Benefit of direct ambulance to coronary care unit admission of acute myocardial infarction patients undergoing primary percutaneous intervention.

BACKGROUND: Early reperfusion therapy in ST-segment elevation myocardial infarction (STEMI) patients improves left ventricular (LV) function and survival. However, emergency room (ER) triage may unnecessarily delay this time-dependent treatment. We sought to determine whether direct admission of STEMI patients from the mobile intensive care units to the intensive coronary care unit (ICCU), bypassing the ER, can shorten the time intervals for primary PCI (PPCI) and improve prognosis.

METHODS: All STEMI patients who underwent PPCI between Jan-2002 to Nov-2005 were included. Baseline, clinical and time interval parameters were compared between groups. Mortality rates were obtained through the population register.

RESULTS: Of 533 admissions, 115 (21%) were admitted directly to the ICCU. These patients were younger (mean (+S.D.) age of 58+13 years) than patients admitted via the ER (62+/-13 years, P<0.01) and had a lower proportion of women (9% vs. 22%, P<0.01), hypertension (45% vs. 62%, P<0.01) and diabetes (15% vs. 27%, P=0.01). Directly admitted patients had a substantially shorter median pain-to-balloon time (210 vs. 247 min, P=0.02) as well as s significantly shorter door-to-balloon time (70 vs. 94 min, P<0.01), a difference that was particularly pronounced during daytime (55 min vs. 90 min, P<0.01). There were no significant differences in LV function at 24 h as assessed by echocardiography or infarct size as determined by peak creatine kinase levels. We observed a trend towards reduced 30-day (5.2% vs. 9.8%, P=0.12) and 1-year (11.1% vs. 16.1%, P=0.25) mortality in directly admitted patients.

CONCLUSIONS: Directly admitted STEMI patients differ from patients admitted via the ER; Direct ICCU admission, based on a pre-hospital ECG, can substantially shorten time to treatment.