateral tunnel) patient models to quantify the HFD that corresponded to patient ages of 3, 8, and 15 years, respectively. RESULTS: SVC:IVC flow ratio inverted at ≈8 years of age, indicating a clear shift to lower body flow predominance. Our data showed that variation of HFD in response to age-related changes in caval inflows (SVC:IVC, 2, 1, and 0.5 corresponded to ages, 3, 8, and 15+, respectively) was not significant for extracardiac but statistically significant for lateral tunnel cohorts. For all 3 caval inflow ratios, a positive correlation existed between the IVC flow distribution to both the lungs and the HFD. However, as the SVC:IVC ratio changed from 2 to 0.5 (age, 3-15+) years, the correlation's strength decreased from 0.87 to 0.64, due to potential flow perturbation as IVC flow momentum increased. CONCLUSIONS: Our analysis provided quantitative insights into the impact of the changing caval inflows on Fontan's long-term HFD, highlighting the importance of SVC:IVC variations over time on Fontan's long-term hemodynamics. These findings broaden our understanding of Fontan hemodynamics and patient outcomes.

Frequency of Pulmonary Hypertension and Its Associated Risk Factors in End-Stage Renal Disease (ESRD) Patients on Maintenance Hemodialysis.

Introduction Pulmonary hypertension (PH) is a recognized complication in patients with end-stage renal disease (ESRD undergoing maintenance hemodialysis (MHD). PH is commonly found in patients with chronic kidney disease (CKD) and ESRD. PH is associated with increased morbidity and mortality in patients with CKD. Methodology This cross-sectional study aimed to assess the prevalence of PH and its associated risk factors in MHD patients. A total of 220 ESRD patients on MHD patients at The Kidney Center, Karachi, Pakistan, aged 18-70 were included. Patients with chronic obstructive lung disease, valvular heart disease, and obstructive sleep apnea were excluded, as these conditions can be responsible for PH. PH was evaluated by echocardiography (ECHO), which was performed by a cardiologist. Results The mean age was 50.65 ± 14.4 years, with 131 (59.5%) males and 89 (40.5%) females. The average duration on hemodialysis was 5.3 ± 2.8 years. Hypertension (89.5%) and ischemic heart disease (24.1%) were prominent comorbidities. Hypertensive nephropathy (42.7%) was the leading cause of ESRD. Left ventricular hypertrophy was mild in most cases (85.5%), whereas regional wall motion abnormality (RWMA) was common (67.3%). The average pulmonary artery pressure was 35.2 ± 15.3 mmHg. Out of 220 patients, 109 patients (49.8%) of them had mild PH, nine patients (4.1%) had severe PH, and 72 patients (32.7%) had moderate PH. Associations between PH and various factors were examined. RWMA, left ventricular hypertrophy, and left ventricular ejection fraction were significantly associated with PH (p < 0.001). Serum calcium and albumin levels were also associated with PH severity (p < 0.05). Other demographic and laboratory parameters did not show a significant association. Conclusion This study highlights the prevalence of PH in MHD patients and identifies associated risk factors. Understanding these associations can aid in better managing PH in ESRD patients.

Case report: Anesthetic management for removal of tumor thrombus in the inferior vena cava and pulmonary artery in renal cell carcinoma.

Anesthetic management of patients with renal cell carcinoma with tumor thrombus in the inferior vena cava (IVC) is challenging. This paper reports the experience of anesthesia management in a patient with advanced renal cell carcinoma with thrombus accumulation in the IVC, right atrium, and pulmonary artery who underwent radical nephrectomy and tumor thrombus removal assisted by cardiopulmonary bypass. The emboli, measuring approximately 3 × 6 cm in the left inferior pulmonary artery and 4 × 13 cm in the right main pulmonary artery, were removed completely. During incision of the IVC under systemic heparinization, significant blood loss occurred in the surgical field. The surgery took 724 min, and cardiopulmonary bypass took 396 min. Intraoperative blood loss was 22,000 ml. The patient was extubated 39 hours after surgery and stayed in intensive care unit for 3 days. At 1 year follow-up, the patient was in good health and leading a normal life.

An Alternative Endovascular Technique for Treatment of Pulmonary Arteriovenous Malformation: Microballoon-occluded Transcatheter Embolization Using n-butyl-2-cyanoacrylate.

