Cardiac biomarkers at high altitude

Area of Science:

• Altitude physiology
• Cardiovascular biomarkers
• High-altitude pulmonary edema (HAPE)

Background:

• Natriuretic peptides (NPs) and high-sensitivity troponin T (hs-cTnT) are established biomarkers for heart failure and acute coronary syndromes, respectively.
• NPs are also elevated in pulmonary hypertension, a key feature of high-altitude pulmonary edema (HAPE).
• Diagnosing high pulmonary artery systolic pressure (PASP) and acute mountain sickness (AMS) in field settings can be challenging.

Purpose of the Study:

• To investigate the utility of common cardiac biomarkers in diagnosing high PASP and AMS.
• To assess the association of NPs, hs-cTnT, and hsCRP with PASP and AMS at varying altitudes.

Main Methods:

• 48 participants were evaluated at 3833m, 4450m, and 5129m after trekking and at rest.
• Quantification of NPs, hs-cTnT, and hsCRP using immunoassays.
• Pulmonary artery systolic pressure (PASP) measured by echocardiography; AMS scores recorded.

Main Results:

• Ascent to high altitude significantly altered NPs, hs-cTnT, hsCRP, and PASP.
• High PASP (≥40 mmHg) was associated with significantly higher NPs (NT-proBNP and BNP).
• NPs were significantly elevated in individuals with AMS, particularly severe AMS. hs-cTnT also increased with exercise and was higher in those with high PASP.

Conclusions:

• NPs and hs-cTnT are associated with high PASP at high altitudes.
• NPs are also associated with the presence and severity of AMS.