Loss of response to calcium channel blockers after long-term follow-up treatment in patients with idiopathic pulmonary arterial hypertension.

Idiopathic pulmonary arterial hypertension (PAH) patients with a positive response to acute vasodilator challenge and a clinical response to calcium channel blockers (CCBs) for at least one year are traditionally designated true responders. Nevertheless, little is known about a sustained response to CCBs over longer periods of time. We evaluated the loss of response to CCBs after long-term treatment in a cohort of idiopathic PAH patients previously classified as being true responders. Our data suggest that idiopathic PAH patients can lose clinical response to CCBs even after one year of clinical stability, reinforcing the need for constant multidimensional reevaluation to assess the need for targeted PAH therapies and to classify these patients correctly.

Loss of response to calcium channel blockers after long-term follow-up treatment in patients with idiopathic pulmonary arterial hypertension / Perda de resposta a bloqueadores dos canais de cálcio após acompanhamento prolongado em pacientes com hipertensão arterial pulmonar idiopática

ABSTRACT Idiopathic pulmonary arterial hypertension (PAH) patients with a positive response to acute vasodilator challenge and a clinical response to calcium channel blockers (CCBs) for at least one year are traditionally designated true responders. Nevertheless, little is known about a sustained response to CCBs over longer periods of time. We evaluated the loss of response to CCBs after long-term treatment in a cohort of idiopathic PAH patients previously classified as being true responders. Our data suggest that idiopathic PAH patients can lose clinical response to CCBs even after one year of clinical stability, reinforcing the need for constant multidimensional reevaluation to assess the need for targeted PAH therapies and to classify these patients correctly.

RESUMO Pacientes com hipertensão arterial pulmonar (HAP) idiopática com resposta positiva ao teste de vasorreatividade aguda e resposta clínica a bloqueadores dos canais de cálcio (BCC) durante no mínimo um ano são tradicionalmente denominados "respondedores verdadeiros". No entanto, pouco se sabe sobre a manutenção da resposta a BCC durante períodos mais longos. Avaliamos a perda de resposta a BCC após tratamento prolongado em uma coorte de pacientes com HAP idiopática previamente considerados respondedores verdadeiros. Nossos dados sugerem que pacientes com HAP idiopática podem deixar de apresentar resposta clínica a BCC mesmo depois de um ano de estabilidade clínica, reforçando a necessidade de reavaliação multidimensional constante para avaliar a necessidade de terapias específicas para HAP e classificar esses pacientes corretamente.

Brazilian Thoracic Society recommendations for the diagnosis and treatment of chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious and debilitating disease caused by occlusion of the pulmonary arterial bed by hematic emboli and by the resulting fibrous material. Such occlusion increases vascular resistance and, consequently, the pressure in the region of the pulmonary artery, which is the definition of pulmonary hypertension. The increased load imposed on the right ventricle leads to its progressive dysfunction and, finally, to death. However, CTEPH has a highly significant feature that distinguishes it from other forms of pulmonary hypertension: the fact that it can be cured through treatment with pulmonary thromboendarterectomy. Therefore, the primary objective of the management of CTEPH should be the assessment of patient fitness for surgery at a referral center, given that not all patients are good candidates. For the patients who are not good candidates for pulmonary thromboendarterectomy, the viable therapeutic alternatives include pulmonary artery angioplasty and pharmacological treatment. In these recommendations, the pathophysiological bases for the onset of CTEPH, such as acute pulmonary embolism and the clinical condition of the patient, will be discussed, as will the diagnostic algorithm to be followed and the therapeutic alternatives currently available.

Differences in health policies for drug availability in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension across Latin America.

Treatment for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension in Latin America differs between countries, with regard to disease etiology, health insurance coverage, and drug availability. A group of experts from Latin America, met to share regional experiences and propose possible lines of collaboration. The available evidence, regional clinical practice data, and the global context of the proceedings of the 6th World Symposium on Pulmonary Hypertension, held in Nice, France, in February 2018, were analyzed. Here, we discuss some priority concepts identified that could guide transnational interaction and research strategies in Latin America: (1) despite being evidence-based, the 6th World Symposium on Pulmonary Hypertension proceedings may not be applicable in Latin American countries; (2) proactive identification and diagnosis of patients in Latin America is needed; (3) education of physicians and standardization of appropriate treatment for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension is vital; (4) our clinical experience for the treatment strategy for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension is based on drug availability in Argentina, Brazil, Colombia and México; (5) there are difficulties inherent to the consultation of patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension, and access to treatment; (6) the importance of data generation and research of Latin American-specific issues related to pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension is highlighted.

