STOCKHOLM – Most acute myocardial infarctions that occur in winter visitors to mountain ski areas happen during the first 2 days of vacation, according to a study conducted in Austria’s Tyrolean Alps.
Dr. Gert Klug
In all, 39% of MIs in the retrospective study occurred on the first day of physical activity, which was usually the day after arrival. Another 15% happened on day 2 of physical activity in what was planned, on average, to be an 8-day vacation, Dr. Gert Klug reported at the annual congress of the European Society of Cardiology.
Most affected individuals were not physically fit, having not regularly engaged beforehand in the minimum 2.5 hr/wk of physical activity recommended in ESC guidelines for cardiovascular risk reduction, noted Dr. Klug of the Medical University of Innsbruck (Austria).
“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,” he said.
Dr. Klug and coworkers reviewed the medical records of more than 1,500 patients admitted to Innsbruck Medical Center for acute MI in 2006-2010. They conducted more detailed follow-up questionnaire interviews with 110 survivors.
In addition to the early timing of the MIs and lack of physical preparation for the rigors of skiing and snowboarding, another common theme was the impact of altitude. The MIs occurred at a mean 1,350 m above sea level in patients who lived at an average altitude of 170 m.
Also notable was the finding that 70% of MI patients had two or more standard cardiovascular risk factors, such as dyslipidemia, diabetes, or smoking. Yet only 19% had previous cardiovascular symptoms before they arrived in the mountains.
“Strenuous exercise without proper preparation – in combination with cardiovascular risk factors, high altitude, and cold ambient temperatures during winter vacations – leads to an increased risk of acute MI in the very early phase of winter holidays. So our advice is to prepare properly for winter vacations by doing a stepwise increase in exercise beforehand,” Dr. Klug concluded.
He noted, however, that in 48% of cases, MI symptom onset occurred when mountain visitors were not skiing or doing other sports.
Dr. Klug declared having no financial conflicts.