Door-to-balloon time in primary percutaneous coronary intervention for patients with ST-Segment Elevation Myocardial Infarction

Abstract

Introduction: Over the past years Primary Percutaneous Coronary Intervention (PCI) has emerged as an effective treatment strategy for acute ST-Elevation Myocardial Infarction (STEMI).1 The survival rate with Primary PCI however is dependent on the time to treatment,2 thus, given the time dependency of survival in patient with STEMI undergoing Primary PCI, the American College of Cardiology and American Heart Association (ACC/AHA) in their management guidelines of acute myocardial infarction also endorsed by European Society of Cardiology (ESC) have established a door- to-balloon time of 90 minutes as a gold standard for Primary PCI.4 The aim of this audit is to measure and compare this key performance measurement for quality of care of patients with STEMI in the Maltese Islands. Methods: This audit was conducted at the only PCI-capable hospital in Malta – Mater Dei Hospital. All the patients coming in through the Accident and Emergency Department with an ST-elevation Myocardial Infarction or a new onset Left Bundle Branch Block (LBBB), thus eligible for a Primary PCI, were included in this audit. This was a prospective audit between January 2012 and December 2012 and using a proforma, data was collected primarily to map out the Door-to-Ballon times for Primary PCI during that period. This data was also used to pinpoint areas were time delays occur when dealing with STEMI cases. Door-to-Balloon times from pre-hospital diagnosis of STEMI using the MRX was also audited and compared to times of in-hospital STEMI diagnosis. Results: During the 12 months duration of the audit, 157 patients were recorded in the CathLab Database as having had an Emergency Primary PCI. Recorded in the audit were 135 patients of which 123 were STEMI patients eligible for a Primary PCI and 12 STEMI patients not eligible for Primary PCI and thus not included in the audit. The Mean Door-to- Balloon times of all 123 patients was found to be 101.45 minutes. Data analysis showed that the times during 'Office Hours' (8am to 5pm) were statistically significantly less than those of 'After hours' (5pm to 8am) (N=123, p<0.001) and those with a Door-to- Balloon time of more than 90 minutes, data analysis showed the number of such cases were statistically significantly less during 'Office Hours' (N=36, p=0.02). With pre-hospital ECG diagnosis of STEMI, data analysis showed that with MRX, Door-to-Ballon times are significantly less when compared to those during 'Office Hours' and 'After Hours' (N=57, p=0.003 and N=66, p<0.001 respectively). Conclusion: From the results obtained, local achievement to remain well within the standards suggested by the ACC/AHA and ESC of Primary PCI ? 90 minutes for STEMI was not reached, however several factors contributing to delays and strategies to minimize delay were pointed out in order to further improve the local practice and thus lowering mortality rates associated with STEMI.