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ORIGINAL RESEARCH article

Front. Cardiovasc. Med.
Sec. General Cardiovascular Medicine
Volume 12 - 2025 | doi: 10.3389/fcvm.2025.1524201

Electrocardiographic signs of cardiac ischemia at rest and during exercise in patients with COPD travelling to 3100 m. Data from a randomized trial of acetazolamide

Provisionally accepted
Marla Christen Marla Christen 1,2Aline Buergin Aline Buergin 1,2Maamed Mademilov Maamed Mademilov 2,3Laura Mayer Laura Mayer 1,2Simon Raphael Schneider Simon Raphael Schneider 1,2Mona Lichtblau Mona Lichtblau 1,2Talant M Sooronbaev Talant M Sooronbaev 2,3Silvia Ulrich Silvia Ulrich 1,2Konrad E. Bloch Konrad E. Bloch 1,2Michael Furian Michael Furian 1,2*
  • 1 Department of Pneumology, University Hospital Zurich, Zurich, Zürich, Switzerland
  • 2 Kyrgyz-Swiss High Altitude Medical Research Center, Tuja-Ashu, Kyrgyzstan
  • 3 National Center of Cardiology and Internal Medicine (Kyrgyzstan), Bishkek, Kyrgyzstan

The final, formatted version of the article will be published soon.

    In patients with chronic obstructive pulmonary disease (COPD), oxygen delivery to the heart may be impaired during altitude travel. We assessed ECG-derived signs of cardiac ischemia, and effects of preventive acetazolamide therapy in COPD patients travelling to high altitude.Methods: Patients with COPD, GOLD grade 2-3, mean±SD, FEV1 66±11%predicted, aged 57±8years, living <1000m, were included in this analysis of secondary outcomes from a randomized, placebo-controlled, double-blind trial (www.clinicaltrials.gov, NCT03156231). Exercise-electrocardiograms were recorded at the National Center of Internal Medicine and Cardiology, Bishkek (760m) and on the day of arrival at Tuja Ashu high-altitude clinic (3100m), Kyrgyzstan. Acetazolamide (375mg/day) or placebo was administered 24h before ascent and during stay at 3100m. The incidence of postexercise ST-elevations (STE) ≥0.3mm in aVR (J+80ms) was the main outcome.Results: At 760m, 3 of 49 (6%) patients randomized to placebo and 3 of 50 (6%) randomized to acetazolamide showed post-exercise STE. At 3100m under placebo, 2(4%) new STE developed and 1(2%) disappeared compared to 760m (P=0.564, McNemar Test). At 3100m under acetazolamide, 1(2%) new STE developed and 2(4%) disappeared compared to 760m (P=0.564). No treatment effect was detected (P=0.242, Fisher Exact Test). Mean difference (95%CI) in STE between post-exercise and rest at 3100m was 0.22mm(0.06 to 0.39) and 0.09mm(-0.06 to 0.24) under placebo and acetazolamide therapy (treatment effect, -0.13mm(-0.35 to 0.08, P=0.230)).In lowlanders with moderate to severe COPD ascending to 3100m, no ECG-derived signs of cardiac ischemia emerged neither at rest nor post-exercise and this was not modified by preventive acetazolamide therapy.

    Keywords: AVR, cardiac ischemia, hypoxia, electrocardiogram, Acetazolamide

    Received: 07 Nov 2024; Accepted: 14 Jan 2025.

    Copyright: © 2025 Christen, Buergin, Mademilov, Mayer, Schneider, Lichtblau, Sooronbaev, Ulrich, Bloch and Furian. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Michael Furian, Department of Pneumology, University Hospital Zurich, Zurich, 8091, Zürich, Switzerland

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