Robert D. Levy

Bio: Robert D. Levy is an academic researcher from McGill University. The author has contributed to research in topics: VO2 max & Vasodilation. The author has an hindex of 16, co-authored 20 publications receiving 2956 citations.

Expression of Endothelin-1 in the Lungs of Patients with Pulmonary Hypertension

Abstract: Background Pulmonary hypertension is characterized by an increase in vascular tone or an abnormal proliferation of muscle cells in the walls of small pulmonary arteries. Endothelin-1 is a potent endothelium-derived vasoconstrictor peptide with important mitogenic properties. It has therefore been suggested that endothelin-1 may contribute to increases in pulmonary arterial tone or smooth-muscle proliferation in patients with pulmonary hypertension. We studied the sites and magnitude of endothelin-1 production in the lungs of patients with various causes of pulmonary hypertension. Methods We studied the distribution of endothelin-1-like immunoreactivity (by immunocytochemical analysis) and endothelin-1 messenger RNA (by in situ hybridization) in lung specimens from 15 control subjects, 11 patients with plexogenic pulmonary arteriopathy (grades 4 through 6), and 17 patients with secondary pulmonary hypertension and pulmonary arteriopathy of grades 1 through 3. Results In the controls, endothelin-1-like immu...

Reference values for a multiple repetition 6-minute walk test in healthy adults older than 20 years.

Abstract: PURPOSE To (1) identify greatest 6-minute walk distance (6MWD) from among several repetitions (best 6MWD) in a wide age range of healthy volunteers to develop reference values for the multiple repetition 6MWD, and (2) investigate the influence of demographics, anthropometrics, and habitual exercise activity on best 6MWD. METHODS Four 6MWD were performed on the same day in a 20-meter corridor by 41 male and 38 female healthy volunteers ranging in age from 20 to 80 years. The greatest 6MWD by each subject from among four 6MWDs was the primary outcome measure. RESULTS Eighty-six percent had their best 6MWD after the first walk; an average increase of 43 meters was observed from first to best 6MWD (P < 0.003). Best 6MWD averaged 698 +/- 96 meters and was inversely related to age (P < 0.001), directly to height (P < 0.001), and was greater in men than women (P < 0.0002). A regression model accounted for 41% of between-subject variability in best 6MWD (P < 0.00000001). In a subset of older subjects, predicted 6MWD significantly underestimated measured best 6MWD when reference values were used from another study where test familiarization was not provided, but this difference disappeared when value were used from the present and a third study where test familiarization was provided. CONCLUSIONS The present study is the first to provide predicted 6MWD values performed with multiple repetitions and for subjects in the 20-40-year-old age range. Selection of appropriate predicted 6MWD values for interpretation of performance should be guided by subject age and degree of test familiarization provided.

Short-term Pulmonary Vasodilation With l-Arginine in Pulmonary Hypertension

Abstract: Background Endothelial dysfunction may contribute to the pathogenesis of pulmonary hypertension through impaired production of the endothelium-derived vasodilator nitric oxide (NO). l-Arginine, the substrate for NO synthase (NOS), has a vasodilatory effect in systemic vascular beds and can correct abnormal endothelium-dependent vasodilation. It has been suggested that these two effects of l-arginine are mediated through NOS metabolism and enhanced NO production. Therefore, we assessed the short-term pulmonary hemodynamic effects of exogenous l-arginine in patients with pulmonary hypertension of various origins. Methods and Results During continuous hemodynamic monitoring, 10 subjects with pulmonary hypertension (mean pulmonary artery pressure [PAP], 54±5 mm Hg [mean±SEM]) received a 30-minute control infusion of hypertonic saline followed by a 30-minute infusion of 500 mg/kg of l-arginine. The hemodynamic effects of l-arginine were compared with those of prostacyclin titrated to maximally tolerated doses....

2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS): Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), International Society for Heart and Lung Transplantation (ISHLT).