PURPOSE: To investigate the safety and efficacy of microballoon-occluded transcatheter embolization using n-butyl-2-cyanoacrylate (NBCA) in patients with a single pulmonary arteriovenous malformation (PAVM). METHODS: From November 2017 to November 2020, this retrospective study included 38 previously untreated patients with a single PAVM who underwent microballoon-occluded transcatheter embolization using NBCA. All 38 patients had follow-up that included simple chest radiography and contrast-enhanced chest computed tomography (CT). RESULTS: A microballoon was successfully placed in a feeding artery of the PAVM to control the delivery of the NBCA cast in all 38 patients, with complete embolization of sacs and the feeding artery achieved in all cases. The mean diameters of the feeding artery, sac, and draining vein were 3.9 ± 0.9 mm, 7.5 ± 2.6 mm, and 4.6 ± 1.3 mm, respectively. A fixed 1:2 NBCA/Lipiodol ratio was used, and the mean amount of embolic mixture per patient was 1.4 mL (range 0.6-2.2 mL). There were no complications related to microballoon adhesion and non-target embolization of the systemic circulation. Follow-up CT in all 38 patients with a mean delay of 34.5 ± 8.8 months (range 20.7-56.5 months) showed no continued perfusion of the PAVM. CONCLUSION: In our hands, microballoon-occluded n-butyl-2-cyanoacrylate embolization seemed to be safe and appeared to be clinically effective in patients with simple and complex types of single PAVM. Therefore, the present technique has the potential to become a standard treatment for a single PAVM.

Invasive haemodynamics predict outcomes in paediatric pulmonary artery hypertension.

BACKGROUND: Invasive haemodynamics are often performed for initiating and guiding pulmonary artery hypertension therapy. Little is known about the predictive value of invasive haemodynamic indices for long-term outcomes in children with pulmonary artery hypertension. We aimed to evaluate invasive haemodynamic data to help predict outcomes in paediatric pulmonary artery hypertension. METHODS: Patients with pulmonary artery hypertension who underwent cardiac catheterisation (2006-2019) at a single centre were included. Invasive haemodynamic data from the first cardiac catheterisation and clinical outcomes were reviewed. The combined adverse outcome was defined as pericardial effusion (due to right ventricle failure), creation of a shunt for pulmonary artery hypertension (atrial septal defect or reverse Pott's shunt), lung transplant, or death. RESULTS: Among 46 patients with a median [interquartile range (IQR)] age of 13.2 [4.1-44.7] months, 76% had CHD. Median mean pulmonary artery pressure was 37 [28-52] mmHg and indexed pulmonary vascular resistance was 6.2 [3.6-10] Woods units × m2. Median pulmonary artery pulsatility index was 4.0 [3.0-4.7] and right ventricular stroke work index was 915 [715-1734] mmHg mL/m2. After a median follow-up of 2.4 years, nine patients had a combined adverse outcome (two had a pericardial effusion, one underwent atrial level shunt, one underwent reverse Pott's shunt, and six died). Patients with an adverse outcome had higher systolic and mean pulmonary artery pressures, higher diastolic and transpulmonary pressure gradients, higher indexed pulmonary vascular resistance, higher pulmonary artery elastance, and higher right ventricular stroke work index (p < 0.05 each). CONCLUSION: Invasive haemodynamics (especially mean pulmonary artery pressure and diastolic pressure gradient) obtained at first cardiac catheterisation in children with pulmonary artery hypertension predicts outcomes.

Transcatheter recanalisation for absent intra-pericardial pulmonary arteries.

Unilateral absence of intra-pericardial pulmonary artery is a rare congenital malformation. If untreated, it can lead to morbidity and mortality in adulthood. Early intervention and restoration of physiologic pulmonary blood flow is necessary. Transcatheter stenting as initial intervention has been rarely reported. We present transcatheter recanalisation and stenting of the obliterated ductus in two newborns with unilateral absence of intra-pericardial pulmonary artery with cross-sectional imaging, procedural details, angiography, and follow up to surgical repair. We believe that such procedure promotes ipsilateral pulmonary vasculature growth to facilitate unifocalization surgery at a later age.

Right main pulmonary artery distensibility on dynamic ventilation CT and its association with respiratory function.

