The following table summarizes the key studies and findings of altitude effect on coronary artery disease (CAD).
In general, the acute physiologic changes associated with altitude result in an earlier onset of angina symptoms or ischemic ST-segment changes (shorter exercise time to symptoms) in patients with CAD and at a similar or slightly reduced rate pressure product (systolic blood pressure × heart rate) than at sea level. This is in part due to direct (impaired coronary flow reserve) as well as indirect effects (lower oxygen saturation results in increased heart rate to maintain total oxygen delivery). Despite these changes, the risk for cardiac death is low for most patients with stable CAD.
In summary, patients with CAD may experience earlier onset and more frequent symptoms at altitude for a given amount of exercise compared with that at a sea level. However, evidence suggests that it is safe for patients with stable angina to exercise at altitude, provided they take precautions as they would at sea level.
John P. Higgins, MD, MPhil, Troy Tuttle, MS, Johanna A. Higgins, MD