Feature | July 31, 2014

The Heart of An Astronaut, Five Years After Space

Cardio Ox investigation will look at how oxidative stress and inflammation caused by conditions of spaceflight affect astronaut hearts for up to five years after astronauts fly on the International Space Station

Cardio Ox investigation Astronaut Oxidative Stress Cardiovascular Health

JAXA astronaut Koichi Wakata, Expedition 38 Flight Engineer, demonstrates the ultrasound used to collect data for the Cardio Ox investigation, in the Columbus Module. Image Credit: NASA

Cardio Ox investigation Astronaut Oxidative Stress Cardiovascular Health

NASA astronaut Reid Wiseman, currently a flight engineer aboard the International Space Station, during prelaunch ground training for use of the Ultrasound-2 device which is used for the Cardio Ox study. Image Credit: NASA

July 31, 2014 — The heart of an astronaut is a much-studied thing. Scientists have analyzed its blood flow, rhythms, atrophy and, through journal studies, even matters of the heart. But for the first time, researchers are looking at how oxidative stress and inflammation caused by the conditions of space flight affect those hearts for up to five years after astronauts fly on the International Space Station. Lessons learned may help improve cardiovascular health on Earth as well.

Oxidative stress reflects an imbalance in the body's ability to handle toxic byproducts from normal, oxygen-consuming cell metabolism. This imbalance produces peroxides and free radicals, which contribute to a number of degenerative conditions. Evidence indicates that oxidative stress and resulting inflammation can accelerate the development of atherosclerosis, a disease in which plaque builds up inside arteries. This disease can lead to heart attacks and strokes.

For this investigation, called Cardio Ox, researchers at NASA's Johnson Space Center in Houston will look at the function and structure of arteries along with specific biomarkers in the blood and urine that indicate inflammation and oxidative stress. These biological samples will be taken from astronauts before their launch, 15 and 60 days after launch, 15 days before returning to Earth, and within days after landing.

The crew will also take ultrasound scans of the carotid artery thickness and brachial artery dilation, recognized indicators of cardiovascular health, at the same time points, for comparison with the biomarkers. The same measurements will be taken and ultrasounds performed at the regular check-ups that all astronauts have one, three and five years after flight.

"This is the first cardiovascular study to cover such a long period," said Steven Platts, Ph.D., principal investigator. The data will create a picture over time, allowing researchers to examine whether blood vessel changes seen during flight returned to normal sometime after flight. They will also be able to determine if the effects of oxidative stress grow worse over time or if astronauts experience chronic inflammation post-flight.

Many studies have looked at oxidative stress on Earth, but only astronauts are simultaneously exposed to so many factors known to cause it. The unique environment of a space mission combines a number of factors that can increase the risk of oxidative damage and inflammation, including radiation, psychological stress, reduced physical activity and, in the case of extravehicular activity, increased oxygen exposure.

"It's a perfect storm of things known to cause oxidative stress all happening at the same time," Platts explained. "So this study will enable us to answer some important questions, such as, do these factors work together to make things worse? Are any of them at high enough exposure to cause damage?" Knowing more about how space may cause changes in cardiovascular health will help scientists develop measures to counter its negative effects, in space and on Earth.

The pre-flight data provide a snapshot of an astronaut's cardiovascular health before exposure to the space environment, which then makes it reasonable to assume that any changes are caused by exposure to the space environment and not by other factors. Other studies have looked at specific factors such as mental stress or exercise and their relationship to oxidative damage, but the space station provides a unique opportunity to integrate a variety of causes in a single person.

Typically, a study eliminates all variables except one and examines that one, but this investigation looks at how the entire workplace environment affects the body. The same factors also affect people in unique Earth-bound job environments, such as long-haul jet pilots or train engineers, those who work in a small room all day at a radiation plant, or in unique conditions such as Antarctica. Such situations subject people to stress similar to that experienced by astronauts. The disruption of daily rhythm and sleep patterns experienced in space could be extrapolated to shift workers on Earth as well.

