['Sleep disordered breathing has been associated with an increased risk for developing coronary heart disease. Data on the effects of sleep disordered breathing on case fatality and prognosis of a myocardial infarction are sparse. The present study aimed to investigate a possible relationship of snoring and case fatality and mortality after an acute myocardial infarction. DESIGN, SETTINGS, PATIENTS, AND MEASUREMENTS: In this study, we enrolled 1660 first acute myocardial infarction cases and examined the effects of self- or relative-reported heavy snoring on case fatality and prognosis. The average follow-up time was 8 years, SD = 262 days.', 'There was a variation in the association between snoring and mortality with time, with a strong association in the first 28 days after infarction but not later during the follow-up. Occasional and regular heavy snorers, when compared to those never having heavy snoring, had a 2.04 (95% confidence interval, 1.50 to 2.79) and 3.30 (95% confidence interval, 2.37 to 4.58) hazard ratio for mortality within the first 28 days after controlling for age, gender, obesity, history of diabetes and hypertension, physical activity, smoking, and education, respectively. There was no association between snoring and new myocardial infarction, stroke, or hospitalization for heart failure during the follow-up.'] Is heavy snoring a risk factor for case fatality and poor short-term prognosis after a first acute myocardial infarction?