Stent-armed kyphoplasty in osteoporotic thoracolumbar fractures-clinical and functional results and a center experience over 10 years.

Background: The optimal treatment of osteoporotic vertebral fractures is still a controversial and under discussion topic. Armed kyphoplasty with expansive intravertebral implants is an emerging procedure, which, in theory, it not only makes it possible to achieve instant analgesia, and to get stabilization gains of benefits of kyphoplasty and vertebroplasty, but also, allows for a more effective maintenance of the restored vertebral height. Methods: A retrospective observational study is presented, in which 30 patients participated, including a total of 33 osteoporotic thoracolumbar compression burst vertebral fractures with involvement of one or both vertebral platforms and of more than one fifth of the posterior wall. These individuals underwent armed kyphoplasty with VBS® stents (or stentoplasty) filled with bone cement over 10 years (between 2012 and 2022) at the same center. Clinical (visual analogue scale, Oswestry Disability Index and Patient Global Impression of Change) and imaging results (restoration and maintenance of vertebral body heights) achieved were investigated. The mean follow-up time was 4.5 years (range, 1-10 years). Results: There was a statistically significant improvement in all clinical and functional parameters evaluated, as well as a statistically significant difference in the various vertebral body heights between preoperative and end of follow-up time [increase of 10.7-15.2-5.0 mm (anterior-median-posterior) in the sagittal plane and 6.7-11.6-9.7 mm (right-median-left) in the coronal plane]. There was a statistically significant direct correlation between vertebral heights in the coronal plane, and between the Beck index assessed at the end of the follow-up period and the improvement in functional disability. Conclusions: The percutaneous transpedicular posterior approach, the ability to anatomically restore the fractured vertebra and to maintain it in the medium-long term, as well as the reduced risk of adverse effects, make stent-armed kyphoplasty a very attractive treatment option for osteoporotic compressive thoracolumbar fractures. A clinical-morphological correlation was demonstrated regarding the surgical treatment of these fractures, it was found that a more effective morphological restoration of vertebral heights in both the sagittal and coronal planes is associated with superior satisfactory clinical functional parameters.

Outcomes and prognostic factors of decompensated pulmonary hypertension in the intensive care unit.

BACKGROUND: Patients with acute decompensation of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) admitted to intensive care unit (ICU) have high in-hospital mortality. We hypothesized that pulmonary hypertension (PH) severity, measured by a simplified version of European Society of Cardiology/European Respiratory Society (ESC/ERS) risk assessment, and the severity of organ dysfunction upon ICU admission, measured by sequential organ failure assessment score (SOFA) were associated with in-hospital mortality in decompensated patients with PAH and CTEPH. We also described clinical and laboratory variables during ICU stay. METHODS: Observational study including adults with decompensated PAH or CTEPH with unplanned ICU admission between 2014 and 2019. Multivariate logistic regression models were used to evaluate the association of ESC/ERS risk assessment and SOFA score with in-hospital mortality. ESC/ERS risk assessment and SOFA score were included in a decision tree to predict in-hospital mortality. RESULTS: 73 patients were included. In-hospital mortality was 41.1%. ESC/ERS high-risk group (adjusted odds ratio = 95.52) and SOFA score (adjusted odds ratio = 1.80) were associated with in-hospital mortality. The decision tree identified four groups with in-hospital mortality between 8.1% and 100%. Nonsurvivors had a lower central venous oxygen saturation, higher arterial lactate and higher brain natriuretic peptide in the end of first week in the ICU. CONCLUSIONS: High-risk on a simplified version of ERS/ESC risk assessment and SOFA score upon ICU admission are associate with in-hospital mortality. A decision tree based on ESC/ERS risk assessment and SOFA score identifies four groups with in-hospital mortality between 8.1% and 100%.

