The impact of moderate altitude on manifestations of coronary artery disease

Reductions in oxygen availability at altitude reduce oxygen supply to the myocardium. This reduction in oxygen supply may be problematic for patients with cardiovascular disease and/or associated comorbidities such as hypertension, diabetes or heart failure. The risk of adverse cardiovascular events may be increased at altitude as a result of the interaction between hypoxia and exercise, which further increases myocardial demand for oxygen. When an acute coronary syndrome occurs, outcomes may be suboptimal given limited access to medical centers with cardiac catheterization laboratories and sudden cardiac death may occur. Pre-travel planning should prioritize optimizing cardiovascular health and mitigating associated risk factors to reduce risk. Patients should have a realistic expectation of the types of activities that can be undertaken, based on their underlying cardiovascular risk profile and travel itineraries should include a period of acclimatization to hypoxia before initiating planned activities. In this review, we provide an overview of the relevant physiology related to hypoxia, its impact on cardiovascular function and clinical considerations and management strategies for patients and providers to reduce risk of adverse events from occurring in austere environments.