Publications by authors named "Demosthenes Papamatheakis"

Right ventricle (RV)-to-pulmonary artery (PA) coupling measured by the ratio of echocardiography-derived tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) is a meaningful prognostic marker in pulmonary hypertension (PH). It's unclear if balloon pulmonary angioplasty (BPA) treatment of chronic thromboembolic pulmonary hypertension (CTEPH) alters RV-PA coupling measured by TAPSE/PASP. We reviewed CTEPH patients treated with BPA at our institution who had a transthoracic echocardiogram (TTE) before BPA and a follow-up TTE at any point during BPA.

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Current predictors of clinical outcomes after pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) are largely limited to preoperative clinical characteristics. N-terminal-pro-brain natriuretic peptide (NT-pro-BNP), a biomarker of right ventricular dysfunction, has not yet been well described as one such predictor. From 2017 to 2021, 816 patients with CTEPH referred to the University of California, San Diego for PTE were reviewed for differences in NT-pro-BNP to predict preoperative characteristics and postoperative outcomes up to 30 days post-PTE.

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Background: Cardiac dysfunction from pulmonary vascular disease causes characteristic findings on cardiopulmonary exercise testing (CPET). We tested the accuracy of CPET for detecting inadequate stroke volume (SV) augmentation during exercise, a pivotal manifestation of cardiac limitation in patients with pulmonary vascular disease.

Methods: We reviewed patients with suspected pulmonary vascular disease in whom CPET and right heart catheterization (RHC) measurements were taken at rest and at anaerobic threshold (AT).

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Objective: Chronic thromboembolic pulmonary hypertension is potentially curable via pulmonary thromboendarterectomy. A minority of patients experience recurrence of their symptoms and are eligible for repeat pulmonary thromboendarterectomy. However, little data exist regarding risk factors and outcomes for this patient population.

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Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is primarily managed by pulmonary thromboendarterectomy (PTE). As advanced surgical techniques permit resection at the segmental and subsegmental level, PTE can now be curative for CTEPH mostly involving the distal pulmonary arteries.

Methods: Between January 2017 and June 2021, consecutive patients undergoing PTE were categorized according to the most proximal level of chronic thrombus resection: Level I (main pulmonary artery), Level II (lobar), Level III (segmental) and Level IV (subsegmental).

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Management of chronic thromboembolic pulmonary hypertension (CTEPH) should be determined by a multidisciplinary team, ideally at a specialized CTEPH referral center. Radiologists contribute to this multidisciplinary process by helping to confirm the diagnosis of CTEPH and delineating the extent of disease, both of which help determine a treatment decision. Preoperative assessment of CTEPH usually employs multiple imaging modalities, including ventilation-perfusion (V/Q) scanning, echocardiography, CT pulmonary angiography (CTPA), and right heart catheterization with pulmonary angiography.

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Background: Airway hemorrhage is a known complication of pulmonary thromboendarterectomy (PTE) in patients with chronic thromboembolic pulmonary hypertension. Predisposing factors for postoperative airway hemorrhage have not been well described. The aims of this study were to determine the incidence and outcomes of airway hemorrhage after PTE and to identify potential risk factors.

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Chronic thromboembolic pulmonary hypertension (CTEPH) is the result of incompletely resolved pulmonary emboli (PE) that lead to chronic right heart failure. The two mechanical treatment options are pulmonary thromboendarterectomy (PTE) and balloon pulmonary angioplasty (BPA). There are no formal criteria for BPA patient selection and treatment decisions vary according to a center's experience with BPA and PTE.

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The management of pulmonary arterial hypertension (PAH) has become more complex in recent years because of increased pharmacotherapy options and longer patient survival with increasing numbers of comorbidities. As such, more opportunities exist for drug-drug interactions between PAH-targeted medications and medications potentially used to treat comorbid conditions. In this review, we provide an overview of pharmaceutical metabolism by cytochrome P450 and discuss important drug-drug interactions for the 14 Food and Drug Administration-approved medications for PAH in the nitric oxide (NO), endothelin, and prostacyclin pathways.

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Over the past 20 years, despite significant advancements in pulmonary arterial hypertension (PAH) medical therapy, many patients require admission to the hospital and are at risk for in-hospital cardiac arrest (IHCA). Prior data found poor survival in PAH patients after cardiac arrest. The purpose of this study was to explore post-IHCA outcomes in PAH patients receiving advanced medical therapies.

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Although pulmonary endarterectomy (PEA) is the treatment of choice for chronic thromboembolic pulmonary hypertension (CTEPH), many patients have inoperable disease, and some have persistent or recurrent pulmonary hypertension (PH) after surgery. Alternative options (balloon pulmonary angioplasty (BPA) and PH-targeted medical therapy) are, therefore, required. Studies of medical therapies for CTEPH have evolved since Aerosolized Iloprost Randomized (AIR), the first randomized, controlled study of a PH-targeted therapy (inhaled iloprost) to include patients with CTEPH.

