Strategies for reducing door to balloon time in patients with acute myocardial infarction undergoing primary angioplasty: the Pavia experience

BACKGROUND: Primary percutaneous coronary intervention (pPCI) is the treatment of choice in patients with ST-elevation myocardial infarction (STEMI) if performed by an experienced team within 120 min of first medical contact. The door to balloon time (DTB) has become a performance measure and is the focus of local, regional and national quality improvement initiatives. The primary objective of the present study was to evaluate whether the implementation of reperfusion strategies could result in shorter DTB times. METHODS: In 2007, at the cath lab of the IRCCS Policlinico San Matteo (a hub of a network including 7 spoke centers), 245 pPCI were performed with a median DTB time of 116 (25th-75th percentile, 96-155) min, and <90 min only in 20% of cases. To improve time to reperfusion, the following strategies were adopted in 2010 and 2011: direct access to the cath lab without initial coronary care unit admission; activation of the cath lab based on pre-hospital ECG; a faster triage with ECG performed within 10 min and use of a dedicated ambulance for patients presenting directly to the emergency room (ER) of the hub. RESULTS: Overall, 226 and 258 pPCI were performed in 2010 and 2011, respectively, with no differences in type of hospital admission (emergency medical service, ER, or spoke) compared with 2007. A significant DTB reduction was observed (2007 vs 2010 vs 2011: 116 [96-155] vs 99 [77-129] vs 97 [80-125] min, p<0.0001), with a significant improvement in the number of patients treated within 90 min (20 vs 41 vs 40%, p<0.0001) as a result of a significant reduction in the time from first medical contact to cath lab (86 [64-124] vs 66 [50-93] vs 62 [46-93] min, p<0.0001). By analyzing only data from 2010 and 2011, median DTB was 88 (73-104) min for patients arriving through the emergency medical service, 139 (116-179) min for patients presenting to spoke centers, and 96 (75-126) min for patients presenting to the ER, with pPCI performed within 90 min in 55%, 8% e 42% of cases, respectively. The longer DTB time of the spoke centers was solely due to transportation to the hub (emergency medical service vs spoke: 56 [42-68] vs 106 [86-147] min, p<0.0001), with no differences in time to reperfusion once the cath lab was reached. CONCLUSIONS: Based on our strategies and experience including 729 STEMI patients treated with pPCI in 2007, 2010 and 2011, a significant improvement in DTB time was achieved. The main factor affecting our results is transportation to the cath lab for patients with direct access to spoke centers. Further exploration and advocacy for DTB implementation in these patients are warranted.