The management of acute coronary syndromes, comprising ST segment elevation myocardial infarction (STEMI) and non-STEMI, is based on prompt restoration of coronary blood flow. Numerous randomised trials have confirmed that mechanical modalities of revascularisation are superior to pharmacological approaches even when transfer to hospital with catheterisation facilities is considered. A similar success rate of percutaneous coronary intervention (PCI) is difficult to achieve during the night and on weekends, however, due to the specific related settings. Experienced interventional team and a well-established hospital logistics are needed 24 h a day to give adequate treatment within a short time. So far, results have been conflicting in the studies on emergency PCI performed during the normal working day compared with out of hours. We therefore carried out a prospective study to specifically investigate this comparison.

METHODS

All consecutive patients with acute coronary syndromes treated by PCI between 1 August 2001 and 31 August 2003 were prospectively allocated to two groups according to the time of the invasive procedure. Patients with STEMI were enrolled if acute chest pain concomitant to ST segment elevation by more than 1 mm in two contiguous leads was confirmed. Patients with non-STEMI were enrolled if they had acute chest pain with ST segment depression by more than 0.5 mm or negative T waves in at least two contiguous leads or a positive cardiac biomarker (troponin I). Patients were then allocated to the out of hours group if they were treated during …