Atualização no Tratamento da Hipertensão Arterial Pulmonar / Update on the Treatment of Pulmonary Arterial Hypertension

Resumo Muitos avanços ocorreram nas últimas décadas na terapêutica da hipertensão arterial pulmonar (HAP), uma doença grave, progressiva, incurável e potencialmente fatal. Para seu tratamento adequado, são fundamentais o diagnóstico hemodinâmico e a classificação de sua etiologia, em que várias delas (colagenoses, hipertensão portal, cardiopatia congênitas, esquistossomose) requerem medidas específicas, além do tratamento farmacológico característico para HAP. O tratamento com fármacos-alvo para HAP baseia-se em produtos farmacêuticos que interferem em três vias fisiopatológicas moleculares: da prostaciclina, da endotelina e do óxido nítrico. Tais fármacos apresentam múltiplas apresentações (oral, endovenosa, subcutânea e inalatória) e mudaram a história da HAP. Essas medicações e suas estratégias de uso, assim como particularidades das diferentes formas de HAP, são o foco desta revisão.

Abstract In the last decades, important advances have been made in the treatment of pulmonary arterial hypertension (PAH), a severe, progressive, incurable, and potentially fatal disease. For an adequate therapy, correct hemodynamic diagnosis and etiology classification are fundamental. Many etiologies - rheumatic disease, portal hypertension, congenital heart diseases, schistosomiasis - require specific measures, in addition to drug therapy for PAH. The specific therapy for PAH is based on medications that act on three pathophysiological pathways - prostacyclin, endothelin, and nitric oxide pathways. These drugs have multiple presentations (oral, intravenous, subcutaneous, and inhaled) and have changed the history of PAH. This review presents an overview of drug therapy strategies and different forms and peculiarities of PAH.

Update on the Treatment of Pulmonary Arterial Hypertension. / Atualização no Tratamento da Hipertensão Arterial Pulmonar.

In the last decades, important advances have been made in the treatment of pulmonary arterial hypertension (PAH), a severe, progressive, incurable, and potentially fatal disease. For an adequate therapy, correct hemodynamic diagnosis and etiology classification are fundamental. Many etiologies - rheumatic disease, portal hypertension, congenital heart diseases, schistosomiasis - require specific measures, in addition to drug therapy for PAH. The specific therapy for PAH is based on medications that act on three pathophysiological pathways - prostacyclin, endothelin, and nitric oxide pathways. These drugs have multiple presentations (oral, intravenous, subcutaneous, and inhaled) and have changed the history of PAH. This review presents an overview of drug therapy strategies and different forms and peculiarities of PAH.

Muitos avanços ocorreram nas últimas décadas na terapêutica da hipertensão arterial pulmonar (HAP), uma doença grave, progressiva, incurável e potencialmente fatal. Para seu tratamento adequado, são fundamentais o diagnóstico hemodinâmico e a classificação de sua etiologia, em que várias delas (colagenoses, hipertensão portal, cardiopatia congênitas, esquistossomose) requerem medidas específicas, além do tratamento farmacológico característico para HAP. O tratamento com fármacos-alvo para HAP baseia-se em produtos farmacêuticos que interferem em três vias fisiopatológicas moleculares: da prostaciclina, da endotelina e do óxido nítrico. Tais fármacos apresentam múltiplas apresentações (oral, endovenosa, subcutânea e inalatória) e mudaram a história da HAP. Essas medicações e suas estratégias de uso, assim como particularidades das diferentes formas de HAP, são o foco desta revisão.

[Chronic exposure to altitude. Clinical characteristics and diagnosis]. / Exposición crónica a la altura. Características clínicas y diagnóstico

Chronic exposure to altitude has been associated with hypobaric hypoxia in its inhabitants. Two entities have been associated with it, high altitude pulmonary hypertension and chronic mountain sickness. Its physiological and pulmonary circulation characteristics are described, as well as its clinical profile and diagnosis.

La exposición crónica a la altitud se ha asociado a hipoxia hipobárica en quienes la experimentan. Dos entidades se han asociado a la hipoxia hipobárica: la hipertensión pulmonar de la alta altitud y el mal de montaña crónico. Se describen sus características fisiológicas y de la circulación pulmonar, así como su perfil clínico y el diagnóstico.

Electrical impedance tomography in pulmonary arterial hypertension.

