Study shows increased risk of heart attack from physical exertion at altitude and low temperatures during winter sports vacations

"Every year, millions of tourists visit the Tyrolean Alps to participate in a variety of winter sports, each of which carries a certain risk of accident and injury," explains Doctor Bernhard Metzler, Associate Professor for Cardiology at the university, and senior author of the report. "Previously it had been shown that sudden cardiac death accounts for a staggering 40 percent of the total fatalities amongst winter sport tourists in the Austrian Alps and, of these, acute myocardial infarction is the leading cause. We were especially interested in the characteristics of patients admitted to our emergency department with heart attack symptoms so that we could study the trigger mechanisms and begin to develop preventative strategies."

The research team reviewed data from over 1,500 patients admitted to the hospital with cardiac conditions between 2006 and 2010. 170 of these -- mostly from Germany and the Netherlands -- had suffered a heart attack during their winter sports vacation, and this group formed the basis of the detailed study. They were questioned to establish background information about residency, personal details and medical history, as well as the circumstances under which they experienced the initial symptoms. Further investigation then determined whether these symptoms occurred during physical activity.

The results showed an average stay of eight days in the Tyrolean Alps. Interestingly, the majority of acute heart attacks (some 56 percent) occurred within the first two days of beginning intense physical exercise, yet just 19 percent had a known cardiac condition. The study also revealed that more than 50 percent of the patients were physically less active prior to the vacation compared to minimum levels recommended by the European Society of Cardiology. Altitude appears to be a major factor, with heart attacks occurring at a mean of 1,350 metres compared to a mean of residency of just 170 metres. Finally, some 70 percent of the study population displayed at least two of the classic risk factors of cardiac artery disease, including smoking, diabetes and hypercholesterolemia.

The first author of the study, Doctor Gert Klug, also from the Medical University of Innsbruck, offers the following explanation, "The fact that most of the infarcts happened in the very early phase of the vacation hints at a causal relationship between lack of preparation for the intense regime of physical exertion and exposure to high altitudes and low ambient temperatures. From previous studies, it is known that each of these factors might trigger acute myocardial infarction."

The authors conclude that tourists should adopt a regime of careful preparation with regular physical activity when planning a winter sports vacation. They recommend a gradual increase in physical activity at the vacation resort to lower the risk of heart attack. Dr. Klug concludes, "An assessment of risk factors and individual patient education might be advisable in patients with multiple risk factors, even if no coronary artery stenosis is known. Prospective data on this topic, however, is still lacking."