BACKGROUND: Heartbeat-based cross-sectional area (CSA) changes in the right main pulmonary artery (MPA), which reflects its distensibility associated with pulmonary hypertension, can be measured using dynamic ventilation computed tomography (DVCT) in patients with and without chronic obstructive pulmonary disease (COPD) during respiratory dynamics. We investigated the relationship between MPA distensibility (MPAD) and respiratory function and how heartbeat-based CSA is related to spirometry, mean lung density (MLD), and patient characteristics. METHODS: We retrospectively analyzed DVCT performed preoperatively in 37 patients (20 female and 17 males) with lung cancer aged 70.6 ± 7.9 years (mean ± standard deviation), 18 with COPD and 19 without. MPA-CSA was separated into respiratory and heartbeat waves by discrete Fourier transformation. For the cardiac pulse-derived waves, CSA change (CSAC) and CSA change ratio (CSACR) were calculated separately during inhalation and exhalation. Spearman rank correlation was computed. RESULT: In the group without COPD as well as all cases, CSACR exhalation was inversely correlated with percent residual lung volume (%RV) and RV/total lung capacity (r = -0.68, p = 0.003 and r = -0.58, p = 0.014). In contrast, in the group with COPD, CSAC inhalation was correlated with MLDmax and MLD change rate (MLDmax/MLDmin) (r = 0.54, p = 0.020 and r = 0.64, p = 0.004) as well as CSAC exhalation and CSACR exhalation. CONCLUSION: In patients with insufficient exhalation, right MPAD during exhalation was decreased. Also, in COPD patients with insufficient exhalation, right MPAD was reduced during inhalation as well as exhalation, which implied that exhalation impairment is a contributing factor to pulmonary hypertension complicated with COPD. RELEVANCE STATEMENT: Assessment of MPAD in different respiratory phases on DVCT has the potential to be utilized as a non-invasive assessment for pulmonary hypertension due to lung disease and/or hypoxia and elucidation of its pathogenesis. KEY POINTS: • There are no previous studies analyzing all respiratory phases of right main pulmonary artery distensibility (MPAD). • Patients with exhalation impairment decreased their right MPAD. • Analysis of MPAD on dynamic ventilation computed tomography contributes to understanding the pathogenesis of pulmonary hypertension due to lung disease and/or hypoxia in patients with expiratory impairment.

Right Ventricle-Pulmonary Artery Coupling in Patients Undergoing Cardiac Interventions.

PURPOSE OF REVIEW: This review aims to summarize the fundamentals of RV-PA coupling, its non-invasive means of measurement, and contemporary understanding of RV-PA coupling in cardiac surgery, cardiac interventions, and congenital heart disease. RECENT FINDINGS: The need for more accessible clinical means of evaluation of RV-PA coupling has driven researchers to investigate surrogates using cardiac MRI, echocardiography, and right-sided pressure measurements in patients undergoing cardiac surgery/interventions, as well as patients with congenital heart disease. Recent research has aimed to validate these alternative means against the gold standard, as well as establish cut-off values predictive of morbidity and/or mortality. This emerging evidence lays the groundwork for identifying appropriate RV-PA coupling surrogates and integrating them into perioperative clinical practice.

Cost-effectiveness of remote haemodynamic monitoring by an implantable pulmonary artery pressure monitoring sensor (CardioMEMS-HF system) in chronic heart failure in the Netherlands.

AIMS: Remote haemodynamic monitoring with an implantable pulmonary artery (PA) sensor has been shown to reduce heart failure (HF) hospitalizations and improve quality of life. Cost-effectiveness analyses studying the value of remote haemodynamic monitoring in a European healthcare system with a contemporary standard care group are lacking. METHODS AND RESULTS: A Markov model was developed to estimate the cost-effectiveness of PA-guided therapy compared to the standard of care based upon patient-level data of the MONITOR-HF trial performed in the Netherlands in patients with chronic HF (New York Heart Association class III and at least one previous HF hospitalization). Cost-effectiveness was measured as the incremental cost per quality-adjusted life year (QALY) gained from the Dutch societal perspective with a lifetime horizon which encompasses a wide variety of costs including costs of hospitalizations, monitoring time, telephone contacts, laboratory assessments, and drug changes in both treatment groups. In the base-case analysis, PA-guided therapy increased costs compared to standard of care by €12 121. The QALYs per patient for PA-guided therapy and standard of care was 4.07 and 3.481, respectively, reflecting a gain of 0.58 QALYs. The resulting incremental cost-effectiveness ratio was €20 753 per QALY, which is below the Dutch willingness-to-pay threshold of €50 000 per QALY gained for HF. CONCLUSIONS: The current cost-effectiveness study suggests that remote haemodynamic monitoring with PA-guided therapy on top of standard care is likely to be cost-effective for patients with symptomatic moderate-to-severe HF in the Netherlands.

Clarifying the Anatomy of Tetralogy of Fallot with S-shaped Ascending Aorta.