The characterization of pulmonary arterial hypertension (PAH) relies mainly on right heart catheterization (RHC). Electrical impedance tomography (EIT) provides a non-invasive estimation of lung perfusion that could complement the hemodynamic information from RHC. To assess the association between impedance variation of lung perfusion (ΔZQ) and hemodynamic profile, severity, and prognosis, suspected of PAH or worsening PAH patients were submitted simultaneously to RHC and EIT. Measurements of ΔZQ were obtained. Based on the results of the RHC, 35 patients composed the PAH group, and eight patients, the normopressoric (NP) group. PAH patients showed a significantly reduced ΔZQ compared to the NP group. There was a significant correlation between ΔZQ and hemodynamic parameters, particularly with stroke volume (SV) (r = 0.76; P < 0.001). At 60 months, 15 patients died (43%) and 1 received lung transplantation; at baseline they had worse hemodynamics, and reduced ΔZQ when compared to survivors. Patients with low ΔZQ (≤154.6%.Kg) presented significantly worse survival (P = 0.033). ΔZQ is associated with hemodynamic status of PAH patients, with disease severity and survival, demonstrating EIT as a promising tool for monitoring patients with pulmonary vascular disease.

Inhaled iloprost as third add-on therapy in idiopathic pulmonary arterial hypertension.

Triple combination therapy is suggested in current pulmonary arterial hypertension guidelines in case of unsatisfactory treatment with oral double combination therapy. However, there is a lack of evidence concerning some of the drug combinations currently employed. We demonstrate the clinical and hemodynamical benefits of inhaled iloprost as third add-on therapy in idiopathic pulmonary arterial hypertension.

Heparin Therapy Improving Hypoxia in COVID-19 Patients - A Case Series.

INTRODUCTION: Elevated D-dimer is a predictor of severity and mortality in COVID-19 patients, and heparin use during in-hospital stay has been associated with decreased mortality. COVID-19 patient autopsies have revealed thrombi in the microvasculature, suggesting that hypercoagulability is a prominent feature of organ failure in these patients. Interestingly, in COVID-19, pulmonary compliance is preserved despite severe hypoxemia corroborating the hypothesis that perfusion mismatch may play a significant role in the development of respiratory failure. METHODS: We describe a series of 27 consecutive COVID-19 patients admitted to Sirio-Libanes Hospital in São Paulo-Brazil and treated with heparin in therapeutic doses tailored to clinical severity. RESULTS: PaO2/FiO2 ratio increased significantly over the 72 h following the start of anticoagulation, from 254(±90) to 325(±80), p = 0.013, and 92% of the patients were discharged home within a median time of 11 days. There were no bleeding complications or fatal events. DISCUSSION: Even though this uncontrolled case series does not offer absolute proof that micro thrombosis in the pulmonary circulation is the underlying mechanism of respiratory failure in COVID-19, patient's positive response to heparinization contributes to the understanding of the pathophysiological mechanism of the disease and provides valuable information for the treatment of these patients while we await the results of further prospective controlled studies.

Use of medical therapies before pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension patients with severe hemodynamic impairment.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism, characterized by non-resolving fibro-thrombotic obstructions of large pulmonary arteries. Pulmonary endarterectomy (PEA) is the treatment of choice for the disease, significantly improving survival. Patients with worse hemodynamic profile have worse prognosis after surgery, raising the question of whether the use of medical therapy prior to surgery to optimize hemodynamics could improve outcomes. The aim of this study was to evaluate the role of medical therapy pre-PEA, according to the hemodynamic profile at the diagnosis. We retrospectively analyzed all patients submitted to PEA, from January 2013 to December 2017. Functional, clinical and hemodynamic data were collected to evaluate the main prognostic determinants. Patients were stratified according to the hemodynamic severity and use of targeted therapies prior to surgery. A total of 108 patients were included. Thirty-five patients (32,4%) used targeted therapy pre-PEA. The use of medical therapy delayed the surgical procedure by about 7 months. There was no difference in overall survival between patients that received targeted therapy and those treated only with supportive therapy (87.8% vs 80.3%, respectively, p = 0.426). Nevertheless, when analyzing the group of patients with severe hemodynamic impairment, defined by low cardiac output(<3.7L/min) at baseline, patients treated with targeted therapies presented a significantly better one-year survival. In higher-risk CTEPH patients, characterized by the presence of low cardiac output, the use of targeted therapies prior to PEA was associated with better outcome, suggesting a potential role for pre-operative use of medical treatment in this particular subgroup.

