Association of onset to balloon and door to balloon time with long term clinical outcome in patients with ST elevation acutemyocardial infarction having primary percutaneous coronary intervention: observational study OPEN ACCESS

Objective To evaluate the relation of symptom onset to balloon time and door to balloon time with long term clinical outcome in patients with ST segment elevation myocardial infarction (STEMI) having primary percutaneous coronary intervention. Design Observation of large cohort of patients with acute myocardial infarction. Setting 26 tertiary hospitals in Japan. Participants 3391 patients with STEMI who had primary percutaneous coronary intervention within 24 hours of symptom onset. Main outcome measures Composite of death and congestive heart failure, compared by onset to balloon time and door to balloon time. Results Compared with an onset to balloon time greater than 3 hours, a time of less than 3 hours was associated with a lower incidence of a composite of death and congestive heart failure (13.5% (123/964) v 19.2% (429/2427), P<0.001; relative risk reduction 29.7%). After adjustment for confounders, a short onset to balloon time was independently associated with a lower risk of the composite endpoint (adjusted hazard ratio 0.70, 95% confidence interval 0.56 to 0.88; P=0.002). However, no significant difference was found in the incidence of a composite of death and congestive heart failure between the two groups of patients with short (≤90 minutes) and long (>90 minutes) door to balloon time (16.7% (270/1671) v 18.4% (282/1720), P=0.54; relative risk reduction 9.2%). After adjustment for confounders, no significant difference was seen in the risk of the composite endpoint between the two groups of patients with short and long door to balloon time (adjusted hazard ratio: 0.98, 0.78 to 1.24: P=0.87). A door to balloon time of less Correspondence to:Y Nakagawa [email protected] Extra material supplied by the author (see http://www.bmj.com/content/344/bmj.e3257?tab=related#webextra) No commercial reuse: See rights and reprints http://www.bmj.com/permissions Subscribe: http://www.bmj.com/subscribe BMJ 2012;344:e3257 doi: 10.1136/bmj.e3257 (Published 23 May 2012) Page 1 of 14