Outcome of primary angioplasty for ST-segment elevation myocardial infarction during routine duty hours versus during off-hours. Results of a single-center in Spain

Background A circadian variation in the time of onset of ST-segment elevation myocardial infarction (STEMI) with peak in the morning hours has been described. We sought to investigate the impact of circadian patterns on the practice of primary angioplasty in individuals residing in Tenerife Island (Spain). Methods 90 consecutive patients with STEMI were treated in our hospital. All patients were admitted within 6 h from symptom onset. Patients were divided into 2 groups according to the time of treatment: routine duty hours (0800–1800) and off-hours (1800–0800). Results There were no differences in baseline clinical characteristics or treatment delays between routine duty hours and off-hours patients. There is a significant higher rate of angioplasty failure and in-hospital mortality from 1800 to 0800 h compared to the time range from 0800 to 1800 h. Conclusions Circadian variations have a profound effect on the practice of primary angioplasty.