Heparin therapy improving hypoxia in COVID-19 patients - a case series [preprint]

INTRODUCTION: Elevated D-dimer is predictor of severity and mortality in COVID-19 patients and heparin use during in hospital stay has been associated to decreased mortality. COVID-19 patient autopsies have revealed thrombi in the microvasculature, suggesting intravascular coagulation as a prominent feature of organ failure in these patients. Interestingly, in COVID19, pulmonary compliance is preserved despite severe hypoxemia corroborating the hypothesis that perfusion mismatch may play a significant role in the development of respiratory failure. METHODS: We describe a series of 27 consecutive COVID-19 patients admitted to the Pulmonology service at Sirio-Libanes Hospital in São Paulo-Brazil treated with heparin in therapeutic doses tailored to clinical severity. RESULTS: PaO2/FiO2 ratio increased significantly over the 72 hours following the start of anticoagulation, from 254(±90) to 325(±80), p=0.013, and over half of the patients were discharged home within an average time of 7.3 (±4.0) days. Half of mechanically ventilated patients were extubated within 10.3 (±1.5) days. The remaining patients showed progressive improvement and there were no bleeding complications or fatal events. DISCUSSION: Even though this uncontrolled case series does not offer absolute proof of DIC as the underlying mechanism of respiratory failure in COVID-19, as well as patients positive response to tailored dose heparinization, it contributes to the understanding of the physiopathological mechanism of the disease and provides valuable information for the treatment of these very sick patients while we await the results of further prospective controlled studies

Lung Cavities in Chronic Thromboembolic Pulmonary Hypertension.

OBJECTIVES: Chronic thromboembolic pulmonary hypertension (CTEPH) is a unique form of pulmonary hypertension (PH) that arises from obstruction of the pulmonary vessels by recanalized thromboembolic material. CTEPH has a wide range of radiologic presentations. Commonly, it presents as main pulmonary artery enlargement, peripheral vascular obstructions, bronchial artery dilations, and mosaic attenuation patterns. Nevertheless, other uncommon presentations have been described, such as lung cavities. These lesions may be solely related to chronic lung parenchyma ischemia but may also be a consequence of concomitant chronic infectious conditions. The objective of this study was to evaluate the different etiologies that cause lung cavities in CTEPH patients. METHODS: A retrospective data analysis of the medical records of CTEPH patients in a single reference PH center that contained or mentioned lung cavities was conducted between 2013 and 2016. RESULTS: Seven CTEPH patients with lung cavities were identified. The cavities had different sizes, locations, and wall thicknesses. In two patients, the cavities were attributed to pulmonary infarction; in 5 patients, an infectious etiology was identified. CONCLUSION: Despite the possibility of being solely associated with chronic lung parenchyma ischemia, most cases of lung cavities in CTEPH patients were associated with chronic granulomatous diseases, reinforcing the need for active investigation of infectious agents in this setting.

Brazilian Thoracic Society recommendations for the diagnosis and treatment of chronic thromboembolic pulmonary hypertension / Recomendações para o diagnóstico e tratamento da hipertensão pulmonar tromboembólica crônica da Sociedade Brasileira de Pneumologia e Tisiologia

ABSTRACT Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious and debilitating disease caused by occlusion of the pulmonary arterial bed by hematic emboli and by the resulting fibrous material. Such occlusion increases vascular resistance and, consequently, the pressure in the region of the pulmonary artery, which is the definition of pulmonary hypertension. The increased load imposed on the right ventricle leads to its progressive dysfunction and, finally, to death. However, CTEPH has a highly significant feature that distinguishes it from other forms of pulmonary hypertension: the fact that it can be cured through treatment with pulmonary thromboendarterectomy. Therefore, the primary objective of the management of CTEPH should be the assessment of patient fitness for surgery at a referral center, given that not all patients are good candidates. For the patients who are not good candidates for pulmonary thromboendarterectomy, the viable therapeutic alternatives include pulmonary artery angioplasty and pharmacological treatment. In these recommendations, the pathophysiological bases for the onset of CTEPH, such as acute pulmonary embolism and the clinical condition of the patient, will be discussed, as will the diagnostic algorithm to be followed and the therapeutic alternatives currently available.

