['The aim of this study was to clarify whether a helicopter ambulance system (doctor helicopter system; DHS) could shorten the time interval to coronary intervention in the treatment of patients with acute myocardial infarction (AMI), in comparison with ground ambulance (GA).', 'The time from the emergency call to coronary angiography (CAG time) or to percutaneous coronary intervention (PCI time), and the inhospital outcome were evaluated in 76 AMI patients. Twenty patients were transported by DHS, and the other 56 were by GA.', 'Both CAG time and PCI time were significantly shorter in the DHS (98.8+/-29.2 min, and 169.6+/-57.4 min) than those of the GA (126.6+/-48.7 min, and 203.2+/-57.0 min; p<0.05) group. Inhospital mortality was lower in the DHS (5.0%) versus the GA (10.7%) group.'] Does use of an air ambulance system improve time to treatment of patients with acute myocardial infarction?