July 27, 2023

Research into the regeneration of the human heart: study shows potential of hypoxia for patients with heart failure

  • Joint study by DLR and University of Texas Southwestern (UTSW) Medical Center on the regenerative capacity of human heart cells after a heart attack or other cardiovascular event
  • Low-oxygen conditions can trigger the heart to repair itself and improve diminished function after myocardial infarction
  • Publication in the journal Circulation Research with the results of the study

According to the Federal Statistical Office in 2022, five out of ten most common causes of death in Germany are heart diseases, which cause over 20 percent of annual deaths.  A joint study by DLR and the University of Texas Southwestern (UTSW) Medical Center on the regenerative capacity of human heart cells after a heart attack or other cardiovascular event shows promising results: The human study, led by the DLR team, supported the hypothesis that low-oxygen conditions can cause the heart to repair itself and improve diminished function after a heart attack. The findings, published in the journal Circulation Research, could herald a "new era in cardiovascular medicine," according to Dr. Sadek (associate director of UTSW's Hamon Center for Regenerative Science and Medicine), who led the preliminary studies in mice. "Contrary to dogma, the decline in heart function after a heart attack may be reversible," Dr. Sadek said. "This study is an outstanding example of how specialized expertise and infrastructure from aerospace medicine can be used to address important medical challenges on Earth," says Prof. Jens Jordan (Director of the DLR Institute of Aerospace Medicine).

Fundamental findings

Previous research at UT Southwestern has identified several key molecular pathways that may compensate for the loss of regenerative capacity of the heart due to increased cardiac stress and oxygenation shortly after birth. Research in mice suggests that some of these key regenerative pathways could be reactivated by prolonged (2 weeks), extremely low-oxygen conditions such as those found on Mount Everest.

To test the safety and feasibility in humans, study leader Prof. Dr. Jens Tank (Head of the Department of Cardiovascular Aerospace Medicine, DLR Institute of Aerospace Medicine) and his team, together with colleagues from the University Hospital of Cologne, recruited four male volunteers who had suffered a heart attack. The men, aged between 54 and 63, are athletes in excellent physical condition and have experience of altitude training.

Study in the hypoxia chamber of the :envihab research facility at the Institute of Aerospace Medicine

The study was conducted in the hypoxia chamber at the :envihab research facility at the Institute of Aerospace Medicine in close collaboration with colleagues at UT Southwestern, including Dr. Sadek, Dr. Benjamin Levine and Dr. Vlad Zaha. This facility has a 300 square meter chamber where environmental conditions such as oxygen levels can be adjusted and subjects can live quite comfortably for extended periods of time. In addition, it is possible to carry out heart examination using the latest imaging methods, such as real-time MRI or PET/MRI. In the pressure chamber, the oxygen level was gradually lowered over a period of two weeks to conditions corresponding to an altitude of around 4,500 meters. The men then spent 4.5 days at this oxygen level before returning to normal conditions. This first study on subjects who have previously suffered an acute heart attack and whose heart muscle is scarred follows on from the preparatory study with experienced professional climbers and paves the way for further studies in the future (link to the previous study here).

Throughout the duration of the study, the four test subjects underwent regular physical examinations and their bodily functions were closely monitored. Further examinations were carried out after the stay in the low-oxygen environment. These showed that both the size and function of the heart had improved significantly. In particular, in one test subject with particularly poor heart function, the previously significantly enlarged left ventricle was reduced in size and the ejection fraction increased by 11 percent. These improvements after a relatively short stay in a moderately oxygen-reduced environment were stable in the long term, according to the study authors: "With the very best medication, we usually only achieve an improvement of 2 to 3 percent," says Dr. Sadek. "This level of improvement is enormous." The study leaders, such as Prof. Dr. Jens Tank, emphasized that these initial results are very promising and clearly show that the research infrastructure at DLR is ideally suited for this purpose.

Publication:

Jan-Niklas Hönemann, Darius Gerlach, Fabian Hoffmann, Tilmann Kramer, Henning Weis, Christine E. Hellweg, Bikash Konda, Vlad G. Zaha, Hesham A. Sadek, Antonius E. van Herwarden, André J. Olthaar, Hannes Reuter, Stephan Baldus, Benjamin D. Levine, Jens Jordan, Jens Tank and Ulrich Limper
Originally published 3 Apr 2023 https://doi.org/10.1161/CIRCRESAHA.122.322334 Circulation Research. 2023;132:1165–1167

Further information:

Contact

Prof. Dr. med. Jens Tank

Head of Cardiovascular Aerospace Medicine
German Aerospace Center
Institute of Aerospace Medicine
Cardiovascular Aerospace Medicine
Linder Höhe, 51147 Cologne

Jan-Niklas Hönemann

German Aerospace Center
Institute of Aerospace Medicine | Department of Internal Medicine III Division of Cardiology, Pneumology, Angiology, and Intensive Care University of Cologne, Germany
Cardiovascular Aerospace Medicine
Linder Höhe 51147, Cologne

Prof. Dr. med. Jens Jordan

Director
German Aerospace Center
Institute of Aerospace Medicine
Linder Höhe, 51147 Cologne

Dr. Ulrich Limper

German Aerospace Center
Institute of Aerospace Medicine
Cardiovascular Aerospace Medicine
Linder Höhe, 51147 Cologne

Friederike Wütscher

Institute Representative for Public Relations
German Aerospace Center
Institute of Aerospace Medicine
Linder Höhe, 51147 Cologne
Tel: +49 2203 601 3328

Prof. Dr. med. Jens Tank
Leiter Kardiovaskuläre Luft- und Raumfahrtmedizin
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Institut für Luft- und Raumfahrtmedizin
Kardiovaskuläre Luft- und Raumfahrtmedizin
Köln
Tel.: +49 2203 601 2572

Jan-Niklas Hönemann
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Institut für Luft- und Raumfahrtmedizin
Kardiovaskuläre Luft- und Raumfahrtmedizin
Köln
Tel.: +49 2203 601 1166
and
Department of Internal Medicine III
Division of Cardiology, Pneumology, Angiology, and Intensive Care
University of Cologne, Germany

Prof. Dr. med. Jens Jordan
Direktor – Institut für Luft- und Raumfahrtmedizin
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Institut für Luft- und Raumfahrtmedizin
Institutsleitung
Köln
Tel.: +49 2203 601 3115

Dr. Ulrich Limper
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Institut für Luft- und Raumfahrtmedizin
Kardiovaskuläre Luft- und Raumfahrtmedizin
Köln
Tel.: +49 2203 601 3063
and
Department of Anesthesiology and Intensive Care Medicine
Merheim Medical Center
Hospitals of Cologne
University of Witten/Herdecke, Germany

Friederike Wütscher
Öffentlichkeitsarbeit/
Institutskommunikation
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Institut für Luft- und Raumfahrtmedizin
Institutsleitung
Köln
Tel.: +49 2203 601-3328