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Background: Despite the development of advanced therapies for pulmonary arterial hypertension, pregnancy remains contraindicated in these patients owing to high maternal and fetal morbidity and mortality. Limited data exist regarding pregnancy management and outcome in this unique patient population. We describe a series of pregnant patients diagnosed as having pulmonary arterial hypertension before or during pregnancy who delivered at a tertiary center with a comprehensive and established pulmonary vascular disease program.

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Chronic thromboembolic pulmonary hypertension (CTEPH) is the result of pulmonary arterial obstruction by organized thrombotic material stemming from incompletely resolved acute pulmonary embolism. The exact incidence of CTEPH is unknown but appears to approximate 2.3% among survivors of acute pulmonary embolism.

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Autonomic innervation of the pulmonary vasculature triggers vasomotor contractility predominately through activation of alpha-adrenergic receptors (α-ARs) in the fetal circulation. Long-term hypoxia (LTH) modulates pulmonary vasoconstriction potentially through upregulation of α-AR in the vasculature. Our study aimed to elucidate the role of α-AR in phenylephrine (PE)-induced pulmonary vascular contractility, comparing the effects of LTH in the fetal and adult periods on α-AR subtypes and PE-mediated Ca responses and contractions.

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Background And Objectives: Atrial arrhythmias (AAs) are common after cardiac surgeries including pulmonary thromboendarterectomy (PTE). This study was done to identify patients at highest risk of developing post-PTE AA and their length of stay (LOS).

Methods: We reviewed 521 consecutive patients referred to University of California San Diego (UCSD) for PTE and examined their demographics as well as their baseline pulmonary hemodynamics to determine risk factors for AA.

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Article Synopsis
  • This report presents the first recorded case of necrotizing soft tissue infection (NSTI) caused by a specific organism in an immunocompromised individual in the Western Hemisphere.
  • The patient, who was neutropenic due to acute lymphoblastic leukemia, showed unusual clinical and laboratory signs that complicated diagnosis and delayed necessary surgery.
  • The case emphasizes the need for medical providers to be aware of atypical organisms and presentation in NSTI cases among immunocompromised patients to improve timely diagnosis and treatment.
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Giang, Michael, Demosthenes G. Papamatheakis, Dan Nguyen, Ricardo Paez, Carla Blum Johnston, Joon Kim, Alexander Brunnell, Quintin Blood, Ravi Goyal, Lawrence D. Longo, and Sean M.

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Chronic thromboembolic pulmonary hypertension (CTEPH), a potentially curable form of pulmonary hypertension with pulmonary thromboendarterectomy surgery, has been the focus of significant medical advances. In addition to new imaging modalities that are now used to help recognize and diagnose CTEPH, additional treatment options have emerged for inoperable cases. These include a newly approved medical therapy for inoperable disease or persistent/recurrent CTEPH as well as percutaneous balloon angioplasty of the pulmonary arteries.

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Schistosomiasis, a parasite-borne disease, is highly prevalent in Africa and Asia; it is estimated that close to 20 million people worldwide have a severe form of the disease. The chronic form can affect the gastrointestinal system and lead to hepatosplenic disease, and it may cause cardiopulmonary complications, including pulmonary hypertension. The exact pathogenesis of schistosomiasis-associated pulmonary hypertension (Sch-PH) remains unclear, although several mechanisms, including parasitic arterial embolization, pulmonary arteriopathy, and portopulmonary hypertension-like pathophysiology, have been suggested.

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Pulmonary hypertension of the newborn is caused by a spectrum of functional and structural abnormalities of the cardiopulmonary circuit. The existence of multiple etiologies and an incomplete understanding of the mechanisms of disease progression have hindered the development of effective therapies. Animal models offer a means of gaining a better understanding of the fundamental basis of the disease.

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This review provides evidence that antenatal hypoxia, which represents a significant and worldwide problem, causes prenatal programming of the lung. A general overview of lung development is provided along with some background regarding transcriptional and signaling systems of the lung. The review illustrates that antenatal hypoxic stress can induce a continuum of responses depending on the species examined.

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Improving time to diagnosis and intervention has positively impacted outcomes in acute myocardial infarction, stroke, and trauma through elucidating the early pathogenesis of those diseases. This insight may partly explain the futility of time-insensitive immunotherapy trials for severe sepsis and septic shock. The aim of this study was to examine the early natural history of circulatory biomarker activity in sepsis, relative to previous animal and human outcome trials.

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Exposure to chronic hypoxia during gestation predisposes infants to neonatal pulmonary hypertension, but the underlying mechanisms remain unclear. Here, we test the hypothesis that moderate continuous hypoxia during gestation causes changes in the rho-kinase pathway that persist in the newborn period, altering vessel tone and responsiveness. Lambs kept at 3,801 m above sea level during gestation and the first 2 wk of life were compared with those with gestation at low altitude.

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Membrane depolarization is critical to pulmonary arterial (PA) contraction. Both L-type Ca(2+) channels (Ca(L)) and Rho-kinase are important signaling components of this process and mitochondrial and non-mitochondrial generated superoxides can be part of the signaling process. Maturation and long-term hypoxia (LTH) each can modify depolarization-dependent contraction and the role of superoxides.

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