RESUMO A hipertensão pulmonar tromboembólica crônica (HPTEC) é uma doença grave e debilitante, causada pela oclusão do leito arterial pulmonar por êmbolos hemáticos e por material fibroso induzido pela presença desses êmbolos. Essa oclusão eleva a resistência vascular e, por consequência, a pressão do território arterial pulmonar, caracterizando a presença de hipertensão pulmonar. Esse aumento da carga imposta ao ventrículo direito leva a progressiva insuficiência do mesmo e, finalmente, ao óbito. No entanto, ao contrário das outras formas de hipertensão pulmonar, a HPTEC possui uma particularidade muito significativa: a existência de tratamento potencialmente curativo através da tromboendarterectomia pulmonar. Dessa forma, o objetivo primordial do manejo deve ser a avaliação do potencial cirúrgico do paciente em um centro de referência em HPTEC. Entretanto, nem todos os pacientes podem ser submetidos à cirurgia. Para esses pacientes outras alternativas terapêuticas viáveis são a angioplastia de artérias pulmonares e o tratamento farmacológico. Nestas recomendações, discutir-se-ão as bases fisiopatológicas para o surgimento de HPTEC, a partir da embolia pulmonar aguda, bem como o quadro clínico apresentado pelo paciente, o algoritmo diagnóstico a ser seguido e as alternativas terapêuticas disponíveis.

Lung cavities in chronic thromboembolic pulmonary hypertension

OBJECTIVES: Chronic thromboembolic pulmonary hypertension (CTEPH) is a unique form of pulmonary hypertension (PH) that arises from obstruction of the pulmonary vessels by recanalized thromboembolic material. CTEPH has a wide range of radiologic presentations. Commonly, it presents as main pulmonary artery enlargement, peripheral vascular obstructions, bronchial artery dilations, and mosaic attenuation patterns. Nevertheless, other uncommon presentations have been described, such as lung cavities. These lesions may be solely related to chronic lung parenchyma ischemia but may also be a consequence of concomitant chronic infectious conditions. The objective of this study was to evaluate the different etiologies that cause lung cavities in CTEPH patients. METHODS: A retrospective data analysis of the medical records of CTEPH patients in a single reference PH center that contained or mentioned lung cavities was conducted between 2013 and 2016. RESULTS: Seven CTEPH patients with lung cavities were identified. The cavities had different sizes, locations, and wall thicknesses. In two patients, the cavities were attributed to pulmonary infarction; in 5 patients, an infectious etiology was identified. CONCLUSION: Despite the possibility of being solely associated with chronic lung parenchyma ischemia, most cases of lung cavities in CTEPH patients were associated with chronic granulomatous diseases, reinforcing the need for active investigation of infectious agents in this setting.

Extended anticoagulation after venous thromboembolism: should it be done?

Most physicians understand venous thromboembolism (VTE) to be an acute and time-limited disease. However, pathophysiological and epidemiological data suggest that in most patients VTE recurrence risk is not resolved after the first 6 months of anticoagulation. Recurrence rates are high and potentially life-threatening. In these cases, it would make sense to prolong anticoagulation for an undetermined length of time. However, what about the bleeding rates, induced by prolonged anticoagulation? Would they not outweigh the benefit of reducing the VTE recurrent risk? How long should anticoagulation be continued, and should all patients suffering from VTE be provided with extended anticoagulation? This review will address the most recent data concerning extended anticoagulation in VTE secondary prophylaxis. The reviews of this paper are available via the supplementary material section.

Pulmonary Embolism and Gas Exchange.

Acute pulmonary embolism (PE) impairs hemodynamics, gas exchange, and lung mechanical capacity. Considering PE pathophysiology, most attention has been paid to hemodynamic impairment. However, the most prevalent symptoms in PE patients come from gas exchange alterations, which have not been in the spotlight for many years. Pulmonary physiology and consequent gas exchange impairment play a pivotal role in the high risk of death from PE. In this review, we will look at the pathophysiology of PE, from the vascular occlusion to the resultant heterogeneity in pulmonary perfusion and gas exchange impairment, discussing in detail its causes and consequences.

The global view.

PURPOSE OF REVIEW: To understand the global distribution of different forms of pulmonary hypertension. RECENT FINDINGS: Different registries have explored the epidemiological characteristics of pulmonary hypertension. Interestingly, there is a clear difference in the prevalence of different forms of pulmonary hypertension in developed regions in comparison with less developed countries. This finding suggests not only that extrapolation of data should be avoided but also that the known prevalence of pulmonary hypertension might be underestimated. SUMMARY: Pulmonary hypertension might be more prevalent than what is currently believed. Specific forms of pulmonary hypertension distributed worldwide might characterize an unrecognized burden that still have to be properly approached. This highlights the heterogeneity of pulmonary hypertension around the world. It is clear that more epidemiological data are still needed as well as studies addressing management alternatives in these specific regions.