We recently encountered several cases of tetralogy of Fallot with an abnormally oriented S-shaped ascending aorta. In this retrospective study, we sought to clarify morphology of this unusual under-recognized variant. Databases were reviewed to identify all patients with tetralogy of Fallot having an S-shaped ascending aorta. Computed tomographic angiography was used for the assessment of cardiac morphology. Out of the 21 patients, 18 (86%) had a right aortic arch, 2 (9%) had a left aortic arch, and the remaining patient (5%) had a double aortic arch. Patients with a right aortic arch, compared to age and sex-matched patients with a right aortic arch but normally oriented ascending aorta, had lesser aortic override (29.3 ± 14% vs 54.8 ± 13.2%; p = 0.0001) and a wider ascending aorta (25.2 ± 6.9 vs 18.0 ± 3.2 mm; p = 0.0003). The S-shaped ascending aorta was located posteriorly, with a higher sterno-aortic distance (25.5 ± 7.7 vs 9.9 ± 4.5 mm; p = 0.0001). The ascending aorta among patients with tortuosity was longer (4.12 ± 1.7 vs 3.07 ± 0.82, p = 0.03) but with similar tortuosity index (1.22 ± 0.19 vs 1.15 ± 0.17, p = 0.23). Of the cases with right aortic arch and S-shaped ascending aorta, 16 (89%) had extrinsic compression of the right pulmonary artery (p = 0.0001), while 7 (39%) had crossed pulmonary arteries (p = 0.008), with no such findings among those with normally oriented ascending aorta. Tetralogy of Fallot with an S-shaped ascending aorta is a variant with lesser aortic override and a more posteriorly located ascending aorta. Compression of the right pulmonary artery and crossed pulmonary arteries is frequent in the presence of a right-sided aortic arch. These findings have important implications for optimal diagnosis and surgical repair.

Hypoxic perfusion of pulmonary arterial vasa vasorum increases pulmonary arterial pressure.

The pathophysiology of pulmonary hypertension (PH) is not fully understood. Here, we tested the hypothesis that hypoxic perfusion of the vasa vasorum of the pulmonary arterial (PA) wall causes PH. Young adult pig lungs were explanted and placed into a modified ex vivo lung perfusion unit (Organ care system, OCS) allowing the separate adjustment of parameters for mechanical ventilation, as well as PA perfusion and bronchial arterial (BA) perfusion. PA vasa vasorum are branches of the BA. The lungs were used either as control (n=3) or intervention group (n=8). The protocol of the intervention group was as follows: normoxic ventilation and perfusion (steady state) -hypoxic BA perfusion -steady state -hypoxic BA perfusion. During hypoxic BA perfusion, ventilation and PA perfusion maintained normal. Control lungs were kept under steady state conditions for 105 minutes. During the experiments, PA pressure (PAP) and blood gas analysis was frequently monitored. Hypoxic perfusion of the BA resulted in an increase in systolic and mean PAP, a reaction that was reversible upon normoxic BA perfusion. The PAP increase was reproducible in the second hypoxic BA perfusion. Under control conditions the PAP stayed constant until about 80 minutes of the experiment. In conclusion, the results of the current study prove that hypoxic perfusion of the vasa vasorum of the PA directly increases PAP in an ex situ lung perfusion setup suggesting that PA vasa vasorum function and wall ischemia may contribute to the development of PH.

Pirfenidone and nintedanib attenuates pulmonary artery endothelial and smooth muscle cells transformations induced by IL-11.

Idiopathic pulmonary fibrosis (IPF) associated to pulmonary hypertension (PH) portends a poor prognosis, characterized by lung parenchyma fibrosis and pulmonary artery remodeling. Serum and parenchyma levels of Interleukin 11 (IL-11) are elevated in IPF-PH patients and contributes to pulmonary artery remodeling and PH. However, the effect of current approved therapies against IPF in pulmonary artery remodeling induced by IL-11 is unknown. The aim of this study is to analyze the effects of nintedanib and pirfenidone on pulmonary artery endothelial and smooth muscle cell remodeling induced by IL-11 in vitro. Our results show that nintedanib (NTD) and pirfenidone (PFD) ameliorates endothelial to mesenchymal transition (EnMT), pulmonary artery smooth muscle cell to myofibroblast-like transformation and pulmonary remodeling in precision lung cut slices. This study provided also evidence of the inhibitory effect of PFD and NTD on IL-11-induced endothelial and muscle cells proliferation and senescence. The inhibitory effect of these drugs on monocyte arrest and angiogenesis was also studied. Finally, we observed that IL-11 induced canonical signal transducer and activator of transcription 3 (STAT3) and non-canonical mitogen-activated protein kinase 1/2 (ERK1/2) phosphorylation, but, PFD and NTD only inhibited ERK1/2 phosphorylation. Therefore, this study provided evidence of the inhibitory effect of NTD and PFD on markers of pulmonary artery remodeling induced by IL-11.