Astronaut Scott Kelly participated in the investigation during his time in orbit and recently completed his one-year post-flight checkup. The study is continuing aboard the station, and a total of 12 astronauts in all will participate during the five-year investigation. You could say the subjects are really putting their hearts into it.

For more information: www.nasa.gov/mission_pages/station/research/news/cardio_ox/#.U9pIFIBdUhw

 

Related Content

Biotronik, BioMonitor 2 implantable cardiac monitor, BioInsight clinical study, first patients enrolled
News | Implantable Cardiac Monitor (ICM)| January 20, 2017
Biotronik has enrolled the first patients in the BioInsight clinical study evaluating the safety and feasibility of...
3-D echocardiography, ASE/EACVI guidelines, congenital heart disease, CHD, Journal of the American Society of Echocardiography, JASE
News | Cardiovascular Ultrasound| January 20, 2017
January 20, 2017 — A new document from the European Association of Cardiovascular Imaging (EACVI) and the American So
ICDs, non-ischemic cardiomyopathy, University of Alabama at Birmingham study, Circulation
News | Implantable Cardioverter Defibrillators (ICD)| January 18, 2017
A new study published in Circulation has found there is a 23 percent risk in reduction of all-cause mortality in non-...
stress, brain activity, cardiovascular risk, PET-CT, MGH, ISSMS, The Lancet study
News | Cardiac Diagnostics| January 18, 2017
A study led by Massachusetts General Hospital (MGH) and Icahn School of Medicine at Mount Sinai (ISSMS) investigators...
ICDs, implantable cardioverter defibrillators, survival rate, elderly patients, JACC study
News | Implantable Cardioverter Defibrillators (ICD)| January 17, 2017
Of patients over age 65 who received an implantable cardioverter-defibrillator (ICD) after surviving sudden cardiac...
University of Utah, Frank Sachse, heart failure, LVAD implantation, left ventricular assist device, biomarker, t-system

Two patients may seem equally sick based upon clinical measures, but differences in their heart physiology could predict who has the potential to recover from heart failure. A study carried out by scientists at the University of Utah finds that patients whose hearts have flattened t-tubules have a decreased chance of showing signs of recovery after implanting a mechanical heart pump. Ordinarily, t-tubules in the heart are long, thin, and rounded. Image courtesy of Frank Sachse.

News | Cardiac Diagnostics| January 17, 2017
Investigators at the University of Utah have identified distinct differences in the hearts of advanced heart failure...
Synergy stent, abluminal polymer DES, bioresorbable polymer DES, bioresorbable polymer metallic stent

The Synergy stent is the first FDA cleared drug-eluting stent to use a bioresorbable polymer drug carrier. When the polymer dissolves after about four months, the devices become a bare metal stent. The technology is supposed to reduce the rate of late stent thrombosis due to vessel inflammation caused by durable polymers.

Feature | Stents Bioresorbable| January 17, 2017 | Dave Fornell
One of the big advancements in drug-eluting stent (DES) technology has been the development of bioresorbable polymers
St. Jude Medical, Amplatzer Amulet LAA Occluder, observational study, TCT 2016
News | Left Atrial Appendage (LAA) Occluders| November 03, 2016
St. Jude Medical Inc. presented favorable results from the largest observational study to date of the company’s...
Medtronic, CoreValve Evolut R TAVR system, U.S. IDE Study, TCT 2016
News | Heart Valve Technology| November 03, 2016
Medtronic plc unveiled new clinical data showing that patients treated with the self-expanding CoreValve Evolut R...
open-heart surgery, PCI, percutaneous coronary intervention, NOBLE trial, left main coronary artery disease, LMCAD, TCT 2016
News | Cardiovascular Surgery| November 03, 2016
Coronary artery bypass (CABG) surgery is the standard treatment for revascularization in patients with left main...
Overlay Init