Abstract: ALAT : alanine aminotransferase ASAT : aspartate aminotransferase APAH : associated pulmonary arterial hypertension BAS : balloon atrial septostomy BMPR2 : bone morphogenetic protein receptor 2 BNP : brain natriuretic peptide BPA : balloon pulmonary angioplasty BREATHE : Bosentan

Guidelines for the diagnosis and treatment of pulmonary hypertension: the Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS), endorsed by the International Society of Heart and Lung Transplantation (ISHLT)

Abstract: Guidelines and Expert Consensus Documents summarize and evaluate all currently available evidence on a particular issue with the aim to assist physicians in selecting the best management strategies for a typical patient, suffering from a given condition, taking into account the impact on outcome, as well as the risk/benefit ratio of particular diagnostic or therapeutic means. Guidelines are no substitutes for textbooks. The legal implications of medical guidelines have been discussed previously. A great number of Guidelines and Expert Consensus Documents have been issued in recent years by the European Society of Cardiology (ESC) as well as by other societies and organizations. Because of the impact on clinical practice, quality criteria for development of guidelines have been established in order to make all decisions transparent to the user. The recommendations for formulating and issuing ESC Guidelines and Expert Consensus Documents can be found on the ESC website (http://www.escardio.org/knowledge/guidelines). In brief, experts in the field are selected and undertake a comprehensive review of the published evidence for management and/or prevention of a given condition. Unpublished clinical trial results are not taken into account. A critical evaluation of diagnostic and therapeutic procedures is performed including assessment of the risk/benefit ratio. Estimates of expected health outcomes for larger societies are included, where data exist. The level of evidence and the strength of recommendation of particular treatment options are weighed and graded according to predefined scales, as outlined in Tables 1 and 2 . View this table: Table 1 Classes of recommendations View this table: Table 2 Levels of evidence The experts of the writing panels have provided disclosure statements of all relationships they may have which might be perceived as real or potential sources of conflicts of interest. These disclosure forms are kept on file at the European Heart House, headquarters of the ESC. Any changes in conflict of interest that arise …

Special article2015 ESC/ERS Guidelines for the Diagnosis and Treatment of Pulmonary Hypertension

Abstract: Published on behalf of the European Society of Cardiology. All rights reserved. & 2015 European Society of Cardiology & European Respiratory Society. This article is being published concurrently in the European Heart Journal (10.1093/eurheartj/ehv317) and the European Respiratory Journal (10.1183/13993003.01032-2015). The articles are identical except for minor stylistic and spelling differences in keeping with each journal’s style. Either citation can be used when citing this article. * Corresponding authors: Nazzareno Galiè, Department of Experimental, Diagnostic and Specialty Medicine–DIMES, University of Bologna, Via Massarenti 9, 40138 Bologna, Italy, Tel: +39 051 349 858, Fax: +39 051 344 859, Email: nazzareno.galie@unibo.it.

Bosentan therapy for pulmonary arterial hypertension.

Abstract: Methods In this double-blind, placebo-controlled study, we randomly assigned 213 patients with pulmonary arterial hypertension (primary or associated with connective-tissue disease) to receive placebo or to receive 62.5 mg of bosentan twice daily for 4 weeks followed by either of two doses of bosentan (125 or 250 mg twice daily) for a minimum of 12 weeks. The primary end point was the degree of change in exercise capacity. Secondary end points included the change in the Borg dyspnea index, the change in the World Health Organization (WHO) functional class, and the time to clinical worsening. Results At week 16, patients treated with bosentan had an improved six-minute walking distance; the mean difference between the placebo group and the combined bosentan groups was 44 m (95 percent confidence interval, 21 to 67; P<0.001). Bosentan also improved the Borg dyspnea index and WHO functional class and increased the time to clinical worsening. Conclusions The endothelin-receptor antagonist bosentan is beneficial in patients with pulmonary arterial hypertension and is well tolerated at a dose of 125 mg twice daily. Endothelin-receptor antagonism with oral bosentan is an effective approach to therapy for pulmonary arterial hypertension. (N Engl J Med

[2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension].

Abstract: Nazzareno Galiè (ESC Chairperson), Marc Humbert (ERS Chairperson), Jean-Luc Vachiery, Simon Gibbs, Irene Lang, Adam Torbicki, Gérald Simonneau, Andrew Peacock, Anton Vonk Noordegraaf, Maurice Beghetti, Ardeschir Ghofrani, Miguel Angel Gomez Sanchez, Georg Hansmann, Walter Klepetko, Patrizio Lancellotti, Marco Matucci, Theresa McDonagh, Luc A. Pierard, Pedro T. Trindade, Maurizio Zompatori and Marius Hoeper The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and of the European Respiratory Society (ERS)