TY - JOUR T1 - Effect of acetazolamide on pulmonary vascular hemodynamics in patients with COPD going to altitude: a randomized, placebo-controlled, double-blind trial JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00412-2022 SP - 00412-2022 AU - Mona Lichtblau AU - Stéphanie Saxer AU - Laura Mayer AU - Ulan Sheraliev AU - Maamed Mademilov AU - Michael Furian AU - Aline Buergin AU - Philipp M. Schweiwiller AU - Simon R. Schneider AU - Felix C. Tanner AU - Talant Sooronbaev AU - Konrad E Bloch AU - Silvia Ulrich Y1 - 2022/01/01 UR - http://openres.ersjournals.com/content/early/2022/10/13/23120541.00412-2022.abstract N2 - Background Chronic obstructive pulmonary disease (COPD) may predispose to symptomatic pulmonary hypertension at high altitude. We investigated hemodynamic changes in lowlanders with COPD ascending to 3100m and evaluated whether preventive acetazolamide treatment would attenuate the altitude-induced increase in pulmonary artery pressure (PAP).Methods In this placebo-controlled, double-blind parallel-group trial, patients with COPD GOLD 2–3 living <800 m, SpO2 >92%, PaCO2 <6kPa, were randomized to receive either acetazolamide (125 0-250 mg d−1) or placebo capsules starting 24h before ascent from 760 m and during a 2-day-stay at 3100 m. Echocardiography, pulse-oximetry and clinical assessments were performed at 760m and after the first night at 3100m. Primary outcome was PAP assessed by tricuspid regurgitation pressure gradient (TRPG).Results 112 patients, 68% men, mean±sd age 59±8 y, FEV1 61±12%pred, SpO2 95±2% were included. TRPG increased from 22±7 to 30±10 mmHg in 54 allocated to placebo and from 20±5 to 24±7 mmHg in 58 allocated to acetazolamide (both p<0.05) resulting in a mean (95%CI) treatment effect of −5 (−9 to −1)mmHg (p=0.015). In patients assigned to placebo at 760/3100m, SpO2 was 95±2/88±3%, in the acetazolamide group respective values were 94±2/ 90±3% (both p<0.05) resulting in a treatment effect of +2(1 to 3)% (p= 0.001).Conclusions In lowlanders with COPD travelling to 3100m preventive acetazolamide treatment attenuated the altitude-induced rise in PAP and improved oxygenation.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of Interest: ML received funding from the Swiss Lung League for this study. SU reports grants from the Swiss National Science Foundation and Lung Zuerich. KEB was supported by Swiss National Science Foundation (Grant ID:172980). SS, LM, US, MM, MF, AB, PMS, SRS, FCT and TS have nothing to declare. ER -